Just got a bunch o' tubes - Let's decide where to put 'em!

[camsna]

Hello fellas! Hopefully this will be fun! 2 questions:

1) Penta 12AX7A. I know of the Chinese version. But I just ran into a few Penta Labs 12AX7As that are 'made in Russia.' Anybody know who makes these? Any good?

2) Onto the fun stuff! I have some preamp tubes to try out in my Blue-Stripe revision Mk. III (simul/eq/'verb) and would LOVE your input. So - with this amp and the following tubes - what would you put where?!

- 3 High-gain JJ ECC83S
- 2 JJ ECC83S
- 2 JJ ECC81
- 3 Penta Labs 12AX7A (Made in Russia)
- 2 Shuguang 12AX7 9th gen.
- 3 Sovtek 12AX7 WA
- 2 RFT ECC83

Also - how do you feel about a 'balanced' PI?

Let 'er rip!

 

[camsna]

* b u m p *

C'mon guys! I could really use your input!

 

[ANIMATED SUSPENSION]

V1 - RFT
V2 -RFT
V3 - Penta
V4 - Penta or Sovtek
V5 - Penta

I only say this because I don't like JJ preamp tubes much and you can't really use the ECC81's anyway !! The Penta 'Russian' tubes are most likely Sovteks.

 

[CoG]

for high gain sounds try the high gain JJs in v1 and v3. I find they let you crank up the gain a little more without getting harsh. They're very dark/smooth sounding, though, too much for some people.

I use a balanced 12AT7 in the PI, which also seems to cut down the MkIII's tendency to get harsh at high levels of gain. I don't think that has anything to do with it being balanced, though, just a 12AT7.

 

[Monsta-Tone]

The PI circuit is unballanced in it's design. I have never been able to tell the difference when using a ballanced PI tube.

 

[MrMarkIII]

I would first try each and every tube in V1, listening for the tone YOU like best. This tube matters the most and will affect tone all down the line.
Then the same procedure in V3. This is the Lead circuit.
Once you nail those down, go back and do V2, V4, and V5.
You really should try a couple NOS Mullards.

 

[Monsta-Tone]

I've got an NOS Mullard in V4 on my DC-10 and it made the clean channel heavenly.

Mr Mark is absolutely right about V1. It will affect everything else, and have the most dramatic effect on tone.

 

[camsna]

Hey, Monsta!

Can you give me a quick rundown of the function of each preamp tube in my Mk III?

Thanks guys! KEEP IT COMIN!!!

 

[Monsta-Tone]

V1 = 1st & 2nd gain stage for all channels
V2 = FX Loop & a few other things, this tube is busy
V3 = 3rd & 4th gain stages for channel 3
V4 = Reverb
V5 = Phase Inverter


For searing gain in channel 3, I would try a high gain in V1 & V3, maybe even V2. If you have a ballanced tube, it wouldn't hurt to try it in V5. I have one and need to experiment a little more with it to see if it's worth it.


Hope this helps.