Hi All
Just finished a 801A amp, something I have been planning to do for few years and finally got to it.
Initial impressions - clean tops and mids, and the lows are nice and tight. J&K audio xformers give this tight sound to the lows. I will be installing their nano-crystal 5K o/p transformers in my 811A replacing my James sometime in the next few months.
- Filament supplies for 801A's are Guido Supplies
- Bias supply is using Pete Millet's bias supply boards
- Input and driver tubes are 6EW7 dissimilar dual triodes in one tube perfect for this application
- First stage is cap coupled using Duelunds
- Second stage is 2:1 stepdown Lundhal IT, which should be good for brief A2 transitions
Power transformer is custom Heyboer. Initially I started with 2 X 6AU4's for full wave rectification, messed up in the drilling for the octal openings and opted for using UF4007's for rectification and a single 6AU4 for slow start on
Next amp in line - as of now, the plan is a 2 stage amp using 12GN7 as the gain stage and using mosfet source follower to drive 211 grid.
cheers
ganti
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Topic - 801A amplifier - sganti 11:02:31 04/03/16 (8)
- RE: 801A amplifier - drlowmu 13:23:02 04/16/16 (0)
- RE: 801A amplifier - hifipaul 06:35:16 04/04/16 (0)
- RE: 801A amplifier - Genp 02:50:53 04/04/16 (0)
- RE: 801A amplifier ...........Sweet.. - drummerwill 20:52:51 04/03/16 (2)
- RE: 801A amplifier ...........Sweet.. - GEO 13:20:41 04/04/16 (1)
- RE: 801A amplifier ...........Sweet.. - drummerwill 20:32:20 04/04/16 (0)
- Nice! (nt) - Tre' 19:58:54 04/03/16 (1)
- RE: Nice! (nt) - nicoch 02:05:21 05/02/16 (0)