AUDIOLAB 8000A Modification

Dear WINDWSS,

I recently bought a 2nd hand 8000s.

I found the op-amp is a 2134...

Can I replace it with a better op-amp like LM4562 ?

In 8000s, which part does the op-amp used for ?
Pre-amp ? Amplification stage for the power output ?

Please advise ....

Finally I have changed the 2134a op-amp to LM4562... for my 8000s

Also I have changed 2x134a op-amp to LME49710... for my 8000p

This is my bi-amp set-up....

->8000s->High frequency->Speaker
->8000s->8000p->Low frequency->Speaker



Both op-amp is from national semiconductor, they have similar audio characteristics....

http://www.national.com/pf/LM/LM4562.html
http://www.national.com/pf/LM/LME49710.html

I also have a 8000s+8000p...

It is possible to configure it to by-pass or not by-pass...

For my configuration I had a active crossover in between S and P, but it works the same way.

There are 2 pre-outs on 8000s, normally you connect it to 8000p.
Now you connect one pair of pre-outs to tape1in. (assume you don't use those )
Connect tape1 out to 8000p.

Connect tape2 out to 8000s's power amp in...

Now when you want to bi-amp but not av-by-passing, select the record mode to tape1.
(assume input is from CD ), input mode to CD.  So source will go through pre-out -> tape1 in->tape1 out->8000p.  Signal is pre-amplified before going to 8000p.

When you want to bi-amp and av-by-pass, select mode to pre power-av, source should be tape2 in, select record mode to tape2.  Now tape2 will go directly to power amp-in and be amplified. tape1 out will go to 8000p by-passed..

Be carefull when you are switching the modes, since some combinations of the modes are connecting your source being directly amplified...