POLL! What to put inside a Marshall Drive Master enclosure!?

[Renegadrian]

Ehi guys, I need your suggestions!!!  

I got some broken pedals from a "wannabe modder" who just managed to ruin PCBs and stuff. I got 3 broken pedals, I have to build him a FF69 in change. Of the 3, I have this Marshall Drive Master. PCB is not so ruined, but hell I'd really work better with a new one! Also, as the enclosure had some rust and some paint was scruffed, I am taking it down to metal, maybe I'll leave it that way with some transparent decal for the controls, maybe I'll put new paint on, not black to make it CUSTOM look.
As for the inside, I was thinking that the DM itself it's not so bad sounding, and the schems really calls for a diode switch! I'd say LEDs as the original and 4148 on the other side.
Else I could consider a FET rendition of the JCM800, like Electritabs' schematic. It has 5 knobs and it'd be MARSHALL in a Marshall box!!! Third oprion, any other 5 knobs circuit...
So please let me know your ideas, suggestions, whatever!!!
I made an online poll for it...here's the link!!! Thank you in advance!!!

http://micropoll.com/t/KEsI1ZBwNi

[Steben]

pfff, location of vote only looks for the US 

[Galego]

I voted, and i'm in Portugal.

Oh, you mean the location beneath the graph....

[Renegadrian]

yeah location doesn't matter, after all...thx for voting!

[Renegadrian]

12 votes only 
6 think I should go with the DM, 4, with jcm800 and 2 other ckts.
come on vote some more!!!

[Johan]

the original drivemaster was identical to the guv'nor with the exception of not having the "loop"-jack...it might be worth trying ti revive it?..
J

[roseblood11]

What about the Okko Dominator? 5 knobs as well, or 6 if you use a pot for the mid frequency.
It has been retraced at the other forum...
It´s a very versatile pedal, it goes from mild blues tones to Heavy Metal

http://www.youtube.com/results?search_query=okko+dominator&aq=f

[Renegadrian]

wow that pedal is a monster, but I guess I'll stick with one of the two options more related to Marshall, as the Marshall engraving stays...

[StereoKills]

I'd go for the JCM800, make that pedal scream!

[Renegadrian]

mmm who knows...

[Renegadrian]

ok I was looking at electrictabs' project again, and first it has 6 pots, then I read somone had problems with it and made me think it's not worth, at least it's not a "safe-results" build for what I understood. So maybe I'd stick with the original, else I was thinking about...TUBES!!!

http://usuarios.lycos.es/darkstats/pre_jcm800_por_gak_2.pdf

but yeah obviously the level is a little higher, involving two power trafos back to back, two tubes...but heck The enclosure is so big!!! Maybe...who knows...Maybe the SMPS can give enough juice for the project!!!

[Renegadrian]

23 votes and the two main options are at the same level more or less...
So I'd say electritabs' is out, maybe Guero's layout is better, it's the FET rendition of the preamp only (the first is the whole amp remade) so a 5 knobbers. Guero's preamp here http://www.handmades.com.br/components/com_joomlaboard/uploaded/files/JCM_800_FET_Guero.pdf
Else the tube preamp above makes me wanna build one...I read some other fellas have succesfully built it.
Else the original ckt.

but mmm I'd like to make a special pedal...maybe one of the first 2 options...

[Johan]

why not do what I havent seen yet(allthou, I do miss a lot of what's going on..), but what would seem like the natural follow up on all fet-emu's....a mu-amp version of the 2203 preamp. take the tube amp schem and replace the tubes and anode resistors with mu-amps, leaving the cathoderisistors/caps and all intermediate stuff as marshall made it... if the third stage is a srpp, you can skip the last cathodefollower....
...hmmmm...I might try this when I get back home....
J


EDIT: something like this.. http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=44760&g2_serialNumber=1

[Renegadrian]

mmm I believe it's not so original, I was looking at the BSIAB schem and I find it so similar to the jcm 800 structure and to the mu amp you suggested...

[Johan]

ah..ofcourse..I had forgoten about that one...sorry...carry on..
J

[petemoore]

  They were large, I both the 5 knobbers: Shred and the Drive masters.
   Never really understood the Bluesdriver either. The SD-1 was my favorite of the driver pedals and I tried to understand by owning many of them.
  I quickly took to the Shredmaster though and I decided that despite the XL sized box it was worth it's space in tone, a really nice 5-interactive-knobs distorter box.

[Steben]

23 votes and the two main options are at the same level more or less...
So I'd say electritabs' is out, maybe Guero's layout is better, it's the FET rendition of the preamp only (the first is the whole amp remade) so a 5 knobbers. Guero's preamp here http://www.handmades.com.br/components/com_joomlaboard/uploaded/files/JCM_800_FET_Guero.pdf
Else the tube preamp above makes me wanna build one...I read some other fellas have succesfully built it.
Else the original ckt.

but mmm I'd like to make a special pedal...maybe one of the first 2 options...

I would suggest not to use the decoupling caps at the source. They boost the gain, but they make the jfet respond less as a triode.
Yes, the gain drops. But with 9V supply the headroom is much smaller than in the a tube circuit. Gain can be 25 - 30 times smaller than the tube circuit.
Just my 50 cents...

In a tube amp, the first stage never clips with a guitar signal. Even at maximum gain (100 in a 12AX7/ECC83) an average output signal into next stage will give 30-20V peak, 10V cruisespeed (single coil). Given supply of +200V, this is "small".
Into 9V circuits, this means equivalent first stage gain of maximum around 3 - 5, which is nicely done with a fetzer valve or triodizer giving good character. Next stages could be left as is, sinc ethey are intended to go into severe clipping, losing much of the tone of the "transient" zone.

[Renegadrian]

23 votes and the two main options are at the same level more or less...
So I'd say electritabs' is out, maybe Guero's layout is better, it's the FET rendition of the preamp only (the first is the whole amp remade) so a 5 knobbers. Guero's preamp here http://www.handmades.com.br/components/com_joomlaboard/uploaded/files/JCM_800_FET_Guero.pdf
Else the tube preamp above makes me wanna build one...I read some other fellas have succesfully built it.
Else the original ckt.

but mmm I'd like to make a special pedal...maybe one of the first 2 options...

I would suggest not to use the decoupling caps at the source. They boost the gain, but they make the jfet respond less as a triode.
Yes, the gain drops. But with 9V supply the headroom is much smaller than in the a tube circuit. Gain can be 25 - 30 times smaller than the tube circuit.
Just my 50 cents...

I don't know man, after all it's a close rendition of the original schem, the first cathode has a 2.7k res and a .68µ cap, here we find a 4.7k and a 1µ cap, so quite similar. at the second cathode we have the same 10k res, with a switchable gain boost cap (the amp hasn't got that but it can be easily implemented), so it should be quite close to the original.

[Steben]

23 votes and the two main options are at the same level more or less...
So I'd say electritabs' is out, maybe Guero's layout is better, it's the FET rendition of the preamp only (the first is the whole amp remade) so a 5 knobbers. Guero's preamp here http://www.handmades.com.br/components/com_joomlaboard/uploaded/files/JCM_800_FET_Guero.pdf
Else the tube preamp above makes me wanna build one...I read some other fellas have succesfully built it.
Else the original ckt.

but mmm I'd like to make a special pedal...maybe one of the first 2 options...

I would suggest not to use the decoupling caps at the source. They boost the gain, but they make the jfet respond less as a triode.
Yes, the gain drops. But with 9V supply the headroom is much smaller than in the a tube circuit. Gain can be 25 - 30 times smaller than the tube circuit.
Just my 50 cents...

I don't know man, after all it's a close rendition of the original schem, the first cathode has a 2.7k res and a .68µ cap, here we find a 4.7k and a 1µ cap, so quite similar. at the second cathode we have the same 10k res, with a switchable gain boost cap (the amp hasn't got that but it can be easily implemented), so it should be quite close to the original.

See my EDIT...   Gain will be relatively monstreous in a 9V supply pedal.

A triode has its typical full non-linearity precisely with cap. And that is strong second + third harmonic.
A jfet has its linearity maxed out as well with cap, yet it boost even more distortion and with a different balance in harmonics.

Don't get me wrong: each distortion can be useful as I said before. Yet emulating a specific circuit needs more thought if you have the right emulating attitude.

[Ice-9]

the original drivemaster was identical to the guv'nor with the exception of not having the "loop"-jack...it might be worth trying ti revive it?..
J

Only other difference is a few componet values. I have Drivemaster at home if you wanted to repair this i could take some pictures of the PCBs in case you need to etch/repair yours.