Improving on Classic Amps

Thanks Guidocorona for clarification - from Wikipedia

"The letter D used to designate this amplifier class is simply the next letter after C, and does not stand for digital. Class D and Class E amplifiers are sometimes mistakenly described as "digital" because the output waveform superficially resembles a pulse-train of digital symbols, but a Class D amplifier merely converts an input waveform into a continuously pulse-width modulated (square wave) analog signal. (A digital waveform would be pulse-code modulated.)"

Naturally, as an audiophile, I am inclined to believe that any amplifier which is heavier, runs hotter and/or has dangerously sharp edges probably sounds better.

Also from Wikipedia:

"Class D amplifiers for driving subwoofers are relatively inexpensive, in comparison to Class AB amplifiers.

A 1000 watt Class D subwoofer amplifier that can operate at about 80% to 95% efficiency costs about $250 USD, much less than a Class AB amplifier of this power, which would cost several thousand dollars."

This second point might also explain some skepticism, heavy hype and promotion from certain manufacturers and the rapid fall in resale values for some.

Old school Class A amps seem to retain their value pretty well.

I do believe that the TacT amps can accurately be described as "digital" amps, that is if they are indeed amps at all.

problem is that I have no idea where class C amps have gone

Class C amplifiers very much exist, but they are not used in audio because they inherently have very high distortion. They are commonly used in RF transmitters, with their outputs fed into tuned circuits (tuned to the frequency being transmitted) which can partially filter out the distortion.

The letter D used to designate this amplifier class is simply the next letter after C, and does not stand for digital

Quoting from a post I made in a recent thread on Class D amplifiers:

Whether or not a class D amp is referred to as digital or analog is not related to its class D power output stage. What would properly be called a digital class D amp is one that can accept a digital input, and which puts that digital signal through some dsp (digital signal processing) to generate the modulation waveform that ultimately controls the switching of the class D power output stage. An analog class D amp would differ in that it would utilize an analog input and have an analog front-end signal path.

Regards,
-- Al

Thank you Al for solving the 'Great class C Caper'!

Cwlondon, like all other types of amps, class D range from 'bargain basement' prices like the subwoofer amps you mentioned, to the stratospheric. For example: Flying Moles used to be under $1K, Bel Canto Ref 1000 Mk.2 $6K, JRDG Continuum 500 $8.8K, JRDG 312 at approx 16.5K, Spectron monos with all the trimmings at $22K, JRDG 301 monos approx $30K, Levinson flagship (forgot model) in $50K range if memory serves. Interestingly, class D amps are somewhat less heavily advertised than other kinds. . . their growing popularity appears to be more of a word-of-mouth phenomenon.

i seem to remember auditioning the tympany 1 ds with a powerful audio research tube amp, with an audio research sp 6 mod something.

i owned a pair of tympany 1bs and i preferred tubes driving them, especially the quicksilver ms 190.

if anything, sell the levinson and buy a conrad johnson mv 125.

personally, if production of audio components ceased after the end of the production cycle of the cj mv 125, i wouldn't shed a tear. stay classic and go vintage tubes !