JLM Opamps in instrument amplifiers

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Jeppe M
Posts: 10
Joined: Sun May 16, 2010 1:53 am

JLM Opamps in instrument amplifiers

Post by Jeppe M »

Hello everyone. I've (almost) completed my first BAD kit with dual JLM 99v opamps and OEP input transformer. So I'm kinda still a n00b.

I'm curently playing bass over an old Musicman HD130 amp which has a solid state preamplifier and tube output amp. The preamp, when driven isn't very musical and sounds a little bad - In my opinion. So... I've read som other boards (http://www.pacair.com/discus/messages/1 ... 1188324124) where other MM owners explained how they changed the opamp in the preamp of the bassamplifier. Does any of you have any experience with useing a JLM 99v as an opamp in an instrument amp? Would'nt the overdrive become more "musical" with better harmonics etc. - more tube like character?

Thanks a bunch.
Jeppe

conleycd
Posts: 31
Joined: Mon Aug 06, 2007 9:26 am

Re: JLM Opamps in instrument amplifiers

Post by conleycd »

For a full complete answer you may need to post a schematic. If your amplifier has a Power Amp In or FX Return you could use this into a BAD (with a DI) and then into the FX return. It would bypass a lot of the existing preamp stage but there would still be some. To me that solution is a lot of over kill.

I think the 99v are described as really clean (in terms of distortion) not colourless but are not like a guitar tube amp.

Again, I think it would make more sense to have the DI to the BAD and take that output to your PA or recording device. Maybe use your existing amp only as a self monitor?

CC

Jeppe M
Posts: 10
Joined: Sun May 16, 2010 1:53 am

Re: JLM Opamps in instrument amplifiers

Post by Jeppe M »

Hey CC.
Thanks for the reply. I'm finishing up my BAD kit this week. I think ill try to use it as a preamp with my bass amp.

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