amp upgrade and small fault - drift with ambient temp.

Pulse-R · 2nd May 2006, 09:57 AM

Hi, all
I have a couple of 8 year old pioneer car amps which I use for a fully active system.
they are bipolar output class AB (high biased, class A to around 10W), not bad sounding overall.

I want to do upgrades to make them much nicer, and one has a small problem. the problem is gain changing with ambient temp. by about 0.2dB/degreesC. this screws up my imaging depending on the weather.

the op-amps are NJM2068S. I was looking at either NE5532 or OPA2227/8 and making little boards to suit (the NJM are a 9-pin SIP). any recommendations?

also, I will be by-passing all the built-in eq controls.

is it worthwhile to replace the output transistors, they are 2SC5101 driven by 2SC3421 in the +ve, and 2SA1909 driven by 2SA1358 in the -ve side.

Where in melbourne (australia) can I get blackgate caps? (for the power supply and signal)

any suggestions will be appreciated

2nd May 2006, 09:57 AM	#1
Pulse-R diyAudio Member Join Date: Mar 2005 Location: Melbourne	amp upgrade and small fault - drift with ambient temp. Hi, all I have a couple of 8 year old pioneer car amps which I use for a fully active system. they are bipolar output class AB (high biased, class A to around 10W), not bad sounding overall. I want to do upgrades to make them much nicer, and one has a small problem. the problem is gain changing with ambient temp. by about 0.2dB/degreesC. this screws up my imaging depending on the weather. the op-amps are NJM2068S. I was looking at either NE5532 or OPA2227/8 and making little boards to suit (the NJM are a 9-pin SIP). any recommendations? also, I will be by-passing all the built-in eq controls. is it worthwhile to replace the output transistors, they are 2SC5101 driven by 2SC3421 in the +ve, and 2SA1909 driven by 2SA1358 in the -ve side. Where in melbourne (australia) can I get blackgate caps? (for the power supply and signal) any suggestions will be appreciated __________________ Digital is only on or off

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