Ben vs. JCM800 Roud 2

Ben Harmless · February 11th, 2004, 03:03 PM

Went to the electronics store today. Picked up a 150ohm (20w) resistor to drain the filter caps, and a 68k as well.

Opened up the beast. Drained the caps, snipped out the 470k resistor/cap combo going into the preamp pot. Replaced the pair with the 68k.

It restored my faith. After snipping out the bright cap the other day, and being blown away by the improvement, I must say that now I've got exactly what I thought I had the first time. I now have full use of my treble and presence knobs without getting sliced to pieces by the highs. I can adjust them to suit single coils or humbuckers, and there is a whole range of useful tones now - I'm not stuck with the treble and presence on "0" all the time.

It's not too invasive, and I didn't fiddle with the gain, so I feel like I've still got a mostly stock JCM800, and I'm in love with it.

If anybody sees me about to mod the thing again, stop me. I probably don't really need it.

Marky D. · February 11th, 2004, 08:13 PM

Now I'm curious to try the 68k resistor replacement on my JMP 2204. Which of the 2 mods made the most impact?

Ben Harmless · February 11th, 2004, 09:56 PM

Oh, definantly the second mod (the 68k resistor). It just plain fixed the amp. The treble cap removal helped a bit, and I imagine if someone were only playing darker sounding humbucker guitars, that would have been enough. For me though, the 86k resistor helped immensely. It's been described as the "warmup mod" online, and I think that's an accurate description.

If you like your tone now, neither of these things might be nessicary. I just came to be a little unhappy with the matching of my tone to my taste. They were easy mods, and they're easy to reverse should I want to return to stock form.

Good luck.

halouis · February 11th, 2004, 11:15 PM

Thats awesome Ben! tweaking the rig until you are grinning ear to ear. that makes me happy.

So now, One of these days, i'll have to open her up and just give it a try. its a simple and almost free mod to do and easily reversible.

rockit!!

February 11th, 2004, 03:03 PM	#1 (permalink)
Ben Harmless Friend of Leo's Join Date: Mar 2003 Location: Albany, NY US of A Posts: 3,239 6 Photos	Ben vs. JCM800 Roud 2 Went to the electronics store today. Picked up a 150ohm (20w) resistor to drain the filter caps, and a 68k as well. Opened up the beast. Drained the caps, snipped out the 470k resistor/cap combo going into the preamp pot. Replaced the pair with the 68k. It restored my faith. After snipping out the bright cap the other day, and being blown away by the improvement, I must say that now I've got exactly what I thought I had the first time. I now have full use of my treble and presence knobs without getting sliced to pieces by the highs. I can adjust them to suit single coils or humbuckers, and there is a whole range of useful tones now - I'm not stuck with the treble and presence on "0" all the time. It's not too invasive, and I didn't fiddle with the gain, so I feel like I've still got a mostly stock JCM800, and I'm in love with it. If anybody sees me about to mod the thing again, stop me. I probably don't really need it. __________________ "I think I'll go for the life of sin, followed by the last-minute, presto-change-o, deathbed repentance." - B. Simpson

February 11th, 2004, 08:13 PM	#2 (permalink)
Marky D. Tele-Meister Join Date: Mar 2003 Location: Minneapolis, MN Age: 47 Posts: 314	Good to hear! Now I'm curious to try the 68k resistor replacement on my JMP 2204. Which of the 2 mods made the most impact?

February 11th, 2004, 09:56 PM	#3 (permalink)
Ben Harmless Friend of Leo's Join Date: Mar 2003 Location: Albany, NY US of A Posts: 3,239 6 Photos	Oh, definantly the second mod (the 68k resistor). It just plain fixed the amp. The treble cap removal helped a bit, and I imagine if someone were only playing darker sounding humbucker guitars, that would have been enough. For me though, the 86k resistor helped immensely. It's been described as the "warmup mod" online, and I think that's an accurate description. If you like your tone now, neither of these things might be nessicary. I just came to be a little unhappy with the matching of my tone to my taste. They were easy mods, and they're easy to reverse should I want to return to stock form. Good luck. __________________ "I think I'll go for the life of sin, followed by the last-minute, presto-change-o, deathbed repentance." - B. Simpson

February 11th, 2004, 11:15 PM	#4 (permalink)
halouis Tele-Afflicted Join Date: Mar 2003 Location: Virginia Posts: 1,404 7 Photos	Thats awesome Ben! tweaking the rig until you are grinning ear to ear. that makes me happy. So now, One of these days, i'll have to open her up and just give it a try. its a simple and almost free mod to do and easily reversible. rockit!!