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.
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 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.

* Discussion on diode transients and measurement thereof here:

Not much meat or it sounds. I didnt read the whole thimg. In my RM-5 preamp I found the coupling of the power transformer to make a great difference. A well coupled primary has less noise, however a loosely coupled primary was worse. Takes some digging to see this. 

I felt it best to use the Grid to take the pulses. What a cord might do I, dont think much.

I would like to see some scope photos of these diodes compared to others all the way down to the slow 1N4000 series.
my M-60s are supplied straight from the wall.  They are not happy running through the P-10!  From the point of view of distortion from the M-60's as a function of voltage, would you expect a measurable difference in distortion over the range of 115-125 Volts?
You would certainly be able to measure a difference, not just distortion but also power.

It seems that conditioners like the P10 are not happy with higher constant loads on them- they work fine with higher power solid state amps that have otherwise low quiescent current draw, but tube amps with larger draws (for filament circuits, perhaps also class A) seem to cause them trouble. For that reason we usually recommend running the amps straight out of the wall.
If you want a really nice conditioner, a company called Elgar used to make some that are quite impressive.
A couple tech questions for Roger. Others please chime in too.

Is it possible to estimate how much amp power will be enough (i.e. never clipping) simply based on speaker specs (assuming they are correct), and listening habit/situation (i.e. distance from speakers, loudness)? 

If so, how?

Yes it is.  See two of my posts ealier in this thread, dated 11-26-2018 and 11-27-2018, which appear on pages 5 and 6 of the thread if you have it sorted with the oldest posts first.

-- Al
I am getting some ground loop noise from my Classé 5300 amp. I read that a Ebtech Hum X will eliminate this. However, the box says do not use on any amps that draw more than 6 volts. I am not sure how many volts my amp draws.  Does anyone know if I can use this with my Classé?