AMP2 : it rocks !

[Mr T]

The AMP2 as I built it is a killer.

Rock solid bass along with extremely detailed and fine mids and highs.
This one is my new reference above all what I've heard, almost whatever the price is.

Thanks to Jan for this.

Let's put it simple : my advice is to aim at perfection for the power supply. It is VERY important and has A LOT to do with overall result.

Picture of the setup used for first listening test : http://www.dcx2496.fr/photos/amp2works.jpg

Mr T

[thomaseliot]

[8D] Congratulations [8D]

I knew already about PS. What we have to learn is that overkill power and bulk caps with R-core transformers deals to a great improvement?

A couple of questions (I can't see your picture on the link): what's sensitivity and power of your speakers? And what's the difference with AMP4? I mean, of course, intrinsic quality of sound at low power. On paper AMP4 would have better performances.

Thanks for sharing!

[Reverie]

That's great to hear Mr. T! [8D]

A friend of mine, head of Electrum Audio - Mike Tehan, has often told me about the success he's had with r-cores. Even though his speciality was valve amps, I'm glad to see they can be applied successfully to class D too. [^]

Perhaps after my current amp4 battery-powered project, I'll try a high power kit, like the amp2, with r-cores too. []

I look forward to hearing your continued experiences.

[thomaseliot]

Hi Mr T

did you make any comparison between AMP2 and AMP4?

anxious to read [8D]

[Mr T]

Hi Thomaseliot,

Comparison is due tomorrow.

First impression is that with such a power supply, silent and extremely fast thanks to the Turboswitch diodes and the low ESR caps, the AMP2 goes a bit further in terms darkness of the background (better contrasts) and detailing of mids and highs, although the latter is very smooth and liflike. Human voices are thrilling.

Of course power is truly unlimited, bass is like concrete and the overall result is a sensation of sovereign easiness and contolled power. I could almost smash the room's walls down without any audible stress. I have installed 50KR feedback resitors on the inputs to obtain a 0.31V sensitivity.

As I built it it's a real beast, to be compared to the best amplifiers on this earth.

Mr T

[V-bro]

May I also congratulate you![8D][8D][8D]

Was wondering about AMP2 a lot, so please keep us posted on your experiences.. I thought I saw photos from your AMP2 before, the copper plates is what I remember....you were testing the PSU, but didn't have a listen yet....am I right?

Where did you get the trannies?

[Mr T]

Thanks,


Yes I have been very slow with this one because that kind of power supply is lethal [xx(] there are a few joules in there [:0]

For example I was doing some measurements and I accidentally made a short between two diodes and a chunk of the probe simply vanished in a wonderful blue light ! I don't know where it went but it's not there anymore. Those diodes are capable of 700A before having trouble.

As you can see the rails are well balanced : -60.14V and +60.16V

http://www.dcx2496.fr/photos/100_1559.jpg
http://www.dcx2496.fr/photos/100_1561.jpg

I bought the trannies here : http://www.selectronic.fr/article.as...r=70.9342-9999

http://www.selectronic.fr/upload/pro...logue/9-05.pdf

Mr T

[V-bro]

Thanx for the link!

I really like the way you built it, I'm not surprised it sounds great. And I have to agree on your safety policy, I once saw a 45V 300.000uF supply go up in smoke, exploding on all sides (wasn't my mistake, but a collegue) can be very very lethal indeed... [xx(]

[ledim]

quote:Originally posted by Mr T
[br]

As I built it it's a real beast, to be compared to the best amplifiers on this earth.

Mr T

Hi,

even better than the next to come PWM amp by selectronic ?

Congratulations, and I'm eagerly waiting for your detailed comparison of the amp4 and amp2.

Ledim

[djQUAN]

I'm also using amp2 in nearly full range. it is driving the front speakers in my car and amp8 driving the subs.

I would suggest not driving amp2 near clipping (in PA applications) since because of the way tripath amps clip, they generate so much harmonics that it is very easy to blow tweeters. I haven't blown mine since my separates use tweeter protection but I have tripped it several times. care with the use of the volume control is very important.