Flea powered (sub10w) Class A Solid State Power amplifier required. But do they exist?

[Thetiminator]

Hi everyone
I use 106db horns so realistically I’m only ever using a watt or so. I’ve tried many valve amps but didn’t really get on with any of them SQ wise (plus my system is running 12-14 hours per day).

At present I’m using some little Class D things as a stop gap which do sound great, but the ultra high damping factor can make the system sound a touch lean with some material. I would just like a little more meat on the bones, especially in the LF’s.

So ideally I’d like a really low powered SS Class A amp with only a few watts to avoid the heat etc. But I haven’t come across any. Is there such a thing and does anyone have any first hand experience?

 

[tsaett]

First Watt sounds like what you need!
http://www.firstwatt.com/

 

[Audiophile Bill]

Can you diy / feel okay building something simple from a schematic? If so there are quite a few things online you can try. I would build the Hiraga Le Monstre or one of the Pass circuits.

 

[Thetiminator]

Interesting re the Hiragana. An engineer had told me that it was the best power amp he’d ever heard BUT only if built properly. Apparently he’d had a few home built ones across his bench that were just hopelessly out of spec - here’s the convo:

“Hiraga le monstre actually gives around 7W or so but sounds amazing when done right. Although it looks like the worlds simplest power amp i do not regard them as suitable for DIY'ers as everything about them is critical and you really need a distortion analyser, scope, low distortion oscillator etc and the knowledge to tweak each one into spec.... the one elsewhere on pfm which I rebuilt was all made according to instructions and with correct parts by the original builder but actually gave about 1.5W and about 3% THD as it arrived with me!”

 

[bonzo75]

Interesting re the Hiragana. An engineer had told me that it was the best power amp he’d ever heard BUT only if built properly. Apparently he’d had a few home built ones across his bench that were just hopelessly out of spec - here’s the convo:

“Hiraga le monstre actually gives around 7W or so but sounds amazing when done right. Although it looks like the worlds simplest power amp i do not regard them as suitable for DIY'ers as everything about them is critical and you really need a distortion analyser, scope, low distortion oscillator etc and the knowledge to tweak each one into spec.... the one elsewhere on pfm which I rebuilt was all made according to instructions and with correct parts by the original builder but actually gave about 1.5W and about 3% THD as it arrived with me!”

The ones I heard, all DIYed, were pretty poor. So that seems right, maybe if Hiraga himself or someone as talented makes it, it might work. The Hiraga based DIYed Altecs sounded poor as well

 

[Thetiminator]

He also said the Pass kits wouldn’t have low enough noise for my speakers (something to do with mosfets in the input stage?) ....here’s what he said:

“One of the prices you pay for the ultimate in low parts count, most direct signal path etc in many of these low power class A designs is low PSRR (power supply rejection ratio), hence they are unusually sensitive to mains hum etc on the supply rails... Now being class A they draw a lot of current continuously and this causes mains hum on the power rails... Not a happy recipe.
QED if using super efficient speakers then you are very unlikely to get low enough mains hum unless you REALLY know what you are doing... and many of the available designs/kits are likely to need better power supplies than those that are supplied with/intended to be used with.... the Hiraga and "Eastone"'s FirstWatt M2 both came in for rebuilds due to just this! and they aren't using 105dB/W speakers.
I would be temped to use fully regulated supplies (as in Naim NAP250 as most well known amp to do this) to guarantee low enough noise”

 

[bonzo75]

The first watt that @manisandher uses with his tune audio Anima is very musical, was made just outside London and cost just over 1k. Excellent system, PM him. He knows the guy who made it

 

[Thetiminator]

Ok Bonzo will do ta....

 

[Thetiminator]

So there doesn’t appear to be a commercially made amp with the kind of specs I’m looking for...looking likely to be a custom build then?

 

[gestalt]

Valvet, Bakoon, and Sparkler come to mind. No opinions on the sonics.

 

[Sablon Audio]

@wil is using Bakoon on his AG Duos. I personally would also look at the Pass SIT.

http://www.firstwatt.com/sitintro.html

 

[bonzo75]

Riviera hybrid integrated, 10w. From Italy, all their amps are good.

 

[microstrip]

Interesting re the Hiragana. An engineer had told me that it was the best power amp he’d ever heard BUT only if built properly. Apparently he’d had a few home built ones across his bench that were just hopelessly out of spec - here’s the convo:

“Hiraga le monstre actually gives around 7W or so but sounds amazing when done right. Although it looks like the worlds simplest power amp i do not regard them as suitable for DIY'ers as everything about them is critical and you really need a distortion analyser, scope, low distortion oscillator etc and the knowledge to tweak each one into spec.... the one elsewhere on pfm which I rebuilt was all made according to instructions and with correct parts by the original builder but actually gave about 1.5W and about 3% THD as it arrived with me!”

Magico demoed the "Ultimate III" using Nelson Pass First Watt amps at Munich 2014. And as far as I remember reading, no one complained about being noisy!

The question that IMHO is fundamental in this thread: what brand and type are your horn speakers?

 

[bonzo75]

Magico demoed the "Ultimate III" using Nelson Pass First Watt amps at Munich 2014. And as far as I remember reading, no one complained about being noisy!

The question that IMHO is fundamental in this thread: what brand and type are your horn speakers?

It was impossible to note anything at that demo. It was a controlled demo, people had to queue for a particular time slot of 30 mins, then the room would be filled, overcrowded, and only chosen tracks like dire straits etc would be played briefly

 

[Thetiminator]

The question that IMHO is fundamental in this thread: what brand and type are your horn speakers?[/QUOTE]

Living Voice Air Partners, essentially the same as the Vox’s but more transparent and better IMO...

 

[microstrip]

It was impossible to note anything at that demo. It was a controlled demo, people had to queue for a particular time slot of 30 mins, then the room would be filled, overcrowded, and only chosen tracks like dire straits etc would be played briefly

I only referred to Munich 2014 as an example - there are other reports on the net on such system.

 

[Audiophile Bill]

w

The question that IMHO is fundamental in this thread: what brand and type are your horn speakers?

Living Voice Air Partners, essentially the same as the Vox’s but more transparent and better IMO...[/QUOTE]

What are you doing below 70hz?

 

[microstrip]

The question that IMHO is fundamental in this thread: what brand and type are your horn speakers?

Living Voice Air Partners, essentially the same as the Vox’s but more transparent and better IMO...[/QUOTE]

Congratulations - did you get your friend pair? I researched the speakers on the net thinking about the Lamm ML3's.

 

[Thetiminator]

w


Living Voice Air Partners, essentially the same as the Vox’s but more transparent and better IMO...

What are you doing below 70hz?[/QUOTE]
Twin DB1’s. But not 70hz. In room mine were measuring flat to c.45hz, so the DB.1’s are rolled off at 45hz with a 12db slope...

 

[Thetiminator]

Living Voice Air Partners, essentially the same as the Vox’s but more transparent and better IMO...

Congratulations - did you get your friend pair? I researched the speakers on the net thinking about the Lamm ML3's.[/QUOTE]

Yep I had two friends with a pair each and was offered both pairs. I wish I’d taken both now but hey ho. I upgraded the cabling in mine from the original Hitachi to the upper end Furutech stuff, changed all the binding posts etc. Made a decent difference..