Does anyone care to ask an amplifier designer a technical question? My door is open.


I closed the cable and fuse thread because the trolls were making a mess of things. I hope they dont find me here.

I design Tube and Solid State power amps and preamps for Music Reference. I have a degree in Electrical Engineering, have trained my ears keenly to hear frequency response differences, distortion and pretty good at guessing SPL. Ive spent 40 years doing that as a tech, store owner, and designer.
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Perhaps someone would like to ask a question about how one designs a successfull amplifier? What determines damping factor and what damping factor does besides damping the woofer. There is an entirely different, I feel better way to look at damping and call it Regulation , which is 1/damping.

I like to tell true stories of my experience with others in this industry.

I have started a school which you can visit at http://berkeleyhifischool.com/ There you can see some of my presentations.

On YouTube go to the Music Reference channel to see how to design and build your own tube linestage. The series has over 200,000 views. You have to hit the video tab to see all.

I am not here to advertise for MR. Soon I will be making and posting more videos on YouTube. I don’t make any money off the videos, I just want to share knowledge and I hope others will share knowledge. Asking a good question is actually a display of your knowledge because you know enough to formulate a decent question.

Starting in January I plan to make these videos and post them on the HiFi school site and hosted on a new YouTube channel belonging to the school.


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Well, it turns out that it was my friend Ralph (we have never met, I simply call him my friend) who misspelled Charley's name.  
He did the measurements of our old M-60 kit for Glass Audio. I met him and hung out back when he was still Avalon Loudspeakers. Different world... nice guy. He is missed.
In a separate post your "intake guy" Clio-something really gave me the business about being a troll and not having anything technical to add.

Actually, I said you bring zero value. The statement wasn't referring to just technical value. Perhaps you got confused with the other part of the paragraph where I said you lack the knowledge or credibility to refute anything Roger says. I was in fact referring to your lack of technical knowledge in that instance, but of course you already copped to that previously.
@ramtubes. 

You mentioned, that in the RM 9, two KT120 or KT150 output tubes could be substituted for four EL34s in each channel. Is there an advantage to using fewer higher output tubes as opposed to using double the number of lower output power tubes, or vice versa? In other words, is the former following a “simpler” path than the latter?
@atmasphere. 

Great comment (on hearing)! I believe our hearing mechanism is somewhat of a “moving target”, so to speak. I’ve wondered why sometimes music through my system sounds great to me, and other times, not as good. Even when playing the same recordings at the same volume. The disparity is occasionally such that I think something is “broken”. Fortunately it sounds good much more frequently than it does not. 
I have for years heard accusations from audiophiles about TAS and now Stereophile requiring advertising from any company wanting one of their products reviewed. I have never seen any proof of that, and have to point of that though I have never seen an ad from Music Reference in Stereophile, a review of the RM-200 by Michael Fremer has twice appeared in the mag; once of the original version, a second of the Mk.2. That the Arma-Sphere M60 and/or MP-3 have not been reviewed is ridiculous. They review all kinds of over-priced status symbols, why not some high-value mid-priced pieces (the stuff most of us are interested in owning)?