Does anyone know the value of the post gain pot on the solid state channel of this preamp?
Thanks in advance.
Thanks in advance.
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Peavey Max Preamp
- Thread starter bluesrx
- Start date
Old thread but starting another one seems unnecessary.
Does the tube pre section of this amp deliver a true tube pre sound or is it more of a gimmick? I play at high volume levels and the blend feature could make this preamp usable for me because in my experience tube preamps generally get way too saturated when you go beyond moderate volume levels. Having said that, this pre wouldn't beat my Tone Hammer if the 'tube' section sounds like a SS pre impersonating a tube sound. Or if the SS pre doesn't sound that great. If they both sound good this could have me going pure SS for power amps!
If anyone is aware of any other blendable models by any companies please let me know too, while I'm on the topic. Thanks!
Does the tube pre section of this amp deliver a true tube pre sound or is it more of a gimmick? I play at high volume levels and the blend feature could make this preamp usable for me because in my experience tube preamps generally get way too saturated when you go beyond moderate volume levels. Having said that, this pre wouldn't beat my Tone Hammer if the 'tube' section sounds like a SS pre impersonating a tube sound. Or if the SS pre doesn't sound that great. If they both sound good this could have me going pure SS for power amps!
If anyone is aware of any other blendable models by any companies please let me know too, while I'm on the topic. Thanks!
There is a few decent demos on YouTube that might help your decision. If I recall there is one that really focuses on the tube grind. Good luck!
Here found it...
You can easily mod the tube side to increase the gain of the tube, which allows you to use a lower-gain tube (like a 5751) that overdrives more gracefully.
This used to be my "go to" preamp; I had two and modified both.
Edit: here's the mod info:
-----------------------------------------------------------------
Peavey Max modification for greater tube gain
Put a 22mfd @ 25wv capacitor or equivalent in parallel with R224 (1.5K).
Make sure the capacitor is installed with the negative side to ground.
This will bypass the first tube stage's cathode resistor and increase gain quite a bit.
The 1.5K resistor is on the same small vertical circuit board as the preamp tube. I found it easier to fit a resistor with axial (as opposed to radial) leads, and once I'd soldered it in place, I used hot-melt glue to secure it.
* * *
This allowed me to start using a lower-gain but more detailed and creamy tube, the 5751. It's got around 70% the gain of an 12AX-7 and is use-compatible. Read more here:
AudioAsylum.com -- Joe's Tube Lore
Net result with a 5751 is more pleasing to my ears either clean or overdriven, but with a 12AX7 you can get nastier.
DI Out Remove Cabinet Voicing Modification
The XLR out on the MAX is "cabinet simulated", meaning that the highs are attenuated.
This mod gets rid of that attenuation...
Find the XLR connector.
Right above it is a small transformer - the white horizontal bar with the black parts above and below it and a white dot in the upper right corner.
To the right of the transformer is a row of five small parts (There appears to be a black mark on the circuit board underneath some of the parts), then a RC4558P integrated circuit chip.
To the right of the IC chip is another row of seven small parts.
Look at that row of seven parts.
On the left is a resistor, then two small round yellow caps, then another resistor, then two glass diodes (They look brown with black marks), and finally another resistor.
The two yellow globs are the caps to remove.
I suggest you unsolder one end of each one, and pull the wire up from the hole so it is no longer connected.
Alternatively (and it saves you disassembling the whole preamp) you can just snip the leads on those yellow caps.
This used to be my "go to" preamp; I had two and modified both.
Edit: here's the mod info:
-----------------------------------------------------------------
Peavey Max modification for greater tube gain
Put a 22mfd @ 25wv capacitor or equivalent in parallel with R224 (1.5K).
Make sure the capacitor is installed with the negative side to ground.
This will bypass the first tube stage's cathode resistor and increase gain quite a bit.
The 1.5K resistor is on the same small vertical circuit board as the preamp tube. I found it easier to fit a resistor with axial (as opposed to radial) leads, and once I'd soldered it in place, I used hot-melt glue to secure it.
* * *
This allowed me to start using a lower-gain but more detailed and creamy tube, the 5751. It's got around 70% the gain of an 12AX-7 and is use-compatible. Read more here:
AudioAsylum.com -- Joe's Tube Lore
Net result with a 5751 is more pleasing to my ears either clean or overdriven, but with a 12AX7 you can get nastier.
DI Out Remove Cabinet Voicing Modification
The XLR out on the MAX is "cabinet simulated", meaning that the highs are attenuated.
This mod gets rid of that attenuation...
Find the XLR connector.
Right above it is a small transformer - the white horizontal bar with the black parts above and below it and a white dot in the upper right corner.
To the right of the transformer is a row of five small parts (There appears to be a black mark on the circuit board underneath some of the parts), then a RC4558P integrated circuit chip.
To the right of the IC chip is another row of seven small parts.
Look at that row of seven parts.
On the left is a resistor, then two small round yellow caps, then another resistor, then two glass diodes (They look brown with black marks), and finally another resistor.
The two yellow globs are the caps to remove.
I suggest you unsolder one end of each one, and pull the wire up from the hole so it is no longer connected.
Alternatively (and it saves you disassembling the whole preamp) you can just snip the leads on those yellow caps.
Last edited:
