2. amps-preamps
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Counterpoint SA-5000 with two monoblocks Threshold SA2e

Hello folks,
With heavy heart today I heard from the Audio Research customer service that Fets for the older SP premaps are no longer available. You could personally use a transistor selection device and measure each Fet out to its specs, but it would cost you and arm and a leg and probably more than AR preamps were now.

Has anyone out there obained a Counterpoint premap and used a Threshold S or SA series power amp and got good results out of it. Any problems by cmbining these two brands?
I am facing output impedance to input impedance problems for the pre and power amp. I assume out there that noone has combined these two brands.
Best,
Stefan
stefanovitch
stefanovitch OP
64 posts
 
Thats the problem. The industry standard Fets are available, but you need to buy certain quantities to created matched sets.
I have found someone who do this too me, but in the case these are also gone, I might consider a SA-5000.
Does anyone out there have matched a SA-5000 with SA/2 monos from Threshold and goten good results out od it.Counterpoints were sometiemes problematic, however, are there any inssues with the low/high input impedances from the pre to the power amp or no problems at all.This is a rare occurence, but I want to make sure it does not happen at all.
johnsonwu
469 posts
 
The SP10 is a full tube preamp the FETs are used for the last-mile regulation of B+ for each triode. You wont have to match them as they are not in parallel. Whoever tells you otherwise just wants to fleece you bad. I recently bought a few of them to repair a friend's unit.
stefanovitch OP
64 posts
 
Those in the PS would not need matching, but those in the main unit yes as the orginal ones with their matched curves are unavailable. Parts from the middle east need to be matched, otherwise you would not borrow or buy it for a friends unit and use those Fets that you may preselect before you put them in.


stefanovitch OP
64 posts
 
What I mean is those type of FETs even not selected with their speficially curves are only used in Audio Research amps. You can buy many of the same type and look for one with the same characteristics or buy a second preamp and repair it, but that is double the costs you woul normally need.

Accroding to shemtaic they don't need to be matched as far as I can see. mhm.
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