[marios_mar]

I would also like to know ,
would buying a 2132 be an upgrade or is there no point in buying a 2132 later on? I will be buying a 2604AP because that's the only one available here. Should I later on order a 2132?
What's the optimum voltage for a 2604?
How much does it cost in the US.
Here its about 3 EUROS they said.
thanks

 

[BPRJam]

As long as your voltage is high enough (>12V IMO), I think you will be just as pleased with the 2604 as with the 2132. In other words, keep the voltage high (like 2x9V), and there is no reason to change to a 2132. At digikey the price of the 2604 is 3.50 USD

If you typically power the amp with lower voltages, like 1x9V, then I think you should go with the 2132. I don't think I wouldn't call either one a sound upgrade, but instead there is a difference in performace at a given voltage. You will get a better response from the 2132 at lower voltages

Bottom line: supply voltage >12V, don't replace the 2604. Supply voltage <12V might be worth considering going to the 2132. Listen to it first, though, and see if it would be worth the trouble.

BPRJam