• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

DIY Dynaco ST70

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
If you have these transformers, you can certainly do it, but don't expect 35W, especially at the frequency extremes. Hammond rates their transformers from 30 Hz to 30 KHz, as I recall, and it will drop off more at 20 Hz. The high end might suffer a little too, as coupling won't be ideal with the 70V secondary taking up winding space. And of course, the feedback compensation components will have to be tweaked with any transformer but an A-470. I'd choose the 1650H or Dynaclone A-470 myself.

On the plus side, if you don't need maximum power, you can run it at a lower voltage and higher current, closer to class A. Most commercial designs have been at the maximum data sheet ratings, because if they were more conservative, a competitor could offer more watts for the same price... We're under no such constraint.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.