magic smoke pilot aa903 - Page 2

zobsky · 27th December 2007, 12:10 PM

Quote:

Originally posted by Wavebourn

This b%%^&*t travels from forum to forum, from topic to topic...

What part is B.S.?

SY · 27th December 2007, 12:32 PM

I'm not thrilled with his approach, either. The main issue with the Williamson is LF stability, which is best addressed by coupling caps- if the time constants of the two RC couplings are staggered by 5:1 or more, the LF stability will be much improved. I wouldn't fool with the operating points; they are chosen for best linearity. A properly operating Williamson driver has more than enough capability to drive its output stage to clipping.

The writer is correct about replacing 12AU7 with something more linear.

Changing the cathode bypass cap on the output stage will indeed extend the LF response. The cost is much worse overload recovery. If you're using a small tube amp to reproduce high level deep bass, I don't have much sympathy...

edit: I see that this site touts "high slew rate capacitors." Res ipsa loquitur.

zobsky · 27th December 2007, 12:41 PM

Thanks

27th December 2007, 12:32 PM	#12
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX Blog Entries: 1	I'm not thrilled with his approach, either. The main issue with the Williamson is LF stability, which is best addressed by coupling caps- if the time constants of the two RC couplings are staggered by 5:1 or more, the LF stability will be much improved. I wouldn't fool with the operating points; they are chosen for best linearity. A properly operating Williamson driver has more than enough capability to drive its output stage to clipping. The writer is correct about replacing 12AU7 with something more linear. Changing the cathode bypass cap on the output stage will indeed extend the LF response. The cost is much worse overload recovery. If you're using a small tube amp to reproduce high level deep bass, I don't have much sympathy... edit: I see that this site touts "high slew rate capacitors." Res ipsa loquitur. __________________ “Listening to records is like ****ing a picture of Brigitte Bardot.” - Sergiu Celibidache

27th December 2007, 12:41 PM	#13
zobsky diyAudio Member Join Date: Mar 2002 Location: Dallas, Tx, USA	Thanks __________________ "Any fool can know. The point is to understand" - Albert Einstein

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
Pilot LED for my new car Amplifier	raghs	Car Audio	11	27th March 2009 05:03 PM
Pilot SA 260 bias	baltimoreblues	Tubes / Valves	1	3rd February 2008 06:00 PM
Flame On!: Tragic loss of magic smoke	KBK	Solid State	28	29th October 2006 05:26 PM
pilot 264	jaron	Tubes / Valves	17	13th March 2006 03:32 PM
Magic Smoke (smells bad works good)(long)	Stocker	Chip Amps	0	28th February 2005 11:44 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

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)