Hello . I start again the topic hot mod v2… for those who do not know what this is. we replace the second lamp on a marshall (jcm-jmp) with it and it gives the amplifier an extra gain stage without disturbing anything inside the amplifier circuit. this was pre-made by mike soldano and was called hot mod. where it was an adapter with a 6C10 lamp which has 3 triodes instead of 2 that the 12ax7 has ..but the 6c10 stopped being produced and so the hotmod stopped coming out… in recent years the hotmod v2 has come out which is an adapter with two 12ax7 lamps ..for this there is no schematic on the internet, but there is for the first hotmod .. observing the first plan we see that all 3 triodes are used .. now the trick is more?!?!. we will use a 12ax7 lamp for the first 2 triodes and another 12ax7 lamp for one triode (but half) .. the issue is this, we have 1 triad left, how could we use it? in the drawing below I show the schematic of the hot mod v1 and the schematic of my own…
I'd use the extra triode as an input recovery for external effects loop, but that would involve some drilling of the chassis in the back for the in/out jacks.
the whole design concerns only the position of the second lamp of the circuit Therefore all triode should only be used for this position. Just based on the plan, there is more than one triode ,, I just think that I could use it ,, that is why I mentioned the switch more gain ..if I put 2-7 and 3-8 in parallel, will anything change? in short if I use the whole lamp for a gain stage ,, is it possible? e.g. will it make the sound fuller?
I forgot to add the first schematic of Mike soldano
I forgot to add the first schematic of Mike soldano
Attachments
If you just copy the second stage of the HotMod, you get this. The switch is a DPDT toggle switch.
No idea if it sounds any good with the extra stage enganged. It will probably be noisy.
Like Parafeed813 already wrote, in your schematic you switch a second triode parallel to the last triode. The last triode is a cathode follower. They have a 'gain' of a little less than 1 (one), so no gain. Switching a second one parallel doesn't change the gain, it only lowers the output impedance. That could alter the workings of the tone control that follows but like Parafeed813, I think that the effect will be minimal.
No idea if it sounds any good with the extra stage enganged. It will probably be noisy.
Like Parafeed813 already wrote, in your schematic you switch a second triode parallel to the last triode. The last triode is a cathode follower. They have a 'gain' of a little less than 1 (one), so no gain. Switching a second one parallel doesn't change the gain, it only lowers the output impedance. That could alter the workings of the tone control that follows but like Parafeed813, I think that the effect will be minimal.
Attachments
Last edited:
Thank you for the schematic but escapes the soldano design…and maybe noise comes .. with the 3 triodes like the original tha sound is awesome … but if you see the version 2 of hot mod , have a switch with gain , and on other version of v2 hotmod ( George lynch edition ) instead switch , has potentiometer ,, this makes me think that in version 2 it uses all 4 triodes.. I can make it work with 2 valves and 3 triodes but I go crazy where one triode is left over 😡
… no .. the switch just add a little more gain .. and the other switch add more bass .. the bass switch is simple . But the gain switch is probably the 4th gain stage
I can't follow you anymore.
You are (still) writing about four gain stages. But the original Soldano Hot-Mod has two gain stages + a cathode follower, which has no gain.
For sure my schematic is not what is inside the "Hot Mod V2" (no bass switch to begin with). But it stays true to the original Soldano design, with the "extra" that you can switch on an extra (so third) gain stage. So it is unclear to me what you mean with: "... but escapes the soldano design...".
You are (still) writing about four gain stages. But the original Soldano Hot-Mod has two gain stages + a cathode follower, which has no gain.
For sure my schematic is not what is inside the "Hot Mod V2" (no bass switch to begin with). But it stays true to the original Soldano design, with the "extra" that you can switch on an extra (so third) gain stage. So it is unclear to me what you mean with: "... but escapes the soldano design...".
Sorry for my English .. let’s take the things from the start … at 90s Mike soldano make an patent call it hot mod , it’s an adaptor with a small circuit and 6c10 valve , and it put it on Marshall jcm/jmp on 2nd position ( cathode follower ) .. this is add an extra stage on circuit of Marshall 
… on 2015 Mike soldano make again the same patent call it hot mod v2 , now with 2* 12ax7 and with bass boost switch and with gain boost switch … the problem is that there is no schematic for this . all I have thought about is to take the old plan and use the fourth triode for extra gain. I can make the old soldano design but with 2 * 12ax7. but half of the two valves will work… so I am looking for help on how to add with a switch the fourth unused stage that I have left .. this is all… and when I say “escape from soldano design” I mean out of range of circuit ..
… on 2015 Mike soldano make again the same patent call it hot mod v2 , now with 2* 12ax7 and with bass boost switch and with gain boost switch … the problem is that there is no schematic for this . all I have thought about is to take the old plan and use the fourth triode for extra gain. I can make the old soldano design but with 2 * 12ax7. but half of the two valves will work… so I am looking for help on how to add with a switch the fourth unused stage that I have left .. this is all… and when I say “escape from soldano design” I mean out of range of circuit ..
"... so I am looking for help on how to add with a switch the fourth unused stage that I have left ..."
But that's exactly what happens in the schematic I presented in post #6 (just compare it with the schematic in post #3 of your earlier thread: Soldano hot mod)
I'm out of this thread. Good luck with your search.
But that's exactly what happens in the schematic I presented in post #6 (just compare it with the schematic in post #3 of your earlier thread: Soldano hot mod)
I'm out of this thread. Good luck with your search.
Last edited:
I hurried to conclude, "your schematic is perfect for what I want". I was observing marshall's schematic and how exactly this adapter works on the amplifier ,,, and I designed a stage still like the previous one, and I noticed that you had sent me the same…. I think it is the only way so and I think it will succeed. I just think that there should be more resistance in the extra stage because it will have noise as you say… .. and something else ,, that I have to add a capacitor to add bass? this 10nf capacitor if I change it to 47nf will the bass change or should a capacitor be inserted at the beginning of the signal and end up in ground?
Attachments
Personally I´d just add extra 20 dB (or more) clean preamp, ahead of an unmolested amplifier.
Easy to remove, less hum/gain/hiss problems, flexible,the works.
Easily footswitchable, of course.
In fact, I wouldn´t even use tubes there, it´s hard to get low noise, low microphonics ones, they require DC filaments, etc. ; Op Amps (or even some discrete FET circuit) will be perfectly fine there.
Rel distortion will appear later in the chain, from real tubes anyway.
Easy to remove, less hum/gain/hiss problems, flexible,the works.
Easily footswitchable, of course.
In fact, I wouldn´t even use tubes there, it´s hard to get low noise, low microphonics ones, they require DC filaments, etc. ; Op Amps (or even some discrete FET circuit) will be perfectly fine there.
Rel distortion will appear later in the chain, from real tubes anyway.
It is!!!
From the very beginning.
People see Musicians and the amp backline, 99% of the time oblivious to the huge pedalboards and monster racks stacked behind the cabinets, or to one side of stage.
Then wonder: "I bought exact same Guitar, exact same Amp, why don´t I sound even close?"
BB King plugged his guitar straight into the amp, most others cram half a Music Shop in between.
From the very beginning.
People see Musicians and the amp backline, 99% of the time oblivious to the huge pedalboards and monster racks stacked behind the cabinets, or to one side of stage.
Then wonder: "I bought exact same Guitar, exact same Amp, why don´t I sound even close?"
BB King plugged his guitar straight into the amp, most others cram half a Music Shop in between.
Yes, we might as well plug a (treble) booster pedal in front of the amp. That's the easiest solution and the most popular one before all the "modded Marshall" craze.
Essentially amps like Laney AOR series, Lee Jackson Ampegs and Bogner amps are a Marshall 2203 with a treble booster in front. Only difference is that the treble booster is a tube input stage built into the amp. Basically not much difference, except that the tube is usually cleaner than the popular Rangemasters, Colorsound ODs, Tube Screamers, DS-1s and et cetera we have come to love.
Soldano actually went a bit further and instead of just boosting a standard Marshall circuit he went on to modify its pre and post distortion responses and the way how the amp actually overdrives. You can't achieve this with an extra gain stage in input; the overall character and dynamics of responding to picking will be different. Likewise as in development of 5150 Brown tried adding an extra gain stage to input of the SLO only to find out the sound is different, and actually better, when he added the extra gain stage(s) "downstream". The amp will respond differently and the OD characteristic will be different.
Essentially amps like Laney AOR series, Lee Jackson Ampegs and Bogner amps are a Marshall 2203 with a treble booster in front. Only difference is that the treble booster is a tube input stage built into the amp. Basically not much difference, except that the tube is usually cleaner than the popular Rangemasters, Colorsound ODs, Tube Screamers, DS-1s and et cetera we have come to love.
Soldano actually went a bit further and instead of just boosting a standard Marshall circuit he went on to modify its pre and post distortion responses and the way how the amp actually overdrives. You can't achieve this with an extra gain stage in input; the overall character and dynamics of responding to picking will be different. Likewise as in development of 5150 Brown tried adding an extra gain stage to input of the SLO only to find out the sound is different, and actually better, when he added the extra gain stage(s) "downstream". The amp will respond differently and the OD characteristic will be different.
https://www.diyaudio.com/forums/ins...jcm-800-2204-marshall-mods-3.html#post6830261
Check it guys ,,only I need it is the transformers …..
Check it guys ,,only I need it is the transformers …..
