amplifier class

[willyhoho]

I am looking for a amp to drive my esl. I am confused when looking in this forum as to the class designation the amp should have. Can someone please clarify this? Do tube amps have different classes too?
Thanks

[SkySeeker]

I am just a beginner on this forum, but it is my impression that Class-D amplifiers are best suited to ESLs.

For example the Hypex (http://www.hypex.nl) modules use a 90V supply voltage, which means that in most cases a 1:50 audio transformer should be sufficient.
Also the output of a Class-D amplifier (see here: http://sound.westhost.com/articles/pwm.htm) needs a capacitor. So the ESL will be just an capacitor parallel to the internal capacitor of the amplifier.

[arend-jan]

Yes, tube amps have different classes too. Google a bit and you will find enough info about different classes and what it means.

I'm having good success with a push-pull class A tube amplifier and ESLs.

[willyhoho]

I did not realize there was so many classes of amplifiers.I did some surfing and found more info (some confusing) on amps and I thought a amp was a amp. Thanks for the replys. Some say you can't go wrong with a class AB. I will do more research.

[AndrewT]

Hi,
when Quad brought out their SS amp specifically designed to power their ELS they used ClassAB.

All their subsequent SS designs suit the ELS and ESL and still they are ClassAB, but with a funny feedback system called current dumping.
That must say something.

[arend-jan]

I had the best results with tubes in push-pull running deep into class A.
I'm running my Quad ESLs with this http://www.nutshellhifi.com/triode1.html DIY PP 300B amp and I can say that it sounds much better than the Quad 303 or 405. No doubt about it.

[willyhoho]

I heard a AMC tube amp today and I think it was a Class A.What a clear,distinct sound. If the amp has no Class designation on the back,is there another way of telling?Age maybe?

[AndrewT]

Hi,
Solid state ClassA get so hot you can tell it's not normal bias ClassAB.
There are a few high bias ClassAB around but these usually have heatsinks that get warm to hot due to their smaller size.
Tube/valve amps are difficult to tell apart.
But our tube experts could probably tell from the valve type and B+ voltage.

[Few]

I too am looking for an amp for ESL's. My venerable B&K ST-140 amp, which I was using to drive my ESL's, died last week---at the same time that my DEQ2496 decided it was no longer interested in turning on. I haven't yet figured out what happened in this chain of events, but I find I'm in the market for another amp to drive my ESL panels. I'd rather stick to solid state and not spend a fortune. Have any class D modules been shown to be particularly cost effective and suitable for ESL service? Or as a more conventional (and less diy) alternative has anyone tried either the Behringer EP1500 or A500
amp? I've read some positive things about them, and the price is certainly right. I understand they can handle a low impedance load, but I haven't seen anything about their ability to drive a highly reactive load. Also, I have a feeling the Behringer DEQ2496 brought about the demise of my old amp so I'm a bit wary of Behringer at the moment.

[Calvin]

Hi,

I can wholeheartedly recommend the HiFi-Akademie amps.

They are a stereo class-d pre-filter-feedback concept for DIY. So freq-response depends on the speakers impedance, but filter components can be easily tuned to suit Your demands.
Capacity (as ESL-manufacturer) recommends and uses them with his panels and they have proved to work exceptionally stable with my panels, which are a real proof with low impedance values and phase angles reaching more than 80°!!! B&Os Ice-Power-modules are for example not specified for the capacitive loads that typical ESLs represent and would start swinging with my panels (or ML-Panels)
I like that the H-As are built with a very straightforward simple signal-path and allow for higher currents than most other designs in their wattage-class. Price is similar to UCDs with Power-supply and You can purchase nice housings too.
Up till now their sonic performance in my setup was just topped by the enigmatic KR-Audio Kronzilla...at slightly elevated costs of course Price/Performance-value is very good.
As an interesing feature it is equipped with a slot where You can put optional crossover modules in (analog as well as digital). So You can easily create a fully active 2way ESL-version.

jauu
Calvin