Power tubes?? Who, What, When Where how?? - Page 14

solarburnDSL50 · 01-23-2010, 05:54 PM

Quote:

Originally Posted by RiverRatt

Marty, I got that Saratov in the mail today. That is one bad-ass tube! I played with the Amperex in the Blackheart head for awhile and then put the Russian tube in. With all the settings the same, it was like hitting the amp with a 10db clean boost. To get the same jangly Vox sound I had with the Amperex, I had to back the volume off a couple of notches. Both tubes are very musical and do that compressed melt-your-face EL84 tone well when cranked, but the Russian tube seems to retain a little more clarity and note separation. It's going to stay in the Blackheart and I moved the Amperex over to the Valve Jr.

I dig that tube as well but I'm tell'n ya the RFT is even better IMA. I do like that Russian tube though. It killed the Sovtec the NT came with and the JJ's. It was a big difference in clean tones and overdrive. The RFT walks away in the early break up to overdrive department.

RiverRatt · 01-23-2010, 08:37 PM

I was bidding on an RFT but it got away from me. That's one good thing about these low-watt Class A amps - it doesn't cost a fortune in tubes to try different ones. That batch of Realistic/Matsushita 12AX7s that I sent you one of, I had one that was noisy as hell in the Marshall, but it sounds great in the little amps. I'm running all Amperex in the Valve Jr. now. That's something I couldn't do in the Marshall! An rx3 EL84 and one of Marty's Eico Amperex ECC83s for a preamp tube. It sounds like a Fender Champ on steroids.

core · 01-23-2010, 11:06 PM

So I learned a few things today. Draining caps is not all that hard and after reading "Complete Guide to Guitar and Amp Maintenance" the blue glow my 6L6GC's are giving off in the 6100 means that they are going bad. What I suspected all along. My tech said they were fine and they do play ok but according to the book it's just a matter of time. I thought it looks kinda cool and wondered why my other amps didn't glow blue. Seems it means it's leaking gas. So I think I'll try out either those TAD 6l6's or the Winged C tubes.

Did some cleaning on the EL34 900 and it's REAL clean, I mean it was well taken care of even though the original owner said he gigged with it a lot since new in 92. I found out the power tubes are Sovtek so I'm sure it could do better. I put the RCA 7025 in V1 the Tele in V2 and the Raytheon in V3 and it seems pretty good but I'm wondering about which power tubes might work best. Mullard reissues, Winged C, Tesla? Still sifting through info but I may end up settling on Winged C.

After looking around some I ran across some RFT el34's that look pretty nice and the Tungsol's had a great review. What do you guys think of those?

MartyStrat54 · 01-24-2010, 01:24 AM

I find it hard to believe that four 6L6's would all have a gas issue. The odds of that happening are high. Some brands put off a glow. I could see where one tube became gassy, but not all four. I'd check into that closer before trashing your tubes.

Just for fun, try your Telefunken in V1 and the 7025 in V2. You might like the tone you get with that combination.

The TAD 6L6's are supposed to be pretty nice. There are several guys who really talk them up.

core · 01-24-2010, 03:01 AM

Hey Marty, that would make sense so I had another look and upon further inspection the two outside tubes have the blue glow pretty prominent and it looks as if it's creeping up the inside of the glass around the middle. One of the two inside tubes has no blue tint at all and appears normal and the other has just the slightest blue tint in one spot. It's barely visible. There is a constant intermittent crackle followed by slight static noise.

RiverRatt · 01-24-2010, 08:51 AM

You won't go wrong with those RFT EL34s in your 900. I bought a pair from Marty back last fall for my DSL50 and they sound really good. They are well balanced with punchy lows and mids and smooth highs. The =C='s and GTEL34Ms are decent tubes but if you can afford the RFTs go with them.

RiverRatt · 01-24-2010, 09:19 AM

Here's a web page for the brave. The page is in Japanese but the captions under the photos are in English. It has a ton of info about Japanese EL34s.

Audio EU Pentode

Here's the Babelfish translated page.

"About EL34/6CA7 there is no famous sphere even at today, probably will be. Loyal Isamu Morikawa MJ magazine July of 82 has explained the model of EL34 with the edition, but, here arranging the sphere which I procure accidentally, you will explain the model whose Matsushita make is a little detailed."

lord_guitarula · 01-24-2010, 10:05 AM

Hey, I've got a quick question .. I was thinking about using my 6100 with a rack poweramp. The thing is, i wouldn't connect any speakers to the 6100 since I don't need the power section of it.

Now I know that you're not supposed to run a tube power amp without a load connected. So what if I pulled all the power tubes out, would that help? If yes, do I need to rebias the amp when I do put them back in?

MartyStrat54 · 01-24-2010, 03:12 PM

Pulling the power tubes will do the trick. You won't have to connect a load, as no signal will reach the output tranny.

If you marked the order of the power tubes, when you put them back the tamp should still be in bias for those exact tubes in the exact order.

MartyStrat54 · 01-24-2010, 03:19 PM

Quote:

Originally Posted by core

Hey Marty, that would make sense so I had another look and upon further inspection the two outside tubes have the blue glow pretty prominent and it looks as if it's creeping up the inside of the glass around the middle. One of the two inside tubes has no blue tint at all and appears normal and the other has just the slightest blue tint in one spot. It's barely visible. There is a constant intermittent crackle followed by slight static noise.

Okay, what are these tubes? Are they old NOS or a recent set? I've seen some older tubes with a soft vacuum glow like hell because of gas in the tube. The getter is what keeps the gas in check, but if there is a lot of gas it will wear the getter out and the gas will cause noises to come from the tube. I have an amp with NOS 8417's and they have a wild blue orange glow to them, but that's the way they are made.

If the tubes are old, then I would recommend that they be replaced. Since I can't actually look at them operating, I just have to assume that a couple are bad and the other two are getting ready to go. I still would like to know what brand they are.

core · 01-24-2010, 03:38 PM

They are Electro Harmonix. I'll try to take a pic later on and see if it shows up for you.

lord_guitarula · 01-24-2010, 03:39 PM

Quote:

Originally Posted by MartyStrat54

Pulling the power tubes will do the trick. You won't have to connect a load, as no signal will reach the output tranny.

If you marked the order of the power tubes, when you put them back the tamp should still be in bias for those exact tubes in the exact order.

Thanks a lot.

MartyStrat54 · 01-24-2010, 04:02 PM

Quote:

Originally Posted by core

They are Electro Harmonix. I'll try to take a pic later on and see if it shows up for you.

Well, at least I know they aren't NOS. When they matched the tubes, they could have been a "soft" set. This means the vacuum isn't as strong as it should be. The tube will break up faster, but they also die faster. That's one of the things that the tube makes don't tell you. I am against selling tubes under the soft, medium and hard characteristic. If you don't mind buying tubes every 6 months, then buy a soft tube. It sounds like that is what the case is here. You got a set of soft tubes and they are all gassy.

core · 01-24-2010, 08:19 PM

Yep! I think I'm getting it now. So when testing tubes it's about how well the vacuum is right? Except I'm not sure what the medium and hard characteristic is.

What tolerance should they be to be a good match? I hear that the numbers don't have to be an exact match but within a couple numbers of each other correct? Also if they do list what the tubes test at what would be a good strong test number for NOS?

Anyway thanks for answering all my questions! It's a learning curve but I'm getting there.

Wilder Amplification · 01-24-2010, 08:23 PM

Quote:

Originally Posted by core

Yep! I think I'm getting it now. So when testing tubes it's about how well the vacuum is right? Except I'm not sure what the medium and hard characteristic is.

What tolerance should they be to be a good match? I hear that the numbers don't have to be an exact match but within a couple numbers of each other correct? Also if they do list what the tubes test at what would be a good strong test number for NOS?

Anyway thanks for answering all my questions! It's a learning curve but I'm getting there.

Not just how well the vacuum is. They test them for transconductance (Tc) and idle plate current (Ip) as well.

Transconductance is the spec that states how much of a current flow increase occurs for a given signal voltage increase on its control grid.

When they match them, they want the Tc and Ip to be close to each other. For Ip, they want valves that idle within 2-3mA of each other.

core · 01-24-2010, 08:43 PM

Ah I gotcha. Thanks!

core · 01-24-2010, 08:45 PM

Quote:

Originally Posted by RiverRatt

Here's a web page for the brave. The page is in Japanese but the captions under the photos are in English. It has a ton of info about Japanese EL34s.

Audio EU Pentode

Here's the Babelfish translated page.

"About EL34/6CA7 there is no famous sphere even at today, probably will be. Loyal Isamu Morikawa MJ magazine July of 82 has explained the model of EL34 with the edition, but, here arranging the sphere which I procure accidentally, you will explain the model whose Matsushita make is a little detailed."

Wow that second link is more babel that the first one!

MartyStrat54 · 01-24-2010, 09:23 PM

Thanks for the input, Jon.

Core, you misunderstood me. A good vacuum makes a better tube, but they don't actually test the vacuum. Like Jon said, there are some electrical parameters that indicate where a tube is at. Tubes are graded by these electrical parameters and from this it can be derived if the tube is soft, medium or hard. Once a physical vacuum has been pulled on a tube and sealed off, there is no way to ever measure it again.

Just so you know, when tubes used to be made in America, a hard vacuum was pulled on every tube, regardless of size. If a poor vacuum was detected, the tube was thrashed. Tube retailers started using the soft, medium and hard ratings as a way to sell more tubes instead of throwing them away. As I said, a soft power tube may appeal to certain players, but the tube will not last as long and is prone to bias drift. A soft vacuum in a preamp tube will cause premature failure and the tube will not function like it should.

core · 01-24-2010, 09:36 PM

Ok I'm definitely getting it now especially when making them for the military and long lasting commercial use, they couldn't afford to have soft or bad tubes. I remember now you talking about that issue in previous posts about them appealing to some players. It's making more sense now.

Here's a pic of my tubes with the standby off ready to play. BTW before I took it in to have it rebiased it didn't glow like that that I recall. In fact I think it must have been a cold bias previously from what I gather as even the heater filaments didn't glow much. Any rate I'm gonna switch them out but just want to verify the findings for future reference.

Wilder Amplification · 01-25-2010, 01:34 AM

Quote:

Originally Posted by core

Ok I'm definitely getting it now especially when making them for the military and long lasting commercial use, they couldn't afford to have soft or bad tubes. I remember now you talking about that issue in previous posts about them appealing to some players. It's making more sense now.

Here's a pic of my tubes with the standby off ready to play. BTW before I took it in to have it rebiased it didn't glow like that that I recall. In fact I think it must have been a cold bias previously from what I gather as even the heater filaments didn't glow much. Any rate I'm gonna switch them out but just want to verify the findings for future reference.

Love that blue glow. However, the inner pair doesn't seem to have any. Are those valves even working?

core · 01-25-2010, 02:20 AM

Quote:

Originally Posted by Wilder Amplification

Love that blue glow. However, the inner pair doesn't seem to have any. Are those valves even working?

Well there is a slight glow you can see better in low light.

PEMAMETAL · 01-26-2010, 07:47 AM

Hello,

I don't know too much about tubes, but I found this on e-bay and bought a pair to try in my JCM 800 2204 Clone. Are They good tubes?
I've never seen groove tubes with fender logo.
What Do you say?

http://cgi.ebay.com/Matched-Quads-Gr...item5ad4861d1c

solarburnDSL50 · 01-26-2010, 08:45 AM

Quote:

Originally Posted by PEMAMETAL

Hello,

I don't know too much about tubes, but I found this on e-bay and bought a pair to try in my JCM 800 2204 Clone. Are They good tubes?
I've never seen groove tubes with fender logo.
What Do you say?

Matched Quads Groove Tubes 6550 tubes, Fender, NEW - eBay (item 390112615708 end time Jan-28-10 18:07:37 PST)

Fender owns GT now. Don't know if they are good or not but you're going to find out since you bought them hehe.

PEMAMETAL · 01-26-2010, 09:23 AM

Quote:

Fender owns GT now. Don't know if they are good or not but you're going to find out since you bought them hehe.

NOt sure about that, because its the first time I'm going to use 6550 tubes. I was using El34 JJ in the power.( My jcm 800 has a switch to choose between el34 and 6550).

solarburnDSL50 · 01-26-2010, 09:27 AM

Quote:

Originally Posted by PEMAMETAL

NOt sure about that, because its the first time I'm going to use 6550 tubes. I was using El34 JJ in the power.( My jcm 800 has a switch to choose between el34 and 6550).

Well let us know when you try them out. I'd like to hear about it.

MartyStrat54 · 01-26-2010, 11:23 PM

Greetings. I was in Leavenworth, KS today. You know...home of the "Big House." The Federal Prison. Had some business over there and got the TWISTER mailed off. It's supposed to get there by Friday.

Why do I get this feeling that nothing will be wrong and he will retube it with all Chinese tubes and say, "It wasn't biased right." Then I'll get it and it will sound just like when I mailed it off. Oh I pray that won't turn true.

I will keep you posted.

solarburnDSL50 · 01-26-2010, 11:51 PM

Quote:

Originally Posted by MartyStrat54

Greetings. I was in Leavenworth, KS today. You know...home of the "Big House." The Federal Prison. Had some business over there and got the TWISTER mailed off. It's supposed to get there by Friday.

Why do I get this feeling that nothing will be wrong and he will retube it with all Chinese tubes and say, "It wasn't biased right." Then I'll get it and it will sound just like when I mailed it off. Oh I pray that won't turn true.

I will keep you posted.

Well hopefully he will realize there are a whole lot of us here who don't like expensive shitty sounding amps and have no problem saying so...

I'm sure he will be sensible and do all he can to get it sounding right again. These guys(Twister)just have to stand behind their product. Its the right thing to do. So we wait and see.

MartyStrat54 · 01-27-2010, 12:02 AM

I really, really hope that there is some bad component somewhere in that amp. I don't want him to email me and say, "It checked out fine. I put the new tubes in it and it sounds great." If that is what happens at least when I sell it I can say that it has just been factory serviced. (Yeah Marty, but what if it still sounds like shit? Good point.)

thrawn86 · 02-03-2010, 12:22 PM

Anyone have experience with the TAD brand?

MartyStrat54 · 02-03-2010, 02:28 PM

Yeah, they are like one of the better Chinese brands. What are you looking at?

01-23-2010, 11:06 PM	#393 (permalink)
core Senior Member Join Date: Dec 2009 Posts: 1,321	Re: Power tubes?? Who, What, When Where how?? So I learned a few things today. Draining caps is not all that hard and after reading "Complete Guide to Guitar and Amp Maintenance" the blue glow my 6L6GC's are giving off in the 6100 means that they are going bad. What I suspected all along. My tech said they were fine and they do play ok but according to the book it's just a matter of time. I thought it looks kinda cool and wondered why my other amps didn't glow blue. Seems it means it's leaking gas. So I think I'll try out either those TAD 6l6's or the Winged C tubes. Did some cleaning on the EL34 900 and it's REAL clean, I mean it was well taken care of even though the original owner said he gigged with it a lot since new in 92. I found out the power tubes are Sovtek so I'm sure it could do better. I put the RCA 7025 in V1 the Tele in V2 and the Raytheon in V3 and it seems pretty good but I'm wondering about which power tubes might work best. Mullard reissues, Winged C, Tesla? Still sifting through info but I may end up settling on Winged C. After looking around some I ran across some RFT el34's that look pretty nice and the Tungsol's had a great review. What do you guys think of those? __________________ ♠ ♠ ♠ ♠ ♠ ♠ ♠ ♠ ♠ Aces & 8's

01-24-2010, 01:24 AM	#394 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Now in Muskogee, by Tulsa Posts: 18,301	Re: Power tubes?? Who, What, When Where how?? I find it hard to believe that four 6L6's would all have a gas issue. The odds of that happening are high. Some brands put off a glow. I could see where one tube became gassy, but not all four. I'd check into that closer before trashing your tubes. Just for fun, try your Telefunken in V1 and the 7025 in V2. You might like the tone you get with that combination. The TAD 6L6's are supposed to be pretty nice. There are several guys who really talk them up. __________________ MARTY MARTIMUS MAXIMUS ONLINE TUBES AND OTHER STUFFHyperlink Wilder modded JCM 2204 (Sold my JMP to Joe.). Many other amps. Strats and Explorer are my main guitars.

01-24-2010, 03:01 AM	#395 (permalink)
core Senior Member Join Date: Dec 2009 Posts: 1,321	Re: Power tubes?? Who, What, When Where how?? Hey Marty, that would make sense so I had another look and upon further inspection the two outside tubes have the blue glow pretty prominent and it looks as if it's creeping up the inside of the glass around the middle. One of the two inside tubes has no blue tint at all and appears normal and the other has just the slightest blue tint in one spot. It's barely visible. There is a constant intermittent crackle followed by slight static noise. __________________ ♠ ♠ ♠ ♠ ♠ ♠ ♠ ♠ ♠ Aces & 8's

01-24-2010, 10:05 AM	#398 (permalink)
lord_guitarula Senior Member Join Date: Aug 2009 Location: Austria Posts: 184	Re: Power tubes?? Who, What, When Where how?? Hey, I've got a quick question .. I was thinking about using my 6100 with a rack poweramp. The thing is, i wouldn't connect any speakers to the 6100 since I don't need the power section of it. Now I know that you're not supposed to run a tube power amp without a load connected. So what if I pulled all the power tubes out, would that help? If yes, do I need to rebias the amp when I do put them back in? __________________ My Band EASY Find us on Facebook MICKEY * AMPS * LIVE RIG - Marshall JMP '75 - TS808 For Leads - AND THAT'S IT!! * AXES * - Gibson Flying V Custom - Gibson Les Paul Custom

01-24-2010, 03:12 PM	#399 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Now in Muskogee, by Tulsa Posts: 18,301	Re: Power tubes?? Who, What, When Where how?? Pulling the power tubes will do the trick. You won't have to connect a load, as no signal will reach the output tranny. If you marked the order of the power tubes, when you put them back the tamp should still be in bias for those exact tubes in the exact order. __________________ MARTY MARTIMUS MAXIMUS ONLINE TUBES AND OTHER STUFFHyperlink Wilder modded JCM 2204 (Sold my JMP to Joe.). Many other amps. Strats and Explorer are my main guitars.

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01-24-2010, 03:38 PM	#401 (permalink)
core Senior Member Join Date: Dec 2009 Posts: 1,321	Re: Power tubes?? Who, What, When Where how?? They are Electro Harmonix. I'll try to take a pic later on and see if it shows up for you. __________________ ♠ ♠ ♠ ♠ ♠ ♠ ♠ ♠ ♠ Aces & 8's

01-24-2010, 08:19 PM	#404 (permalink)
core Senior Member Join Date: Dec 2009 Posts: 1,321	Re: Power tubes?? Who, What, When Where how?? Yep! I think I'm getting it now. So when testing tubes it's about how well the vacuum is right? Except I'm not sure what the medium and hard characteristic is. What tolerance should they be to be a good match? I hear that the numbers don't have to be an exact match but within a couple numbers of each other correct? Also if they do list what the tubes test at what would be a good strong test number for NOS? Anyway thanks for answering all my questions! It's a learning curve but I'm getting there. __________________ ♠ ♠ ♠ ♠ ♠ ♠ ♠ ♠ ♠ Aces & 8's

01-24-2010, 08:43 PM	#406 (permalink)
core Senior Member Join Date: Dec 2009 Posts: 1,321	Re: Power tubes?? Who, What, When Where how?? Ah I gotcha. Thanks! __________________ ♠ ♠ ♠ ♠ ♠ ♠ ♠ ♠ ♠ Aces & 8's

01-24-2010, 09:23 PM	#408 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Now in Muskogee, by Tulsa Posts: 18,301	Re: Power tubes?? Who, What, When Where how?? Thanks for the input, Jon. Core, you misunderstood me. A good vacuum makes a better tube, but they don't actually test the vacuum. Like Jon said, there are some electrical parameters that indicate where a tube is at. Tubes are graded by these electrical parameters and from this it can be derived if the tube is soft, medium or hard. Once a physical vacuum has been pulled on a tube and sealed off, there is no way to ever measure it again. Just so you know, when tubes used to be made in America, a hard vacuum was pulled on every tube, regardless of size. If a poor vacuum was detected, the tube was thrashed. Tube retailers started using the soft, medium and hard ratings as a way to sell more tubes instead of throwing them away. As I said, a soft power tube may appeal to certain players, but the tube will not last as long and is prone to bias drift. A soft vacuum in a preamp tube will cause premature failure and the tube will not function like it should. __________________ MARTY MARTIMUS MAXIMUS ONLINE TUBES AND OTHER STUFFHyperlink Wilder modded JCM 2204 (Sold my JMP to Joe.). Many other amps. Strats and Explorer are my main guitars.

01-24-2010, 09:36 PM	#409 (permalink)
core Senior Member Join Date: Dec 2009 Posts: 1,321	Re: Power tubes?? Who, What, When Where how?? Ok I'm definitely getting it now especially when making them for the military and long lasting commercial use, they couldn't afford to have soft or bad tubes. I remember now you talking about that issue in previous posts about them appealing to some players. It's making more sense now. Here's a pic of my tubes with the standby off ready to play. BTW before I took it in to have it rebiased it didn't glow like that that I recall. In fact I think it must have been a cold bias previously from what I gather as even the heater filaments didn't glow much. Any rate I'm gonna switch them out but just want to verify the findings for future reference. __________________ ♠ ♠ ♠ ♠ ♠ ♠ ♠ ♠ ♠ Aces & 8's

01-26-2010, 07:47 AM	#412 (permalink)
PEMAMETAL Senior Member Join Date: Dec 2008 Location: Campinas - Brazil Posts: 183	Re: Power tubes?? Who, What, When Where how?? Hello, I don't know too much about tubes, but I found this on e-bay and bought a pair to try in my JCM 800 2204 Clone. Are They good tubes? I've never seen groove tubes with fender logo. What Do you say? http://cgi.ebay.com/Matched-Quads-Gr...item5ad4861d1c

01-26-2010, 11:23 PM	#416 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Now in Muskogee, by Tulsa Posts: 18,301	Re: Power tubes?? Who, What, When Where how?? Greetings. I was in Leavenworth, KS today. You know...home of the "Big House." The Federal Prison. Had some business over there and got the TWISTER mailed off. It's supposed to get there by Friday. Why do I get this feeling that nothing will be wrong and he will retube it with all Chinese tubes and say, "It wasn't biased right." Then I'll get it and it will sound just like when I mailed it off. Oh I pray that won't turn true. I will keep you posted. __________________ MARTY MARTIMUS MAXIMUS ONLINE TUBES AND OTHER STUFFHyperlink Wilder modded JCM 2204 (Sold my JMP to Joe.). Many other amps. Strats and Explorer are my main guitars.

01-27-2010, 12:02 AM	#418 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Now in Muskogee, by Tulsa Posts: 18,301	Re: Power tubes?? Who, What, When Where how?? I really, really hope that there is some bad component somewhere in that amp. I don't want him to email me and say, "It checked out fine. I put the new tubes in it and it sounds great." If that is what happens at least when I sell it I can say that it has just been factory serviced. (Yeah Marty, but what if it still sounds like shit? Good point.) __________________ MARTY MARTIMUS MAXIMUS ONLINE TUBES AND OTHER STUFFHyperlink Wilder modded JCM 2204 (Sold my JMP to Joe.). Many other amps. Strats and Explorer are my main guitars.

02-03-2010, 02:28 PM	#420 (permalink)
MartyStrat54 Senior Member Join Date: Feb 2009 Location: Now in Muskogee, by Tulsa Posts: 18,301	Re: Power tubes?? Who, What, When Where how?? Yeah, they are like one of the better Chinese brands. What are you looking at? __________________ MARTY MARTIMUS MAXIMUS ONLINE TUBES AND OTHER STUFFHyperlink Wilder modded JCM 2204 (Sold my JMP to Joe.). Many other amps. Strats and Explorer are my main guitars.

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