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John
23-03-2009, 19:15
Any thoughts round good low powered amps suitable for high efficency speakers something between 9 to 15 watts

Mike
23-03-2009, 19:34
There are many possibilities here... what sort of speaker sensitivity are we talking?

Do you want to build or buy?... And, what price point? :)

John
23-03-2009, 20:30
96db
not sure if my DIY skills are up to building a good amp
Price range £1000 approx can be new or second hand

Spectral Morn
23-03-2009, 21:17
If you want a class A power amp the Pass labs Aleph0 or Aleph 3 are worth looking for small bricks that are mostly heat sinks...very plain art deco. You will probably need a pre with balanced outs to match though....(I think the Aleph series is balanced )its XLR and single ended...can't remember.

Always meant to check these out but I don't (A) have the money now or (B)speakers that are sensitive enough.

The Pathos TT r integrated amp is a Class A valve hybrid 35 watts..but needs very sensitive speakers...you must treat it like a low power Single ended valve amp. Again fantastic, excellent sound...but I don't have speakers sensitive enough. Its very big, very heavy, two man lift and fantastic looking.

Your budget would get you the pass labs but you would need a bit more for the Pathos except maybe a mk1 you want a later one though....they're better.

regards D S D L

aquapiranha
23-03-2009, 21:55
96db
not sure if my DIY skills are up to building a good amp
Price range £1000 approx can be new or second hand

My fostex's are 95db, and I can shake the windows with just shy of 1.8 watts!!

so the world is your oyster there.

Clive
23-03-2009, 21:59
WD KEL84, 15W. £479 basic kit or up to £700 with relay inputs, upgraded caps and fully assembled. Seriously good, even though it's push pull.:)

Steve Toy
23-03-2009, 23:50
Push-pull (done right) plays real world music. SE works with speakers that carry their own set of compromises although I know this option can work where space in-room permits.

I come from the flat earth school of thought on this and I ended up with push-pull valves....

Marco
24-03-2009, 05:26
LOL. Oi, don't be so defensive Stevie boy!

I don't think Clive meant it like that :eyebrows:

Marco.

Clive
24-03-2009, 08:16
LOL. Oi, don't be so defensive Stevie boy!

I don't think Clive meant it like that :eyebrows:

Marco.
Indeed, I've now edited and added a smilie.

jandl100
24-03-2009, 09:01
In my fairly limited experience, solid state class A can be a pretty boring affair. I've had home dems of Pass Labs Aleph 3 (just plain uninteresting into my 100dB+ Avantgarde Unos, should have been a good match ...) and another, but this one class A to AB switchable beast whose name slips my mind at the moment :doh:. Anyways, both of those were dead tedious to listen to, although the switchable one perked up a bit when in class AB.

Valve class A is a totally different container of piscine wonders, though.

Mr. C
24-03-2009, 09:51
Not all class 'a' solid state amplifiers are implemented the same.
Some are more involving, musical and engaging than others.
One of my desires a few years ago was a pair of pass labs X600 monos, very large, superb construction, generated enough heat to warm Siberia a good 10 degree's, the electric meter went into warp drive when you powered up.
Impressive to admire, yet ultimately failed to engage, very sweet and open sound, large staging, great room filling presence. Bass while large was lumpy and over blown.Not much in the way of drawing into the music. Partnering was important too.Lots of happy Pass labs owners out there, for me just did not tick the box's
The little Sugden unit again when paired right can sing nicely, not going to blow your doors off, however a good sound.

Cack Handed
24-03-2009, 16:18
If you want a genuine surprise try and find an original wooden Sugden A21, either the very first Richard Allan version or the first Sugden variant. If you don't love it I will buy it off you.

John
24-03-2009, 18:12
Cheers for all your input more than likely go for the WAD as I know it be quite good

Mike
24-03-2009, 21:40
If you want a genuine surprise try and find an original wooden Sugden A21, either the very first Richard Allan version or the first Sugden variant. If you don't love it I will buy it off you.

Ah!... beat me too it! That would be my choice of SS class A too. ;)

Personally I'd be looking at valves though, no surprise there. With speakers of 96dB I'd also be looking at something single ended as the circuits tend to be much more simple. And they sound nice! :)

I've nothing against PP amps either, it's only rather recently that I've become interested in single ended amps. I've used a WD KEL84 at home for several days and it came surprisingly close to the WD88VA (which is also in your price range - just), but I wouldn't have swapped. :eyebrows:

The old WAD 300B amps sound very very nice too, if one of those pops up it would be well worth investigating.

Cheers...

Beechwoods
24-03-2009, 22:00
If you want a genuine surprise try and find an original wooden Sugden A21, either the very first Richard Allan version or the first Sugden variant. If you don't love it I will buy it off you.

If you find one, and like, I've got a nice condition, fully working R21 tuner here that would go nicely with it. It's just been swapped out of my system in favour of a Quad FM3, which works with my pre and power amp better.

I've always wanted to hear an A21. It is a legend in all-transistor amps...

Magna Audio
25-03-2009, 09:26
Thought I'd share my limited experiences of PP and SE.
I love my project build Class A push pull - well I would, i made ever joint and screwed every nut and bolt holding it together.

I've heard a few other amps. Notably the Berning ZH270 in to 12" DMT's and a pair of 20W SE mono's driving Avantgarde Duo's - umm nice!

My amp was ~20W but I attenuated it by bypassing the splitter stage 6SN7's, sig going straight to driver stage 6SN7's.
Did this as the vol into the big Tannoy's was too loud (for wife) on 1st click of TVC:doh:
Now I am around 8 clicks or less depending on source vol, for wife listening and 16-18 clicks for my listening sessions (out of 24 of course).

The attenuation gained by the bypass was around 21dB.

I did a comparison of my amp to a EL34 based amp in my home and that was warm and cuddly to the extreme. My amp was musical, accurate, fast, full width and etched, by comparison - That's the way I like em.

Details of the amp are here
http://home-and-garden.webshots.com/album/535523301vfXSDn
It's a fairly humble circuit but features the Heffa klump mains transformer and Lundahl audio transformers and silent silicon voltage reg.

Doubt any of this will help but you have to try a few to find out...

If you lived near me I happily unplug and bring the amp round for you to hear...

Forgot to say - your other friend is tube rolling - I can go warmish full blow with Kenrad black 6SN7's or pin drop sharp and edgy with 1940's VT-231 Sylvania white labels.
Current tube of choice is Sylvania brown base top getters or Electro Harmonix.
For KT88 power tubes I started out on Svetlana's, tried Tesla's (bit dry), and now use Electro Harmonix - more resonant and engaging. One day I will burn money with some GEC's ;-)
My amp has been running pretty much daily since 2002 with very few issues - It does get warm - 20W tail resistors and whatever the tubes put out...

Spectral Morn
25-03-2009, 10:04
Nice photos Speedy Steve


you should put some in the gallery section of the forum. Just click on the img tag on your photo site.


Regards D S D L

snowflake
25-03-2009, 12:09
I understand that you're looking for a Class A amplifier and I'm just offering an alternative. Have you considered a class D/class T amp? If you have efficient speakers, perhaps you might want to consider the Trendsaudio TA-10.1

http://www.trendsaudio.com/

There are pretty good reviews out there for this amp and I think they offer very good value for money. I almost bought them, but i realized that I needed more power.

Ali Tait
25-03-2009, 17:33
I have a wooden-sleeve Sugden and yes it's a nice amp.I also have a KEL84 and an original WAD 300b PP.The 300b is probably the best of the three,but you don't see them coming up for sale very often.A close second would be the KEL,and would also be my recommendation.They do come up fairly often,or you could just buy a new one.It's a real giant-killer of an amp IMHO,and one of the most musical amps around.I have some Fostex MLTL's and they are a very nice match with the KEL.Can be made even better with some decent coupling caps etc. and some NOS valves.

John
25-03-2009, 18:21
Cheers Ali the KEL84 is top of the list
Speedy Steve great looking amp

Magna Audio
25-03-2009, 21:06
Glad you like it.
so far I've had it running Monitor Audio Silver 9i's. Then ProAc D25's and now the Tannoy's.
It's being used on many other types of speakers too.

See
http://en.wikipedia.org/wiki/Valve_audio_amplifier_-_technical#Biasing

for the project leaders / creators other projects and explanation of tube amps - a lot of which is over my head:)

I brought most of the cases and transformers back from Sweden on my numerous business trips over there as special baggage - those were the days.

The story about the cases was that Dave met a chap who had a metal box factory who was into Hifi. Dave said he could build him an amp that was better than whatever he had in return for use of the CNC / folding machine.
Hey-presto pretty cool looking cases.
His water cooled transistor amp was interested. Warmed a fairly large aquarium.

This is the output transformer site - some interesting circuits there plus all the iron you could ever need. Shame the postage costs are so high.
http://www.lundahl.se/