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.


128x128ramtubes
Question: Tube Phono preamp. Would replacing the 1N4007 diodes (in bridge config) in power supply with HEXFREDs or Schottkys improve it? The bridge feeds a CRC filter which then feeds a tube regulator. Thanks.
Excess headroom is a myth," at least as far as I am concerned.

Best regards,
-- Al
And the same, even more so, goes for preamps, if it's loud enough that's all you need, there is no advantage to have it "able to be louder" if it's loud enough already 

Cheers George 
Hello, RM!  You mentioned the recent measurements of the Cary SLI100.  Reminds me a bit of one a few years back on the 300SEI.

https://www.stereophile.com/content/cary-audio-design-cad-300sei-integrated-amplifier-page-3

That's something of a sort of classic amp with quite a few fans.

Compound question.

Your thoughts on Dennis Had and legacy Cary gear?

Your thoughts on the disparity between the measurements and folks who say things like that in the subjective review?

Thank you.
Roger,
Just wanted to say hello from someone who knew you back in the day when you were at Audio Art in Richmond. I really like the fact that you are sharing your craft and are encouraging dialogue with those who share your passion.
dale grigg
Reminds me a bit of one a few years back on the 300SEI.


Just look at the frequecy response into a quite easy simulated speaker load!! that’s unacceptable, over 5db variation. no power at 200hz and at 4.5khz, nothing below 50hz and above 10khz,  and two peaks at 60hz and 1.5khz
https://www.stereophile.com/images/archivesart/cad300fig1.jpg

Cheers George