my class a preamp

[evilspirit]

An externally hosted image should be here but it was not working when we last tested it.

 

[blu_line]

Nice !
Especially your casing

 

[tcpip]

Aren't all discrete transistor preamps Class A? I thought only (some) opamp-based preamps operate in Class B.

 

[PMA]

Aren't all discrete transistor preamps Class A? I thought only (some) opamp-based preamps operate in Class B.

No, it depends on output stage design, regardless discrete/IC technology.

 

[jan.didden]

[BPre-amp links.....[/B]

Impressive! Very well executed.
Can we have some schematic details...?

Jan Didden

 

[tcpip]

No, it depends on output stage design, regardless discrete/IC technology.

Oh, okay. I was under the impression that anyone making line-level circuits would always build Class A to avoid crossover distortion. I thought crossover distortion (and Class B) was a necessary evil tolerated only in power amps to get high efficiency and power outputs.

Sorry if this is off-topic....

 

[tcpip]

Evilspirit, your preamp looks very classy.

Why do you have that huge heatsink inside a preamp?

 

[evilspirit]

because of the high quietude carrent

 

[Jay]

because of the high quietude carrent

I haven't calculate, and I easily forget, but are you sure 45mA requires such a big heatsink???

 

[evilspirit]

final assembled static currency 130MA per channel

 

[tcpip]

final assembled static currency 130MA per channel

Assuming you are using +/-15V for supply rails, your quiescent current of 0.13A is dissipating 3.9W of power. Is that figure high enough to require such large heatsinks? Given my limited knowledge, I would have used something perhaps one-tenth that size. Not that there's any harm in having a larger heatsink, just asking...