New comer

[Confucius 753]

Hello everybody

By mere chance I came across NVA amplifiers on the ebay and became very intrigued by their quality vs. cost As far as I understand they are unsuitable to my Martin Logan Hybrid electrostatics with 2ohms at 20 kHz but still, they seem a kill at their price. Are they really that good ???
I saw a schematic diagram on the web, elusively simple, a very classic and well known solid state design with a very good PS, the heart and core of self respecting
amplifier.

Confucius 753

[zebbo]

Hello Confucius, welcome to the site.
The Mk2 amps are fine into that sort of load. I was using some of the baby Logans, (Scenarios), before I changed to the NVA Cube 1s. Just make sure you use NVA cables.

[applemarc]

I ran NVA amps with my Martin Logan Summits with no problem a pair of mono amp will be fine or even an AP50

[Confucius 753]

Hello

Are you sure about the Logans ? They exhibit exactly the characteristic Mr. Dunn advices against in the NVA site, namely their impedance goes from a 4 ohms
to 2 ohms at above 10kHz. If I had a detailed schematic diagram I maybe could run a simulation to check if I am near oscillation zone. As far as I understand
that's the main danger. Once started oscillation may destroy the output devices of the amplifier and burn the tweeter if you have dynamic speakers.

[_D_S_J_R_]

The devices used today are pretty tough and different I think to those mentioned on the schematics I've looked at..

[applemarc]

Yes Had the summits before the PMC's they where my fourth pair of Martin Logan speakers I did use statements with them

[Confucius 753]

Hello

Were you satisfied by the results ?

[Confucius 753]

The main issue is one of amplifier stability meaning frequency response (no peaks) and adequate phase margin

[Dr Bunsen Honeydew]

Theory is theory and reality is reality, you are being simplistic and also believing specifications, which is usually a dubious pursuit apart from in gross terms. If it works it works, if it doesn't it doesn't.