Preamp Tubes? - Who, What, When, Where, Why, and How? - Page 18

solarburnDSL50 · 06-20-2009, 12:52 AM

Quote:

Originally Posted by joshuaaewallen

Is this something you're interested in? 12AX7A by Rca - Buy or Repair at PLCCenter

Yes. Thanks Josh. Marty sent me some for now so I won't need any but its great to know where they are. Good work bro!

solarburnDSL50 · 06-20-2009, 03:20 AM

Quote:

Originally Posted by joshuaaewallen

V1:

V2:

I've gotta tell ya Marty... I am in love with this combination. It is just superb in every channel.

Saturday I will be roll'n these 2 in V1 & V2 as well. Its so cool to be able to say "I think I'll try that too" and pop them in.

How is it that you and me have the same tubes...

joshuaaewallen · 06-20-2009, 08:22 AM

Quote:

Originally Posted by solarburnDSL50

Saturday I will be roll'n these 2 in V1 & V2 as well. Its so cool to be able to say "I think I'll try that too" and pop them in.

How is it that you and me have the same tubes...

Hey Solar! Cool to hear that you will be rolling these same tubes! I dig that kinda thing because it gives a great opportunity to hear others feed back of the same thing your trying (that's one reason why I dig that Marty has a TSL122 as well, it means I know we can get on the same page pretty quickly when we are comparing notes). Granted you running a different amp, but... I would imagine that the tonal qualities of these tubes should be pretty similar either way. Any hoo... I look forward to your thoughts on these and how they behave in your DSL. Plus... Knowing you like to boost w/ overdrive pedals, I am curious how these behave in that scenario as well. Keep us posted!

solarburnDSL50 · 06-20-2009, 04:25 PM

Quote:

Originally Posted by joshuaaewallen

Knowing you like to boost w/ overdrive pedals, I am curious how these behave in that scenario as well. Keep us posted!

Ok. My Father-in-law just left the house for lunch with a friend. He lives with us by the way so I am limited to times I can crank at home. I got to give it a good goose and I have to say it sounded good with out a boost.

Then I kicked it with the Route 808! Holy Moly Spicolli...

Danger Will Robinson...ok enough of that.

I can't hear what did you say...?

I can't put it into words right now. It just ripped! I'm surprised I don't have the cops at my door. At this volume my Greenbacks will be brok'n in real soon.

I have to say I prefer the DSL boosted slightly and I wasn't even using my fav pedal which is the CTO-1.

Both channels were very good. Nice harmonics, musical feedback, nice mids and lows, guitar roll off natural, etc. Cleans sound full with a nice feel. These in V1 & V2 are a good combo. You know they sat well with my blues and Raunch & Roll.

So I agree these sound good. With them out of the way and marked with a + I can roll the other ones. I have 2 solid combos I like in the Marshall to compare to now.

1.V1-RFT
V2- RCAa

2.V1-7025
V2-Amperex

I'm just gonna roll the V1 & V2 positions for now.

MartyStrat54 · 06-20-2009, 04:32 PM

HEY JOSH! Thanks for the heads up on the tube seller, "bmsanborn." I see what happened. I was looking and searching for him in the tube section under audio equipment and his listings were under musical instruments, guitar.

I've ran into him before. The lucky dog. He seems to always score huge lots of desirable tubes like RFT/Siemens EL34's. His prices are actually fair for a tube of this quality.

Marty

joshuaaewallen · 06-20-2009, 04:39 PM

Quote:

Originally Posted by MartyStrat54

HEY JOSH! Thanks for the heads up on the tube seller, "bmsanborn." I see what happened. I was looking and searching for him in the tube section under audio equipment and his listings were under musical instruments, guitar.

I've ran into him before. The lucky dog. He seems to always score huge lots of desirable tubes like RFT/Siemens EL34's. His prices are actually fair for a tube of this quality.

Marty

No problem. Actually sometimes finding a seller on ebay can be a pain, so I just googled the seller name, and wallah! There it was.

Spinal Tap

MartyStrat54 · 06-20-2009, 05:01 PM

[QUOTE=joshuaaewallen;46119]Here's a dumb question... Is a 12AX7A the same as a 7025?

You know, I first want to say that I feel pleased about the fact that I had posted (maybe several times on several threads) a link called 12AX7. It was written by the guy who matches up all of the tubes for Mesa Boogie. Anyway, he came up with a formula for Marshall amps. "Try a 7025 in V1 and a high gain 12AX7 in V2." Wow! Who does that sound like. It's nice to know that I reached the same conclusions as this guy. Maybe we are on to something.

Anyway, the original 12AX7 was rated as follows:

This is the original version of this tube. The earliest ones were all made in the USA by the usual manufacturers like RCA, Sylvania, GE and Tung Sol. Very early ones have rather large size plates. The "plain" version without the "A" suffix can only be used in parallel filament circuits, not series.

The 12AX7A was rated as follows:

This later version can be used in series or parallel filament circuits. Many manufacturers produced plain 12AX7's well into the 60's and 70's, but I believe these are 12AX7A's marked 12AX7.

The 7025 was an "industrial" tube rated as follows:

This is the "hi fi" low noise version of the 12AX7. All other specifications are the same as 12AX7. Tubes marked with 12AX7 and 7025 both should be low noise, too.

Pay attention to that last sentence. I've found out that 12AX7's and 12AX7A's that are co-marked 7025, are in fact a low noise 7025's. The box/tube has to state both numbers.

Marty

solarburnDSL50 · 06-20-2009, 05:16 PM

[quote=MartyStrat54;46212]

Quote:

Originally Posted by joshuaaewallen

Here's a dumb question... Is a 12AX7A the same as a 7025?

You know, I first want to say that I feel pleased about the fact that I had posted (maybe several times on several threads) a link called 12AX7. It was written by the guy who matches up all of the tubes for Mesa Boogie. Anyway, he came up with a formula for Marshall amps. "Try a 7025 in V1 and a high gain 12AX7 in V2." Wow! Who does that sound like. It's nice to know that I reached the same conclusions as this guy. Maybe we are on to something.

Anyway, the original 12AX7 was rated as follows:

This is the original version of this tube. The earliest ones were all made in the USA by the usual manufacturers like RCA, Sylvania, GE and Tung Sol. Very early ones have rather large size plates. The "plain" version without the "A" suffix can only be used in parallel filament circuits, not series.

The 12AX7A was rated as follows:

This later version can be used in series or parallel filament circuits. Many manufacturers produced plain 12AX7's well into the 60's and 70's, but I believe these are 12AX7A's marked 12AX7.

The 7025 was an "industrial" tube rated as follows:

This is the "hi fi" low noise version of the 12AX7. All other specifications are the same as 12AX7. Tubes marked with 12AX7 and 7025 both should be low noise, too.

Pay attention to that last sentence. I've found out that 12AX7's and 12AX7A's that are co-marked 7025, are in fact a low noise 7025's. The box/tube has to state both numbers.

Marty

Great info especially about the 7025.

joshuaaewallen · 06-21-2009, 10:39 AM

Quote:

Originally Posted by MartyStrat54

... The 7025 was an "industrial" tube rated as follows:

This is the "hi fi" low noise version of the 12AX7. All other specifications are the same as 12AX7. Tubes marked with 12AX7 and 7025 both should be low noise, too.

Pay attention to that last sentence. I've found out that 12AX7's and 12AX7A's that are co-marked 7025, are in fact a low noise 7025's. The box/tube has to state both numbers.

Marty

Wow, Thanks Marty. Essentially identifying tubes accurately can be somewhat tricky. One really has to make sure he's seeing all of the numbers. In essence, I have two "Made In Germany" 12AX7A's, and they are basically "low noise" 12AX7's. But the RCA (Lindall) tube you sent over that is marked on the tube as both 12AX7A & 7025 is an actual 7025. Correct?

MartyStrat54 · 06-21-2009, 04:09 PM

My 700th post on the forum!

Whoo! Whoo! (Mellow out Marty..."Okay.")

Yeah Josh, those Lindal tubes were sold on EBAY as 7025's. As I told you, those are actually RCA tubes. Lindal didn't make tubes, but they sure did buy a lot and relabeled them.

From EBAY:

UP FOR BIDS IS A NOS/NIB TRIO OF LINDAL 7025 12AX7A TUBES. THESE TUBES HAVE A HALO GETTER AND COPPER GRID POSTS.
TUBES WERE TESTED ON THE CALIBRATED TV-7/U TUBE TESTER WHERE THE MINIMUM IS 32/32 THESE TUBES TESTED AT 58/56, 48/50, 52/54.

Hope all is going well.

Marty

joshuaaewallen · 06-21-2009, 06:50 PM

Quote:

Originally Posted by MartyStrat54

My 700th post on the forum!

Whoo! Whoo! (Mellow out Marty..."Okay.")

Yeah Josh, those Lindal tubes were sold on EBAY as 7025's. As I told you, those are actually RCA tubes. Lindal didn't make tubes, but they sure did buy a lot and relabeled them.

From EBAY:

UP FOR BIDS IS A NOS/NIB TRIO OF LINDAL 7025 12AX7A TUBES. THESE TUBES HAVE A HALO GETTER AND COPPER GRID POSTS.
TUBES WERE TESTED ON THE CALIBRATED TV-7/U TUBE TESTER WHERE THE MINIMUM IS 32/32 THESE TUBES TESTED AT 58/56, 48/50, 52/54.

Hope all is going well.

Marty

Congratulations on being a MEGA-POSTER on The Marshall Forum Marty! You Da Man!

You've certainly added a lot of insightful posts to this forum. Thanks Marty.

MartyStrat54 · 06-22-2009, 08:22 PM

Well I guess I am a "Mega Man"...man. Sure is quiet out there. Almost like a whole lot of tube rollin' is going on. I'm sure Joe has his calculator and slide rule out to make note of all the different configurations. That, or a wide open amp.

Yeah, I'm waiting to hear from the repair shop. A couple of my babies had to go in. I guess they all need to go sometime (except maybe an old 800).

solarburnDSL50 · 06-22-2009, 09:14 PM

Quote:

Originally Posted by MartyStrat54

Well I guess I am a "Mega Man"...man. Sure is quiet out there. Almost like a whole lot of tube rollin' is going on. I'm sure Joe has his calculator and slide rule out to make note of all the different configurations. That, or a wide open amp.

Yeah, I'm waiting to hear from the repair shop. A couple of my babies had to go in. I guess they all need to go sometime (except maybe an old 800).

For frigg'n sure bros! Drool, sweat and slobber too. I'm sure I'll be buy'n this time around hehe. SOOOO many tubes to roll...burnt fingers...

Hope the news isn't dire from the shop. Keep us posted.

Jesstaa · 06-23-2009, 04:33 AM

Alright everybody,
hope nobody cares if I jump in here.

I've looked through the first 3 pages of this thing pretty thoroughly, but then realised I couldn't be bothered reading through the next 15.

So anyway, I was wondering, Marty, and the rest of you uber-tubers, could I get some info on my JCM 900 4100, I'm looking for a nice combination for old school hotted up thrash and british metal, the kinda thing people used modded plexi's and 800's for. I don't wanna get those tones exactly (Or I'd just have my amp modded) but I wanna get close, so then I can figure my own tone out with some pedals.

Currently I have some high gain JJ 12ax7's in there, which are apparently 104/105 and 110/110 for the balanced tube in P.I position, which is V1 in the 4100's isn't it? And I haven't actually been able to test these yet (I ordered a KT77 retube kit, but my bias circuit was funky and it wouldn't accept anything other than 6L6's, and KT77's should've worked).

Also, will the slightly different sizes associated with different tubes/N.O.S different brands have any problems when it comes to the tube covers, which are currently pretty tight on my 12AX7's and cover each tube.

Edit: I'm gonna need tubes which are available in Australia/able to be shipped here.

Double edit: If somebody could direct me to the best N.O.S tube dealer for Australia, that'd be great, cause I also have 2 old valve radios I'd like to retube, and the receiver tubes aren't made anymore, and I think all of the 5Y3 rectifier tubes made today are different, also I doubt they've made those mini radio tubes (12ax7 size) tubes since the 70's.

Cheers guys,
Jesse.

MartyStrat54 · 06-23-2009, 05:11 PM

Well it's a shame you didn't jump on board sooner. There is a lot of interesting sound tests performed with various USA and European tubes. That and a little humor thrown in.

I will only be able to answer some on your questions. First off, how clean does your clean sound need to be? If it can be a little gritty, then I would suggest a medium to high gain 12AX7 in V1. If you need a clean "clean," then I would recommend a 7025 (NOS) in V1. V2 I would recommend a high gain 12AX7 such as a Mullard long plate 12AX7. You have a high gain tube (110/110), but the JJ's are a darker sounding tube and you will want to get away from that for your sound.

What makes this tough is that we are basically moving away from current production tubes and are using NOS tubes. Granted, we may still use current production tubes in V3 and V4, as they have less of an impact on the gain and tone. BTW, V1 will be the tube located the farthest distance from the power tubes and power transformer. V1 is the most sensitive tube in the amp. Anyway, it is hard for me to say what tubes to recommend when you live in Australia. Most of the big online tube stores will ship there, so that's not a problem, but you are limited to what they have. They do sell NOS tubes, but they are expensive.

As stated, the JJ tubes you are running tend to be a little dark sounding. Not what you want for your sound. I would recommend a high gain Tung-Sol short plate 12AX7 in V1 and a Mullard long plate in V2 and then use your current V3 and the 110/110 tube in V4. Note: The PI tube does not need to be high gain or perfectly matched, but since you have it, try it out. You may want to do a little tweaking with these two tubes as well. Hopefully you will get the Tung-Sol and it will be at least 110/110. It is a much brighter tube and sounds smoother overall. That will result in a more crunchier sound.

The NOS tubes have no problem accepting the shields. The only tube I've had problems with are the Sovteks. If the JJ's fit, the Tung-Sol and Mullard will fit.

Another 900 with 6L6's? Yeah you could have spared yourself some anguish if you had read some of my other posts (different threads) about swapping power tubes. It can be done, but you have to change the value of the final bias resistor to get into the bias range of the KT77's. If you still have the tubes you can get a tech to do this. Do you have a tech in your area?

American/Canadian Tube Sellers that will ship worldwide.

Welcome to TubeDepot.com!

thetubestore.com Audio and vacuum tubes for your amplifier.

https://www.tubeworld.com/index_high.htm

Australian Company

Kableflags: The Cable Management Safety Product for Home and the Workplace (Call them. They state they sell audio tubes.)

Marty

Jesstaa · 06-23-2009, 10:54 PM

I don't really need much of a clean, although it's nice to have (And currently it's pretty amazing, but I plan on using a different amp and having an A/B/Y box for cleans) and the 4100 only has 3 pre amp tubes.

Edit: Yeah, I have a tech in the area, that's where my amp is currently. I took it in there when trying to switch tubes because it wouldn't stay biased, and I wanted to make sure that nothing was damaged in it (Cause I bought it second hand), I should be getting it back today, but I don't plan on ever taking it back there, they've had it for like 5 weeks just to figure out that I should leave 6L6's in there for now. Bloody useless.

Double Edit: How would I determine the date of an Phillips miniwatt 6V6? I have one in an old radio and it's still doing just fine, and I'm wondering how rare it is, it appears to have no getter (Unless the weird silver ring around the bottom is the getter, but it seems too light of a colour to be getter) it also appears to be painted black (I'd guess it was burnt out, but it's very neat, and the tube still works fine)

http://cgi.ebay.com/Three-RCA-12BZ7-...1|293:1|294:50

That could be a good score, if you get back on in time. Seller will refund if they're shit, and you have a tube tester to test them.

MartyStrat54 · 06-24-2009, 12:02 AM

A lot of 6V6's were treated with what was called a smoke top. Nice little edge down at the bottom of the tube. There is a getter, you just can't see it. The only way you could tell how old it is, is if all of the original labeling was still on the tube. There would be a date code somewhere on the tube. It is hard to make any money with just one tube. Most buyers have single-ended amps and they want a close match pair.

I sold two pairs of 6V6's on EBAY. Both pairs were really nice and I lost my ass selling them. The market is soft on certain tubes right now and has been that way for over six months.

Ebay would be the only way to sell it since you just have one.

Marty

jamesbreese · 06-24-2009, 02:39 PM

Good grief. That was the longest post on this forum I have ever been through, but all very good and interesting info! Nice pictures too.

MartyStrat54 · 06-24-2009, 03:52 PM

Quote:

Originally Posted by jamesbreese

Good grief. That was the longest post on this forum I have ever been through, but all very good and interesting info! Nice pictures too.

Yeah, we've been running so long now that we had to hire a gaffer and a couple of staff photographers. They do good work.

I see you are from Tulsa. I was born and raised in Blackwell, Oklahoma which is just south of the Kansas border on I-35. I've been to Tulsa many, many times and was just there several months ago. I have a college friend who plays in a cover band and they have released some original material as well.

If you read all of this thread, power to you, but at least you are caught up.

Marty

jamesbreese · 06-25-2009, 09:59 AM

I know where your talking about... I drive up the 35 to Wichita from time to time and that one of the gas stops. Small town.

Whats your buddy's band name?

MartyStrat54 · 06-25-2009, 02:19 PM

Quote:

Originally Posted by jamesbreese

I know where your talking about... I drive up the 35 to Wichita from time to time and that one of the gas stops. Small town.

Whats your buddy's band name?

It used to be a lot bigger in the 70's. The EPA shut down the biggest employer.

My buddies band is called the Brandon Clark Band. They play almost every night.

David "Dave" Duval (guitar) is my buddy. We were in a short lived band back in the early 80's. Here is a link:

Brandon Clark on MySpace Music - Free Streaming MP3s, Pictures & Music Downloads

If you Google or Dogpile "Brandon Clark" you will get a boat load of sites.

I graduated from high school in 1972, but didn't go to college until 1982. I played in the jazz band, stage band and a special group called the Roustabouts. I was ten years older than everybody else. I had better equipment and a 1969 big block Corvette. Ah, the good ole days.

http://www.north-ok.edu/roustabouts

Those are bad pictures, but what it is basically is a production styled song and dance act with a live band. Very fast paced. I was there in 1982-84. At the time it was a two-year college, now it is a four year. The Roustabouts also have a MySpace account that is okay.

Anyway, have a good one.

Marty

MartyStrat54 · 06-26-2009, 03:17 PM

JOE-Solarburn, has finished rolling the ten tubes I sent him. He seemed to be quite jacked up over his selections. I'm sure he won't be disappointed.

I haven't been quiet. I have just been buying EL34 and 12AX7 tubes on EBAY as usual. Bought me a quad of RFT EL34's. Thought about putting them in the TSL100.

I scored six 12AX7's and four 7025's made by Philips/Amperex of Canada. I lost out on eight of these, but I can't win them all.

Tried to win some fat bottle EL34 Sylvania's and lost out on that one too.

Right now, I have some auctions coming up and I will be placing my bid soon.

Other news, one of the two techs has been on vacation, so my amps haven't even been looked at yet. Just so you know. Hopefully, I will know what's up by Monday or Tuesday.

Marty

solarburnDSL50 · 06-26-2009, 03:38 PM

Marty,

If you get anymore of the 12AX7A, Raytheon, 1960's Medium Black Plate's keep me in mind. I wouldn't mind hav'n a couple more of those.

I pretty much figured out what sounded good in my set up but will continue to roll my new inventory as I play along. It takes quite awhile to find the best order/combination of tubes working together. I think I got some gems to work with.

MartyStrat54 · 06-26-2009, 09:09 PM

Well I'm sure that you did end up with some good torpedoes. You have enough tubes to keep you going for several birthdays. How many did you buy? Eight?

The neat thing about tubes is that a different guitar will affect the gain of the tube. V1 is hooked up in line with the guitar and if you have hot ceramic pickups like my Explorer's 500T's, it will blow the front end of an amp clean out. (Well maybe not as much as an EMG81, LOL!

). You get my point. You may say, "That tube is lame (in V1)." Then you get a humbucker plugged into it and it is like, "Holy Hogwash, Batman!" I love my Strat and it sounds really sweet, but my Schecter and my Gibson rip stage one of the preamp circuit up. It's like when I told Josh to not audition the tubes with dead strings. He took my advice and he was chopping wood with the 7025 and the ICBM Amperex.

Oh, I just got some more tubes. Brand new Joint Army/Navy Sylvania's. NIB and NOS. Never been used. Four tubes. Winning bid, $51.00. Who says NOS are too expensive? Not me.

I read a thread, but I can't remember what it was called. I think it was someone asking about preamp tubes in an 800. One of the members posted that Tung-Sol is having trouble with the Tung-Sol (short plate) in the V3 position. It can't handle the voltage. I told you guys in the past that most current production AX7's are running at or above their rated plate voltage. Apparently this is the case here and the Tung-Sol is failing. Another reason to use NOS tubes. They "can" handle the plate voltage. They were "made" to better specifications with better materials. I told you guys about how tube manufacturer's were always trying to outdo the competition. This alone made for some very high quality tubes. I told you how it wasn't about price in 1962. Well, it's all about price with current production tubes and to keep profits up, the tubes are...well cheap.

When was the last time you've seen any specifications on any current production tube? I've never seen any...ever. Why do you think that is? If you have a 1965 Tube Manual and you look up the specs on a 12AX7, every tube manufacturer was expected to meet (or exceed) the stated specifications. You can Google all day and not find any specs at all on new tubes. They don't want you to know about their failure rate. They don't want you to know that their tube can take about half the plate voltage as a 45 year old RCA! Wouldn't you think with today's equipment and materials that a better tube could be made? Hell no. Take a look at Blackburn which is the former Mullard U.K. They were going to start selling high quality AX7's all made on sixty year old equipment. Why? Because it does the job better than anything that anyone has come up with. If anyone is going to come out with a consistently good tube, they will be made on original equipment, using original techniques and the same materials. Period! Trying funky manufacturing techniques results in a funky tube. Hopefully the economy will get better and Blackburn will pursue making tubes. Even if they are twice the price as say an EH or a (fake) Mullard, it would still be a good deal and I would have peace of mind knowing that someone was actually making a good tube again.

solarburnDSL50 · 06-27-2009, 12:52 AM

Quote:

Originally Posted by MartyStrat54

Well I'm sure that you did end up with some good torpedoes. You have enough tubes to keep you going for several birthdays. How many did you buy? Eight?

The neat thing about tubes is that a different guitar will affect the gain of the tube. V1 is hooked up in line with the guitar and if you have hot ceramic pickups like my Explorer's 500T's, it will blow the front end of an amp clean out. (Well maybe not as much as an EMG81, LOL!

). You get my point. You may say, "That tube is lame (in V1)." Then you get a humbucker plugged into it and it is like, "Holy Hogwash, Batman!" I love my Strat and it sounds really sweet, but my Schecter and my Gibson rip stage one of the preamp circuit up. It's like when I told Josh to not audition the tubes with dead strings. He took my advice and he was chopping wood with the 7025 and the ICBM Amperex.

Oh, I just got some more tubes. Brand new Joint Army/Navy Sylvania's. NIB and NOS. Never been used. Four tubes. Winning bid, $51.00. Who says NOS are too expensive? Not me.

I read a thread, but I can't remember what it was called. I think it was someone asking about preamp tubes in an 800. One of the members posted that Tung-Sol is having trouble with the Tung-Sol (short plate) in the V3 position. It can't handle the voltage. I told you guys in the past that most current production AX7's are running at or above their rated plate voltage. Apparently this is the case here and the Tung-Sol is failing. Another reason to use NOS tubes. They "can" handle the plate voltage. They were "made" to better specifications with better materials. I told you guys about how tube manufacturer's were always trying to outdo the competition. This alone made for some very high quality tubes. I told you how it wasn't about price in 1962. Well, it's all about price with current production tubes and to keep profits up, the tubes are...well cheap.

When was the last time you've seen any specifications on any current production tube? I've never seen any...ever. Why do you think that is? If you have a 1965 Tube Manual and you look up the specs on a 12AX7, every tube manufacturer was expected to meet (or exceed) the stated specifications. You can Google all day and not find any specs at all on new tubes. They don't want you to know about their failure rate. They don't want you to know that their tube can take about half the plate voltage as a 45 year old RCA! Wouldn't you think with today's equipment and materials that a better tube could be made? Hell no. Take a look at Blackburn which is the former Mullard U.K. They were going to start selling high quality AX7's all made on sixty year old equipment. Why? Because it does the job better than anything that anyone has come up with. If anyone is going to come out with a consistently good tube, they will be made on original equipment, using original techniques and the same materials. Period! Trying funky manufacturing techniques results in a funky tube. Hopefully the economy will get better and Blackburn will pursue making tubes. Even if they are twice the price as say an EH or a (fake) Mullard, it would still be a good deal and I would have peace of mind knowing that someone was actually making a good tube again.

I've read many times to watch certain new production preamp tubes in particular slots(cathode follower)because they can't handle the voltages. They are running right at the edge of capacity, no room for error. I've read other tube experts saying its a crap shoot buying NP preamp tubes and using them in your amps. I didn't think it was that bad but that is the reputation new production tubes have garnered for those who work closely with them. The ones that sell them or test production runs.

There are only a couple new production preamp tubes I like anyways but there are more NOS I'm finding really sound good. Its a relief knowing you have a tube that will handle whatever slot you put it in. That it sounds great, has been tested so you know its good. I have to say I am getting them for a great price too. How am I losing in this? I'm not. Its for me and what I want tone wise. I'm doing the work and judging the results good or bad. Its the process of seeking good tone and I'm being rewarded. Otherwise it would be just another waste of time and money. I don't like wasting money. I don't have money "to" waste.

I say use what you like and what works for you. Me...I'm playing around with the NOS and finding some pretty cool dynamics, touch and response. I have to say it is actually fun hearing the differences and finding the tube or tubes that sound good in my amps and make them more musical to my ears. After that its up to me to play it to where the music actually sounds good hehe.

I'm having a good time and enjoy playing my stuff.

Jesstaa · 06-27-2009, 01:43 AM

I managed to find a half decent arrangement with the tubes I currently have (2 National tubes and 3 JJs) not quite sure which tubes are which in a 900, but going with the Phase inverter as V3, I got a JJ in V1, a National in V2 and a balanced JJ in V3, it's still got a strong tone, but it's brightened up a bit with the National, with any more than 1 national in the amp, it's kinda flat sounding.

MartyStrat54 · 06-27-2009, 09:13 PM

Just an FYI post. I know I have already wrote about it, but this is for any new member who happens to drop in. Apparently, Tung-Sol is not holding up in the V3 position on Marshall amps (V2 on earlier Marshall amps). This is the tone stack/cathode follower circuit. I'd advise not running a Tung-Sol in this slot.

Forum thread:

These pre-amp valves for my 2203.....

Marty

RiverRatt · 06-28-2009, 02:46 AM

I've actually been running a Tung-Sol RI in V3 and V4 occasionally. I haven't left it in there for long at a time. I've been playing with those two sockets, and my amp seems to sound a little better with the Tung-Sol or a Sovtek 12AX7WA in V3. What exactly happens if this tube fails? Is there a danger of harming the amp, or just a loss or degradation of the signal?

MartyStrat54 · 06-28-2009, 05:01 PM

Quote:

Originally Posted by RiverRatt

I've actually been running a Tung-Sol RI in V3 and V4 occasionally. I haven't left it in there for long at a time. I've been playing with those two sockets, and my amp seems to sound a little better with the Tung-Sol or a Sovtek 12AX7WA in V3. What exactly happens if this tube fails? Is there a danger of harming the amp, or just a loss or degradation of the signal?

A preamp tube failing is not going to do any damage to the amp. When they fail they could blow a fuse if they short out. If they open it won't blow the fuse.

Yeah, the Tung-Sol is actually a pretty good sounding tube. It's too bad that it can't handle all of the various positions and the different circuit loads and voltages that those positions present.

Marty

MartyStrat54 · 06-30-2009, 03:12 PM

NOS versus Current Production

In 1959, these were the specs all RCA tubes were manufactured by.

1.Vacuum/Air Pressure-1/000,000,000 that of atmospheric pressure at sea level.
2.Plate-Diameter gauged to 0.0002 inch.
3.Grids-Diameters measured to 0.0001 inch.
4.Cathode coating-Weight variation less than 0.00007 oz.
5.Grid Wire-Diameter varies less than 0.00009 inch.
6.Cathode-Sleeve Wall-Approximately 0.002 inch thick.
7.Heater Wire-Diameter varies less than 0.00002 inch.
8.Glass Bulb-Inspected under polarized light for strains.

This was standard business in 1959. Do you think your Sovtek can match this?

Marty

06-20-2009, 04:32 PM	#515 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,580	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? HEY JOSH! Thanks for the heads up on the tube seller, "bmsanborn." I see what happened. I was looking and searching for him in the tube section under audio equipment and his listings were under musical instruments, guitar. I've ran into him before. The lucky dog. He seems to always score huge lots of desirable tubes like RFT/Siemens EL34's. His prices are actually fair for a tube of this quality. Marty __________________ MARTY 2009 Gibson Explorer-Hell Raising Machine 1989 Fender Strat Plus USA 2008 Fender Tele USA 2004 Schecter Elite w/DiMarzio's TSL100 with custom 4x12 cab. TSL122 with Man 'O War Speakers. TSL602 #1 with JBL D123 Speakers and 602 #2 with Altec 417 Speakers. "Oh so sweet my friends." DSL401 #1 with Red Fang Speaker and 401 #2 with JBL D123 Speaker. Tubes: Let's just say they are NOS that kick ass.

06-20-2009, 05:01 PM	#517 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,580	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? [QUOTE=joshuaaewallen;46119]Here's a dumb question... Is a 12AX7A the same as a 7025? You know, I first want to say that I feel pleased about the fact that I had posted (maybe several times on several threads) a link called 12AX7. It was written by the guy who matches up all of the tubes for Mesa Boogie. Anyway, he came up with a formula for Marshall amps. "Try a 7025 in V1 and a high gain 12AX7 in V2." Wow! Who does that sound like. It's nice to know that I reached the same conclusions as this guy. Maybe we are on to something. Anyway, the original 12AX7 was rated as follows: This is the original version of this tube. The earliest ones were all made in the USA by the usual manufacturers like RCA, Sylvania, GE and Tung Sol. Very early ones have rather large size plates. The "plain" version without the "A" suffix can only be used in parallel filament circuits, not series. The 12AX7A was rated as follows: This later version can be used in series or parallel filament circuits. Many manufacturers produced plain 12AX7's well into the 60's and 70's, but I believe these are 12AX7A's marked 12AX7. The 7025 was an "industrial" tube rated as follows: This is the "hi fi" low noise version of the 12AX7. All other specifications are the same as 12AX7. Tubes marked with 12AX7 and 7025 both should be low noise, too. Pay attention to that last sentence. I've found out that 12AX7's and 12AX7A's that are co-marked 7025, are in fact a low noise 7025's. The box/tube has to state both numbers. Marty __________________ MARTY 2009 Gibson Explorer-Hell Raising Machine 1989 Fender Strat Plus USA 2008 Fender Tele USA 2004 Schecter Elite w/DiMarzio's TSL100 with custom 4x12 cab. TSL122 with Man 'O War Speakers. TSL602 #1 with JBL D123 Speakers and 602 #2 with Altec 417 Speakers. "Oh so sweet my friends." DSL401 #1 with Red Fang Speaker and 401 #2 with JBL D123 Speaker. Tubes: Let's just say they are NOS that kick ass.

06-21-2009, 04:09 PM	#520 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,580	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? My 700th post on the forum! Whoo! Whoo! (Mellow out Marty..."Okay.") Yeah Josh, those Lindal tubes were sold on EBAY as 7025's. As I told you, those are actually RCA tubes. Lindal didn't make tubes, but they sure did buy a lot and relabeled them. From EBAY: UP FOR BIDS IS A NOS/NIB TRIO OF LINDAL 7025 12AX7A TUBES. THESE TUBES HAVE A HALO GETTER AND COPPER GRID POSTS. TUBES WERE TESTED ON THE CALIBRATED TV-7/U TUBE TESTER WHERE THE MINIMUM IS 32/32 THESE TUBES TESTED AT 58/56, 48/50, 52/54. Hope all is going well. Marty __________________ MARTY 2009 Gibson Explorer-Hell Raising Machine 1989 Fender Strat Plus USA 2008 Fender Tele USA 2004 Schecter Elite w/DiMarzio's TSL100 with custom 4x12 cab. TSL122 with Man 'O War Speakers. TSL602 #1 with JBL D123 Speakers and 602 #2 with Altec 417 Speakers. "Oh so sweet my friends." DSL401 #1 with Red Fang Speaker and 401 #2 with JBL D123 Speaker. Tubes: Let's just say they are NOS that kick ass.

06-22-2009, 08:22 PM	#522 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,580	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? Well I guess I am a "Mega Man"...man. Sure is quiet out there. Almost like a whole lot of tube rollin' is going on. I'm sure Joe has his calculator and slide rule out to make note of all the different configurations. That, or a wide open amp. Yeah, I'm waiting to hear from the repair shop. A couple of my babies had to go in. I guess they all need to go sometime (except maybe an old 800). __________________ MARTY 2009 Gibson Explorer-Hell Raising Machine 1989 Fender Strat Plus USA 2008 Fender Tele USA 2004 Schecter Elite w/DiMarzio's TSL100 with custom 4x12 cab. TSL122 with Man 'O War Speakers. TSL602 #1 with JBL D123 Speakers and 602 #2 with Altec 417 Speakers. "Oh so sweet my friends." DSL401 #1 with Red Fang Speaker and 401 #2 with JBL D123 Speaker. Tubes: Let's just say they are NOS that kick ass.

06-23-2009, 04:33 AM	#524 (permalink)
Jesstaa Senior Member Join Date: Apr 2009 Location: Gippsland, Vic, Australia. Posts: 797	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? Alright everybody, hope nobody cares if I jump in here. I've looked through the first 3 pages of this thing pretty thoroughly, but then realised I couldn't be bothered reading through the next 15. So anyway, I was wondering, Marty, and the rest of you uber-tubers, could I get some info on my JCM 900 4100, I'm looking for a nice combination for old school hotted up thrash and british metal, the kinda thing people used modded plexi's and 800's for. I don't wanna get those tones exactly (Or I'd just have my amp modded) but I wanna get close, so then I can figure my own tone out with some pedals. Currently I have some high gain JJ 12ax7's in there, which are apparently 104/105 and 110/110 for the balanced tube in P.I position, which is V1 in the 4100's isn't it? And I haven't actually been able to test these yet (I ordered a KT77 retube kit, but my bias circuit was funky and it wouldn't accept anything other than 6L6's, and KT77's should've worked). Also, will the slightly different sizes associated with different tubes/N.O.S different brands have any problems when it comes to the tube covers, which are currently pretty tight on my 12AX7's and cover each tube. Edit: I'm gonna need tubes which are available in Australia/able to be shipped here. Double edit: If somebody could direct me to the best N.O.S tube dealer for Australia, that'd be great, cause I also have 2 old valve radios I'd like to retube, and the receiver tubes aren't made anymore, and I think all of the 5Y3 rectifier tubes made today are different, also I doubt they've made those mini radio tubes (12ax7 size) tubes since the 70's. Cheers guys, Jesse. __________________ GEAR LIST Marshall JCM900 4100 (6L6) (1995) Marshall Valvestate 1965A cab (????) Cort VX-2V (2008) TUBES/SPEAKERS Power: Groove Tube 6L6GCB Phase Inverter: Sovtek 7025 Pre: V1 - N.O.S Mullard ECC83. V2 National 12AX7A Speakers: Celestion G10L-35 Marshall forever My tube amp & Real Music appreciation forum Last edited by Jesstaa; 06-23-2009 at 06:32 AM.

06-23-2009, 05:11 PM	#525 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,580	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? Well it's a shame you didn't jump on board sooner. There is a lot of interesting sound tests performed with various USA and European tubes. That and a little humor thrown in. I will only be able to answer some on your questions. First off, how clean does your clean sound need to be? If it can be a little gritty, then I would suggest a medium to high gain 12AX7 in V1. If you need a clean "clean," then I would recommend a 7025 (NOS) in V1. V2 I would recommend a high gain 12AX7 such as a Mullard long plate 12AX7. You have a high gain tube (110/110), but the JJ's are a darker sounding tube and you will want to get away from that for your sound. What makes this tough is that we are basically moving away from current production tubes and are using NOS tubes. Granted, we may still use current production tubes in V3 and V4, as they have less of an impact on the gain and tone. BTW, V1 will be the tube located the farthest distance from the power tubes and power transformer. V1 is the most sensitive tube in the amp. Anyway, it is hard for me to say what tubes to recommend when you live in Australia. Most of the big online tube stores will ship there, so that's not a problem, but you are limited to what they have. They do sell NOS tubes, but they are expensive. As stated, the JJ tubes you are running tend to be a little dark sounding. Not what you want for your sound. I would recommend a high gain Tung-Sol short plate 12AX7 in V1 and a Mullard long plate in V2 and then use your current V3 and the 110/110 tube in V4. Note: The PI tube does not need to be high gain or perfectly matched, but since you have it, try it out. You may want to do a little tweaking with these two tubes as well. Hopefully you will get the Tung-Sol and it will be at least 110/110. It is a much brighter tube and sounds smoother overall. That will result in a more crunchier sound. The NOS tubes have no problem accepting the shields. The only tube I've had problems with are the Sovteks. If the JJ's fit, the Tung-Sol and Mullard will fit. Another 900 with 6L6's? Yeah you could have spared yourself some anguish if you had read some of my other posts (different threads) about swapping power tubes. It can be done, but you have to change the value of the final bias resistor to get into the bias range of the KT77's. If you still have the tubes you can get a tech to do this. Do you have a tech in your area? American/Canadian Tube Sellers that will ship worldwide. Welcome to TubeDepot.com! thetubestore.com Audio and vacuum tubes for your amplifier. https://www.tubeworld.com/index_high.htm Australian Company Kableflags: The Cable Management Safety Product for Home and the Workplace (Call them. They state they sell audio tubes.) Marty __________________ MARTY 2009 Gibson Explorer-Hell Raising Machine 1989 Fender Strat Plus USA 2008 Fender Tele USA 2004 Schecter Elite w/DiMarzio's TSL100 with custom 4x12 cab. TSL122 with Man 'O War Speakers. TSL602 #1 with JBL D123 Speakers and 602 #2 with Altec 417 Speakers. "Oh so sweet my friends." DSL401 #1 with Red Fang Speaker and 401 #2 with JBL D123 Speaker. Tubes: Let's just say they are NOS that kick ass.

06-23-2009, 10:54 PM	#526 (permalink)
Jesstaa Senior Member Join Date: Apr 2009 Location: Gippsland, Vic, Australia. Posts: 797	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? I don't really need much of a clean, although it's nice to have (And currently it's pretty amazing, but I plan on using a different amp and having an A/B/Y box for cleans) and the 4100 only has 3 pre amp tubes. Edit: Yeah, I have a tech in the area, that's where my amp is currently. I took it in there when trying to switch tubes because it wouldn't stay biased, and I wanted to make sure that nothing was damaged in it (Cause I bought it second hand), I should be getting it back today, but I don't plan on ever taking it back there, they've had it for like 5 weeks just to figure out that I should leave 6L6's in there for now. Bloody useless. Double Edit: How would I determine the date of an Phillips miniwatt 6V6? I have one in an old radio and it's still doing just fine, and I'm wondering how rare it is, it appears to have no getter (Unless the weird silver ring around the bottom is the getter, but it seems too light of a colour to be getter) it also appears to be painted black (I'd guess it was burnt out, but it's very neat, and the tube still works fine) http://cgi.ebay.com/Three-RCA-12BZ7-...1\|293:1\|294:50 That could be a good score, if you get back on in time. Seller will refund if they're shit, and you have a tube tester to test them. __________________ GEAR LIST Marshall JCM900 4100 (6L6) (1995) Marshall Valvestate 1965A cab (????) Cort VX-2V (2008) TUBES/SPEAKERS Power: Groove Tube 6L6GCB Phase Inverter: Sovtek 7025 Pre: V1 - N.O.S Mullard ECC83. V2 National 12AX7A Speakers: Celestion G10L-35 Marshall forever My tube amp & Real Music appreciation forum

06-24-2009, 12:02 AM	#527 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,580	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? A lot of 6V6's were treated with what was called a smoke top. Nice little edge down at the bottom of the tube. There is a getter, you just can't see it. The only way you could tell how old it is, is if all of the original labeling was still on the tube. There would be a date code somewhere on the tube. It is hard to make any money with just one tube. Most buyers have single-ended amps and they want a close match pair. I sold two pairs of 6V6's on EBAY. Both pairs were really nice and I lost my ass selling them. The market is soft on certain tubes right now and has been that way for over six months. Ebay would be the only way to sell it since you just have one. Marty __________________ MARTY 2009 Gibson Explorer-Hell Raising Machine 1989 Fender Strat Plus USA 2008 Fender Tele USA 2004 Schecter Elite w/DiMarzio's TSL100 with custom 4x12 cab. TSL122 with Man 'O War Speakers. TSL602 #1 with JBL D123 Speakers and 602 #2 with Altec 417 Speakers. "Oh so sweet my friends." DSL401 #1 with Red Fang Speaker and 401 #2 with JBL D123 Speaker. Tubes: Let's just say they are NOS that kick ass.

06-24-2009, 02:39 PM	#528 (permalink)
jamesbreese Junior Member Join Date: Feb 2009 Location: Tulsa, Ok Posts: 12	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? Good grief. That was the longest post on this forum I have ever been through, but all very good and interesting info! Nice pictures too.

06-25-2009, 09:59 AM	#530 (permalink)
jamesbreese Junior Member Join Date: Feb 2009 Location: Tulsa, Ok Posts: 12	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? I know where your talking about... I drive up the 35 to Wichita from time to time and that one of the gas stops. Small town. Whats your buddy's band name? __________________ J. Breese Tulsa, OK JCM2000 DSL 100 1960A 30 Watt Celestions 1960B 75 Watt Celestions

06-26-2009, 03:17 PM	#532 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,580	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? JOE-Solarburn, has finished rolling the ten tubes I sent him. He seemed to be quite jacked up over his selections. I'm sure he won't be disappointed. I haven't been quiet. I have just been buying EL34 and 12AX7 tubes on EBAY as usual. Bought me a quad of RFT EL34's. Thought about putting them in the TSL100. I scored six 12AX7's and four 7025's made by Philips/Amperex of Canada. I lost out on eight of these, but I can't win them all. Tried to win some fat bottle EL34 Sylvania's and lost out on that one too. Right now, I have some auctions coming up and I will be placing my bid soon. Other news, one of the two techs has been on vacation, so my amps haven't even been looked at yet. Just so you know. Hopefully, I will know what's up by Monday or Tuesday. Marty __________________ MARTY 2009 Gibson Explorer-Hell Raising Machine 1989 Fender Strat Plus USA 2008 Fender Tele USA 2004 Schecter Elite w/DiMarzio's TSL100 with custom 4x12 cab. TSL122 with Man 'O War Speakers. TSL602 #1 with JBL D123 Speakers and 602 #2 with Altec 417 Speakers. "Oh so sweet my friends." DSL401 #1 with Red Fang Speaker and 401 #2 with JBL D123 Speaker. Tubes: Let's just say they are NOS that kick ass.

06-26-2009, 09:09 PM	#534 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,580	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? Well I'm sure that you did end up with some good torpedoes. You have enough tubes to keep you going for several birthdays. How many did you buy? Eight? The neat thing about tubes is that a different guitar will affect the gain of the tube. V1 is hooked up in line with the guitar and if you have hot ceramic pickups like my Explorer's 500T's, it will blow the front end of an amp clean out. (Well maybe not as much as an EMG81, LOL!). You get my point. You may say, "That tube is lame (in V1)." Then you get a humbucker plugged into it and it is like, "Holy Hogwash, Batman!" I love my Strat and it sounds really sweet, but my Schecter and my Gibson rip stage one of the preamp circuit up. It's like when I told Josh to not audition the tubes with dead strings. He took my advice and he was chopping wood with the 7025 and the ICBM Amperex. Oh, I just got some more tubes. Brand new Joint Army/Navy Sylvania's. NIB and NOS. Never been used. Four tubes. Winning bid, $51.00. Who says NOS are too expensive? Not me. I read a thread, but I can't remember what it was called. I think it was someone asking about preamp tubes in an 800. One of the members posted that Tung-Sol is having trouble with the Tung-Sol (short plate) in the V3 position. It can't handle the voltage. I told you guys in the past that most current production AX7's are running at or above their rated plate voltage. Apparently this is the case here and the Tung-Sol is failing. Another reason to use NOS tubes. They "can" handle the plate voltage. They were "made" to better specifications with better materials. I told you guys about how tube manufacturer's were always trying to outdo the competition. This alone made for some very high quality tubes. I told you how it wasn't about price in 1962. Well, it's all about price with current production tubes and to keep profits up, the tubes are...well cheap. When was the last time you've seen any specifications on any current production tube? I've never seen any...ever. Why do you think that is? If you have a 1965 Tube Manual and you look up the specs on a 12AX7, every tube manufacturer was expected to meet (or exceed) the stated specifications. You can Google all day and not find any specs at all on new tubes. They don't want you to know about their failure rate. They don't want you to know that their tube can take about half the plate voltage as a 45 year old RCA! Wouldn't you think with today's equipment and materials that a better tube could be made? Hell no. Take a look at Blackburn which is the former Mullard U.K. They were going to start selling high quality AX7's all made on sixty year old equipment. Why? Because it does the job better than anything that anyone has come up with. If anyone is going to come out with a consistently good tube, they will be made on original equipment, using original techniques and the same materials. Period! Trying funky manufacturing techniques results in a funky tube. Hopefully the economy will get better and Blackburn will pursue making tubes. Even if they are twice the price as say an EH or a (fake) Mullard, it would still be a good deal and I would have peace of mind knowing that someone was actually making a good tube again. __________________ MARTY 2009 Gibson Explorer-Hell Raising Machine 1989 Fender Strat Plus USA 2008 Fender Tele USA 2004 Schecter Elite w/DiMarzio's TSL100 with custom 4x12 cab. TSL122 with Man 'O War Speakers. TSL602 #1 with JBL D123 Speakers and 602 #2 with Altec 417 Speakers. "Oh so sweet my friends." DSL401 #1 with Red Fang Speaker and 401 #2 with JBL D123 Speaker. Tubes: Let's just say they are NOS that kick ass.

06-27-2009, 01:43 AM	#536 (permalink)
Jesstaa Senior Member Join Date: Apr 2009 Location: Gippsland, Vic, Australia. Posts: 797	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? I managed to find a half decent arrangement with the tubes I currently have (2 National tubes and 3 JJs) not quite sure which tubes are which in a 900, but going with the Phase inverter as V3, I got a JJ in V1, a National in V2 and a balanced JJ in V3, it's still got a strong tone, but it's brightened up a bit with the National, with any more than 1 national in the amp, it's kinda flat sounding. __________________ GEAR LIST Marshall JCM900 4100 (6L6) (1995) Marshall Valvestate 1965A cab (????) Cort VX-2V (2008) TUBES/SPEAKERS Power: Groove Tube 6L6GCB Phase Inverter: Sovtek 7025 Pre: V1 - N.O.S Mullard ECC83. V2 National 12AX7A Speakers: Celestion G10L-35 Marshall forever My tube amp & Real Music appreciation forum

06-27-2009, 09:13 PM	#537 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,580	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? Just an FYI post. I know I have already wrote about it, but this is for any new member who happens to drop in. Apparently, Tung-Sol is not holding up in the V3 position on Marshall amps (V2 on earlier Marshall amps). This is the tone stack/cathode follower circuit. I'd advise not running a Tung-Sol in this slot. Forum thread: These pre-amp valves for my 2203..... Marty __________________ MARTY 2009 Gibson Explorer-Hell Raising Machine 1989 Fender Strat Plus USA 2008 Fender Tele USA 2004 Schecter Elite w/DiMarzio's TSL100 with custom 4x12 cab. TSL122 with Man 'O War Speakers. TSL602 #1 with JBL D123 Speakers and 602 #2 with Altec 417 Speakers. "Oh so sweet my friends." DSL401 #1 with Red Fang Speaker and 401 #2 with JBL D123 Speaker. Tubes: Let's just say they are NOS that kick ass.

06-28-2009, 02:46 AM	#538 (permalink)
RiverRatt Senior Member Join Date: May 2008 Location: Between Memphis and Nashville Posts: 517	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? I've actually been running a Tung-Sol RI in V3 and V4 occasionally. I haven't left it in there for long at a time. I've been playing with those two sockets, and my amp seems to sound a little better with the Tung-Sol or a Sovtek 12AX7WA in V3. What exactly happens if this tube fails? Is there a danger of harming the amp, or just a loss or degradation of the signal?

06-30-2009, 03:12 PM	#540 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Formerly Phoenix, now north of KC Posts: 2,580	Re: Preamp Tubes? - Who, What, When, Where, Why, and How? NOS versus Current Production In 1959, these were the specs all RCA tubes were manufactured by. 1.Vacuum/Air Pressure-1/000,000,000 that of atmospheric pressure at sea level. 2.Plate-Diameter gauged to 0.0002 inch. 3.Grids-Diameters measured to 0.0001 inch. 4.Cathode coating-Weight variation less than 0.00007 oz. 5.Grid Wire-Diameter varies less than 0.00009 inch. 6.Cathode-Sleeve Wall-Approximately 0.002 inch thick. 7.Heater Wire-Diameter varies less than 0.00002 inch. 8.Glass Bulb-Inspected under polarized light for strains. This was standard business in 1959. Do you think your Sovtek can match this? Marty __________________ MARTY 2009 Gibson Explorer-Hell Raising Machine 1989 Fender Strat Plus USA 2008 Fender Tele USA 2004 Schecter Elite w/DiMarzio's TSL100 with custom 4x12 cab. TSL122 with Man 'O War Speakers. TSL602 #1 with JBL D123 Speakers and 602 #2 with Altec 417 Speakers. "Oh so sweet my friends." DSL401 #1 with Red Fang Speaker and 401 #2 with JBL D123 Speaker. Tubes: Let's just say they are NOS that kick ass.

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