JCM800 220 starting point for 70's and 80's classic rock tone

pjd3

New Member
Joined
Nov 11, 2019
Messages
16
Reaction score
7
Hello all,

I'd be interested to hear your opinions on a ground Zero start point for my next project - a JCM800 2204 amp for 70's and 80's popular classic rock.

I use either a Fender Vibroverb normal channel (robinette) or a 20W Plexi (Sluckey) when gigging and for hard rocking Marshall tones been stepping on a Runoffgroove Thunderchief Tube-to-Fet conversion pedal. While that pedal has actually served me fairly well for fooling an audience into thinking they hear decent tone emulation for the 70's and 80's hard rock Marshall tones, the pedal obviously doesn't have the level of depth, 3D'ism, dynamics, smoothness and complexity that is very apparent from a good and well done JCM800 cascaded gain stage with cold clipper thing that we hear in those good old wonderful amps. My 20W plexi is great as a clean rhythm channel and pedal platform but isn't the thing to use for the higher gain stuff as is.
I've been hearing some very nice youtube clips of 2204 builds that are definately contenders, one in particular a british fellow that seems to have a 2204 with a classic AC/DC sound, with many switched mods that do various gain or EQ variations for added varieties of tone textures and responses. Perfect.

So, that is my question to all of you out there. If you were an old (64 years old) local classic rocker looking to build a JCM800 2204 amp that at its unmodded starting point did a good AC/DC sound, with a slew of switchable mods, which year/model, schematic would you start with as your basic foundation for mods? My bands play the popular selections of "AC/DC, ZZtop, Toto, Foreigner, Bon Jovi, Van Halen, etc... What would you consider as a ground zero JCM800 2204 starting point model/year for an amp build (with mods)? I guess I imagine the range would be from early AC/DC to 80's era Bon Jovi (seems to be much more gainy than early AC/DC. I picture having a selection of switches that when say, in the down position is the classic unchanged circuit, and each switch bringing in a modification for whatever, gain, eq, cold clipper cathode variations, maybe plate load resistor values, things like that, subtle but useful.

thanks for wading through my long winded post! I want this to be a real good sounding impressive, fun and flexible/useful amp! and I have some Mullard Blackburns and/or Winged C's that can to into it.

Best, and thanks,
Phil D.
 

PelliX

Well-Known Member
Joined
Jun 16, 2020
Messages
2,550
Reaction score
5,036
Hello all,

I'd be interested to hear your opinions on a ground Zero start point for my next project - a JCM800 2204 amp for 70's and 80's popular classic rock.

I use either a Fender Vibroverb normal channel (robinette) or a 20W Plexi (Sluckey) when gigging and for hard rocking Marshall tones been stepping on a Runoffgroove Thunderchief Tube-to-Fet conversion pedal. While that pedal has actually served me fairly well for fooling an audience into thinking they hear decent tone emulation for the 70's and 80's hard rock Marshall tones, the pedal obviously doesn't have the level of depth, 3D'ism, dynamics, smoothness and complexity that is very apparent from a good and well done JCM800 cascaded gain stage with cold clipper thing that we hear in those good old wonderful amps. My 20W plexi is great as a clean rhythm channel and pedal platform but isn't the thing to use for the higher gain stuff as is.
I've been hearing some very nice youtube clips of 2204 builds that are definately contenders, one in particular a british fellow that seems to have a 2204 with a classic AC/DC sound, with many switched mods that do various gain or EQ variations for added varieties of tone textures and responses. Perfect.

So, that is my question to all of you out there. If you were an old (64 years old) local classic rocker looking to build a JCM800 2204 amp that at its unmodded starting point did a good AC/DC sound, with a slew of switchable mods, which year/model, schematic would you start with as your basic foundation for mods? My bands play the popular selections of "AC/DC, ZZtop, Toto, Foreigner, Bon Jovi, Van Halen, etc... What would you consider as a ground zero JCM800 2204 starting point model/year for an amp build (with mods)? I guess I imagine the range would be from early AC/DC to 80's era Bon Jovi (seems to be much more gainy than early AC/DC. I picture having a selection of switches that when say, in the down position is the classic unchanged circuit, and each switch bringing in a modification for whatever, gain, eq, cold clipper cathode variations, maybe plate load resistor values, things like that, subtle but useful.

thanks for wading through my long winded post! I want this to be a real good sounding impressive, fun and flexible/useful amp! and I have some Mullard Blackburns and/or Winged C's that can to into it.

Best, and thanks,
Phil D.

I think just a plain 2204 with an FX loop (in fact, make it a series/parallel switchable loop with adjustable level for the parallel setting) should cover most territory. Of course you'll need the odd pedal and effect here and there... and EVH tones are a subject unto themselves. I play covers also from that period and genre, certainly some ZZ Top and the odd AC/DC classic. Stock JCM800 SC20 gets me well in the ballpark, though I'm a heretic and sometimes grab the AC15 for Angus' stuff....
 

Dblgun

Well-Known Member
Joined
Jan 6, 2019
Messages
491
Reaction score
897
Location
AZ
I'm a fan of the earlier circuit, JTM, 1986/7,1959 etc. as were several of the original bands you cover. The JCM800 series are a bit buzzy for me, although somewhere in the middle between the two is about right for my taste.

One option you may consider is a Dirty Shirley or Twin Sister build based on Dave Friedmans amps. I have worked a few and one may be what you're after. They do a pretty solid job of covering everything you mentioned.
 

machinated

Member
Joined
Aug 8, 2019
Messages
42
Reaction score
92
Dirty Shirley is an excellent suggestion - Headfirst do a PCB that can do a couple of channels and you can incorporate your own FX loop and mods for different sounds.
 

pjd3

New Member
Joined
Nov 11, 2019
Messages
16
Reaction score
7
thanks all, am looking into all the suggestions here.

Just to mention, this amp will be built into an old Carvin combo that a friend is giving me. I'm gutting it for this project. Also, I have boards, turrets and turret tools coming from Mojotone so will be using that for the build. I have only done eyelet board builds and have been just really looking forward to doing a turret board build. I know its all just connections but you know, curiosity gets the better of ya some time.

The front panel on this combo is laid out in a dual channel arrangement so, lots of hole to fill in 2 discrete horizontal rows. I figured one row would be for the pots and the other row (above or below) will be for all the fun modification that I decide to impliment in there. I havent thought about an effects loop for this one, at least not for a timebased reverb, I had planned on generating FX externally to the amp either with a "Speaker-to-line" conversion or somekind of speaker mic/transducer to a preamp into effect to another local amp - even perhaps use the normal channel of a Fender amp for generation the timebased stuff when the Marshall 2204 is switched in. I hate playing without reverb - hopeless reverb junkie.

Best,
Phil Donovan
 

dro

Well-Known Member
Joined
Aug 1, 2015
Messages
1,437
Reaction score
2,657
Location
Blue Springs Mo
Not quite as old as you. (61) I know we've shared allot of the same history.
For me I went with the JMP2204 but have also had a 212 combo of the 800.
Never needed an FX loop. Rarely used any effect other than an Echo, and occasional chorus.
Just plug it in and go.
 

Matthews Guitars

Well-Known Member
Joined
Aug 17, 2019
Messages
6,385
Reaction score
10,306
I'd go back a few years and settle in the JMP era, not the JCM800 era. All the classics you mentioned were making those tones in the 70s with JMPs before JCM800s existed.

Granted, some JCM800 amps are the SAME circuit as they were just cosmetic reworks of the existing models (at first) but it had to be said.

In my opinion you'd be better off to build this amp in a Marshall style chassis rather than try to force-fit into a totally different Carvin chassis, because it's easier, and because you'll be working with a chassis layout that is well known and should not contain any mysterious surprises due to part placement interactions that haven't been encountered before.
 

V-man

Well-Known Member
Joined
Jan 25, 2009
Messages
4,590
Reaction score
3,876
AC/DC is MV and NMV JMPs. Either is a winner. If you were building a 2204 out of whole cloth, I would go with the 1979 schematic, which has all the gain issues settled, going forward with the JCM 800 legacy, as well as the VI cap placement, which is allegedly rounder in sound than the HI 2203/4s.

The other thing you may want to find is blackbacks for the Highway to Hell sound.
 

Chris-in-LA

Well-Known Member
Joined
Jul 19, 2018
Messages
3,308
Reaction score
3,418
Location
Los Angeles
AC/DC is MV and NMV JMPs. Either is a winner. If you were building a 2204 out of whole cloth, I would go with the 1979 schematic, which has all the gain issues settled, going forward with the JCM 800 legacy, as well as the VI cap placement, which is allegedly rounder in sound than the HI 2203/4s.

The other thing you may want to find is blackbacks for the Highway to Hell sound.
What is VI and HI?
 

V-man

Well-Known Member
Joined
Jan 25, 2009
Messages
4,590
Reaction score
3,876
vertical inputs JMP-‘84 JCM
Horizontal inputs mid ‘84-1990
 

Latest posts



Top