Preamp Tubes? - Who, What, When, Where, Why, and How? - Page 8

joshuaaewallen · 04-30-2009, 07:35 PM

Quote:

Originally Posted by MartyStrat54

... I was over at your other place for a while, but thought that I would come over and talk about the BZ7. To me, it seems as if maybe the amp just doesn't like them installed permanently. Some circuits place different voltages on the BZ7 over what an AX7 would see. Since it has less plate resistance, maybe it is getting hotter than it should? However, in all of my old reference materials, a BZ7 is listed as a replacement/substitute for an AX7. Who am I to argue with all of these old books? The AX7 is a lot older tube than a BZ7. I don't think the BZ's were around until the early 60's.

One thing on EBAY that you see a lot. "SOLD AS IS/NO RETURNS." (This gives you a real secure feeling when placing that bid.) I guess I could send you another and if it goes bad, then it goes back to what I said a long time ago with BZ7 #1, "the amp doesn't like them." And I'd hate to see good tubes go bad if it is indeed the amp that is eating them. I'll let you make the call on this one....

Well, my replacement 12BZ7 arrived. It is a GE, vintage... (or so I'm told)... Described by the seller as,

Quote:

BLACK RIBBED WELDED PARALLEL PLATES, HORSESHOE SHAPED TOP GETTER WITH DUAL CROSSBARS, 5-52 DATE CODED. WHITE PRINT.
PRODUCED BY CBS-HYTRON USA
EMISSION 103/103. MINMUM GOOD IS 70. Gm 113/113. SCALE TO 120.
UNUSED TUBE IN ORIGINAL BOX.

I'm gonna find out if my amp is 12BZ7 eater, or not... Stay tuned.

solarburnDSL50 · 04-30-2009, 07:40 PM

Quote:

Originally Posted by joshuaaewallen

Well, my replacement 12BZ7 arrived. It is a GE, vintage... (or so I'm told)... Described by the seller as,

I'm gonna find out if my amp is 12BZ7 eater, or not... Stay tuned.

Nom Nom Nom.

MartyStrat54 · 04-30-2009, 10:20 PM

Well, I hope that beautiful old 1955 tube doesn't get a bite taken out of it. Look at that quality of craftmanship. Wow! It's like a 28 year-old Pamela Anderson with her third set of implants.

GOOD LUCK!!!

joshuaaewallen · 05-01-2009, 03:53 AM

Quote:

Originally Posted by MartyStrat54

Well, I hope that beautiful old 1955 tube doesn't get a bite taken out of it. Look at that quality of craftmanship. Wow! It's like a 28 year-old Pamela Anderson with her third set of implants.

GOOD LUCK!!!

solarburnDSL50 · 05-01-2009, 08:04 PM

Ok. I've rolled a few different new production 12AX7's in th NT now. I also decided to try my NOS CV4024 12AT7 along with a 12AX7 in it. I like this combination so far. Now even with 12AX7's in the NT it is clear and very present sounding. What notes and chords are played really come through. Fuzz and mud are never a problem on the bright setting with gain maxed. The thick setting can get muddy with chords but single notes are effected less by the higher gain of this voicing.

With the CV4024 mixed in there the thick voicing really gets cleared up at higher gain settings. I would never play with the gain maxed on the thick setting. About 3 o'clock on the gain is as far as I go with it.

The chime and roundness is still intact and is not loss with the lower gain of the AT7. I was worried it might thin out a bit compared to the AX7. Guitar roll off is still there and expressive. So far using the NOS CV4024 has not thinned the tone in my Marshall or the NT.

Where I think using the Mullard AT7 pays off is the harmonic overtones and musical feedback it gives mixed with an AX7. If I'm not mistaken the lead notes sound a bit chewier. Its subtle but I think the bloom of the notes is better. It gives you that tone in the finger sound. Its overdriven enough to have body and bloom but not so much it loses expression/feel from the gain. Hard for me to describe but I'm trying.

Now all this tone posturing was done with humbuckers. All this can go out the window when I plug my Strat in.

Well I have done all the new production tube rolling I want to at this point. The field is set on both amps for the NOS tube party I'm going to have thanks to Marty. Again today I have little time for experimenting. Hopefully tomorrow I can start rolling the NOS AX7's in my beloved Marshall.

MartyStrat54 · 05-01-2009, 09:32 PM

JOE:

I'm surprised how happy you are with a 12AT7 in your tube section. I'm gonna have to try that sometime. It must have a smoothing effect on the amp, especially when played at moderate volumes where the headroom is still abundant.

I've used 5751's but then they are just a little hotter than a 12AT7. You've had that tube for quite some time. It's now been in several amps. My question to you is: Do you really want any high gain tubes? You seem happy with the lower gain sound and your style of playing. Let me know on that, hey?

Marty

solarburnDSL50 · 05-01-2009, 10:54 PM

Quote:

Originally Posted by MartyStrat54

JOE:

I'm surprised how happy you are with a 12AT7 in your tube section. I'm gonna have to try that sometime. It must have a smoothing effect on the amp, especially when played at moderate volumes where the headroom is still abundant.

I've used 5751's but then they are just a little hotter than a 12AT7. You've had that tube for quite some time. It's now been in several amps. My question to you is: Do you really want any high gain tubes? You seem happy with the lower gain sound and your style of playing. Let me know on that, hey?

Marty

I actually have 2 of the CV4024's. They really don't have that many hours on them cause I have only been experimenting recently with them. Jerry from FJA was surprised I had it in the V1 position and not the PI. I have a Jan GE 5751 and put it in the Marshall. I didn't like it at all. I have found the CV4024 to be less taming than the 5751 in the Marshall"s preamp section. The gain between these 2 you would think the 5751 would be stouter but it didn't play out that way. My experiment was using both as the PI and the Marshall was duller sounding with the 5751 in it. Now I tried the CV4024 in my HT dual pedal that has 1 12AX7. It didn't do well in that. A 12AX7 was definitely better.

I haven't tried the 5751 in the V1 or V2. I have with the CV4024 and it sounds good wherever I placed it but only 1 AT7. I tried both of the AT7's in the NT and it was a no go. Didn't like the lower dynamics with both in at the same time. With 1 AT7 I think there is a little smoothing effect but single notes still have bite on them. Sustain is still intact. On chording its taking off a bit of hair but really it is a subtle effect. Its not bringing the gain down much overall even though the gain structure of the AT7 is at 60.

Actually I like both high gain and lower gain mixed. I don't like to use more than 1 lower gain tube in the amps I have. It tends to lose too much body then and those nice overtones go away. So I don't want to neuter the gain section as I am going for a solid blues/rock midgain tone. Keep me in mind for the high gainers too cause I do like what they bring to the table for sure.

Also keep in mind I like to boost my amps not for more gain but for gain with more body to it. So I start with a solid tube foundation and then boost to taste depending on what I am playing and what dynamics I want happening. Generally I keep the amps gain low. The Marshall's gain rarely goes past noon. Then I boost it. I like it better this way than increasing the amps own gain which renders a different texture of gain. Boosting gives me that punch I want and still sounds good with guitar roll off.

Shit I wrote a book!

Joe

MartyStrat54 · 05-02-2009, 03:11 PM

I spent a good part of yesterday afternoon testing and recording tube ratings. I was surpised to find out that I had many AX7's in the "above average" ratings and I even had some that were up there with the ICBM. I have six, super strong Raytheon BP's coming in and I will need to test these tubes as well. I bought two lots of new tube boxes. I got tired of having all of these unprotected, loose tube lying around. I should have them in by the time I start shipping everyone's tubes out. Kevin is going the full Monte and getting four tubes.

Joe, I wonder if your 5751 is good? I'm sure you will agree with me that it isn't normal for the AT7 to outperform the 5751 in the gain category. Something is amiss. The tube may be weak for a variety of reasons. I have two 1958 Tung-Sol 5751's and they will outperform and of the AT7's that I have and I have some really hot ones such as JAN (Joint Army/Navy) 12AT7's that are some of the best I ever have had. I bought a box of five and I'm using one as the PI in my old Randall hybrid amp with the 8417 power tubes. It works great in there.

The way I see it, having an AT7 in V1 will work as long as you don't (as you say) crank the gain more than twelve o'clock. In this situation V2 will have enough gain reserve to compensate for the lower gain of the AT7. The result is a completely different sound. On the other side of the fence is putting two super gain 12AX7's in V1 and V2. This is a raging animal that is waiting for a hard power chord followed up by some feverish licks. The tube harmonics I got with two hot tubes was incredible. It made my power tubes sound better as well.

To each his own. I know I'm getting old and I don't play as good as I used to, but I still like the high gain sound. I learned on another thread that the choke mod works better with 100 watt heads than say a 40-60 watt head.
One thing about tube mods, they work well on any size amp.

Marty

solarburnDSL50 · 05-02-2009, 06:00 PM

Quote:

Originally Posted by MartyStrat54

I spent a good part of yesterday afternoon testing and recording tube ratings. I was surpised to find out that I had many AX7's in the "above average" ratings and I even had some that were up there with the ICBM. I have six, super strong Raytheon BP's coming in and I will need to test these tubes as well. I bought two lots of new tube boxes. I got tired of having all of these unprotected, loose tube lying around. I should have them in by the time I start shipping everyone's tubes out. Kevin is going the full Monte and getting four tubes.

Joe, I wonder if your 5751 is good? I'm sure you will agree with me that it isn't normal for the AT7 to outperform the 5751 in the gain category. Something is amiss. The tube may be weak for a variety of reasons. I have two 1958 Tung-Sol 5751's and they will outperform and of the AT7's that I have and I have some really hot ones such as JAN (Joint Army/Navy) 12AT7's that are some of the best I ever have had. I bought a box of five and I'm using one as the PI in my old Randall hybrid amp with the 8417 power tubes. It works great in there.

The way I see it, having an AT7 in V1 will work as long as you don't (as you say) crank the gain more than twelve o'clock. In this situation V2 will have enough gain reserve to compensate for the lower gain of the AT7. The result is a completely different sound. On the other side of the fence is putting two super gain 12AX7's in V1 and V2. This is a raging animal that is waiting for a hard power chord followed up by some feverish licks. The tube harmonics I got with two hot tubes was incredible. It made my power tubes sound better as well.

To each his own. I know I'm getting old and I don't play as good as I used to, but I still like the high gain sound. I learned on another thread that the choke mod works better with 100 watt heads than say a 40-60 watt head.
One thing about tube mods, they work well on any size amp.

Marty

You may be right about the 5751 not being a good one. It dulling the tone up like it did surprised me. Maybe I'll mess with it again and see if I get anything different out of it. It was a quick demo I did of it cause it was like yuk!

I think the CV4024 mixed in creates a midgain sweet spot that I like. That being said I haven't got to really crank it up for more than a few moments due to the father-in-law living with us. It limits my ability to get a good feel for these tube changes at a good volume although I do torture the household here and there. Like I said though using them(CV4024)still is experimental. I haven't really settled on having an AT7 in there all the time. It can sound good though. I think the PI may be a better position for it. I don't know yet.

Those NOS tubes you gave me livened things up a bit today. Its been awhile since I played at high gain. It was righteous! Marshall wanted to take off! What is nice about them is the guitar roll off still sounds good too. I stepped on the Germania to add even more and it was reeling mad then. Wow how fun was that? Very! Felt like I needed a cig cause I just had sex.

I just woke up from a nap so I have to mess around with them more and I am definitely interested in all these NOS tubes I'm learning about. Really cool stuff. I wonder how the NT will like em'? Stay tuned. I can't wait to get the EL84's from you. I've been pricing some NOS and ouch are they spensive. What do you think of this site?:

KCA NOS Tubes. Audio tubes for guitar amplifiers and audiophile equipment. 12AX7, 6L6GC, 12ay7, el34, el84, Fender amplifier,5AR4, 5U4GB, cv4004, 6SN7, 8417, 7027, gz34, Mullard, EF86, 6ca7, 6bq5, 7025, 12at7

MartyStrat54 · 05-02-2009, 07:29 PM

I went to that link and they wanted 70 or 80 bucks apiece for Raytheon BP 12AX7's. I just bought six for less than $30 a piece and they all test in the high altitude regions of my meter. So I guess I won't let $27.45 each bother me too bad.

They did have some fair prices on JAN Sylvania 6L6WGB's. Standard matching is within 3 mV of each other. The price was $178 for a quad. That's not bad for brand new tubes.

I'll have to spend a little more time looking at the prices and finding the bargains, cuz $70 bucks for an AX7 is getting a little pricey. Ya know?

Marty

ts31966 · 05-02-2009, 08:21 PM

Hi all!

Well, I have been trying a million different combinations. A few tubes I have are microphonic. I am not going to throw them away though. They sound to good for that. I am going to experiment with the rubber bands that I saw on fleabay.

Some of the NOS tubes make some strange noises sometimes. I am hoping that with a burn in period they will burn in and quiet down.

I saw a device on EAT's website to quiet microphonic tubes but they are very expensive. I am hoping to get them for cheaper.

Has anyone here experimented with the rubber bands? If so will the metal sleeves fit over the top of your 12ax7 with the rubber bands on?

My 5150 III takes 8 12ax7's so it is taking me alot of time to get into different combinations. I am going to see if I can find some books with some useful information on tube positioning. Sometimes my high gain channel gets quiet with different tube combinations. But only the high gain channel. I have a theory on this but I have to go over the schematics to figure it out.

steelhorse · 05-02-2009, 08:37 PM

I'm curious to see if the bands help you out too. I've not ever heard of anyone using them but I've seen them in use online. I think a few folks here also use them.

What are you trying to achieve with the pre's in your EVHIII? I ask because I've not heard a bad one in fact I was very close to purchasing one myself that is until I saw Mesa come out with the MK V. I thought the EVH III is a great amp. Does it have too much gain or not enough gain? Too noisy?

Overall what is your opinion of this amp, like what genre's, etc.

Seems like a roadworthy amp that's for sure.

ts31966 · 05-02-2009, 09:09 PM

The 5150 III is the quietest high gain amp I have tried without a noise gate. That is it's greatest strength. There are alot of great sounding high gain amps but they also have alot of noise.

My goal with the EVH 5150 III is to make it sound even better. It does sound great out of the box. But your whole guitar signal goes through your tubes. Each different tube has a unique sound and characteristics.

Every product that you buy that is mass produced will never have the best components in it. I am just trying to find the best tubes that will make it sound its best.

My favorite tone is Van Halen's tone on all the albums with David Lee Roth. I know to get that tone a better purchase would have been a mojove amp but I want to get it out of my 5150 III.

I might still buy a mojove amp also though.

MartyStrat54 · 05-02-2009, 10:24 PM

Quote:

Originally Posted by ts31966

The 5150 III is the quietest high gain amp I have tried without a noise gate. That is it's greatest strength. There are alot of great sounding high gain amps but they also have alot of noise.

My goal with the EVH 5150 III is to make it sound even better. It does sound great out of the box. But your whole guitar signal goes through your tubes. Each different tube has a unique sound and characteristics.

Every product that you buy that is mass produced will never have the best components in it. I am just trying to find the best tubes that will make it sound its best.

My favorite tone is Van Halen's tone on all the albums with David Lee Roth. I know to get that tone a better purchase would have been a mojove amp but I want to get it out of my 5150 III.

I might still buy a mojove amp also though.

Did you buy a tester? I use the high silicone bands on both my pre and power tubes. No, you can't put one on V1 and still use the RF shield. The bands are a must for combo amps, not so much for heads ( a lot less vibrations).

Mathematically, trying to come up with the perfect eight tube combination could take you well into next year. That's a lot of tweaking. It took me about a month per amp to get the tubes in that sounded good. Then along comes some monster high gain NOS tubes and it changed my way of thinking ASAP. I realized that a strong 7025 followed by a stronger 12AX7 is the way to make all three channels of my TSL kick ass. V3 and V4 are good tubes, but they only have to be average in strength, say 85 to 90 per cent. V1 is riding about 95 and V2 is 105 to 125, you know insane high gain.

I just spent a lot of time testing and rating tubes and I found that I had six 7025's still left and two of them are screamers running past 100 per cent. I have six, BP Raytheon's that I won on Ebay that are all super high gain tubes. Once they get here I will test them for accuracy.

I hope you have great success getting tubes into your EVH. I guess it will just take a little time and a schematic.

Marty

ts31966 · 05-02-2009, 10:49 PM

I have found exactly the same thing Marty. V1 and V2 makes the amps tone. The rest of the tubes just need to be quiet. But the 5150 is set up a little differently than most amps. Channel 1 and 2 are similar but channel 3 has its own voicing.

I haven't bought a tube tester. I need to learn more. I want the amplitrex but I don't know if it is worth it for me.

Tell me this Marty, I have this tube that sounds great but on channel 3 with the gain maxed out and the guitar volume maxed out the tube starts freaking out. It makes all kinds of weird noises and the distortion from the tube is all over the place. The tube is not microphonic. The tube is a black plate brimar labeled raytheon.

Also Marty what do you know about 12dt7's. I have a whole bunch of black plate raytheons. They sound great for channel 1 and 2 but channel 3 doesn't have as much gain with them in the v1 and v2 position.

I am thinking that both triodes do not have the same gain in this tube and this is lowering the output on channel 3. I am going to have to call fender Monday about that.

Most of my tubes are old. They sound great but I think they need to burn in. Have you guys had experience with tubes settling once you leave them powered on for awhile?

steelhorse · 05-02-2009, 11:12 PM

Check out David Brays amps before deciding on an amp to replicate Ed's sound.

solarburnDSL50 · 05-03-2009, 01:14 AM

Quote:

Originally Posted by MartyStrat54

I went to that link and they wanted 70 or 80 bucks apiece for Raytheon BP 12AX7's. I just bought six for less than $30 a piece and they all test in the high altitude regions of my meter. So I guess I won't let $27.45 each bother me too bad.

They did have some fair prices on JAN Sylvania 6L6WGB's. Standard matching is within 3 mV of each other. The price was $178 for a quad. That's not bad for brand new tubes.

I'll have to spend a little more time looking at the prices and finding the bargains, cuz $70 bucks for an AX7 is getting a little pricey. Ya know?

Marty

Crap man our power went out at 5pm and has just come back on. I was playing my NT when it went out. Fortunately it is ok after being shut down all of a sudden. I had taken out the AT7 and put the RCA 12AX7 in paired with an AC5 right now. Boy I was hearing some nice overtones and neat bell like tones while playing open chords and then the power went dead.

All seems well and I'm going to continue to roll the NOS between the NT and DSL. Those RCA are sweet no doubt! Thanks again mate. I've run out of time to play as it is late now so I will pick it up tomorrow. Sure wish I could still be playing though.

Marty I will run by any tubes I might want to try before I buy to get your opinion on what kind of deal it is. I'm not going to be buying until after I get the EL84's from you anyways. What you gave me already will keep me going for awhile as it is so I'm pretty much set and having fun.

MartyStrat54 · 05-03-2009, 02:57 PM

Quote:

Originally Posted by ts31966

I have found exactly the same thing Marty. V1 and V2 makes the amps tone. The rest of the tubes just need to be quiet. But the 5150 is set up a little differently than most amps. Channel 1 and 2 are similar but channel 3 has its own voicing.

I haven't bought a tube tester. I need to learn more. I want the amplitrex but I don't know if it is worth it for me.

Tell me this Marty, I have this tube that sounds great but on channel 3 with the gain maxed out and the guitar volume maxed out the tube starts freaking out. It makes all kinds of weird noises and the distortion from the tube is all over the place. The tube is not microphonic. The tube is a black plate brimar labeled raytheon.

Also Marty what do you know about 12dt7's. I have a whole bunch of black plate raytheons. They sound great for channel 1 and 2 but channel 3 doesn't have as much gain with them in the v1 and v2 position.

I am thinking that both triodes do not have the same gain in this tube and this is lowering the output on channel 3. I am going to have to call fender Monday about that.

Most of my tubes are old. They sound great but I think they need to burn in. Have you guys had experience with tubes settling once you leave them powered on for awhile?

Well the EVH's are super high gain heads and they have a fairly complicated preamp section. How do they split the tubes between channels 1, 2 and 3?

About the Brimar. It almost sounds like a rattling plate. The plate are welded to a post and if one (or some) of the welds come loose, the plate will move microscopically. However, it could also be that when the controls are fully maxed out, the tube is suffering from threshold distortion. Apparently, you can stick other tubes in there and max them out and there isn't any problems. Is this correct?

12DT7's a rare and a superior sub for any 12AX7. Both sides are rated at 100mu, the same as a 12AX7. However, the rP (plate resistance) is different than that of a 12AX7. A 12DW7 is the one that is lopsided. It is 100mu on triode one and 17 on triode two. This is basically 1/2 of a 12AX7 and 1/2 of a 12AU7. You are not going to realize much gain in V3. This is probably your tone stack section (it is for a Marshall). You will want a tube in here that adds flavor to the tone controls and is somewhat balanced. It doesn't have to be perfect and it doesn't have to be a high gain tube. Just a decent one. (Those 12DT7's are expensive. Did you get them a long time ago? I haven't seen any for sale for a long time.)

As far as how the tubes work in Channel Three? Well, if the tubes are kicking butt in Channel 1 and 2, they should do the same in Channel 3. Yes, you may want to consult Fender on that. Hopefully they won't frown about you changing out the tubes. You know, warranty issues???

As far as old tubes go. I have found that an old good tube will get a little stronger the longer it is on. Not much but some. I have taken readings on a tube and then left it intentionally in the tester for an hour and then retested it. Some tubes read the same and some read a little stronger.

Hope this helps. Marty

ts31966 · 05-03-2009, 03:25 PM

First let me thank steelhorse for the heads up on David Bray amps. I checked out the audio clips and I like them alot.

Marty, I don't know what is going on exactly. Yes, I will get a tube that makes channel 1 and 2 sound great, (rich harmonics, full and balanced) then I go to channel 3 and it has less gain than channel 2. This is with just changing v1. The first one that did this was a black plate raytheon 12ad7. But later I discovered a gold pin 12ax7s that I got from eurotubes, that was supposed to be hand selected for low noise and high gain, this tube did the same thing. The box it came in was labeled high gain with the testing for each triode on the box.

The Brimar/Raytheon tube sounds great but when you max out the guitar volume it goes crazy. It is the only tube that does this. I got these old tubes a couple of years ago.

I am going through the schematics right now to try to figure out which tube is best suited for each position. I have been doing this by trial and error but it is taking me too long.

Thanks for the info on the 12dt7 Marty. What you said is exactly what I have read but something strange is going on with those tubes.

ts31966 · 05-03-2009, 04:27 PM

It is the V1 tube. Depending on the tube in V1 channel 1 and 2 can sound great but channel 3 will have less gain. The tone of channel 3 is still great but it is like channels 2 and 3 have changed places.

The black plate raytheon tube all do it. I have some black plate sylvania
12ad7's with square getters but they work fine in V1.

Like I said it also happened with a jj 12ax7s with gold pins that I got from Bob at eurotubes. This tube was hand selected for noise, microphonics, and high gain. The test results for each triode is on the box. But when I put it in channel 3 sounds wimpy also.

I really need to get a tube tester so I can quite using my amp as the tube tester.

On a side note I tried a tungsol reissue I got from upscale audio. It sounds pretty good. It is quiet, a little more fizzy than NOS but I would say it one of the best new tubes. The JJ's that came in my amp are very good also. Probably as good as the tungsol reissue. I don't know why those would be better than the one I bought at eurotubes but they are.

MartyStrat54 · 05-03-2009, 05:07 PM

Quote:

Originally Posted by ts31966

It is the V1 tube. Depending on the tube in V1 channel 1 and 2 can sound great but channel 3 will have less gain. The tone of channel 3 is still great but it is like channels 2 and 3 have changed places.

The black plate raytheon tube all do it. I have some black plate sylvania
12ad7's with square getters but they work fine in V1.

Like I said it also happened with a jj 12ax7s with gold pins that I got from Bob at eurotubes. This tube was hand selected for noise, microphonics, and high gain. The test results for each triode is on the box. But when I put it in channel 3 sounds wimpy also.

I really need to get a tube tester so I can quite using my amp as the tube tester.

On a side note I tried a tungsol reissue I got from upscale audio. It sounds pretty good. It is quiet, a little more fizzy than NOS but I would say it one of the best new tubes. The JJ's that came in my amp are very good also. Probably as good as the tungsol reissue. I don't know why those would be better than the one I bought at eurotubes but they are.

Does the EVH use four 12AX7's for Channels 1 and 2 and another set of four 12AX7's for Channel 3? Is that how it is set up? Are you saying your stock OE tubes do not created this problem, only the NOS tubes?

I haven't a clue as to why you are having difficulties getting Channel 3 to respond to known, good tubes. Maybe the problem goes beyond the tubes, that is unless you have certain tubes that will work and all channels respond as they should.

Unless you know what condition the NOS tubes are in, you are just wasting your time. You could have a tube that is 56/78 and another that is 88/94. Which tube would you want in your amp?

It's good to hear info on current production tubes. In fact, I wish others would join and give their opinions on the current production tubes they are using. I sent Josh a gold pin JJ and he didn't like it very much. On the other hand, I am using four EH 12AX7's in an all tube HiFi amp and they sound really good. I've used Sovtek WA's and WB's and didn't like them. However, I ordered some of the LPS's and they aren't bad. I sort of look at Sovtek as the bottom and then everything else is straight up from there.

I'd really like someone to be able to A/B Tung-Sol and Mullard reissue tubes. I've toyed with the idea of getting four each and just trying them in an amp and seeing how it sounds with either the T-S's or the Mullards. I might do that, unless another member can supply feedback.

Marty

solarburnDSL50 · 05-03-2009, 06:01 PM

Quote:

Originally Posted by MartyStrat54

Does the EVH use four 12AX7's for Channels 1 and 2 and another set of four 12AX7's for Channel 3? Is that how it is set up? Are you saying your stock OE tubes do not created this problem, only the NOS tubes?

I haven't a clue as to why you are having difficulties getting Channel 3 to respond to known, good tubes. Maybe the problem goes beyond the tubes, that is unless you have certain tubes that will work and all channels respond as they should.

Unless you know what condition the NOS tubes are in, you are just wasting your time. You could have a tube that is 56/78 and another that is 88/94. Which tube would you want in your amp?

It's good to hear info on current production tubes. In fact, I wish others would join and give their opinions on the current production tubes they are using. I sent Josh a gold pin JJ and he didn't like it very much. On the other hand, I am using four EH 12AX7's in an all tube HiFi amp and they sound really good. I've used Sovtek WA's and WB's and didn't like them. However, I ordered some of the LPS's and they aren't bad. I sort of look at Sovtek as the bottom and then everything else is straight up from there.

I'd really like someone to be able to A/B Tung-Sol and Mullard reissue tubes. I've toyed with the idea of getting four each and just trying them in an amp and seeing how it sounds with either the T-S's or the Mullards. I might do that, unless another member can supply feedback.

Marty

Marty I have Tung Sol and Mullard reissues and both sound really good in the Marshall. The Tung Sols are warm and fat with good frequency response across the board. The Mullards are similar to my ears. These 2 pres are staples for me out of the new production models. JJ pres in my Marshall sounded dull and flat. Frequency response was terrible with dynamics suffering badly.

From what I have picked up you don't want to use a Tung Sol or LPS in a cathode follower stage. LPS make good PI tubes. Here is what I read:

It really depends on the amp with the cathode followers and the voltages on them.

The tube heaters reside inside the cathodes, the cathodes have special coatings on them to insulate them from the heaters.

In typical applications, only 1 to 5 volts is present on the cathodes.

But in cathode follower designs, several hundred volts is present.

On a typical 12AX7 spec. The Heater to cathode voltage difference (difference between the heter voltage and voltage on the cathode) should not exceed 150v to 180v.

On many cathode follower designs like the SLO, almost 200 volts can be seen on the cathode follower stages.

Most of the New Sensor stuff can only handle 100v cathode to heater voltage, and that is why they are not recommended. Too bad they can't even be made to proper specs.

MartyStrat54 · 05-03-2009, 06:53 PM

Got a web address on that info you posted? The sad thing about that is New Sensor makes Tung-Sol, Mullards, EH's, Sovtek, Svetlana and Genalex. Everything is made in the same plant. Makes you wonder if they all are the same, but I guess there is some difference. As I said before, I looked at a picture of a Tung-Sol 12AX7 up against a Mullard 12AX7 and I couldn't tell them apart.

Whatever the case may be, the article suggests that they aren't up to the task of handling high voltage.

Marty

solarburnDSL50 · 05-03-2009, 07:20 PM

Quote:

Originally Posted by MartyStrat54

Got a web address on that info you posted? The sad thing about that is New Sensor makes Tung-Sol, Mullards, EH's, Sovtek, Svetlana and Genalex. Everything is made in the same plant. Makes you wonder if they all are the same, but I guess there is some difference. As I said before, I looked at a picture of a Tung-Sol 12AX7 up against a Mullard 12AX7 and I couldn't tell them apart.

Whatever the case may be, the article suggests that they aren't up to the task of handling high voltage.

Marty

Raises the ole' eye brow huh. Now I can here the difference for sure between an EH compared to the Tung Sol and Mullard when I put them in the NT. The EH was brighter on the top end and the other 2 were both darker because of how warm they are. Like you said I can really hear differences in tubes when in the NT.

I haven't had any Tung Sols or Mullards fail on me when in V1 or V2 for several months of home playing. Don't know how road worthy they would be. At home though you may want to just get 1 of each and see how they sound in V1 or V2. Thats not too much of a cost risk. I like em'. Actually the Ruby AC5 is good in those slots too. If I can find some extra Tung Sol/Mullards I will send them to you. I'll see what I have in the drawer. Email me your addy I forgot to write it down.

Here's the link of the forum thread I was reading. The thread is only 3 pages, not too long. Baron55 is the one who posted the above info.:

http://acapella.harmony-central.com/...r+stage&page=2

MartyStrat54 · 05-03-2009, 08:21 PM

Man, there is a load of garbage on that forum. A lot of repeat nonsense. Sounds like one guy ruined some tubes in his amp, couldn't take the voltage. All the more reason that NOS tubes rule.

I looked at the schematic of my TSL100 (122) and man does it have high voltage on the 12AX7's. I mean a lot higher than 300V! Of course the current draw is very low in the circuit.

I wish that New Sensor would be honest and publish the "real" specs on their tubes. Ha! They won't do that...they'd loose business.

Marty

ts31966 · 05-03-2009, 11:35 PM

Marty, according to Eurotubes the tubes he sent me tested over 100%. All the tubes I bought had excellent test results according to the people who sold them.

What I am saying is that obviously some or most of these tube resellers are full of it!

I talked to a guy that owns an amplitrex. He said that the amplitrex will reject tubes that appear good on an older calibrated tube tester. Such as a tv-7.

The guy I purchased the 12dt7's from said he tested all of them. He is a very reliable and honest tube reseller. A very nice and fair guy.

I will call fender tomorrow. I will find out what is going on with the v1 position in this amp. I tested the 12dt7's in a marshall combo and they sound great. It was a 2 channel amp. I can't remember which model. I know it is all tube though. It has 2 twelve inch speakers and uses el34's.

I have a groove tube mullard reissue. I will test it tomorrow. I bought it from upscale audio and it is supposed to be hand selected. High gain, low noise, non-microphonic.

The guy at upscale has never sold me anything of poor quality. He is the one who sold me the tungsol reissue.

solarburnDSL50 · 05-03-2009, 11:44 PM

Quote:

Originally Posted by MartyStrat54

Man, there is a load of garbage on that forum. A lot of repeat nonsense. Sounds like one guy ruined some tubes in his amp, couldn't take the voltage. All the more reason that NOS tubes rule.

I looked at the schematic of my TSL100 (122) and man does it have high voltage on the 12AX7's. I mean a lot higher than 300V! Of course the current draw is very low in the circuit.

I wish that New Sensor would be honest and publish the "real" specs on their tubes. Ha! They won't do that...they'd loose business.

Marty

HCAF can be a real cluster....if ya know what I mean. There are some knowledgeable guys that really are helpful too. Unfortunately its always comedy central there and riddled with catch phrases and retard isms that has created a whole other language. Staying on topic is a miracle when it happens.

Quality and durability seem to be a big problem with the new production tubes and we are stuck with that unless you buy NOS. Then you need a tester or know someone that has one and will do it for you. The big question is why can't they reproduce the good stuff?

Aren't there enough of us buying tube amps that it would work out for all? Sheesh!

MartyStrat54 · 05-04-2009, 12:34 AM

I was on a different thread and the guy had a hyperlink to a cool old video of how they made audio tubes at the old Mullard Blackburn plant. The video is a copy of the original film. After watching this 25 minute long video, it became apparent to me that we will never be able to replicate what they were doing in that plant of 6300 people. The techniques and the tricks of the trade, the materials used, all vanished back in the mid-80's.

How do they make audio tubes in Saratov, Russia? Like the famous Blackburn plant? I seriously doubt it. Mullard was making tubes there after WWl and Mullard expanded and had six plants with the Blackburn plant being their flagship. All of these tube factories in a country the size of England. They also made Brimar's in England, but they were never much competition to Mullard.

I'm all for automation, but making tubes involved a lot of human intervention. People who had made tubes for years and knew how to make batch after batch of superior tubes. That's why everyone wants them today. And RCA and Raytheon black plates, GE Five Star tubes and JAN Sylvanias. Oh they will all be gone at some point when I don't care anymore, but I will still remember what was the glory days of the tube industry. I was ten years old in 1964 and tubes ruled in everything. Our TV was all tube and so was both of our table radios. My grandfather had a 1947 Chevy and it had a tube radio in it. That's why the original heaters for tubes were six volt, just like the car's electrical power supply and the same power found in a military Jeep.

Joe, I will be dumbfounded if one of the tube manufacturer's starts making tubes that will rival a 1950-60's tube.

Marty

solarburnDSL50 · 05-04-2009, 01:00 AM

Quote:

Originally Posted by MartyStrat54

I was on a different thread and the guy had a hyperlink to a cool old video of how they made audio tubes at the old Mullard Blackburn plant. The video is a copy of the original film. After watching this 25 minute long video, it became apparent to me that we will never be able to replicate what they were doing in that plant of 6300 people. The techniques and the tricks of the trade, the materials used, all vanished back in the mid-80's.

How do they make audio tubes in Saratov, Russia? Like the famous Blackburn plant? I seriously doubt it. Mullard was making tubes there after WWl and Mullard expanded and had six plants with the Blackburn plant being their flagship. All of these tube factories in a country the size of England. They also made Brimar's in England, but they were never much competition to Mullard.

I'm all for automation, but making tubes involved a lot of human intervention. People who had made tubes for years and knew how to make batch after batch of superior tubes. That's why everyone wants them today. And RCA and Raytheon black plates, GE Five Star tubes and JAN Sylvanias. Oh they will all be gone at some point when I don't care anymore, but I will still remember what was the glory days of the tube industry. I was ten years old in 1964 and tubes ruled in everything. Our TV was all tube and so was both of our table radios. My grandfather had a 1947 Chevy and it had a tube radio in it. That's why the original heaters for tubes were six volt, just like the car's electrical power supply and the same power found in a military Jeep.

Joe, I will be dumbfounded if one of the tube manufacturer's starts making tubes that will rival a 1950-60's tube.

Marty

joshuaaewallen · 05-04-2009, 08:27 AM

Quote:

Originally Posted by MartyStrat54

I was on a different thread and the guy had a hyperlink to a cool old video of how they made audio tubes at the old Mullard Blackburn plant. The video is a copy of the original film. After watching this 25 minute long video, it became apparent to me that we will never be able to replicate what they were doing in that plant of 6300 people. The techniques and the tricks of the trade, the materials used, all vanished back in the mid-80's...

How do they make audio tubes in Saratov, Russia? Like the famous Blackburn plant? I seriously doubt it. Mullard was making tubes there after WWl and Mullard expanded and had six plants with the Blackburn plant being their flagship. All of these tube factories in a country the size of England. They also made Brimar's in England, but they were never much competition to Mullard.

I'm all for automation, but making tubes involved a lot of human intervention. People who had made tubes for years and knew how to make batch after batch of superior tubes. That's why everyone wants them today. And RCA and Raytheon black plates, GE Five Star tubes and JAN Sylvanias. Oh they will all be gone at some point when I don't care anymore, but I will still remember what was the glory days of the tube industry. I was ten years old in 1964 and tubes ruled in everything. Our TV was all tube and so was both of our table radios. My grandfather had a 1947 Chevy and it had a tube radio in it. That's why the original heaters for tubes were six volt, just like the car's electrical power supply and the same power found in a military Jeep.

Joe, I will be dumbfounded if one of the tube manufacturer's starts making tubes that will rival a 1950-60's tube.

Marty

Hey Marty, How's it goin'? You guys have been BUSY on the forum. Wow! Question... Do you recall which thread has this video you mentioned? I'd really like to see that.

I threw that GE 12BZ7 (I think it's a '52 vintage) into my amp with a couple of tube dampers on it... Boy... I forgot how great that tube sound in V2! Sustain and harmonics for days. I just need to play a wee bit less sloppy

. With the dampers and normal playing I'll see how that tube holds up. If it becomes a rattler then I guess we'll know for sure that it just can't survive life it a high gain combo.

V1:

V2:

V3:

V4:

In the absence of the 12BZ7, I had the Gold Pin JJ in V2... I didn't mind it as bad as I did before, but that may have been because I hadn't plugged in for nearly a week after pulling the rattling BZ7 outta there (maybe my ears had forgotten to some small extent)... It seems pretty smooth, with not too bad distortion, but less harmonic (talking good harmonics here), and darker...

I am coming to agree w/ you greatly about NOS vs. New Production tubes. If amp makers build amps to sound good w/ new tubes and most folks never experience NOS quality and tone... Then most folks will never really know what they are missing. There really is a difference!

The balancing act is to try to find some "decent" new tubes to have on supply so that when NOS stuff is no longer available we can still play with satisfaction.

Anyhoo... I have a box of tubes headed your way, and as soon as I have a few extra $$$, I'd like to buy a few tubes off you that are in the ICBM type category, and locate a few current production tubes of different makes and do some comparisons.

Great posts! Take care guys, talk at ya later!

04-30-2009, 10:20 PM	#213 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,391	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? Well, I hope that beautiful old 1955 tube doesn't get a bite taken out of it. Look at that quality of craftmanship. Wow! It's like a 28 year-old Pamela Anderson with her third set of implants. GOOD LUCK!!!

05-01-2009, 09:32 PM	#216 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,391	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? JOE: I'm surprised how happy you are with a 12AT7 in your tube section. I'm gonna have to try that sometime. It must have a smoothing effect on the amp, especially when played at moderate volumes where the headroom is still abundant. I've used 5751's but then they are just a little hotter than a 12AT7. You've had that tube for quite some time. It's now been in several amps. My question to you is: Do you really want any high gain tubes? You seem happy with the lower gain sound and your style of playing. Let me know on that, hey? Marty

05-02-2009, 03:11 PM	#218 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,391	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? I spent a good part of yesterday afternoon testing and recording tube ratings. I was surpised to find out that I had many AX7's in the "above average" ratings and I even had some that were up there with the ICBM. I have six, super strong Raytheon BP's coming in and I will need to test these tubes as well. I bought two lots of new tube boxes. I got tired of having all of these unprotected, loose tube lying around. I should have them in by the time I start shipping everyone's tubes out. Kevin is going the full Monte and getting four tubes. Joe, I wonder if your 5751 is good? I'm sure you will agree with me that it isn't normal for the AT7 to outperform the 5751 in the gain category. Something is amiss. The tube may be weak for a variety of reasons. I have two 1958 Tung-Sol 5751's and they will outperform and of the AT7's that I have and I have some really hot ones such as JAN (Joint Army/Navy) 12AT7's that are some of the best I ever have had. I bought a box of five and I'm using one as the PI in my old Randall hybrid amp with the 8417 power tubes. It works great in there. The way I see it, having an AT7 in V1 will work as long as you don't (as you say) crank the gain more than twelve o'clock. In this situation V2 will have enough gain reserve to compensate for the lower gain of the AT7. The result is a completely different sound. On the other side of the fence is putting two super gain 12AX7's in V1 and V2. This is a raging animal that is waiting for a hard power chord followed up by some feverish licks. The tube harmonics I got with two hot tubes was incredible. It made my power tubes sound better as well. To each his own. I know I'm getting old and I don't play as good as I used to, but I still like the high gain sound. I learned on another thread that the choke mod works better with 100 watt heads than say a 40-60 watt head. One thing about tube mods, they work well on any size amp. Marty

05-02-2009, 07:29 PM	#220 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,391	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? I went to that link and they wanted 70 or 80 bucks apiece for Raytheon BP 12AX7's. I just bought six for less than $30 a piece and they all test in the high altitude regions of my meter. So I guess I won't let $27.45 each bother me too bad. They did have some fair prices on JAN Sylvania 6L6WGB's. Standard matching is within 3 mV of each other. The price was $178 for a quad. That's not bad for brand new tubes. I'll have to spend a little more time looking at the prices and finding the bargains, cuz $70 bucks for an AX7 is getting a little pricey. Ya know? Marty

05-02-2009, 08:21 PM	#221 (permalink)
ts31966 Junior Member Join Date: Apr 2009 Posts: 17	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? Hi all! Well, I have been trying a million different combinations. A few tubes I have are microphonic. I am not going to throw them away though. They sound to good for that. I am going to experiment with the rubber bands that I saw on fleabay. Some of the NOS tubes make some strange noises sometimes. I am hoping that with a burn in period they will burn in and quiet down. I saw a device on EAT's website to quiet microphonic tubes but they are very expensive. I am hoping to get them for cheaper. Has anyone here experimented with the rubber bands? If so will the metal sleeves fit over the top of your 12ax7 with the rubber bands on? My 5150 III takes 8 12ax7's so it is taking me alot of time to get into different combinations. I am going to see if I can find some books with some useful information on tube positioning. Sometimes my high gain channel gets quiet with different tube combinations. But only the high gain channel. I have a theory on this but I have to go over the schematics to figure it out.

05-02-2009, 08:37 PM	#222 (permalink)
steelhorse Senior Member Join Date: May 2008 Posts: 3,852	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? I'm curious to see if the bands help you out too. I've not ever heard of anyone using them but I've seen them in use online. I think a few folks here also use them. What are you trying to achieve with the pre's in your EVHIII? I ask because I've not heard a bad one in fact I was very close to purchasing one myself that is until I saw Mesa come out with the MK V. I thought the EVH III is a great amp. Does it have too much gain or not enough gain? Too noisy? Overall what is your opinion of this amp, like what genre's, etc. Seems like a roadworthy amp that's for sure. __________________ www.ricojronline.com 760-956-6619 Garmopat Pedal Mods "I wouldn't mind hearing your head smash through a glass door. That would be cool..." luekmeyer

05-02-2009, 09:09 PM	#223 (permalink)
ts31966 Junior Member Join Date: Apr 2009 Posts: 17	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? The 5150 III is the quietest high gain amp I have tried without a noise gate. That is it's greatest strength. There are alot of great sounding high gain amps but they also have alot of noise. My goal with the EVH 5150 III is to make it sound even better. It does sound great out of the box. But your whole guitar signal goes through your tubes. Each different tube has a unique sound and characteristics. Every product that you buy that is mass produced will never have the best components in it. I am just trying to find the best tubes that will make it sound its best. My favorite tone is Van Halen's tone on all the albums with David Lee Roth. I know to get that tone a better purchase would have been a mojove amp but I want to get it out of my 5150 III. I might still buy a mojove amp also though.

05-02-2009, 10:49 PM	#225 (permalink)
ts31966 Junior Member Join Date: Apr 2009 Posts: 17	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? I have found exactly the same thing Marty. V1 and V2 makes the amps tone. The rest of the tubes just need to be quiet. But the 5150 is set up a little differently than most amps. Channel 1 and 2 are similar but channel 3 has its own voicing. I haven't bought a tube tester. I need to learn more. I want the amplitrex but I don't know if it is worth it for me. Tell me this Marty, I have this tube that sounds great but on channel 3 with the gain maxed out and the guitar volume maxed out the tube starts freaking out. It makes all kinds of weird noises and the distortion from the tube is all over the place. The tube is not microphonic. The tube is a black plate brimar labeled raytheon. Also Marty what do you know about 12dt7's. I have a whole bunch of black plate raytheons. They sound great for channel 1 and 2 but channel 3 doesn't have as much gain with them in the v1 and v2 position. I am thinking that both triodes do not have the same gain in this tube and this is lowering the output on channel 3. I am going to have to call fender Monday about that. Most of my tubes are old. They sound great but I think they need to burn in. Have you guys had experience with tubes settling once you leave them powered on for awhile?

05-02-2009, 11:12 PM	#226 (permalink)
steelhorse Senior Member Join Date: May 2008 Posts: 3,852	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? Check out David Brays amps before deciding on an amp to replicate Ed's sound. __________________ www.ricojronline.com 760-956-6619 Garmopat Pedal Mods "I wouldn't mind hearing your head smash through a glass door. That would be cool..." luekmeyer

05-03-2009, 03:25 PM	#229 (permalink)
ts31966 Junior Member Join Date: Apr 2009 Posts: 17	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? First let me thank steelhorse for the heads up on David Bray amps. I checked out the audio clips and I like them alot. Marty, I don't know what is going on exactly. Yes, I will get a tube that makes channel 1 and 2 sound great, (rich harmonics, full and balanced) then I go to channel 3 and it has less gain than channel 2. This is with just changing v1. The first one that did this was a black plate raytheon 12ad7. But later I discovered a gold pin 12ax7s that I got from eurotubes, that was supposed to be hand selected for low noise and high gain, this tube did the same thing. The box it came in was labeled high gain with the testing for each triode on the box. The Brimar/Raytheon tube sounds great but when you max out the guitar volume it goes crazy. It is the only tube that does this. I got these old tubes a couple of years ago. I am going through the schematics right now to try to figure out which tube is best suited for each position. I have been doing this by trial and error but it is taking me too long. Thanks for the info on the 12dt7 Marty. What you said is exactly what I have read but something strange is going on with those tubes.

05-03-2009, 04:27 PM	#230 (permalink)
ts31966 Junior Member Join Date: Apr 2009 Posts: 17	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? It is the V1 tube. Depending on the tube in V1 channel 1 and 2 can sound great but channel 3 will have less gain. The tone of channel 3 is still great but it is like channels 2 and 3 have changed places. The black plate raytheon tube all do it. I have some black plate sylvania 12ad7's with square getters but they work fine in V1. Like I said it also happened with a jj 12ax7s with gold pins that I got from Bob at eurotubes. This tube was hand selected for noise, microphonics, and high gain. The test results for each triode is on the box. But when I put it in channel 3 sounds wimpy also. I really need to get a tube tester so I can quite using my amp as the tube tester. On a side note I tried a tungsol reissue I got from upscale audio. It sounds pretty good. It is quiet, a little more fizzy than NOS but I would say it one of the best new tubes. The JJ's that came in my amp are very good also. Probably as good as the tungsol reissue. I don't know why those would be better than the one I bought at eurotubes but they are.

05-03-2009, 06:53 PM	#233 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,391	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? Got a web address on that info you posted? The sad thing about that is New Sensor makes Tung-Sol, Mullards, EH's, Sovtek, Svetlana and Genalex. Everything is made in the same plant. Makes you wonder if they all are the same, but I guess there is some difference. As I said before, I looked at a picture of a Tung-Sol 12AX7 up against a Mullard 12AX7 and I couldn't tell them apart. Whatever the case may be, the article suggests that they aren't up to the task of handling high voltage. Marty

05-03-2009, 08:21 PM	#235 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,391	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? Man, there is a load of garbage on that forum. A lot of repeat nonsense. Sounds like one guy ruined some tubes in his amp, couldn't take the voltage. All the more reason that NOS tubes rule. I looked at the schematic of my TSL100 (122) and man does it have high voltage on the 12AX7's. I mean a lot higher than 300V! Of course the current draw is very low in the circuit. I wish that New Sensor would be honest and publish the "real" specs on their tubes. Ha! They won't do that...they'd loose business. Marty

05-03-2009, 11:35 PM	#236 (permalink)
ts31966 Junior Member Join Date: Apr 2009 Posts: 17	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? Marty, according to Eurotubes the tubes he sent me tested over 100%. All the tubes I bought had excellent test results according to the people who sold them. What I am saying is that obviously some or most of these tube resellers are full of it! I talked to a guy that owns an amplitrex. He said that the amplitrex will reject tubes that appear good on an older calibrated tube tester. Such as a tv-7. The guy I purchased the 12dt7's from said he tested all of them. He is a very reliable and honest tube reseller. A very nice and fair guy. I will call fender tomorrow. I will find out what is going on with the v1 position in this amp. I tested the 12dt7's in a marshall combo and they sound great. It was a 2 channel amp. I can't remember which model. I know it is all tube though. It has 2 twelve inch speakers and uses el34's. I have a groove tube mullard reissue. I will test it tomorrow. I bought it from upscale audio and it is supposed to be hand selected. High gain, low noise, non-microphonic. The guy at upscale has never sold me anything of poor quality. He is the one who sold me the tungsol reissue.

05-04-2009, 12:34 AM	#238 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,391	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? I was on a different thread and the guy had a hyperlink to a cool old video of how they made audio tubes at the old Mullard Blackburn plant. The video is a copy of the original film. After watching this 25 minute long video, it became apparent to me that we will never be able to replicate what they were doing in that plant of 6300 people. The techniques and the tricks of the trade, the materials used, all vanished back in the mid-80's. How do they make audio tubes in Saratov, Russia? Like the famous Blackburn plant? I seriously doubt it. Mullard was making tubes there after WWl and Mullard expanded and had six plants with the Blackburn plant being their flagship. All of these tube factories in a country the size of England. They also made Brimar's in England, but they were never much competition to Mullard. I'm all for automation, but making tubes involved a lot of human intervention. People who had made tubes for years and knew how to make batch after batch of superior tubes. That's why everyone wants them today. And RCA and Raytheon black plates, GE Five Star tubes and JAN Sylvanias. Oh they will all be gone at some point when I don't care anymore, but I will still remember what was the glory days of the tube industry. I was ten years old in 1964 and tubes ruled in everything. Our TV was all tube and so was both of our table radios. My grandfather had a 1947 Chevy and it had a tube radio in it. That's why the original heaters for tubes were six volt, just like the car's electrical power supply and the same power found in a military Jeep. Joe, I will be dumbfounded if one of the tube manufacturer's starts making tubes that will rival a 1950-60's tube. Marty

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