JCM800 2 channel donor - build suggestions?

[Gainzilla]

Hi all,

I've got a donor amp that started its life as a JCM800 channel switcher (2210, 100w, reverb, 2x12). It's got an extra preamp socket installed and both trannies look good. The original amp had a clean channel with volume, treble, and bass. Lead channel had gain, TMB tone stack, master, presence, and verb.

Thoughts on what I should do with this?

I was thinking Fender clean, and Marshall-ish lead? But what specifically?

- Naylor inspired?
- Cornford RK100?
- JCM800?

Does anyone have a favorite Marshall-inspired design?

Cheers!

[strelok]

Just my personal preference but my all time favorite Marshall style circuit is the 2203 style preamp coupled with the '68 era 100 watt output and power supply ala rockstah mod 5. I've had this setup, with some slightly different values in my metro 68 100 watt kit for years and its my favorite amp. Granted the mercury OT and dual tapped PT for 400 and 500 volts b+ really make the cake, but it might give you a nice place to start. I also really dig the lower filtering, I much prefer the looser feel it gives the amp.

[Stevem]

With only one tone stack your not gone truly get both out of one amp.

[Gainzilla]

Just my personal preference but my all time favorite Marshall style circuit is the 2203 style preamp coupled with the '68 era 100 watt output and power supply ala rockstah mod 5

That's a cool idea. Do you find that to be a pretty versatile circuit, or is it just more fun to play? For me, plugging in a gainy amp is like getting into a really fast car that makes you drive like a jerk. Too much fun! maybe that's what I need... A mid-life crisis amp!

With only one tone stack your not gone truly get both out of one amp

Thats the beauty of it. This was one of the two channel Marshalls, so it already has the separate volume treble and bass for a clean channel!

I cold maybe do a fender clean with fixed mid, or maybe add a switch with a couple values... Thoughts?

[M Fowler]

Pick which two channels you want rather then 3 channel and build it

[Gainzilla]

Wow, is that the Andy Zeug's preamp? I just found some sound samples, and the "Rhythm" channel has about as much gain as any amp I've ever heard. hehe

Ok, noted.

[strelok]

Just my personal preference but my all time favorite Marshall style circuit is the 2203 style preamp coupled with the '68 era 100 watt output and power supply ala rockstah mod 5

That's a cool idea. Do you find that to be a pretty versatile circuit, or is it just more fun to play? For me, plugging in a gainy amp is like getting into a really fast car that makes you drive like a jerk. Too much fun! maybe that's what I need... A mid-life crisis amp!

I find it pretty versatile for what I play which mostly consists of blues, 70s/80s rock and a little metal. Of course its fantastic for the EVH thing.

One thing I might add though with this circuit is the PPIMV is absolutely critical. I never, ever use the regular master, in fact the knob broke off a while back while it was being transported and I haven't bothered to replaced it cause its always set to 10. I use the gain knob and PPIMV almost exclusively. If you turn up the PPIMV and use the regular master to set the volume the distortion turns into a bee's nest. The other way around is...well there's something magical about the phase inverter distortion. Obviously not as good as having it run full bore, but I like it better than an attenuator for bedroom/practice levels. Close mic'd you still really got to crank it for the best tone though. Additionally you get a quite a lot of extra gain from the PI. 6-7 on the gain is right in EVH territory. Higher than that your more into the hair metal or just metal territory. Obviously all this depends on speakers and guitar. I just use a 1x12 with a Scumback G12M-65 as I never am in a situation where I need to be louder than what that provides.

[Gainzilla]

Thanks for your thoughts on the mod5! When I first heard about it I was really intrigued, but a older of the clips I'd heard sounded really thin. You don't find it to be that way?

I might have to give the PPIMV a go in this thing, whatever I wind up doing. It seems like a lot of people swear by them.

Cheers!

[Reeltarded]

PPIMV sounds like paper under about 7 and a half. NFB kill. It's a drag for me. Jose setup with or without clipping and some poking around with mixing can do the same thing but way more and it generally sounds like a Marshall when you are done.

[Reeltarded]

Dual channel amp.. you have 5 small holes in that, right?

Autonomous PIs. three holes are the gain channel, two holes are the clean.

Dirty channel is 1,2,3, CF, PI. Channel gets normal control set, simple master, plus Jose master with switchable clipping.

Clean is 1, CF, PI. You use as many holes as you have left for a two knob TS or three if you have space.

The dirty channel can do anything you can think of if you use separate gains for the first two stages and dink with bright caps.

[strelok]

I like the idea of a separate PI for each channel.

I don't think it sounds thin, at least compared to how the circuit sounds without it installed and just using the normal 2203 master. At low volumes that configuration sounds like a thin buzzy mess to me.

It's not the same as a cranked amp for sure. Nothing ever is. But it's satisfactory to me for playing at home.

Keep in mind with the recordings there's a big difference between how the amp sounds in the room and how it will sound on the recording when close mic'd to the speaker. If I sit in front of the speaker and play, it sounds like shit at bedroom volumes. However I tend to stand and find a sweet spot in the room that sounds good.

So it's all about what you're looking to do with the amp, and as reel mentioned whether or not you'll miss the NFB. It doesn't bother me personally, but maybe I'm used to it. So the question is what do you want to do with the amp? Are you looking for something that sounds good in the room at reasonably low volumes and gets better as you turn it up for gigs and such? Or do you want to record at reasonable volume levels? If its the latter you should look into a low powered (10 watts or less) setup with a low wattage speaker as it will sound far better at that volume. Of course if you record in someplace with good sound isolation then that won't matter and you can dime the volume and run someplace safe haha.

Edit: I also don't have any experience with the Jose master so I can't offer an opinion on how the two compare.

[Reeltarded]

The Jose makes the CF sweat. I like that setup with the Jose at 90% and the simple master wide open with about 12ish DB of clipper action. It's not quiet but it's completely outrageous and cleans up. With dual gains the amp can sound like anything from tweedy to infinity. Slope, res, and pres. Umm.. Street Fighting Man to stylized prog gain.

[Gainzilla]

Ok, I've been watching a bunch of YouTube clips on various style Jose circuits, and I think you've got me convinced.

It looks like the Friedman BE100 could be a good candidate. My donor amp is currently fitted with an extra preamp socket (total of 6!) for reverb and tube buffered loop. The way I see it, my options are:

• Use a tube buffered loop rather than the SS loop and add reverb.
• OR - Remove the extra socket and build the stock be100 + reverb.

I realize a Jose is a Jose, so nothing special really about the Friedman over any other Jose. It just already has the clean and relay switching sorted out. Lol

Also, this is a 2x12 combo. Not sure if this amp needs the closed back cab or not to sound great.

Thoughts?

[Reeltarded]

It'll sound better through a quad of 4x12s.

[Gainzilla]

LOLZ