JCM 800 1959 Master Volume/"One Wire" Mod

This amp has a post phase inverter master volume, master is set to .5 here.
The bright channel is stock and the normal channel has the Randy Rhodes "one wire" mod.
The heaters have been rewired and shielded cable been used to reduce noise.
There are some additional mods to control the gain levels in cascaded mode and keep the bass from going to flabby.
At the moment there's a Tung Sol in V1, EH in V2 and a SovTek in V3, with EH EL34s.
It's recorded using the usual cheapo digicam, still need to get a laptop interface for the SM57

Lemme know whatcha think.

Category:

Music

Tags:

• Marshall
• JCM
• 800
• 1959
• randy
• rhodes
• EL34
• 12AX7
• ECC83
• mod
• gain
• distortion
• Tung
• Sol
• electro
• harmonix
• sovtek
• slash

[1234Sebster]

I know randy rhoads had a cascade mod but i herd he also had it modded for gain to ? and i also herd the amp was originally just a 1959 SLP

so any advice or info on this subject will be much appreciated

[PaoloJM]

@1234Sebster the cascade mod is a mod for gain. i didn't hear that he had additional gain mods, though i may be wrong about that. this amp is a 1959, but it's a JCM800 style shell. There are lots of these around as well as 2203s in JMP style shells.

[erigm]

Sounds great! I know the RR one-wire mod, but what additional mods were done to keep the bass from getting flubby?

[PaoloJM]

Cut the V1a cathode bypass down and installed some grids stoppers directly on the valve socket, this is a PCB model, The helped with the farting and flab on high gain.

[NicoGreenDay95]

I have the same mod, amazing sound, settings pleaseeee ;)

[WyldeMagiK]

Whats the deal, I thought ya had to plug the other end of the jumper in to MIX the two channels...how come no 'UNPLUGGED' cable noise when u plugged that in?

[johnwator]

what changes did you do to control the bass...? i'm going to do this mod to my 1987 and want to try the one wire mod.

[iamjimmy86]

I'm new to figuring out and understanding all these different mods people are doing, but exactly did that boost the gain it sounded like, when you plugged just the one end of jumper cable in?

[EuphorbusBTB]

Nice man!!! RR and the MV ooh lala, or instead of the MV, powerscaling

[DB73093]

Plugging another input boosts the gain? shweeet

[therealozzy1981]

you misspelled RHOADS

[erigm]

Cool, thanks for the tips. I'll give it a try. Usually when I do a one-wire type mod I keep the cathode values the same, but change the coupling cap between first and second stage to 470pf or 1000pf.