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.


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bdp24's avatar
bdp24
9,989 posts
 
I couldn't agree more with both clio09 and gpgr4blu. Thanks guys.
ramtubes's avatar
ramtubes OP
460 posts
 
@pwhinson 
I used to think that power was power with only minor differences in the sound.  However in trying to decide on the best amplifier for my Thiel 2.4s I've auditioned the Bel Canto m600s (their current production monblock), the Bryston 4 cubed stereo amp, and the Pass x150.8.  They were PROFOUNDLY different.  The Bel Canto rather oddly was very recessed the dark sounding, the Bryston was a little shrill with very little mid range "meat" on the bones but the Pass was JUST RIGHT.  Honestly, I'm being a little sarcastic here but these were not subtle differences.  I left the experience feeling that the "electrical" handshake between the power amp and the speaker is considerably more complicated than I originally imagined.  Thoughts?


Those are all big amplifiers. Given the low impedance in Thiels you want the amp with the most current. 

I would only listen to one amp at a time with one as a referene in a strict A/B test. Swapping amps has to much time between, levels are often not matched. I wish dealers had A/B boxes but its a lot of work and they dont want that kind of testing. You may find out the less expensive amp sounds the same or better. When you compare good amps with good specks they really cant sound much different, can they?

Now throw in a high distortion, low damping amp and you will hear that.
ramtubes's avatar
ramtubes OP
460 posts
 
@fleschler  EAR 912 with tubes rated for 100,000 hours and non-microphonic.


I have looked at the rating of many tubes, last I looked Tim was using 7DJ8s. Those are 10,000 hour tubes If you get 10,000 be happy. 

Most tubes are rated for 10,000 hours and 10,000 turn-ons .So watch that. 
ramtubes's avatar
ramtubes OP
460 posts
 

@grgr4blu I have enjoyed posts by Ralph and Ramtubes on this forum. They are both highly qualified as designers and manufacturers. They both provide answers to technical questions about gear. Sometimes, they include opinions based on their understanding of the science behind gear. Nevertheless, their posts are almost always informative to the membership here. Occasionally, they are self referential, although I do not view their contributions as self promotion that should be banned such as posts by Audiotroy which usually contain rank self promotion and, at other times, stealth promotion under the guise of informing the Audiogon community of his opinion ( almost always favoring the gear he sells) based upon his vast experience which he claims is more valuable than the opinions of other dealers who are out for the money--- while he is out to help the Audiogon community. Of course, these are extreme comparisons about what should and should not be permitted here. I suspect the line should be drawn somewhere in between the services provided by Ralph and Ramtubes and the disservice provided by Audiotroy. Might I add that Ralph and Ramtubes are not close to that line IMHO.


I toatlly agree about not promoting ones product and plan to watch it carefully. I would like to see people make some simple A/B boxes and will tell them how  for no charge. If I make one for someblody its a one off and not a product, just a tool, and a very good one. Perhaps I can make one and we can pass it around to those really interested and can convince me they can properly perform the experiment.

I will remind everyone that this thread is to answer and discuss technical topics. If you want me to answer personally pease direct the question to me.

Furthermore If anyone wants to debate a topic, be sure to have vetted sources to support your premise or be good at supporting it yourself. We have had a few on here that went on an on with no support, clairty or sensiblity. 
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