Please Read and express your feelings and opinions....


I noticed  that lately or maybe for the last five yrs, there is so much arguments,name calling, attacking cables , speakers , components makers and more, more of disagreement with members, even Audio dealers are being attack here...Very few know how to apologize when they are wrong.What can we do as Audiogon members to improve our communication to each other? How to give the informations, recommendation to members who need it? This is without involving Audiogon, any opinion or ideas ,  For me this is fun and place to learn in audio...thank you all
128x128jayctoy
To add a data point to Steve’s (Fleschler’s) input, my 300B-based class A biased VAC Renaissance 70/70 MkIII amplifier provides a choice of 6 different feedback settings, ranging from 0 (no feedback) to 7.5 db. All of those choices represent relatively modest amounts of feedback, even for a tube amp (for example ARC amps commonly have feedback in the area of 10 to 14 db or so), but nevertheless I prefer the 0 db setting. I suspect one reason for that is that my speakers (Daedalus Ulysses) have an exceptionally flat impedance curve. Presumably that tends to lessen their sensitivity to differences in amplifier output impedance, which in turn will vary among the different feedback settings, and will be highest at the 0 db setting. I’d imagine that with a lot of other speakers one of the other feedback choices would be preferable, depending on how the impedance of the speaker varies over the frequency range, and also on how much bass damping it requires (damping factor being inversely proportional to output impedance).

Regards,
-- Al
Thanks Al, I didn't know that older VAC amps have variable feedback.  

My 125 watt Class A/B tube amps also have variable global negative feedback at reportedly 4,6,8 and 10 db.  My similarly high efficiency speakers, unlike yours, have a difficult impedance curve with low impedance in the bass (3.2 ohms).  I set my feedback to 4 db, or minimum.  Until I improved my system with the SR fuses and Total Contact, I used to set it to 6 db for CDs and 4 db for LPs and 78s.  Now everything sounds open and tonally firm at 4 db.  

If I were to replace my amps, I would probably buy the VAC 200IQ.
@geoffkait 
Please, Geoff, enlighten the unwashed masses here as to what this "sufficiently advanced technology" is that appears to us as voodoo. 

kosst_amojan
@geoffkait
Please, Geoff, enlighten the unwashed masses here as to what this "sufficiently advanced technology" is that appears to us as voodoo.

Oh, I dunno, costco, but I suspect in your case it could be just about anything that looks at you a little cross-eyed. 🙄

Pop quiz. Multiple choice. Oh boy, oh boy!

Which of the following are not woo?

a. Green Pen
b. Mpingo disc
c. Silver Rainbow Foil
d. Tice Clock
e. Intelligent Chip
f. Demagnetizing CDs