diytube.com

Posted: **Thu Nov 03, 2011 9:47 pm**

I'm gathering parts for a 6550 Clementine , and have on hand two Hammond output transformers 1627SE trans that are 2.5 k ohm 30 watts , 16,8 and 4 ohms out with an ultra linear winding , a peerless power transformer with HV winding 425-375-0-375-425 , 5volt 4 amp 6.3V at 5 amps ,2.5 volt 5 amp. I believe i will use two 5V4 for rectifiers and two chokes 7 Henries 140ohm at 130 Ma to ha a PS for each channel
What type of changes will i have to make to the board if the B+ is about 500 volts or so to the 6550's .

Mark

Posted: **Fri Nov 04, 2011 2:45 am**

I also have a Paeco transformer thats 289 VAC that would be about 408 DC out at 200 ma with a fullwave bridge , and it has a second winding 207 VAC that would be 292 DC at 125 ma with a full wave bridge , and four 6.3 volt windings . If thse voltages would work out beter

Posted: **Fri Nov 04, 2011 3:43 am**

You want to run it UL?

What's wrong with the 500V B+?

Cheers!

Posted: **Fri Nov 04, 2011 5:06 am**

I would use the 500V snap-in caps that Ed and I were discussing the other day. You might be able to score some surplus or on eBay, but Mouser has them: LINK. Max diameter you can use on the Clementine is 25mm. Height is whatever your enclosure limits (31mm for a 2" box). Definitely use a CL90 on the primary, too.

Obviously the 2.5K outputs are a bit low, but I imagine you'll use the 4 ohm tap for an 8 ohm load? Also note the limited gain you'll have with 6dB of feedback if you go UL (like the Clem ULtra notes), so make sure you have a good preamp or line stage for it. Otherwise you can just triode strap.

Shannon