Don Richard

$62,000 for a pair. A true bargain.😁 97A Monoblock Amplifiers (per pair) $61,995.00

Link?

Very nice. Pricey, but nice.

Push pull amps can run Class A, and 12 dB feedback is fine, assuming the amp is designed with that in mind. The danger is using too much negative feedback in order to linearize a poorly designed amp. You seem to have a strange fascination with turds. They have therapies these days that can help with that.😈

I had a guy try to pull that stunt on me about 5 years ago. Old school audiophool salesman.

Especially when used in a push-pull circuit. With about 12 dB negative feedback.

Trigger warning for subjectivists - you may not want to read what's in that link. 😀 Edit: Too late. It seems that some have already read the link...

In cold weather the range is reduced, by as much as 40+%: https://insideevs.com/tesla-model-3-range-drop-cold-weather/

He said that alnico was a conductor of electricity and ferrite wasn't. That is an accurate statement.

I had to google pigeon chess, lol. No, it isn't, but we are discussing a subject with a lot of incomplete information available online. What we know is that alnico speakers have performance advantages over ferrite speakers, and the performance of ferrite speakers can be improved with the use of shorting rings, which can introduce other issues, such as requiring larger magnets. At this point I'm honestly not sure exactly why alnico drivers don't need shorting rings but a design engineer I met at an audio show told me that it was because alnico was a conductor of electricity and ferrite wasn't. I'll make some calls and check into this further.

Shorting rings don't "kill off" anything. They act as the secondary of a transformer which causes a magnetic field to be generated and which subsequently opposes (shapes) the magnetic field generated by the voice coil in such a way that it stays within the VC gap. This lowers distortion. Speakers that use alnico magnets have less of this problem to begin with, as detailed in the JBL PDFs you referenced.

Ferrite magnet assemblies are sandwiched between iron plates, with an iron slug inside the voice coil. There is no electrical continuity through the ferrite. Alnico magnet assemblies have the magnet itself inside the voice coil. The magnetic circuit and an electrical circuit are formed by iron pieces that wrap around the voice coil and form a gap on the outside of the voice coil. This configuration acts similarly to a shorting ring WRT controlling magnetic flux variations.

Having electrically conductive metal in the magnetic circuit of an alnico driver forms a complete electric circuit that serves the same function as a shorting ring. Ferrite does not conduct electricity, therefore the separate shorting coils sometimes seen in those drivers. It seems that magnetic field modulation by the voice coil would show a greater effect at higher power levels?

Yes, and the rest of the magnet assembly is also metal in speakers with alnico.

From the JBL PDF: "Now to factual differences, There are three main advantages of alnico over ferrite: 1) Greater immunity to flux modulation Shorting rings are used to reduce flux modulation, which reduces distortion. Which alnico magnet structures use shorting rings?

Ferrite does not conduct electricity, so drivers made from ferrite often use shorting rings to reduce distortion. Alnico is a conductor and naturally does what a shorting ring does: http://www.htguide.com/forum/showthread.php?23768-What-exactly-do-shorting-rings-do

Sorry, I'm done feeding the troll (that would be you)😈

No. No. No. It appears reading comprehension is not your strong point...😁

Any amplifier that's clipping is non-linear at that point.

FIFY

Here's the rub - if you do not hear the same orchestra with the same conductor in the same hall in which the recording was made, it is not a valid comparison either.

That PD5VH looks like it was run over by a truck. Might still be able to clean it up and use it though. Spare?

Simple explanation: If the input impedance of an amplifier is too low relative to the output impedance of the source device, frequency response will be affected, usually resulting in less bass. If the output impedance of the amplifier is too high the output voltage will track the impedance of the loudspeaker, which varies with frequency. Such an amplifier that will show a flat frequency response with a resistive load (resistance doesn't vary with frequency) and a variable frequency response when connected to a loudspeaker. I have never heard of this $10K amplifier challenge before this thread, and my reading of his rules is if one of the two amplifiers has an EQ circuit in it that cannot be bypassed, then the other amplifier has an EQ curve identical to the first amplifier inserted into it's signal chain. The first amplifier could instead have an EQ inserted to "unEQ" it's non-bypassable EQ if desired.

If you keep reading that Wiki article it explains and answers most of your questions.

If Clark is talking about input impedance vs frequency and output impedance vs frequency, these are factors that can certainly affect the sound quality of amplifiers and affect frequency response. These things are not EQ or Audyssey, however.