In Reply to: Re: 211 slow warm-up??... posted by mgreene on August 18, 2004 at 05:39:30:
Mike -My 211 is based heavily on PAE's design, with a 6C45 choke loaded and driving the 211 thru an oil cap. Output and chokes are from Magnequest.
The power supply is a bit strange design with an ACRO-550 driving 866jr --> 6CG3 --> Swinging choke ---> 15uf vintage oil ---> smoothing choke ---> 30uf vintage oil.
B+ is low for 211's at 825vdc. I tried a few operating points between 600-1000vdc and was pleased with this compromise. 211's are run at 65ma. I've used various 211's but run GE VT4C's 90% of the time.
The only electrolytics are in the lower 250vdc supply for the driver stage and bias supplies. Bias is solid state rectified, driver stage uses a very slow starting Bendix 6106 rectifier, also choke loaded.
The supply preheats the filament for 4 minutes before B+ is applied, and then the 6CG3 slow start the 866jr's in a "Slagle" configuration.
I would bet that the oil caps and choke loaded supply contribute to the lack of any significant sonic changes with warm-up, just my swag. In any case, I don't appreciate any significant improvement after the first 15-20 minutes.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Re: 211 slow warm-up??... - Gary Kaufman 08/18/0413:45:04 08/18/04 (8)
- Re: 211 slow warm-up??... - tubes_down_under 01:14:57 08/19/04 (4)
- Re: 211 slow warm-up??... - Gary Kaufman 06:32:38 08/19/04 (3)
- Re: 211 slow warm-up??... - dave slagle 09:14:06 08/19/04 (2)
- Re: 211 slow warm-up??... - Gary Kaufman 10:44:21 08/19/04 (1)
- Since we are using the -same- 211 circuit... - mrfixit 18:32:33 08/19/04 (0)
- Re: 211 slow warm-up??... - mgreene 14:02:25 08/18/04 (2)
- Re: 211 slow warm-up??... - Gary Kaufman 14:26:28 08/18/04 (1)
- Wondered about that - thanks.. nt - mgreene 06:46:01 08/19/04 (0)