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

[RiverRatt]

It is interesting how far we've come since this thread started. I was just going through my old tubes last night, trying to remember what I had before this madness started. I had a couple of GE tubes, a weak Sylvania, an even weaker RCA, and the two RCA side-getters. Now I have much more of an understanding as to what tube combinations will give you a good tone, and even what a good tone IS. Thanks to Josh for getting this started, thanks to Joe for lighting a fire under us all, and thanks to Marty for everything else. It's been a lot of fun so far, and there's still a lot of glass out there that I haven't tried yet!

 

[solarburn]

I think alot of us changed our minds the more we rolled. When we got ahold of the BP's RCA's, Telefunken, Amperex, RFT's and moved therm around in V1 & V2 we found how to get the best of each and what slot they needed to be in for that to happen. I say we learned alot here just by doing it. We've got a fair amount of leg work done and now is the time to be viewing this thread and taking advantage of what's been found.

The cool thing now is if there is a particular tube I want to try all I have to do is pop it in V1 and I get the most of that tubes personality coming through. So I can take that and decide quickly if I want it and where I want it. There is a methodology here and its less time consuming than when we first started. Its easier because we know our amps better than we ever did in the first place and what tubes can and can't do.

Looking back though I rolled for hours and days in a row at times. Doing that I learned quite a bit about my amp. What tubes warm things up, add bite, add sustain and dynamics. What adds buzzy fizzy hairy gain and what tubes just plain dull it up. Learned what a microphonic tube sounds like or when a tube has static that sometimes all that it needs is the legs cleaned off with some contact cleaner. I also learned that certain vendor's back their shit up. They get my business.

NOS rules for quality gain and dynamics IME. Musical feedback and rich overtones throughout. Playing the blues or rock that is full of midgain stuff then rolling guitar volume off for a clean tone that doesn't die as soon as you pick it from lack of sustain is what I enjoy so much about a good tube or tubes. Its where the tone of the fingers shine. Its Rocktacular!

Now I just wish I could play...

I've had too much coffee.:eek2:

 

[el zilcho]

This thread is great. I'm new here but I managed to read the whole thing and learned a lot.

One thing I don't understand is why you guys don't experiment more with v3 and v4? If I pop a Mullard cv4024 in V4 I get a HUGE difference in tone, but the change varies differently depending on the presence and master volume settings.

 

[solarburn]

This thread is great. I'm new here but I managed to read the whole thing and learned a lot.

One thing I don't understand is why you guys don't experiment more with v3 and v4? If I pop a Mullard cv4024 in V4 I get a HUGE difference in tone, but the change varies differently depending on the presence and master volume settings.

Ahh another AT7 lover hehe. Its a good thing in certain spots, like your PI slot. It will drive your power tubes less but handle more current than a 12AX7 at volume. I like it too. I even like it in V1 but don't tell anybody. Shoosh!

I can hear differences more in the PI slot than V3 if we are talking similar preamp sections. V3 doesn't seem to matter one way or the other in my amp.

 

[MartyStrat54]

This thread is great. I'm new here but I managed to read the whole thing and learned a lot.

One thing I don't understand is why you guys don't experiment more with v3 and v4? If I pop a Mullard cv4024 in V4 I get a HUGE difference in tone, but the change varies differently depending on the presence and master volume settings.

Welcome to our little piece of tube heaven. To answer your question, we did do a lot of rolling in V3 and V4. It is in the prior pages of this thread. What happened is that we did all sorts of stuff like taking a really high gain 12AX7 and putting it in V3 and V4. Then we took low gain 12AX7 and did the same thing. In a nutshell, high or low gain tubes in V3 were not that noticeable. Sure, you are going to hear some change, but it's not drastic. However, using 12AT7's or 5751's in V4 compared to a 12AX7 did make a difference. As I explained it, it created a larger window for the tone to go through. Also, if you didn't know the Presence control circuit is tied into V4 (Phase Inverter).

So after doing all of this stuff, we all pretty much settled on our V3 and V4 tubes. This made rolling tubes in V1 and V2 a snap.

I was going to post a comment to SolarBurn's response, but what you have asked in right down the alley about what I wanted to tell Joe.

Yes, we rolled a lot of tubes and we rolled all four positions and we all shared our experiences. Joe (SolarBurn) was more into using lower gain tubes than I was. However, he got me to try them and they just weren't for me. However, I know quite a few people that run a 12AT7 in V1 or a 5751. In fact one guy I know has a DSL100 and he uses two black plate 5751's in V1 and V2. Getting back to what Joe said, all of this tube rolling created a platform that as individuals, we could work from. Until we had V3 and V4 worked out, it took a lot of time to figure out what tube sounded best in what slot. Think of it this way. What we thought was the least important was actually the most important. Getting V3 and V4 squared away changed everything.

So that is why you don't hear us talking about V3 and V4 that much. We used to, but we got those slots hammered out and now it is just the joy of trying different tubes in V1 and V2.

Once again, welcome to the thread.

 

[MartyStrat54]

Thank you Alan and Joe for your responses. I look forward to sharing even more tube info with you in the future.

 

[RiverRatt]

Also, if you didn't know the Presence control circuit is tied into V4 (Phase Inverter).

I did not know this. So now I have to go back and try all my V4 tubes again and see how they affect the presence control.

 

[el zilcho]

Ahh another AT7 lover hehe. Its a good thing in certain spots, like your PI slot. It will drive your power tubes less but handle more current than a 12AX7 at volume. I like it too. I even like it in V1 but don't tell anybody. Shoosh!

I can hear differences more in the PI slot than V3 if we are talking similar preamp sections. V3 doesn't seem to matter one way or the other in my amp.

For a long time, I used the Mullard 12at7 in v1 and a JAN phillips 5751 in v2. It helped to kill the fizz I didn't like on the lead channel of my DSL. More recently, I removed the bright cap from the lead channel's gain knob and now I've gotten back to using 12ax7s for v1 and v2.

But yeah, that 12at7 is kind of an oddball in how it affects tone in the PI. I don't want to say it thins it out, but it's like a bunch of the low mids are gone compared to using a 12ax7. Almost sounds like phase cancellation. I like the dynamics with the 12at7, but not so much the tone. Actually I do like it at low volumes, it kind of makes the amp sound like it's cranked.

With 12ax7s in the PI, I can only hear small differences between tubes if I'm playing at low volumes (more difference if the presence is up, but I usually barely use it). I hear more difference at higher volumes but it's hard to stay subjective for long when your ears are being pummeled. I need an iso-booth.

Right now I'm using a jan 5751 in v4. It seems like a good spot for a nice bulletproof tube, and I get a little of the dynamics that I like from the 12at7 but with a tone I still like.

Welcome to our little piece of tube heaven. To answer your question, we did do a lot of rolling in V3 and V4. It is in the prior pages of this thread. What happened is that we did all sorts of stuff like taking a really high gain 12AX7 and putting it in V3 and V4. Then we took low gain 12AX7 and did the same thing. In a nutshell, high or low gain tubes in V3 were not that noticeable. Sure, you are going to hear some change, but it's not drastic. However, using 12AT7's or 5751's in V4 compared to a 12AX7 did make a difference. As I explained it, it created a larger window for the tone to go through. Also, if you didn't know the Presence control circuit is tied into V4 (Phase Inverter).

So after doing all of this stuff, we all pretty much settled on our V3 and V4 tubes. This made rolling tubes in V1 and V2 a snap.

I was going to post a comment to SolarBurn's response, but what you have asked in right down the alley about what I wanted to tell Joe.

Yes, we rolled a lot of tubes and we rolled all four positions and we all shared our experiences. Joe (SolarBurn) was more into using lower gain tubes than I was. However, he got me to try them and they just weren't for me. However, I know quite a few people that run a 12AT7 in V1 or a 5751. In fact one guy I know has a DSL100 and he uses two black plate 5751's in V1 and V2. Getting back to what Joe said, all of this tube rolling created a platform that as individuals, we could work from. Until we had V3 and V4 worked out, it took a lot of time to figure out what tube sounded best in what slot. Think of it this way. What we thought was the least important was actually the most important. Getting V3 and V4 squared away changed everything.

So that is why you don't hear us talking about V3 and V4 that much. We used to, but we got those slots hammered out and now it is just the joy of trying different tubes in V1 and V2.

Once again, welcome to the thread.

Thank you for the welcome.

That all makes sense. I can't for the life of me remember what you guys liked for v3 and v4. GEs? Or just whatever's available NOS and cheap?

 

[MartyStrat54]

Well we have all posted this before, but we can do it again. I have so many amps, so I'll just pick a couple.

2006 TSL602

V1-1959 Amperex Bugle Boy 12AX7
V2-1962 Raytheon Black Plate (High Gain) 12AX7
V3-1961 Sylvania Gray Plate 12AX7
V4-1961 Sylvania Gray Plate 12AX7

Power
V5 and V6-xf2 Mullard EL-34's

2007 TSL100

V1-1963 Telefunken ECC83
V2-1966 Amperex 7025 (High Gain)
V3-1960 GE Short Black Plate 12AX7
V4-1964 Sylvania Gray Plate 12AX7

Power
V5, V6, V7 and V8-RFT EL34's

Actually, you can get away with using certain CP tubes in V3 and V4. Right now the best bargain in a 12AX7 is the Electro-Harmonix 12AX7. If I had to use them, I would, but I sell tubes and that's why I use all NOS. Also, there was a statement going around for some time and that was you should not use Tung-Sol's in V3. I did some checking and all of this happened back in 2005. I think it's safe to lift the ban. BTW, EH advertises their 12AX7 to work well in any slot. Well to me, that means V3 and V4.

 

[SpiritOfTheAge]

Ive been on a mission for the last few days and have come up trumps. Ive got 1xBrimar 12ax7 NOS on its way, as well as 2xRFT 12ax7's that test as good as new and last but not least those 2xValvos which also test as good as new. I had no idea that there were so many great valves around on ebay at much better prices than are availabler from many actual valve sellers online.

I missed out on a phillips/miniwat that was pulled from a radio but not tested, it went for much more than i was willing to pay given its uncertainty, as ever people are still paying silly money for things on ebay.

 

[solarburn]

For a long time, I used the Mullard 12at7 in v1 and a JAN phillips 5751 in v2. It helped to kill the fizz I didn't like on the lead channel of my DSL. More recently, I removed the bright cap from the lead channel's gain knob and now I've gotten back to using 12ax7s for v1 and v2.

But yeah, that 12at7 is kind of an oddball in how it affects tone in the PI. I don't want to say it thins it out, but it's like a bunch of the low mids are gone compared to using a 12ax7. Almost sounds like phase cancellation. I like the dynamics with the 12at7, but not so much the tone. Actually I do like it at low volumes, it kind of makes the amp sound like it's cranked.

With 12ax7s in the PI, I can only hear small differences between tubes if I'm playing at low volumes (more difference if the presence is up, but I usually barely use it). I hear more difference at higher volumes but it's hard to stay subjective for long when your ears are being pummeled. I need an iso-booth.

Right now I'm using a jan 5751 in v4. It seems like a good spot for a nice bulletproof tube, and I get a little of the dynamics that I like from the 12at7 but with a tone I still like.

Thank you for the welcome.

That all makes sense. I can't for the life of me remember what you guys liked for v3 and v4. GEs? Or just whatever's available NOS and cheap?

I too like the dynamics of having the AT7 in V1. It would clear the gain up. At low volume that was ok but the higher the volume went the less I liked it. I also boost often so that AT7 would be getting a lil' extra goose when I used Lead 1 or the crunch channel. Still at volume is where is suffers but there were some things I liked that it did. I liked soloing with it and how it felt and the texture of the tone. It was Iommi-ish to me at times. I still throw it in there every now and again.

Its hard work being pummeled at volume while listening closely to how a tube is effecting the overall tone of the amp hehe.

I've got a RFT in the PI right now. Its bold, fat and kicks ass the more volume given. I think its helping manage some toppiness inherent in the amp. In fact my whole tube array is geared for warm, fat but articulate tone. I want it as dynamic and organic as I can get it without it being flubby loose or razor tight. I want the notes to bloom and sing when I solo. Probably asking too much of this amp but at the same time I do accept its limitations. Love the amp regardless. Its come along ways.

I've tried the following CP 12AX7's in that slot:
Tung Sol-It was ok. Not a standout for me.
Mullard RI-Again ok but this one to me is a milder AX7
LPS-I like this tube but only as a PI. Its aggressive and has bite.
AC5 Chinese-It was ok.

Any of those will do. I've done it with other NOS too but The PI slot is a position I don't really want to waste using my NOS on unless I hear something really noticeable, like my RFT. I have a few of them. Something to consider if the NOS stash is small and monies tight. Do I really need to burn these up in V3 or the PI?

 

[solarburn]

More recently, I removed the bright cap from the lead channel's gain knob and now I've gotten back to using 12ax7s for v1 and v2./QUOTE]

el zilcho how much difference was there after the mod in the red channel? Did it tame that over brightness well and did it effect any other frequencies negatively? It didn't swing it over to too much lowend or hurt articulation at all?

I'm interested in the mod.

 

[MartyStrat54]

Ive been on a mission for the last few days and have come up trumps. Ive got 1xBrimar 12ax7 NOS on its way, as well as 2xRFT 12ax7's that test as good as new and last but not least those 2xValvos which also test as good as new. I had no idea that there were so many great valves around on ebay at much better prices than are availabler from many actual valve sellers online.

I missed out on a phillips/miniwat that was pulled from a radio but not tested, it went for much more than i was willing to pay given its uncertainty, as ever people are still paying silly money for things on ebay.

Good! You got the fever. Yes there are a lot of tubes out there, don't you agree? It's amazing that most of them are at least 40 years old. You did well with the Brimar, RFT's and the Valvos. I'm especially interested in the Valvo's. Did you notice if they are slant top getters? If so, if you can put up some pictures, I would love to see them. I'm trying to see who all made slant tops over in Europe.

Enjoy your new little "toobs."

 

[RiverRatt]

I thought the bright cap was either C12 or C17, depending on the board revision. I tried clipping that cap and ended up soldering it back after a few months. Maybe I did the wrong cap, but I didn't notice much of a difference.

I've been working those Matsushita 12AX7s into the rotation lately, and they are starting to grow on me. I really like them in V1 using the Classic channel clean mode. They have more hair than the Tele smooth plate I've been using. I think if my Mullard was a little stronger, they would sound pretty close. Not bad at all for $5 a tube! I'm really wanting to try an Amperex, Valvo and Brimar, and maybe pick up a ribbed-plate Tele to compare to the smooth plate, but Christmas is kicking my ass this year. The older kids get, the more expensive they get!!!

 

[solarburn]

I thought the bright cap was either C12 or C17, depending on the board revision. I tried clipping that cap and ended up soldering it back after a few months. Maybe I did the wrong cap, but I didn't notice much of a difference.

I've been working those Matsushita 12AX7s into the rotation lately, and they are starting to grow on me. I really like them in V1 using the Classic channel clean mode. They have more hair than the Tele smooth plate I've been using. I think if my Mullard was a little stronger, they would sound pretty close. Not bad at all for $5 a tube! I'm really wanting to try an Amperex, Valvo and Brimar, and maybe pick up a ribbed-plate Tele to compare to the smooth plate, but Christmas is kicking my ass this year. The older kids get, the more expensive they get!!!

For realz! I just sent you a pm and then read this. I have a ribbed for her pleasure Tele if you want to demo it. I would like to try a Brimar 12AX7 too. Expensive NOS tube though. I've tried Amperex(good tube)but not the Valvo either. Still really digg'n what I have in mine though so I'm not feeling a pull to get anything like right now.

 

[MartyStrat54]

I've tried Amperex(good tube)

I didn't think you ever tried one. I never heard you make any remarks about it. Was it a V1 or V2 tube? Good tube, but not your favorite. You prefer the Tele over it, right? Do you own an Amperex, or should I say Philips tube?

 

[MartyStrat54]

Well here I am buying a lot more tubes and with that comes a lot more bad tubes. In this week alone, my tube tester has saved me over $425. I had a real sweet pair of NOS 6CA7's and they tested at 52 and 54. That sucked, especially since I paid almost $175 for the pair. Then I had a batch of Mullards and one was dead and another one had a bad short in it. Then another batch of Mullards and two out of eight no good.

On the plus side, I did score some more Black Plate Raytheon's and I found a guy in Canada that has a whole bunch of Philips tubes. They are called Electrohome and they sound as good as any other Philips tube. A good bargain as well. I bought 24 of those. I couldn't pass them up.

I watched EBAY today. A guy had two sets of two Colbalt Blue Tesla EL34 tubes. Not much activity and I thought for a while, "Hell, I'll buy them." An hour before the auction ended one set was at $168 and the other was at $242. I had to laugh, because although these are real Tesla's, they were made near the end, right before the company folded. I'm sure they are good EL34's, but not that good. You can get a pair of xf3's for that.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140363558521&ssPageName=STRK:MEWAX:IT

The Tele craze on the thread created more sales to other individuals. Now I'm getting low on Tele's. I am answering many, many PM's every day now. As long as I can keep the tubes coming in, then I'll have the tubes to send out.

 

[el zilcho]

More recently, I removed the bright cap from the lead channel's gain knob and now I've gotten back to using 12ax7s for v1 and v2./QUOTE]

el zilcho how much difference was there after the mod in the red channel? Did it tame that over brightness well and did it effect any other frequencies negatively? It didn't swing it over to too much lowend or hurt articulation at all?

I'm interested in the mod.

It's pretty dramatic, especially if you're like me and you keep the gain pretty low on the lead channel. With the gain on 10 it will sound the same as before. But with the gain down the voicing is very, very similar to the green channel. It's a broad reduction in high frequencies. The other frequencies aren't affected, but your relative perception of them will be different. If you like having the lead channel be a bit edgier than the green channel, you're probably better off replacing it with a smaller value cap. Removing the cap altogether makes it like a high gain extension of the green channel.

BTW, my amp is a DSL 100 made in 2000. The front board says JCM2-61-00 issue #3 and the bright cap was labeled C12. The stock value is 470pf.

 

[solarburn]

I didn't think you ever tried one. I never heard you make any remarks about it. Was it a V1 or V2 tube? Good tube, but not your favorite. You prefer the Tele over it, right? Do you own an Amperex, or should I say Philips tube?

I'm pretty sure in one of your packs you sent me it had an Amperex in it. Maybe I'm confusing it with a Tungsram. Did you ever send me any of these? If not I haven't tried an Amperex. Now my memory isn't clear on it but I know I haven't tried either of these any other time. I was thinking it was from you when I wrote that. I also remember it was good and I'm sure I put it in both V1 and V2 too if and when I demoed it.

 

[solarburn]

It's pretty dramatic, especially if you're like me and you keep the gain pretty low on the lead channel. With the gain on 10 it will sound the same as before. But with the gain down the voicing is very, very similar to the green channel. It's a broad reduction in high frequencies. The other frequencies aren't affected, but your relative perception of them will be different. If you like having the lead channel be a bit edgier than the green channel, you're probably better off replacing it with a smaller value cap. Removing the cap altogether makes it like a high gain extension of the green channel.

BTW, my amp is a DSL 100 made in 2000. The front board says JCM2-61-00 issue #3 and the bright cap was labeled C12. The stock value is 470pf.

Yeah I've always heard this mod referred to as the C12 mod. I do keep my gain low on the red channel. Around 3.5 using lead 2 and then maybe 5 on lead 1 which to me is where it is overly bright. Using lead 2 eq'd right warms it up quite a bit and having the gain low I can still get good note separation.

Did you remove it all the way or use a cap with a smaller value? This mod is easily changed back as well so I find this very attractive and may get it done. Thanks for the input on this ez.

Ok boyz...tubes right?