More lows from Marshall JMP 2204?
- Thread starter Searay
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LPMojoGL
Well-known member
I've never had a 2204 that was lacking in the bass dept. 6550s, EL34s, didn't matter. Preamp dialed to the sweet spot, 7.5-9, always had enough low end for me. I have 2 2204s at the moment. Both have plenty of low end, more than the Mesa .50 Caliber Plus and EVH Stealth 50, unless I dial that depth knob up.
Tho, I've never liked a huge bass sound from my guitar amps. I prefer bright n tight, with healthy mids.
I used a Catalinbread Echorec in front of my JMP 2204 to thicken up the tone.
Tho, I've never liked a huge bass sound from my guitar amps. I prefer bright n tight, with healthy mids.
I used a Catalinbread Echorec in front of my JMP 2204 to thicken up the tone.
Since it is stock, have the 3 large caps been replaced? When they get that old the amp can feel loose and lacking bass..Fresh caps may be the easiest update. I also like to change the PI caps from .022 to .047 for a little more bass in the output section, tends to balance that big bright cap...
Fixed depth. Listed to the advice here. I agree that the .0047/220k never does the marshall thing properly but its the default. Its literally 2 parts and 5 min of work and fully reversible that nothing is changed.
Be careful... This started me on the marshall modding never ending hole.
Be careful... This started me on the marshall modding never ending hole.
Speeddemon
Well-known member
Agreed.
My Engl Savage 60 (which does the pissed off Marshall sound quite well...2x EL34, not too bassy) is from the late 90's.
A while ago I started noticing more and more hum coming through, and slightly temperamental behaviour as well.
I replaced the 3 biggest filter caps and the amp was less noisy, and fresher and fuller sounding. Those caps must've dried up pretty well... One of them seemed to be on the verge of bulging out and after replacing it, I tried to re-measure the ESR (internal resistance, the lower the better) value of said cap and it failed. Must've have been a ticking time bomb.
napalmdeath
Well-known member
Try a Hot Mod V2 EVO. Plug and play Mod, with an additional gain stage, & a boost in the lows with the bass switch. It worked wonders for my Runt 50, and I no longer need an EQ in the loop. $220. Best $220 I ever spent. Cured all the shortcomings of the Runt for me. More gain, more harmonics, more low end, more goodness.
https://legendarytones.com/hot-mod-...4-high-gain-plug-in-tube-modification-module/
https://legendarytones.com/hot-mod-...4-high-gain-plug-in-tube-modification-module/
Racerxrated
Well-known member
Caps if old and worn will definitely thin out the sound. If it sounds good but just needs more lows the caps are probably fine unless you see bulging/leaking around the points.
I would try what FB suggests. Def
on 6550s. GEs will change your world.
I would try what FB suggests. Def
on 6550s. GEs will change your world.harddriver
Well-known member
The Fixed depth mod and the regular depth mod with the pot are all viable solutions to what you want. Also the suggestions of 6550's are good an will provide more lowend definition but it you love your EL34's you can try EH 6CA7's which are true beam forming elements tube like an old Sylvania 6ca7 , 6L6 and 6550. Those tubes are more full frequency spectrum tubes whereas the EL34 does have emphasis on mids.
You could try the tubes first but if you already like you EL34's then try the Fixed depth on the NFB circuit, I believe that is what is n the JEL modded Friedman. If the .0047uf is too much bass then try a .0033uf, if still too much then try a .0022uf which will be pushing more low mids to mids the fixed depth mod is easy to install. The depth mod with the pot is also easy to install but you have to have a extra 3/8" hole in the chassis or remove a speaker jack if you don't want to drill in a vintage chassis.
I suggested the Variable Depth mod with the pot because you can set it to you personal liking of turn it all the down if needed. Unless your filter caps are really really in bad shape even new onse won't give oodles of low end it you want quite alot of low end. New filter caps just brings back more definition and tighter lows IMHO.
Look up headfirst amplification JEL mod for Marshall and you can start there with the fixed depth mod. Here's what it sounds like.
You could try the tubes first but if you already like you EL34's then try the Fixed depth on the NFB circuit, I believe that is what is n the JEL modded Friedman. If the .0047uf is too much bass then try a .0033uf, if still too much then try a .0022uf which will be pushing more low mids to mids the fixed depth mod is easy to install. The depth mod with the pot is also easy to install but you have to have a extra 3/8" hole in the chassis or remove a speaker jack if you don't want to drill in a vintage chassis.
I suggested the Variable Depth mod with the pot because you can set it to you personal liking of turn it all the down if needed. Unless your filter caps are really really in bad shape even new onse won't give oodles of low end it you want quite alot of low end. New filter caps just brings back more definition and tighter lows IMHO.
Look up headfirst amplification JEL mod for Marshall and you can start there with the fixed depth mod. Here's what it sounds like.