2. amps-preamps
  3. 140029-80294

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
tomic601's avatar
tomic601
13,037 posts
 
using a few of your own words, perhaps you did veer into “ tall poppy “ turf a bit...

in my inteactions w very talented engineers over the years - and there have been many , many outside of audio, ego is also an essential design ingredient... there are some speaker people doing a bit more than just buying off the shelf cones...some of them make amplifiers..

” I was about to write that the M7-HPA measures well for an amplifier with zero loop-negative feedback. Actually it measures well period. John Atkinson.....

I think he liked how it sounded also with cone speakers ;-) I think there are several paths the enlightenment....
tomic601's avatar
tomic601
13,037 posts
 
I see I veered away myself...

a ? ( repeated ) have you measured the 240 ?

and on the RM-10 can you talk about 35 WPC vs the class A 25 wpc version w hand wound transformers?

I think either one could drive my 85 DB, 6 Ohm (+/- 3 ) speakers. Loud is 90 db C weighting, slow on the venerable R-Shack analog
most of my listening is done low 80’s....

current amp is a NAIM SS class A/B solod state...it has plenty of grunt.....
pbnaudio's avatar
pbnaudio
1,614 posts
 
ramtubes

Was the preamp you mention above marketed by Beveridge Audio, I searched it and the only preamp that came up was RM1 and RM2 by Beveridge.  I'd be very interested in getting one of them.

Thanks

Peter
PBN Audio
fleschler
2,029 posts
 
Funny that the latest ARC amps I've heard sound greyish, muted dynamics, etc.  My friend has an ARC 75 which is no match for his Classic 60s or my voltage regulated amps.  Worse, his amps, Ref 5 preamp and $10K CD player all have had significant break-downs after only a year or two.  Yuk!

My question remains, I'd like to know what you opinion is of the VAC IQ (continuous autobias) amplifiers. They sounded great wherever I heard them and they appear to be conventional designs well executed. They must have good impedance outputs to make them adaptable to drive many types of speakers like your own amps.
tomic601's avatar
tomic601
13,037 posts
 
i may jinx myself but my REF5se is going on 6K hours.....zero issues...I am on the 3rd 6550 ( a USA made TungSol )
.....
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