Both preamp and power amp have volume controls. Preferred method to control volume levels?

Very volume control is a resistive device.  the good ones are a resistive ladder. the poor ones are a sliding resistor.  It is best to get the sliding resistor out of the circuit.

I have a great preamp so I use it for volume control and turn the amp to full up (which is how an amp is made that doesn't have volume control).

Also, most sliding contact controls have a good metal to metal contact at the full up position so at full up you should get the best contact.

If you are planning to keep the amp and the preamp is excellent, then I would have a technician take the amp volume control out of the circuit.

OTOH, there are people that swear they have a position on the amp that they like best.

Jerry

You could always try both ways and see if one sounds better than the other. As Jerry states above it's usually best to use your better volume control for controlling volume.

The designer and builder of the Whammerdyne line is a friend of mine and I forwarded your question to him. See his answer below:

- Always run the volume control full open on the Whamm amp and use the volume on the pre-amp as the master volume control. This is the best impedance match as the set up. It’s the correct load that way with volume control on the amp full open.

Thank you all! Very helpful.

the more front the more good ,,, because less signall have to be anetauated  ,, most hig end guru advice that too on most seminar  so it must be correct,,,anyone can solve my problem of trasiator can come here https://youtube.com/shorts/zRakw_KIfWI?feature=share thanks!

Treat the power amp as a "rough tune" and the preamp as a "fine tune." Start with power 9-11 o'clock with pre zeroed out. Turn slowly and see what happens.