JCM 800 Mod Demo

[hirskdubbi]

too fizzy

[JayPshred]

Not enough gain try again

[MrSandydillon]

that sounds awesome very cool deep

[Guitarbque]

wow - beefy !!

[4711shaun2]

this sounds fantastic PaoloJM.. can you go into more detail re the mods here beyond what you've already given.. like the specific gain increases at various stages in the preamp ? i'm getting a '79 2204 shortly and will try some of these out with it.. thanks.. bye.

[gmuchiutti5150]

Great! Can you give me some details of the mod ? you didn't added an extra preamp tube or another gain stage, right ? thx, bye. (:

[PaoloJM]

@gmuchiutti5150 No, no extra gain stages. Dropped the 10k cathode res on V1b to 5k. Changed the 470k with the 470p across on the pot divider to just a 68k. Changed grid wires to shielded type. There's a resonance mod fitted also.

[and1424]

Hello! Great sounding amp! Wanted to know how many wires you shielded other than stock ones. Just the one to 68k grid resistor ??? Saludos!

[PaoloJM]

@and1424 hi. none of the wires were shielded in the original jcm800s. this is an '81 model. i've used shielded wire for the input to grid one as you suggested.

[luigiperso]

best mod for this is adding a powerbrake :)

well done though

[luisgarciaalanis]

what is the mod to give it more gain?

[PaoloJM]

@luisgarciaalanis

There's a few, in different places through the preamp.

Adding small amounts at each stage is best IMO.

Do you want actual details?

[stingerz1]

Nothing sounds like a Marshall

there sound defines the Rock Guitar

Great Tone

[stingerz1]

Does any one know where to find the

6550 to EL34 conversion instructions

I picked up a 78 JMP that needs a cap

job and has already been converted to

the EL34's i wanted to check to see

if had been done correctly or to European

specks. Great sound event the clean..

Drop D Heavy..

[hotguit]

wow

great tone, very heavy!

[cjgplexi]

You want that thing to sound even better put some sozo caps in it.I did it to my 2204 jcm800 and now its bad ass.

[WARinMYhead1]

great tone!