OPA 2132 Preamp Schematic?

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Vikki

Well-known member
Joined
Jun 5, 2004
Messages
276
Looking to build a preamp/buffer along the lines of the Sunrise magnetic acoustic pickup buffer box, can anyone guide me to a schematic that may be suitable. I think the sunrise buffer uses a opa 2132.
Regards
Vikki(uk)
 
> Sunrise magnetic acoustic pickup buffer box

http://www.sunrisepickups.com/brochure.html

> I think the sunrise buffer uses a opa 2132.

Unlikely on the face of it.

Sunrise Battery consumption: 150 microamps {0.15mA}

OPA2132 Quiescent Current per amplifier 4.8 mA {so 10mA for the dual}
 
Vikki said:
Looking to build a preamp/buffer along the lines of the Sunrise magnetic acoustic pickup buffer box, can anyone guide me to a schematic that may be suitable. I think the sunrise buffer uses a opa 2132.
Regards
Vikki(uk)
There are several possibilities. A low-current low-noise opamp, a single stage using BJT's, or a single stage using FET's. In the absence of any other info, the jury is open. All these are capable of excellent performance with a  magnetic pickup.
There is no objective justification to the use of 18V instead of 9V.
 
abbey road d enfer said:
There are several possibilities. A low-current low-noise opamp, a single stage using BJT's, or a single stage using FET's. In the absence of any other info, the jury is open. All these are capable of excellent performance with a  magnetic pickup.
:eek:
OK Abbey.  I give up!

I thought I was an expert (maybe inpert??) on minimal amplification but you have me beat.

How do you do an excellent RIAA pickup for magnetic cartridge with a single BJT or FET ??
 
ricardo said:
:eek:
OK Abbey.  I give up!

I thought I was an expert (maybe inpert??) on minimal amplification but you have me beat.

How do you do an excellent RIAA pickup for magnetic cartridge with a single BJT or FET ??
The Sunrise is a magnetic guitar pickup.
 
I've repaired one of these for a friend that was bought directly from the manufacturer maybe a decade ago (that's when he bought it, not when I repaired it). It was built on perfboard and just floating in space wrapped in heatshrink. I am not kidding. The batteries were kind of flopping around, which eventually broke the wire connected to the PCB. I added a power jack, a charge pump, and power filter, and it probably would have been easier to rebuild it. Maybe the build quality improved after that. I hope so.

It was a single op amp stage with a polystyrene input capacitor (which was exposed to the heatshrink! awesome!), aluminum electrolytic output capacitor, and a very tiny gain bump of about 1.5x done with a non-interting stage.

It was really nothing special, either in terms of values, build construction, or sound, so I would imagine that you could take literally any op amp schematic with 1M input impedance and a non-inverting stage and kluge it together. Use a film cap if you decide to heat-shrink it I suppose, unless you like playing capacitance drift roulette.

EDIT: Jason on Madbean recently did a buffer with charge pump layout for someone to use with their bass. He shared it on OshPark and it would probably only be a couple bucks for 3 boards. Here's the surprisingly long thread leading up to it: http://www.madbeanpedals.com/forum/index.php?topic=24739.0
 
Thank you for all the ideas, sorry for the delay but keep getting an error when i try to view the site but it worked o.k. tonight....
Regards
Vikki(uk) :D
 

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