Recent content by markmal

Placed all in spreadsheet. It shows "reaction flux" is 2.5E-10 % from the original magnet flux. Eddy current losses of power is 5.8E-12% from power of ribbon current. using solid core. With using laminated core it will be 5.8E-16% So, yes, you guys are right! These losses can be ignored...

My example just shows a principle where tiny fluctations of some parameter of a media are not hidden by an absolute value of the parameter. Pressure can be very high but even tiny fluctuations of it are detectable. Same with magnetic field. It can be weak or strong, but tiny fluctuations of it...

Thank you Jim, I'll try to program your formulas in spreadsheet.

Yes, Carl, you and some other guys told me that the fluctuations of flux are very little comparing to flux from magnegnet and should be ignored. But I have some feeling that something is not right in this comparison. Let me explain you why. Example. Atmospheric pressure is big, heavy -...

I agree. It is subjective and may be psychological. I mentioned DIY-ability as well. Regarding SS amps, circuits I saw in past were frightening big, with hundreds of elements. May be today's IC schematics are more simple. What schematic would you recommend for a ribbon mic preamp with 80-90dB...

I want to build, so you call, "retro", but, this is based on contemporary elements. Retro design is often simplistic and because of this it creates less noises, distortions and coloration to sound. That is why lots of audiophile level devices made on tubes. Yes these are bulky, eat power, but...

This means to me that current still appears. Especially on high frequencies. If these current can induce flux in step-up transformer, can it also induce some amount of feedback flux into core? Yes, I realize that the amount will be very low, but you know, if we take a glass as an analogy, even...

Today's ribbons also use transformers. It is the only way to increase such low voltage without adding noise. I have another question. There is one transformer in mic ~ 1:35, and another one in preamp. Is it really required to have two? Can they be replaced by one with "summarized" ratio...

250Ohms is after transformer. 2-3K is input impedance of preamp, I believe. Old magnets were huge, so they may produce flux equivalent to today's small neodims.

It is still unclear to me how mic transformer would work if there is no current? How it passess and increases voltage? Thaks for the link. I am thinking which amp to make. I'll take a look. Currently I am thinking about RCA OP-6 because of its huge 90dB gain.

preamp is going to be tube preamp with very high input impedance, dozens of K Ohms, according to http://www.aikenamps.com/CommonCathode.htm Does it mean there will be practically no current in ribbon, thus no currents in core?

Yes, it is a language thing. it is about ribbon mike design. "ribbon mic motor" is wide used term, though, I agree, it may be not correct from terminology point of view. Any dynamic/ribbon mic can be used as a loudspeaker and vice versa, dynamic/ribbon loudspeaker can be used as a mic. I...

Hmm. That would be very nice. #1. What would be equipment that can measure so weak fluctuations of flux in cores? I do not believe that can be available for me from budget perspective. #2. It is possible, but also requires couple of hundreds for machining solid cores and thousands to make...

This method is possible, but it is indirect. Though nature of current in this wire will be same with nature of eddy currents, value will be different, and it will be a portion of value of eddy currents. Some portion of energy will create current in the wire and some still create eddy currents...

May be. But how can I find from experiment are there Eddy currents or there are no. How could I measure them? What makes you be so sure? Could you prove your point? These are not Eddy currents. This is good EMF.