Studio Reference Amplifier

[Dragan100]

IF Zobel NET has HIGH temp, then there are HI-freq oscillations content superponed to audio content,
you must look OUT signals (before Zobel NET OUT) with oscilloscope,
look at 10KHz square wave OUT response, if are there Overshoot, Ringing, Settling time (or oscillations)
Post some response oscillograms here...

 

[Moth flutter fire]

That's how it worked. The setting is smooth and fine. I still ask, will 23mV on the emitter resistors be OK?

How do you change the bias voltage can be adjusted?

 

[Sunny22g]

 

[mira1]

How do you change the bias voltage can be adjusted?

If everything is correct, by turning the trimmer P1, you can observe the 0R33/5W emitter resistors.

 

[Sunny22g]

Hi mira. Set dmm 200 mv. See this trimpot. See the voltage across emiter resistor. Set bias like this.

 

[mira1]

Yes, that's how it should be.

 

[Sunny22g]

Hi
Send u pcb clean picture.

 

[m0rten]

Together with a friend, I want to build one of the higher powered APEX amps. We already have a few decent transformers in the 800-1200VA range which needs to be put to work.

At the moment I have come down to 2 different basic designs in 5 (not so) different amplifiers.

Not having the expertise to immediately say which of these would be the better choice, I ask the experts.

The ones I have in mind are the following_

Non symmetrical input: F250 and SR250
Symmetrical input: HV23/HV25 and HV350.2

I have a few questions:

1 - Is one basic design "better" than the other in these amps?
2 - In each group, which amp is going to perform "best"?
3 - Is there a clear overall favourite? (Which one would Mile recommend?)
4 - What supply voltage range is usable for these amp?

Thanks for any input on this!

🙂 morten