Another 6L6 schematic - Page 3

Wavebourn · 6th January 2007, 05:29 AM

Over years of experimenting with economical tube power amps I come finally to the solution used, as I found, long time ago by Altec Lansing in their 1569A amp. The wheel is reinvented... You are welcome to reinvent it again!

ray_moth · 6th January 2007, 06:37 AM

I'm sorry, I just wondered if 12AT7 might sound better than 12AU7 in that position. I would think it probably should.

Salas · 6th January 2007, 11:02 AM

I have used E80CC instead of 12AU7, and 12AT7. Each time the open loop gain goes up as a result, the spare feedback over-tightens the sound. I reverted back to 12AU7. But maybe it will sound better with 12AT7 when I will use bigger woofers.

Salas · 6th January 2007, 12:52 PM

Quote:

Originally posted by Wavebourn
Over years of experimenting with economical tube power amps I come finally to the solution used, as I found, long time ago by Altec Lansing in their 1569A amp. The wheel is reinvented... You are welcome to reinvent it again!

I am happy that my amp looks like a classic good scheme. Any Ideas of how can I make it perform even better? Modifications suggested?

Wavebourn · 6th January 2007, 06:32 PM

Quote:

Originally posted by salas

I am happy that my amp looks like a classic good scheme. Any Ideas of how can I make it perform even better? Modifications suggested?

Yes. A phase splitter with separate anode and cathode loads between input amp and a differential cascade for better symmetry, all directly coupled. If you go with push-pull for power economy, go to the logical end instead of stopping on half-measures. It is my suggestion. However, the result will be again classical, but you come to it going by your own way.

Salas · 6th January 2007, 07:02 PM

Thanks. Do you have a link to such a classic schematic so I can study it?

Wavebourn · 6th January 2007, 07:41 PM

Quote:

Originally posted by salas
Thanks. Do you have a link to such a classic schematic so I can study it?

Try: http://www.google.com

Good luck!

Edit: I've found it for you: http://www.one-electron.com/FC_ProAudio.html

jean-paul · 6th January 2007, 08:18 PM

Quote:

Originally posted by Wavebourn

Try: http://www.google.com

Do not advertise your secret membership of this community too much; other mortals might want to find things themselves otherwise

Salas · 6th January 2007, 09:59 PM

Thanks again.

sorenj07 · 6th January 2007, 10:50 PM

Well, here's the latest schematic. Mostly plagiarized from the Williamson, but I didn't like the biasing scheme for the outputs so I substituted my own. I figure tubes should draw around 45-50mA each. My only concern was leaving out the pot between the two 220K resistors after the .47uF coupling caps - is one needed?

EDIT: Once again, the OPT is the 6600-8 a-a 60W Edcor.

6th January 2007, 05:29 AM	#21
Wavebourn diyAudio Member Join Date: Sep 2006 Location: Pleasant Hill, CA	Over years of experimenting with economical tube power amps I come finally to the solution used, as I found, long time ago by Altec Lansing in their 1569A amp. The wheel is reinvented... You are welcome to reinvent it again! __________________ If I disappear suddenly, that means I finally created a time machine and pushed wrong button that brought me to Stalin's Russia. In any experiment any result is the result. Even if it is negative.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
looking for a pre-amp schematic	steamPunk	Tubes / Valves	3	3rd August 2008 01:49 PM
DBX 500 schematic	d3imlay	Solid State	0	2nd August 2008 05:12 PM
F3 schematic	kenev	Pass Labs	2	24th January 2008 03:24 PM
Need Six-pac amp schematic	Sarge	Tubes / Valves	1	31st July 2004 08:30 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	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

6th January 2007, 06:37 AM	#22
ray_moth diyAudio Moderator Emeritus Join Date: Jan 2004 Location: Jakarta	I'm sorry, I just wondered if 12AT7 might sound better than 12AU7 in that position. I would think it probably should.

6th January 2007, 11:02 AM	#23
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	I have used E80CC instead of 12AU7, and 12AT7. Each time the open loop gain goes up as a result, the spare feedback over-tightens the sound. I reverted back to 12AU7. But maybe it will sound better with 12AT7 when I will use bigger woofers.

6th January 2007, 07:02 PM	#26
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	Thanks. Do you have a link to such a classic schematic so I can study it?

6th January 2007, 09:59 PM	#29
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	Thanks again.

6th January 2007, 10:50 PM	#30
sorenj07 diyAudio Member Join Date: May 2006	Well, here's the latest schematic. Mostly plagiarized from the Williamson, but I didn't like the biasing scheme for the outputs so I substituted my own. I figure tubes should draw around 45-50mA each. My only concern was leaving out the pot between the two 220K resistors after the .47uF coupling caps - is one needed? EDIT: Once again, the OPT is the 6600-8 a-a 60W Edcor.