tube question

[Spivonious]

So it's come time to replace the tubes in my amp (at least I think it is...I've noticed lower gain and the clean channel is getting pretty scratchy). Rather than just replace them with what Genz Benz put in there, I'd like to take this opportunity to perhaps improve the amp.

Looking at the manual, I see these descriptions:

#1: input buffer and hot channel 2nd gain stage
#2: warm channel 2nd gain stage and cathode follower
#3: hot channel 3rd gain stage and cathode follower

The warm channel is the clean channel, and the hot channel is the distortion channel. The amp has a serial effects loop (post master) a pan reverb, and separate EQ controls per channel.

Can one of the tube gurus here explain what each preamp tube does? Would it make sense to get a lower gain tube (e.g. 12AT7) for position 2?

As far as what I'm looking to improve, I'd like to make the clean channel cleaner and the amp as a whole a bit warmer. Right now it's very bright. Current gain levels are adequate, but more could never hurt

The tubes in there now are (according to the manual) #1: JJ 12AX7; #2,#3: Ruby Tubes 12AX7. It has two Ruby Tubes EL34s in the power section.

[markD]

i use a 12ay7 or a 12at7 in my amps for a lower gain clean sound. it should be fine as long as the clean and gain channels don't share a tube for their gain stages. it sounds okay, but sometimes it changes the tone of your dirty channel.

[Dreamland_Rebel]

Tungsol's in the preamp.
S.E.D. Winged C's in the power section.

[Firebird V]

12au7 are a very clean preamp tube and you could put that in a tube reverb or clean position. 12ax7c's are nice high gain pre tubes. Winged C's for power tubes are a great choice too.

[6string40]

Tungsol's in the preamp.
S.E.D. Winged C's in the power section.

+ infinity (sorry...that was really lame, cheezy, etc)

But, honestly, this is THE way to go...I can't stress how good this combination sounds. You will be VERY happy with this setup.

[Spivonious]

I dropped the amp today just to take a look inside and also to check out the tubes. IT's a combo so it's hard to work with them when they're hanging upside-down.

What I found makes me wonder how the amp was still getting any sound at all. In one of the EL34s, the little "hat" at the very top of the top is broken off.

All in all, though, looks like a very well-built amp. It's all circuit boards, but the soldering is very clean and every connection and component looks solid.

Are the "Winged Cs" really worth the extra price? I can get Ruby Tubes (what's in there now) for $30. The SEDs cost $46 at thetubestore.com.

[6string40]

Are the "Winged Cs" really worth the extra price? I can get Ruby Tubes (what's in there now) for $30. The SEDs cost $46 at thetubestore.com.

Absolutely worth the extra price! I've used Groove Tube, Ruby, EHX, JJ, Sovtek and SED. In my experience, Ruby are the worst of the bunch. The SED are well worth the money, though if you are looking for less expensive, try the JJs...you should be able to get them for less than $30 per matched pair and they'll blow the Rubys outta the water. I've always used tubedepot.com and they've always been great--helpful, friendly and fast.

[Spivonious]

okay then, winged Cs are ordered. I'll post again when they come in.

[Spivonious]

They've arrived.


First impression...much more headroom; the sound definitely stays cleaner at higher volumes. I'll get to try them out at band volumes next week.

[Spivonious]

I should have just replaced them all. The clean channel 12AX7 went today. First popping then white noise. Dirty channel is fine.

I guess my clean channel overdriving early problem was a sign of the tube going.

[Spivonious]

Got the new Tung-Sols today and played with them for 10 minutes or so before going back to work.


Holy crap what a difference! Much tighter bass response and also noticeably higher gain. Well worth the small price premium over the bargain tubes.

I'm still getting popping on the clean channel though. Any ideas? I did notice one of the tube sockets was sticking out of the chassis less than the other two. Maybe a bad connection to the board?

[6string40]

Holy crap what a difference! Much tighter bass response and also noticeably higher gain. Well worth the small price premium over the bargain tubes.

Let me be the first to say...told you so!

Congrats on your new found tone!