Why Don't We See More High Current Electronics?

Unsound says: Well Weseixas, I think we part ways on your appraisal of Class A. More often than not (but not always), I've found the more Class A the better the sound. The only problem is many so called pure Class A amps either don't have enough power for the the speakers I prefer, or the cost is beyond my budget. ...And of course, the issues of size heat, efficiency, etc..

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Is predictive bias-level adjustment a la Krell and Levinson enough, or must it be pure, brute-force Class A operation only?

Unsound ,

I won't disagree, i can only express my involvement at many levels and again iterate that I find high Class-A Bias amplifiers not to sound like live music IMO, tending to be soft and laid back ( gentle) and nothing like the recording or live music, of course there are exceptions, but for the most part, , yes, this has been my observation.

Again speaker topology play's a big role here and of course there are those that prefer soft and gentle to
"real " and if you have a speaker which is forward sounding or "bright" it will have an issue on anything but Class-A.



Class- D have what i speak of in spades, unfortunately other issues with that topology leaves it a bit dry making ClassA/AB still the best output stage topology IMO.

regards,

Irv,

We have taken Krell's and re-biased them to 10% of their original class-a bias after service and recapping and the difference is astronomical.

Anyone with an older Krell KSa 200/300 et al series should give it a try, no more 1400 watts being pulled at Idle .

regards

I appreciate the discussion of amplifier topology and performance. It's informative for electronics novices (like me).

An amp with high input impedance is important

not "dry" or "lean"

lively with bass weight and clarity.

An issue is my Cary SLP 05 preamp has fairly high output impedance into the lower frequencies. My speakers are Mirage OMD 28 /Impedance 6 Ohms nominal /3.5 Ohms minimum 87db efficient /Crossover Point 550 Hz and 2.5 kHz

I hate to repeat myself, but a Threshold S500 with new caps and a re bias appears to be just what your looking for. Though Threshold made very well received pres, many used them with tubed Audio Research and some used tube c-j pres. If memory serves me correctly the input impedance was 75 KOhms. 250 Watts per channel 8 Ohms, 500 Watts per channel 4 Ohms. 20% Class A bias into 8 Ohms. Class A bias halving as power doubles into 4 Ohms.