|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
69.133.194.66
In Reply to: RE: 1959 Ampex 6973 Monoblocks posted by Michael Samra on April 29, 2010 at 04:10:09
And how does it Sound Michael?
The Mind has No Firewall~ U.S. Army War College.
Follow Ups:
FABULOUSSSSOOOO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
If the power supply waveform isn't pretty,neither is the sound in most cases.
Looking at the schematic and the inside of my chassis, I see the cathode resistor connects to a bias balance circuit. I've seen this before on the Heathkit W-3AM (see attached). This could be nice given that real 6973's are so hard to come by and if they don't match well, this compensates. But then if I did have well matched outputs it might sound better to bypass this network and take the big cathode resistor directly to ground. Any opinions on that?
No
leave the cathode bias balancing circuit in because its a fantastic way to match the tube currents. Look at the actual circuit and you will see by the time you measure the cathode to ground,your resistance will pretty close to just putting in a resistor and this way you can get almost perfect current draw from each tube. We know tubes usually don't stay matched over time and being this is a PP circuit,matching is more critical with the output stage.
If the power supply waveform isn't pretty,neither is the sound in most cases.
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: