Getting the most out of my JMP Superbass

Dewey Finn · 11-05-2009, 01:12 PM

Hi. I have a 79 JMP MKII Superbass that I would like to get a much more aggresive sound out of. It currently has a Master volume mod and a Jumped input mod. I don't care for the jumped input tone as it seems buzzy. I don't think it needs an added pre amp tube but who knows. Are these amps solid state rectified? Would a valve rectifier add more overall balls? I was also thinking of a half power mod as the amp is LOUD and I can't open it up at the gigs we play. Any suggestions would be awesome.

MajorNut1967 · 11-06-2009, 06:00 PM

Quote:

Originally Posted by Dewey Finn

Hi. I have a 79 JMP MKII Superbass that I would like to get a much more aggresive sound out of. It currently has a Master volume mod and a Jumped input mod. I don't care for the jumped input tone as it seems buzzy. I don't think it needs an added pre amp tube but who knows. Are these amps solid state rectified? Would a valve rectifier add more overall balls? I was also thinking of a half power mod as the amp is LOUD and I can't open it up at the gigs we play. Any suggestions would be awesome.

Well you couldn't install a Valve Rect. in that amp without changing the Power trans. You need a AC output for the Rect. tube! The are ways around it but its a bit off work and you will need a separate filament trans. with a center tap.

Wilder Amplification · 11-06-2009, 07:04 PM

On top of that you would need two rectifier valves on a 100 watt head because a single one can't handle the electrical current demand of a 100 watt head (100 watt heads require at least double the current of a 50 watt), so you'd have to parallel two of them so that each rec valve is passing only 1/2 the current. Throw in the fact that the heater/filament of 1 5AR4 rec valve draws about 2 amps, you'd need a seperate 5VAC @ 4 amps transformer just to run the heaters/filaments of two rec valves.

On top of that, rec valves will cause the amp to "sag", i.e. lose low end tightness and cause the amp to sound/feel "looser" than it currently does. You're much better off staying with the SS rectifier.

Now, the first thing I'd do for a more aggressive tone would be to convert the amp from Super Bass spec to Super Lead spec, which just involves changing out some component values as well as adding a couple of treble bypass caps that the SLs had that the SBs did not. This will give you much better clarity and brightness than the SB spec will.

Dewey Finn · 11-07-2009, 03:53 PM

Thanks for the feedback. I would really like to get the amp to sound like a Langener modded plexi. I want it to clean up when the volume on the guitar is rolled back too. Not too much to ask for is it?

Wilder Amplification · 11-07-2009, 03:57 PM

Quote:

Originally Posted by Dewey Finn

Thanks for the feedback. I would really like to get the amp to sound like a Langener modded plexi. I want it to clean up when the volume on the guitar is rolled back too. Not too much to ask for is it?

I offer the exact mod you're talking about. Check out my website and gimme a call.

Dewey Finn · 11-08-2009, 08:16 PM

Cool. Where are you located?

American Viking · 11-08-2009, 09:16 PM

Quote:

Originally Posted by Dewey Finn

Would a valve rectifier add more overall balls?

the amp is LOUD and I can't open it up at the gigs we play.

A half power mod is going to castrate your balls rather than beef them up. I wouldn't worry about a tube rec. Louder is better, get some different gigs and turn it up.

olalaolele · 11-08-2009, 10:38 PM

On top of that, rec valves will cause the amp to "sag", i.e. lose low end tightness and cause the amp to sound/feel "looser" than it currently does. You're much better off staying with the SS rectifier.

Wilder Amplification · 11-08-2009, 11:16 PM

Quote:

Originally Posted by Dewey Finn

Cool. Where are you located?

We're in Rohnert Park California. You can find our contact info here -

http://www.wilderamplification.com/contact

11-05-2009, 01:12 PM	#1 (permalink)
Dewey Finn Junior Member Join Date: Oct 2009 Posts: 10	Getting the most out of my JMP Superbass Hi. I have a 79 JMP MKII Superbass that I would like to get a much more aggresive sound out of. It currently has a Master volume mod and a Jumped input mod. I don't care for the jumped input tone as it seems buzzy. I don't think it needs an added pre amp tube but who knows. Are these amps solid state rectified? Would a valve rectifier add more overall balls? I was also thinking of a half power mod as the amp is LOUD and I can't open it up at the gigs we play. Any suggestions would be awesome.

11-07-2009, 03:53 PM	#4 (permalink)
Dewey Finn Junior Member Join Date: Oct 2009 Posts: 10	Re: Getting the most out of my JMP Superbass Thanks for the feedback. I would really like to get the amp to sound like a Langener modded plexi. I want it to clean up when the volume on the guitar is rolled back too. Not too much to ask for is it?

11-08-2009, 08:16 PM	#6 (permalink)
Dewey Finn Junior Member Join Date: Oct 2009 Posts: 10	Re: Getting the most out of my JMP Superbass Cool. Where are you located?

11-08-2009, 10:38 PM	#8 (permalink)
olalaolele Junior Member Join Date: Nov 2009 Posts: 1	Re: Getting the most out of my JMP Superbass On top of that, rec valves will cause the amp to "sag", i.e. lose low end tightness and cause the amp to sound/feel "looser" than it currently does. You're much better off staying with the SS rectifier. __________________ Meilleur taux prets personnels \| Simulation calcul prets personnels en ligne \| taux prets personnels

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