View Full Version : Alan Kimmel Link

07-25-2006, 09:18 PM
It's no secret that I consider Alan Kimmel, currently working with Grommes to design the rebirth of their hi-fi heritage, to be the greatest designer of tube amps currently working. His PHI-26 is the best sounding amp I have ever heard.

I am posting the link to his informal paper on MU Stage design for anyone interested in tube or MOS-FET amp topology. I can tell you that his execution of these ideas has made me a believer, and what I most believe in is what works the best.

The typing is a little rough in places, but the paper is easy to understand if you have studied tube characteristics informally. You might want to save this rather than just bookmark it if you have any interest. This has been a hard to find paper in the past.

Clark in Peoria

09-09-2006, 11:00 PM
Here is a link to a page in the ModWright site. This company has introduced its first built from scratch product, a tube line stage preamplifier. Alan helped out with the gain stage; the company previously comitted to use his design philosophy and went straight to the horse's mouth.

Alan's Mu Stage design ideas have raised tube amplification to a new level. The use of complex circuits and many super expensive components are no longer necessary to overcome design shortcomings, so the price of high end plunges to a new low. Note in the reviews:

The SWL 9.0SE ($2,200) earned the Blue Note best of 2005 Award, alongside the Wavac PR-T1 Line preamplifier ($30,000) and the Lamm Industries L2 Reference Preamplifer ($14,790), in the preamp category.

Also note that several reviewers issued the ultimate compliment; they purchased the review units!


My $995 Grommes PHI-26 amp sounds like ten times the price, at least. Highly recommended. Its component and build quality levels are equal to the design quality, superb, so you can't lose.

I wonder if Nelson Pass has read Alan's article. Alan covers using MOS-FET's instead of pentodes; his hybrid design (triode voltage gain stage to MOS-FET current amplification stage, see article http://www7.taosnet.com/f10/mustage.html) looks like a sensational idea.

Clark in Peoria

Ian Mackenzie
09-10-2006, 02:51 AM
I don't know but I will refer Nelson Pass to the link.