my first and favourite amp is my jcm800 4104 combo. Having bust a lumbar disc I was afraid of carrying it around, but summoned up the courage to bring it to practice last night and it just sounds immense.
Sacriligiously, I was using the Low input with an OD3 for gain so I had a clean option, but I’d love to use the amps High input gain. Problem is the delay and reverb in front really do mush it up.
Wondering if anyone (ahem..
@ICBM ) knew if it’s fairly straight forward to add an effects loop to a 4104? Any idea of a ballpark figure for how much it would cost? Would it destroy the amps value (although it will never be sold barring some sort of financial disaster) and would it cause some sort of collapse of the space/time continuum if I modify my stock g12-65 vertical input 800?
Cheers for any help
Comments
I doubt it will affect the value in any way - it may even increase it, they are not 'valuable' vintage amps and originality is not the be all and end all - especially if you used the Marshall unit, I think. It's not the same as some sort of hack mod with holes drilled in the front etc.
I would think about £100 for fitting including the unit will be in the right ballpark, although I haven't priced the Marshall one. The Tube Town kit is around £30 including shipping.
If you *really* don't want to mod the amp permanently, it would be possible to rewire it so the High input is the only input, and the Low input becomes a send/return point, using a TRS (stereo) jack, but you will then need to have some sort of outboard level-matching box because the signal level will be too high for pedals.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
If you weren’t in sunny Scotland I’d be very gladly putting the work your way - apologies for my southern location.
The only problem with fitting it is that there are four holes - two jacks and two push-buttons - and the two for the buttons have no covering around them so they're going to need to be very cleanly and accurately drilled. Although if you didn't want to do that I think you could preset the two switches to your preferred modes, remove the buttons and just leave them hidden inside.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
I'd recommend the Tubetown loop of the ones mentioned, or the Metroamp loop, both of which use high voltage discreet transistors which won't clip.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
The problem is balancing noise in the loop against headroom. The possible signal swing on a Marshall preamp is huge, depending on where you set the gain/volume, and at the top end it still clips, unless you pad it down so much the loop is then noisy.
At least, in my experience. You can hear it, and some of my customers actually like it! After all, by that point it's just adding some diode-like clipping, as in certain other high gain preamps.
https://www.tube-town.net/ttstore/Kits/Misc-Kits/Kit-Seriel-FX-Loop-LND150::5973.html
Doesn't take long to solder together and only need 4 connections inside the amp, so a pretty easy install. if it is a combo amp you could probably fit the kit sitting vertical with the jacks coming out the bottom of the chassis, so you don't have to drill the rear panel out, usefull if the rear panel is covered in text and you want to keep the amp looking original.
The 2204 and 2203 amps have gone up in value in the last few years, I almost bought one 4 years ago for less than £500 and you can't get them at that price now, the combo version has not done the same though from the ones I have seen.