There's something special about class A amps ....

[Ritmo]

Congratulations Joe! How do the Pass monos compare to the 911s driving the CR1s?

Mike

Originally Posted by C220MC275

Joe,

If you or your speakers don't need tons of power, and you can accommodate to the heat they generate, there is NOTHING like a well built class A amplifier.

Sent from my iPhone using A.Aficionado

I don't necessarily agree with your comments Jerome. I asked Rich Maez at Boulder about Class A vs Class AB & he had this to say -

"Biasing is a thin veneer spec that has just a fraction to do with the overall sound and character of an amplifier - it's a detail, not a foundation. When you start to look at marketing speak and how manufacturers position themselves by designing products around a potential future product brochure, you run the risk of buying or ranking something based on advertising. The 1060 will operate in Class A biasing up to 17 watts and yes, many other amps run in Class A up to a higher power output level. In reality this means very little - the biasing scheme used to keep an amplifier in a particular mode of operation can't make up for for an overall amplifier design that's not of the same calibre and may actually be necessary to compensate for non-linearities in operation. In other words, if you start out with a much better circuit design to begin with, you don't need to over-compensate with higher biasing.

Class A doesn't guarantee good sound, it's simply a portion of the design. There have been some very cheap Class A amps in the past that offered no great sound quality as a selling feature. It's sort of like the way paddle shifters have become a selling feature in cars today: in the proper vehicle, they're a benefit but offer no performance benefit in a car that doesn't have a high level of performance to begin with.

Class A biasing is beneficial when it comes to sound quality, but there are many, many other things that it affects, most notably reliability: constant thermal cycling leads to failures. Our 2000 Series products are pure Class A up to full rated power output, but we go through a lot of effort to maintain thermal stability and eliminate rapid cycling, all of which is very, very expensive to implement - and by this I don't mean shiny metalwork."

Bodhi

[Jerome W]

Originally Posted by Bodhisattva

I don't necessarily agree with your comments Jerome. I asked Rich Maez at Boulder about Class A vs Class AB & he had this to say -

"Biasing is a thin veneer spec that has just a fraction to do with the overall sound and character of an amplifier - it's a detail, not a foundation. When you start to look at marketing speak and how manufacturers position themselves by designing products around a potential future product brochure, you run the risk of buying or ranking something based on advertising. The 1060 will operate in Class A biasing up to 17 watts and yes, many other amps run in Class A up to a higher power output level. In reality this means very little - the biasing scheme used to keep an amplifier in a particular mode of operation can't make up for for an overall amplifier design that's not of the same calibre and may actually be necessary to compensate for non-linearities in operation. In other words, if you start out with a much better circuit design to begin with, you don't need to over-compensate with higher biasing.

Class A doesn't guarantee good sound, it's simply a portion of the design. There have been some very cheap Class A amps in the past that offered no great sound quality as a selling feature. It's sort of like the way paddle shifters have become a selling feature in cars today: in the proper vehicle, they're a benefit but offer no performance benefit in a car that doesn't have a high level of performance to begin with.

Class A biasing is beneficial when it comes to sound quality, but there are many, many other things that it affects, most notably reliability: constant thermal cycling leads to failures. Our 2000 Series products are pure Class A up to full rated power output, but we go through a lot of effort to maintain thermal stability and eliminate rapid cycling, all of which is very, very expensive to implement - and by this I don't mean shiny metalwork."

Bodhi

Very interesting.
Yes I agree. This is why I stated " well built class A amps ". There is some crap there also...

Originally Posted by C220MC275

Very interesting.
Yes I agree. This is why I stated " well built class A amps ". There is some crap there also...

Hi Jerome,

Yes I read your comment "well built class a amplifier". I was just picking up on Rich's point that the circuit design is more important than the biasing scheme..

Cheers,
Bodhi

[joeinid]

Originally Posted by Ritmo

Congratulations Joe! How do the Pass monos compare to the 911s driving the CR1s?

Mike

Hi Mike,

Right now I prefer the XA100.5's, but they really need more break in. I'll have to figure out what I hear but the Pass amps are really nice.

[joeinid]

Originally Posted by GaryProtein

[/B]
You mean that they can keep you warm in winter when the furnace goes out?

.

Who needs a furnace anyway?

[jdebonth]

Joe, the pass amps have the same gain as the dart. You should get a pair of XLR splitters and hook up the stereo dart to the tweeter/midrange and the pass amps to the woofers

[joeinid]

Originally Posted by jdebonth

Joe, the pass amps have the same gain as the dart. You should get a pair of XLR splitters and hook up the stereo dart to the tweeter/midrange and the pass amps to the woofers

Really? I could just use a separate XLR run to the amps. I'll have to try that.

[djwhog]

Agreed to class Special, even my Halo and low levels is so so clean and accurate too

yep they run warm, but good in a WY basement in the winter 7 months a year

[Volks]

Ive always had an interest in the Clearaudio Balance Amplifier Pure Class A......its kinda rare,but i would love to demo it for a long time....they also make a matching Pre-Amp to go along with it.

"The Clearaudio designed loudspeaker protection is a world first, realised through opto-couplers that react in microseconds to any failure in input or output devices and decouple the electronics either from the loudspeakers, or the mains power. This system ensures that in normal use, nothing will be in the signal path to your speakers.
Protection and peace of mind without destroying fidelity is another innovative feature from Clearaudio."


Maximum output power: 2 x 50 W/ 8 Ohm Class A
2 x 94 W/ 4 Ohm Class A
Frequency response: 20 Hz to 20 kHz (- 0.2 dB)
Signal to noise ratio: 100 dB (A)
Distortion: 0.02 % at 1/10 maximum output power
Input impedance: Unbalanced and balanced 10 kOhm
Gain: 34.4 dB
Input sensitivity: 370 mV for maximum output
Power consumption: 250 W (±5%) at maximum output
150 W (±5%) nominal
Mains voltage: 115 V or 230 V
Dimensions (W/H/D in inch): 17 x 8.7 x 10.6
Dimensions (W/H/D in mm): 435 x 220 x 270
Inputs: Unbalanced (RCA)
Balanced (XLR), switchable on back panel
Weight: 30 kg
Manufacturers guarantee*: 5 Years