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
Ralph, couldn't he use a Jensen transformer to make he XLR to RCA change? Would it still offer the proper grounding?
Bob
ramtubes you stated " My stand on power cords is entirely intellectual from an amplifier designer and transformer makers point of view. I know what is inside a transformer and how it works. When you know
about transformers, house wiring etc. we can further discuss this interesting topic."

 Caelin Gabriel of Shunyata Research Inc. knows much more than I do and he is an electrical engineer with a high pedigree in the audio industry. Whether his cables and noise suppression equipment are correct or not, I don’t know. However here are three of his quotes concerning power cables and sonic degredation due to faulty power supplies in equipment.

" Misconception #3: There is up to a hundred feet of wire in the walls, so the last 6 feet of power cord can’t possibly make any difference.

Answer: “The power cord is not the last 6 feet, it is the first 6 feet from the perspective of the component. As stated in #1 the local current and electromagnetic effects directly affect the sonic performance of the component.”

So, he feels that the upstream house wiring all the way the transmission towers are not as relevant as the Power Cables leading to the equipment.

Misconception #4: There is a tremendous amount of electrical interference and EMI coming from outside the home that we need to protect our equipment from. This implies that we need some sort of power conditioner or filter to protect the equipment.

Answer: “Most of the EMI that affects the audio quality of a system is generated by the audio components themselves. Electromagnetic waves that traveling through space dissipate in power at the square of the distance from the source. Further, very high frequencies that propagate through the power circuit do not survive for long. Power lines present a high impedance to MHz and GHz signals due to the relatively high inductance of power lines.

"A primary source of audible sonic degradation is caused by the power supplies in our audio/video components. Most components use FWBR (full wave bridge rectifier) power supplies that generate an incredible amount of transient noise when the rectifiers switch off. The design of a power cable can significantly affect the reactance of these signals within the power supply. The power cable is effectively part of the primary winding of the power transformer. The transition between the various metals used in a power cable and its connectors can cause electromagnetic reflections and diode-like rectification of the noise impulses as they propagate away from the power supply. If the power cable presents a high impedance to these signals they will be reflected back into the power supply where they will intermodulate, thus increasing the high frequency noise levels of the component. Most power supply filters are ineffective at blocking very high frequency noise components and much of it is passed through to the DC rails. The sonic effects of this include: high background noise levels, blurred or slurred transients and a general lack of clarity and purity of the sound or visual image.”

Here he is stating that the equipment power supply creates the sonic degradation.

Misconception #5: There is some sort of conspiracy among audio designers that keeps them from producing a "proper" power supply that is not affect by power cable quality.

Answer: “This concept is like saying that if a speaker where properly designed, you wouldn’t need to use a good quality speaker cable. PowerSnakes have been tested with the most modest of mid-fi equipment and the most exotic state of the art components. We have yet to find a component that cannot be improved by replacing the power cord.

"As long as power supply design is based upon FWBRs or switching supplies, the power cord will always be significant.”

Basically, he is stating that power supply design generally is at fault resulting in power cords making a significant difference.

Are your RM series amps and pre-amps designed to prevent all of these problems? Are most equipment designers not designing their equipment correctly? You would know as I don’t.
@fleschler - sounds like you are trying to pick a fight with Roger, or perhaps bait him. Seriously, you should re-examine this tactic.
Roger doesn't suffer fools gladly. Not that I'm calling anyone a fool ;-) .