|Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum|
Please consider donating to help us continue to serve you.
Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
||Thread Tools||Search this Thread|
|16th July 2007, 11:05 PM||#1|
Join Date: Apr 2007
Location: Kingston WA>
TCJ Cathode-Coupled Amplifier
I recently finished up my first tube project (a Bottlehead S.E.X kit)which turned out better than expected and I would like to move forward with a simplified scratch-built project. I thought I'd give John Broskie's "TCJ Cathode-Coupled Amp" a try.
My initial plan is to use Edcor's XPWR104
with a pair of Tung Sol 5687s. Ok so far?
I feel confident that I can safely follow the schematic, but I have a question regarding the heater circuit. JB suggest referencing the heater circuit to +40 V. How do I do this? Does this mean that my heater circuit should be 40V-46.3V (low-hi)
|17th July 2007, 06:28 PM||#3|
Join Date: Oct 2002
Blog Entries: 2
You've got the basic idea. Make a voltage divider between B+ and ground out of two resistors sized so as to draw a milliamp or two and for their junction to have about 40V on it. Bypass the lower one with an appropriate cap to ground (1-100uF).
If you're using DC heaters, attach the (-) end to the junction point at 40V.
You can do something a little trickier which will really suppress common-mode noise and that is to build your heater supply with two regulators, one +3 and one -3. The common point is then the one biased up.
The heaters should be locally bypassed for RF.
"You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is."
|Thread Tools||Search this Thread|
|Thread||Thread Starter||Forum||Replies||Last Post|
|6T9 push pull with Cathode Coupled input||Brit01||Tubes / Valves||5||18th January 2009 12:58 PM|
|Direct-coupled cathode/source follower driver in PP?||ray_moth||Tubes / Valves||83||17th July 2008 03:53 AM|
|cascode vs asymmetrical cathode coupled||oldeurope||Tubes / Valves||47||18th April 2008 05:37 PM|
|Help with a cathode coupled pentode driver?||Svetlana||Tubes / Valves||2||26th July 2006 02:06 PM|
|Cathode-coupled Phase Splitter Formula||MelB||Tubes / Valves||5||14th February 2005 09:51 PM|
|New To Site?||Need Help?|