RE: KT66 versus 6L6GC

Posted by elflow (A) on March 2, 2010 at 08:23:22

In Reply to: RE: KT66 versus 6L6GC posted by Jim McShane on March 1, 2010 at 07:20:54:

Hi Jim,

Can you help me understand one aspect of the power supply of the HF 87/89 amps. The 50 ohm 10 watt resistor, in my book it should not be there. Did the Eico engineers decide to lower the B+ prior to the release of the amp, or was there some other snafu that resulted in too high B+ voltage? I realize the resistor is a natural place to put a choke, but I am sure Eico engineers were not thinking of us 50 years later, and no other Eico amp ever had a choke, so chokes must have been above Eico's price point. Or have I totally missed something??
As an aside, I have a HF 87 that even after rebuilding the PS with a Citation II style rebuild, I still did not like the amp. Since ther PT had the bias tap I copied the HF 89 circuit. Wow! It was a night and day difference. The before performed below a stock Dyna ST 70, after
it can best the stock Dyna in every way.

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Follow Ups Full Thread

Topic - Eico hf87 running various tubes. - Michael Samra 03:41:36 02/28/10 (20)

Compare to HF35 or HF20 conversion? - Mossback 04:07:15 03/1/10 (1)

RE: Compare to HF35 or HF20 conversion? - Michael Samra 05:13:11 03/2/10 (0)

RE: Eico hf87 running various tubes. - diamondsouled 12:49:40 02/28/10 (17)

RE: Eico hf87 running various tubes. - Michael Samra 17:16:17 02/28/10 (16)

KT66 versus 6L6GC - FenderLover 22:24:08 02/28/10 (15)

RE: KT66 versus 6L6GC - Michael Samra 02:50:47 03/1/10 (14)

RE: KT66 versus 6L6GC - Mossback 04:02:26 03/1/10 (13)

RE: KT66 versus 6L6GC - Jim McShane 07:20:54 03/1/10 (12)

RE: KT66 versus 6L6GC - elflow 03/2/1008:23:22 03/2/10 (4)

RE: KT66 versus 6L6GC - Jim McShane 11:11:19 03/2/10 (3)

RE: KT66 versus 6L6GC - DJL 13:25:51 03/2/10 (2)

RE: KT66 versus 6L6GC - Michael Samra 21:55:15 03/2/10 (1)

RE: KT66 versus 6L6GC - DJL 08:02:36 03/3/10 (0)

Thanks... - Mossback 00:38:40 03/2/10 (0)

Looks like it's time... - Rick B 20:43:10 03/1/10 (0)

RE: KT66 versus 6L6GC - kenster 16:19:24 03/1/10 (4)

RE: KT66 versus 6L6GC - Jim McShane 18:20:04 03/1/10 (3)

RE: KT66 versus 6L6GC - kenster 21:29:23 03/2/10 (2)

RE: KT66 versus 6L6GC - Jim McShane 06:47:23 03/3/10 (1)

RE: KT66 versus 6L6GC - kenster 07:55:44 03/4/10 (0)

Follow Ups

RE: KT66 versus 6L6GC - elflow 03/2/1008:23:22 03/2/10 (4)

RE: KT66 versus 6L6GC - Jim McShane 11:11:19 03/2/10 (3)

RE: KT66 versus 6L6GC - DJL 13:25:51 03/2/10 (2)

RE: KT66 versus 6L6GC - Michael Samra 21:55:15 03/2/10 (1)

RE: KT66 versus 6L6GC - DJL 08:02:36 03/3/10 (0)

RE: KT66 versus 6L6GC

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