JCM-800 Clone Doin' Early Van Halen

[Arch Stanton]

Mods from stock circuit:

50KΩ mid pot
25µF "fat cap" across V2
variac'ed @ 90 VAC
Two 6CA7s pulled

Jalen "FW" pickup
Scumback BM75
SM-57

 

[7 Stringer]

Sounds crazy good man. Very Romeo sounding!!!!!

A Delight to the ears.

I'd do that to my 800!!!!

 

[SpiderWars]

Sounds great! Which Laney is that? Looks like a work in progress from the last pic, what are the two pots going to be for?

 

[Arch Stanton]

Sounds great! Which Laney is that? Looks like a work in progress from the last pic, what are the two pots going to be for?

This amp started life as a 1989 Laney AOR 100 series II

Those two pots are an abandoned PPIMV circuit - which I was experimenting with back in the MetroAmp days (2005 ish).

 

[JackBootedThug]

nice!

 

[Arch Stanton]

 

[mentoneman]

those clips sound great!

 

[Arch Stanton]

those clips sound great!

I love that old amp.

 

[dcburn mk.ii]

Sounds awesome!
Man wish I could pull those riffs off.

 

[Arch Stanton]

Sounds awesome!
Man wish I could pull those riffs off.

Me too.

I should have practiced more before I recorded those yesterday.

 

[SoooRad]

That first clip in particular is quite good! I'm looking at tweaking my GH50L a bit into something a bit more Marshally. I doubt I will actually take the plunge, but its been bouncing around my head a fair bit.

 

[Arch Stanton]

That first clip in particular is quite good! I'm looking at tweaking my GH50L a bit into something a bit more Marshally. I doubt I will actually take the plunge, but its been bouncing around my head a fair bit.

Man, I've torn this amp down and built it up again so many times, I've lost count.

It's had PPIMV, Cerrem mod, Jose clipping diodes, bright cap, fat cap, NFB resistor value changes, one-wire-mod, etc etc

 

[Kapo_Polenton]

This amp started life as a 1989 Laney AOR 100 series II

Those two pots are an abandoned PPIMV circuit - which I was experimenting with back in the MetroAmp days (2005 ish).

I've done similar to my AOR Pro tubes 50 watter. Great tone but with this circuit I find yours a little too wooly sounding and I'd drop that V2 bypass cap to a .68 or 1UF. Did you have the Master up and the preamp dialed back some? That preamp gets a bit too out of control too. It's funny that with all the mods, I also essentially come back to something very close to stock. I also like a 47K NFR vs the razor edges of a 100K though i suppose that leaves some gain on the table.

Are you biasing the amp for the variac or just plug and go? I bet with a little EQ tweak this would get very close to " that" tone.

 

[Arch Stanton]

Are you biasing the amp for the variac or just plug and go? I bet with a little EQ tweak this would get very close to " that" tone.

No, I tried that and I tend to agree with Jim Gaustad.. it sounds better without re-biasing.