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
Atmaspheres:

I have 6,000 LPs. A lot of them have a good bottom, some have an excellent bottom. 

I love the Theodorakis performance, but alas it’s like listening through cotton.

Let’s see what it sounds like in my new room. I’ll let you know. 

M


Thanks a lot Roger for your kind explanation why Tube SET amplifier sounds good.

I had used only 4 tube amplifiers in my life.

Jadis 500 made in France

Silbatone 300B SET made in Korea

Rogue Cronus Magnum II made in USA

Line Magnetic 508 SET made in China

I really like the sound of SET over PP.


You can see my audio history in the below link.

https://forum.audiogon.com/discussions/the-most-musical-sound-in-my-40-year-s-audio-history

Thanks again for your kind advice

Thomas
Hello Roger

I have one more question to you.

I used to let my Silbatone 300B SET turn on for 3, 4 hours.

But I started hearing sum hum out of it.

Thus I had to replace key capacitors in it.



After that incident, I never let my tube amplifier on more than 1 and half hour.

I cool the amplifier for at least 15 minutes before turning it again.


Will this help to extend the life of capacitors in it?

thanks in advance

Thomas

@krelldreams, though you asked Roger for a recommendation of a low-powered tube amp for use with Maggies, I hope he doesn’t mind if I chime in on the question. As a long-time Maggie owner (my first bought in 1973, the original Tympani T-I; I now own Tympani T-IVa’s), I can assure you a typical low-powered tube amp is about the worst kind you can partner with a Maggie. But what do you consider a "lower" powered tube amp? Under a hundred watts? Under 50? Maggies are very insensitive speakers, and benefit from a "higher"-powered amp. Another factor working against tube amps with Maggies is that the speaker present a 4 ohm and lower load to an amp, and almost all tube amps prefer a higher-impedance load, producing less power at higher distortion into lower impedances than into higher.

While this may strike some as inappropriate in an answer to a question posed to the designer/manufacturer of Music Reference amps, I’m doing it anyway ;-) . There is one tube amp I can suggest for use with Maggies, the one I use: the Music Reference RM-200 Mk.2. Unique amongst tube amps, it produces slightly higher, not lower, power into a 4 ohm load than into an 8 ohm one. About 100 watts/ch into 8 ohms, a little more into 4. Most 100w tube amps produce only 60 or so watts into 4 ohms. The RM-200 is also a real good amp in general terms. Low distortion ("clean" sound, including at bass frequencies, The Achilles heel of many tube amps), low output impedance (no tube amp colorations, such as added "warmth" and/or "soft" highs), stable into reactive loads (usable with ESL’s and ribbons), long tube life (some popular tube amps burn through a set of output tubes in as little as a couple thousand hours, and a replacement set are not cheap), and tasteful, classic styling, all at a reasonable price. Review, both subjective and objective, available on the Stereophile website.

@bdp24 

Thanks for the compliment and notes on the RM-200.

I was also introduced to the Tympani speakers in 1973-4. At the time this product could only be bought from ARC dealers and was essentially a speaker that Jim made for Bill. Both were just starting out. At the time the largest amp ARC made was 75 watts/ch. Bill also required you buy his electronic crossover for the 3 way system which was a total of 8 panels. Those were the days. Great sound at nothing like today's high prices. Marketing took a back seat to engineering not its the other way round.