|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
|
|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
In Reply to: Will direct coupling shorting tube life?? posted by bouncy ball on May 20, 2012 at 19:04:57:
Many questions,
Is 425 VDC the highest voltage in the circuit?? What is the VDC (B+) that feeds the output transformer?
What does the 2A3 plate dissipate as your amp is configured??
What is the VDC after the output transformer, on the plate of the 2A3, at the tube socket?
What is the VDC on the grid of the 2A3, at the tube socket?
What is the VDC on the filament of the 2A3, at the tube socket, and what is the Ohmic value of your self bias cathode resistor for the 2A3?
Do you use solid state or tube rectification?? What type?
Solid state will require some design work to cope with "instant on".
Do you use any thermistor to reduce turn-on surges?
NOTE : I am familiar with DC 2A3 amps that give tens of thousands of hours of good use to 2A3s, and it is safe to run up to 480 VDC on the plate (maximum) of a VINTAGE 2A3, and, up to 510 VDC on the plate of a JJ 2A3-40, without arc-over on turn on, using conservative current draw (41 to 43 mA.) and about 245 VDC P-K. Define yours !!
What is your driver tube, and its op points?? Do you have a schematic with operating voltages you can share??
How sure are you that you were measuring the output tubes properly and uniformly both times??
Jeff Medwin
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Specific Information is needed ......Define circuit - drlowmu 06:22:40 05/21/12 (4)
- yes, your are right - bouncy ball 18:42:30 05/21/12 (2)
- More hints on Dc amp optimization..... - drlowmu 22:09:25 05/21/12 (1)
- thank you so much. Once I have "de-bugged" everything, will try the operation point that u suggest (nt) - bouncy ball 07:25:32 05/22/12 (0)
- RE: Good Stuff Jeff. - griboon 17:19:00 05/21/12 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
