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
jafox
1,460 posts
 
Thank you for the responses above.  The preamp is Aria WV5, the last design by Michael Elliot of Counterpoint 10 years ago.  The last thing I want to do is to put anything else in the line such as a transformer.

My experience has been that the most sensitive cable in the system is the IC from line stage and amp, where I was using ARC, BAT, Aesthetix, Counterpoint, Wolcott and CAT.  Just putting some cheap 4-5m RCA IC here is going to destroy much of what my system can achieve with a good IC here.  And so why not just use one leg of the XLR cable when I have a single-ended amp?  I just thought it might be a good idea to not just float the negative line.
prof
3,474 posts
 
Mr. Gabriel Claimed:
 
“As stated in #1 the local current and electromagnetic effects directly affect the sonic performance of the component.”




Then you’d the no it would be a cinch for Gabriel to supply measured results showing the output of an audio device is changed when using his cables.

Funny how that is conspicuously missing.
teo_audio
2,197 posts
 
Prof uses the measurement canard which is as old as it gets and is well proven to be ineffective when it comes to human hearing at it's limits - which is the subject at hand.

Interestingly enough, his entire job rides on doing things that are either unmeasurable or so close to being unmeasurable that it is not worth bothering to try.

Hoisted by his own petard. (modern translation: he blew himself up)
ieales's avatar
ieales
1,201 posts
 
@teo_audio 
Interestingly enough, his entire job rides on doing things that are either unmeasurable or so close to being unmeasurable that it is not worth bothering to try.
Not true. It is relatively trivial to measure the diode switching noise*. IF that noise is reflected through the transformer, increased by the transformer** and ameliorated by the power cable, then the results should be eminently measurable.

* Discussion on diode transients and measurement thereof here:  https://electronics.stackexchange.com/questions/323507/bridge-rectifier-4-diodes-vs-single-chip

** Power transformers step down in operation, so must be step-up on any signal reflected back through them.
ramtubes's avatar
ramtubes OP
460 posts
 

daveyf

first the swapped polarity from amp to speaker does no harm and most will not hear any difference as long as the swap is the same on both sides. All you have done is invert absolute phase which has been a point of contention for many years.

As to one speaker not playing. probably just a loose wire.

No damage will occurr 

For the phase hawks out there. The battery test is valid and is the standard. Though easy it is not entirely correct and JBL tested for in, + not out. Below resonance a cone speaker flips its polarity. So in the normal condition above resonance the cone is moving in for +.

Just something to throw at someone who thinks they know everything about speakers.
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