RE: adding a CCS to the 6SN7 LTP is a better first step....

Posted by Jim Doyle (A) on December 24, 2010 at 14:36:33

In Reply to: adding a CCS to the 6SN7 LTP is a better first step.... posted by Jim Doyle on December 22, 2010 at 16:21:27:

Awesomeness. When you get Kevin's CCS kit - keep this in mind - those
MOSFETs are VERY EASY to fry from static electricity - especially this
time of year. Full grounding protocols in place, otherwise you will be
ordering extra MOSFETs. In fact, when I ordered mine, I bought extra
MOSFETs from Kevin and then actually NEEDED to draw on the spares!

Looking at the HF87 Schematic I have handy.... Your CCS will replace
R11. Since that phase splitter is DIRECT COUPLED to the gain-stage and feedback summing stage, your CCS is GOING TO NEED a heatsink! Be careful
with the heatsink - because the back of the MOSFET and it's tab will be
at 125V DC potential - it's likely to zap you, or short out - if not mounted properly.

Nice amp... Love the direct coupled driver. Look's abit to sensitive though - googling for it claims 0.3V input sensitivity for full power. That's abit too much for modern 2V sources like a CD player. You could knock it down abit with a 12AT7 or such - and once you have an adjustable CCS it will be MUCH EASIER to try out different drivers.

-- Jim

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Follow Ups Full Thread

Topic - Requirements for an interstage transformer - DAK 15:53:10 12/20/10 (17)

RE: For HF-87 stick with Long Tail PS - JKT 16:03:40 01/25/11 (0)

RE: Requirements for an interstage transformer - Stuben 18:05:25 12/26/10 (1)

RE: Requirements for an interstage transformer - DAK 09:02:06 12/27/10 (0)

adding a CCS to the 6SN7 LTP is a better first step.... - Jim Doyle 16:21:27 12/22/10 (4)

RE: adding a CCS to the 6SN7 LTP is a better first step.... - Jim Doyle 12/24/1014:36:33 12/24/10 (0)

RE: adding a CCS to the 6SN7 LTP is a better first step.... - DAK 18:18:57 12/22/10 (2)

RE: adding a CCS to the 6SN7 LTP is a better first step.... - DAK 01:24:11 12/24/10 (1)

RE: adding a CCS to the 6SN7 LTP is a better first step.... - Stuben 18:15:26 12/26/10 (0)

Requirements for an interstage transformer - Interstage Tranny 18:26:25 12/20/10 (8)

RE: Requirements for an interstage transformer - DAK 19:24:39 12/20/10 (7)

RE: Requirements for an interstage transformer - Palustris 08:28:51 12/21/10 (6)

RE: Requirements for an interstage transformer - DAK 13:58:02 12/21/10 (5)

Simplest Use of interstage transformer @ HF-87 - Interstage Tranny 15:13:42 12/21/10 (4)

RE: Simplest Use of interstage transformer @ HF-87 - DAK 16:52:55 12/22/10 (0)

RE: Simplest Use of interstage transformer @ HF-87 - Palustris 17:48:35 12/21/10 (2)

RE: Simplest Use of interstage transformer @ HF-87 - DAK 16:49:59 12/22/10 (1)

RE: Simplest Use of interstage transformer @ HF-87 - Palustris 18:29:17 12/22/10 (0)

Follow Ups

RE: adding a CCS to the 6SN7 LTP is a better first step.... - Jim Doyle 12/24/1014:36:33 12/24/10 (0)

RE: adding a CCS to the 6SN7 LTP is a better first step....

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