Question about Non-Reverb Mark II Tubes

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Brad737
Mark II
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Joined: Thu Apr 16, 2015 3:14 pm
Location: Cincinnati, OH

Question about Non-Reverb Mark II Tubes

Post by Brad737 » Thu Oct 07, 2021 4:42 pm

Hello, all.

I have a question regarding the tube layout on my amp. This is a 60 watt, non-reverb, with Graphic EQ. I found a IIC manual online, and it breaks down the preamp tubes as follows:

V1 A) Input amplifier
B) Tone control
V2 A) Effects return
B) Mixer amplifier
V3 A) Rev return amp
B) 1/2 lead drive
V4 A) 1/2 lead drive
B) Reverb driver

Of course, V5 is the phase inverter. Since there is no reverb, there is one less preamp tube. Are both sides of V3 dedicated to the lead drive? Am I correct in assuming that if I wanted to use NOS tubes in the preamp that V1 and V3 are where I should concentrate my efforts?

Thanks,
Brad
Last edited by Brad737 on Mon Oct 11, 2021 10:16 am, edited 1 time in total.
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Brad737
Mark II
Posts: 84
Joined: Thu Apr 16, 2015 3:14 pm
Location: Cincinnati, OH

Re: Question about Non-Reverb Mark II Tubes

Post by Brad737 » Mon Oct 11, 2021 10:16 am

Hello,all.

I heard back from Mike B. about the Non-Reverb tube layout. The preamp tubes are as follows:

V1 - A) Input amplifier
B) Tone control
V2 - A) Effects return
B) Mixer amplifier
V3 - A) 1/2 lead drive
B) 1/2 lead drive
V4 - Phase Inverter

He didn’t mention specific tubes, but he did suggest NOS tubes in V1, V2, and V3.

I hope this helps,
Brad
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MK IIB
Mark III
Posts: 198
Joined: Tue Sep 20, 2011 11:15 am

Re: Question about Non-Reverb Mark II Tubes

Post by MK IIB » Tue Oct 12, 2021 4:45 pm

Hey Brad
Thanks for the post/info.
I myself posted this exact same question and didn't get a definitive reply but like you presumed that V3 alone was dedicated to the lead drive although will still somewhat be affected by V1 tube choice as it's cascaded and affects the overall gain/feel of both "channels"

P.s what NOS tubes are you thinking in trying?

Brad737
Mark II
Posts: 84
Joined: Thu Apr 16, 2015 3:14 pm
Location: Cincinnati, OH

Re: Question about Non-Reverb Mark II Tubes

Post by Brad737 » Tue Oct 12, 2021 8:01 pm

Well, I’m not sure exactly. I’m just going to swap a few around and see how they sound. I have 10 or 15 Mullards, a Bugle Boy or 2, a few Telefunkens. I always use the Sovtek 12AX7LPS as phase inverters. As for power tubes, I have 4 or 5 sets of proper power tubes...STR 387 and 415s, but I’ll have to split these up between my two Boogies.
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