Anyone knows what the CAE Crunch (aka Dookie) mod is?

[Badside]

I am researching building a Plexi style for a friend in a Green Day tribute band. Doesn't have to be exact replica, but it appears he's mostly been using a modded 1959SLP with a "crunch" mod (apparently now done by CAE as the Crunch mod).

Listening to some of the clips, it sounds very JCM800ish except perhaps a bit fatter. So I guess it cascades the channels and add a MV... perhaps.
Not looking for anything exact, just trying to have a rough idea of what it is.

[Badside]

So reading around, it would seem the CAE 3+ preamp is based on those mods so I looked at the schematic to figure out the difference. The crunch side is indeed very JCM800ish, except there is no cold stage (so more gain right there, both stages are biased with a 2k7) and the 500k/500p peaker before the Gain is replaced by a 1M/250p.
Now, twice the resistance for half the capacitance gives us the same -3dB point, but it's going to be playing with the following pot which stays 1M. Wonder how much that changes the tone. For sure it will diminish the available gain, which will then be counteracted by the warmer 2nd stage. So it would seem in the end the difference is just a slightly different voicing in the early stage, which would make the distortion shaped slightly different, but not by much.
2nd stage is also bypassed by a 1u.

My main 2204 has two warm stages but the 2nd is bypassed with a big electro cap. That 1u might clean things up (something I did by using a smaller coupling cap instead).

Foor for thoughts...

Any experience with these kinds of tweaks?

[caphead]

I have some experience with the CAE circuits. In my experience when cloning a mod vs an established circuit I've found that in most cases any part value that is stock in the original circuit that is close in value to the objective circuit of the mod is usually kept. What I mean by this is that most likely the 'dookie' mod probably kept the 2.7k and .68 combination on the first two cathodes and with the stock 1k on the third with an added 1uF, as well as I'm guessing the .022 coupling cap after the first stage stayed in place of the .1 cap that is shown in the CAE 3+ schematic. The real key to the mod it seems is the 1M/220p treble peaker and the 220k plate load on the first stage. This is all subjective, but my experience with this circuit as taken verbatim from the CAE schematic is that it looses a bit of its 'marshall-ness with the values written, which is what seems to be what your after. I hope this helps.

[Reeltarded]

Never seen the schematic but 2k7//.68 x2 with a 5uF over the 820R sounds pretty close to it and add the 220k plate to put some teeth on it.. growly.

Dunno about the mixer situation. 100 ways to arrive at 30 different great combos.

[Badside]

I have some experience with the CAE circuits. In my experience when cloning a mod vs an established circuit I've found that in most cases any part value that is stock in the original circuit that is close in value to the objective circuit of the mod is usually kept. What I mean by this is that most likely the 'dookie' mod probably kept the 2.7k and .68 combination on the first two cathodes and with the stock 1k on the third with an added 1uF, as well as I'm guessing the .022 coupling cap after the first stage stayed in place of the .1 cap that is shown in the CAE 3+ schematic. The real key to the mod it seems is the 1M/220p treble peaker and the 220k plate load on the first stage. This is all subjective, but my experience with this circuit as taken verbatim from the CAE schematic is that it looses a bit of its 'marshall-ness with the values written, which is what seems to be what your after. I hope this helps.

Thanks for the useful info! Somehow I didn't even notice the 220k on the first stage.
On my main personal amp (a 2204), I experimented with the plate cap and settled with a 150k for best tone.
To be fair, with the warm 2nd stage (as in the CAE) my amp gets pretty close to the Dookie tone, but listening to clips of amps with the Crunch mode they seem a bit brighter and lighter, while being warmer and fatter than a JCM800 for example.

So I guess I could probably just build him a 2204 (I don't see the need for 100W) with the warm 2nd stage, and higher plate load and the different treble peaker and he'd be a happy camper.

Thanks for the information!