mono vs. stereo

[schmalex]

Hi - a novice question -

Can you someone briefly explain to me the benefits, if any, of 2 mono GC amps versus 1 stereo GC amp? I can speculate about possible answers, but I can’t seem to find any concise answers to this. I want to build my 1st GC amp and I’m trying to decide on a kit. It is certainly less expensive to build the stereo amp – one power supply, which is probably my primary goal. But, I must say the word “monoblock” has a certain audiophile allure (like tubes). Does this have any validity?

To stem any questions about my purpose or intent: I don’t aspire to multi-channel home theatre, only stereo music; I listen to Cds and LPS – mostly jazz and indy rock – and not real loud; and I have diy seas 27tffc/L15 monitors and a powered sub.

Thanks

[macboy]

...It is certainly less expensive to build the stereo amp – one power supply...

That is the key benefit of two monoblocks vs. one stereo amp - one power supply per channel, vs. a shared power supply. This improves the channel separation, due to the fact that each amp does not affect the power supply of the other. The power supply capacitors get charged only 120 times per second (100 in europe), so as the amplifier draws current from the power supply between each charging, the power supply voltage drops. The amount or rate of drop is inversely proportional to the amount of capacitance in the power supply. Since any amplifier has a finite PSRR (Power supply rejection ratio), any variation in the power supplies will show up (attenuated by the PSRR) in the output. Although the bleedthrough is very very small, it is also very real.