Pure class A amplifiers = "slow" amplifiers?

At least you didnt look at the fostex w400a hr price. Iam working out a design using these with a ribbon;) in a 2 way......

JohnK I respectfully disagree. Under-powered loudspeakers tend to lack dynamics. Different speakers have different amplification requirements. There are pros and cons for each speaker design. I have yet to hear highly sensitive loudspeakers that perform to my satisfaction.

Hi folks, I know this is subject of controversy. In general pure class A has been regarded as the best way in solid state amplification to get the purest sound. In my experience many pure class A solid state amplifiers (Accuphase, Pass Labs, Plinius) sound "slow" and are lacking "dynamics".

What you may be observing is simply a lack of distortion. A very high priced Class A amp is likely to be top notch. Furthermore, the design eliminates crossover distortion which is responsible for very high order harmonic disortion (in very small amounts but perhaps audible in some cases).

If you remove higher order harmonics (distortion) then music will indeed sound more laid back and natural - it will lack that edgy sound that you hear with most pop music today such as Red Hot Chilli Peppers, Green Day, Arctic Monkeys etc. (where distortion has been deliberately added in the mastering stage to make it sound "loud" - see CD loudness wars on google).

My speakers run Class A to two thirds power and I am very familiar with the harsh sound of modern pop CD's. The modern hypercompressed CD effect is such that they sound "fast" or "edgy" or "snappy" at low volumes (perceptively this sounds better to many people which is why the mastering engineers do it) - however - at higher volumes the sound is noticeably harsh and unpleasant compared to a properly mastered CD with proper dynamic range and without "hard-clipped" square signals (often, on a modern CD, a single track is clipped or flat-lined over 10,000 times!! I am not joking! If someone tried to sell you a towel and you got home and found it full of holes then you would take it back and demand your money back - this whole thing perpetrated by the recording industry is totally scandalous).

So laid back slow or natural sounding amplifier is GOOD, at least in this context, IMHO!!

Absolutely agree with Shadorne's reasoning.

We are surrounded by mass media broadcast sounds that are reproduced with compressed software/inferior equipment to begin with so it sounds good on bulk of the mass produced home and car stereos, radios and TVs. A shadorne says: Fast, edgy, snappy, punchy, grainy, thin, boom and sizzle sound is what we are used to in our everyday life.

So when we hear live sound or pure signal (from superior software of course) being reproduced it sounds so different than mass media delivered sound that you question your sanity (;-)) and your equipment (Class A amps for example). At times you almost want that punchy and edgy definition sound back where faster sounding leading edges are IN your face.

I have always preferred a fast, lively sound since owning a Linn LP-12 and discovering the British "PRAT" sound.

Electronics, generally speaking, with ultra-wide bandwidth will have a faster presentation for a more accurate portayal of musical transits and phase. Faster is better and conveys the musical energy far better than slower designs although some may prefer that type of sound. Remember, it's all subjective what each of us enjoy.

That said, the sound can be smooth or it can be edgy - speed has nothing to do with tonality. The Delta Sigma Italian amps & preamps we distribute are flat to 3Mhz, lightning fast with the tonal purity of a great OTL design.

So we can have speed and harmonic purity - it simply takes some searching for the special designs.

Jim Ricketts/tmh audio