jcm800 idea?

[fakiekid]

i've got a jcm 800 combo from the erly 80's, i really like the distortion but if i plug into it i cnt have clean without taking the lead out and plugging it in.

i've tried a/b ing between the lo and hi input but you just loose overall volume. is there a way to make a pedal that could clean it up, like a "clean" pedal instead of a distortion pedal?

ive tried wiring a volume pot into a pedal so that when you turn it on it drops the guitar volume, like when you roll it bck on your guitar. Not werking though!

any ideas other than buying a second amp?

 

[The Golden Boy]

Re: jcm800 idea?

You can do a couple of things.

Volume on the guitar- what kind of guitar are you playing? I use LPs and guitars wired like LPs- I added a treble bleed cap on the neck pickup, when I roll the volume off, it removes bass from the signal, and it cleans up really nice.

The other thing, you're just about there, have an OD pedal with the gain/drive turned all the way down and lower the volume on the pedal.

In either case you're not hitting the preamp with the same signal it takes to overdrive it- so it comes out "clean."

 

[muttonchopsrule]

Re: jcm800 idea?

i guess you could try using an a/b switch into both inputs to achive "channel switching" of sorts, and maybe using some sort of pedal into the lo input to give you a clean boost...maybe a boss GE7 or similar?

 

[idsnowdog]

Re: jcm800 idea?

You could use a A/B switch one path has your distortion pedal to the high sensitivity input, and the other has clean boost pedal like the dod bi-fet preamp to the lower sensitivity input.

 

[fakiekid]

Re: jcm800 idea?

ive tried a/bing the channels, i'm not quite sure what happens, but the volume just drops, like the resistance is being interfeared with.

surely driving the lo side to the same volume would distort it tho?

i play a gibbo lp classic with a custom and a 59 and a mexican strat jb/duckbucker/duckbucker

 

[ErikH]

Re: jcm800 idea?

The low input it just that, low gain. It bypasses a gain stage and yes, there is a little volume loss there.

To get what you want though, I'm afraid another amp is in order unless you set the 800 to as clean as possible and use an overdrive/distortion pedal out front.

Turning the pre-amp volume down some will help clean it up a little more. Just bump up the master volume to compensate.

 

[Rich_S]

Re: jcm800 idea?

You can't A/B the lo and hi inputs on a JCM800. Inserting a plug into the "lo" jack bypasses a gain stage and disconnects the "hi" input from the circuit.

I know where you're coming from - I had the same problem with my JCM800s for years. I suggest using passive means (guitar volume or volume pedal) to go from crunch down to clean (add treble bleed caps to the volume pots if you want to retain brighness). Adjust your high gain input to give a good crunch sound when the guitar volume is maxed out. Then for your highest-gain sound use a clean boost such as the Duncan, a Boss GE-7 (that's my choice) or an overdrive pedal.

Or, you might want to try a compressor to limit your signal for cleans, then switch it out for dirty - that's sort of the Andy Summers approach to the MV Marshall.

 

[fakiekid]

Re: jcm800 idea?

thanks guys it has come to no avail that this can't be done! would be an amazing invention tho!!

 

[Brow]

Re: jcm800 idea?

If you have a look at http://www.projectguitarparts.co.uk/Pages/electronics.htm and scroll down to the 'Solo Master' pedal and have a read on that.

That pedal (or something similar) may do what you're asking.

 

[metal]

Re: jcm800 idea?

sorry to hijack but has enaybody heard the solo part on the new rhcp song ? does a jcm800 can do that creamy singing smooth lead?