if you all had a choice to start again what....

[PixelPlay]

Please help
I have been pointed in the direction of the Pass amps by a very reliable friend.
After reading through the forum I am convinced that his advice is correct and this is made cirtain by the way that the forum members are willing and able to help where they can.
I would like to know which amps you would like to build if you had the chance to start over.
There are many types of variations doing the rounds and I would be interested to see which lands on top. I personally am looking to build a set of monos to drive full range ESL's
Thank you all for your time.

ESL

[Allen Newby]

I would also be interested to see what lands on top. Not least because every designer/builder thinks that his/her variation on a Pass design is the best and will happily argue the point!

If you are thinking about driving the ESL's directly, you would need a very high voltage amp, eg a tube amp or possibly a class D amp. See this thread for example:Class D for ESL's

If the speakers use a conventional step up transformer then you may have a "difficult load". The Zen/Aleph series for example have increased distortion with low impedance loads but work well into 8 Ohms if not pushed too hard. What impedance do the the ESL's present to the amp?

If you you are thinking about a Pass amp, it is worth questioning how you feel about simplicity vs complexity and if you are thinking of building one, your experience.

For example, I really like Zen V4. Zen V1 was too simple for my taste and has too high a distortion. Some designs eg Zen V8 and Zen V9 might sound better to some ears but are the circuits are quite complicated. The same is true for the super-symmetry series. Initial concept; simple, later improvements; complex. The su-sy circuits also look a bit tricky to bias and set up. I went for LTP Zen which is similar to Aleph CCS but with input CCS modulation. I think it is very fine indeed, but then I would!

[vitalstates]

Hi Pixelplay

from the photo they look like Rob MacKinlay's Acorns???? If so, I have been running a pair of ESL 3s (which have the same demands)with a WAD 6550 PP amp for a number of years(see my website for details). As a SS alternative I know a number of people in Oz have been using Aleph 4 with very good results.

I believe Rob would be the person to ask as it was he that first brought the Aleph to my attention.

google eraudio for Rob's email address

Regards

Ed

[JCM]

There are many types of variations ... and I would be interested to see which lands on top.

None would, because not everyone would agree.

I personally am looking to build a set of monos to drive full range ESL's.

In that case, you might want to go right to an Aleph. You can get the benefit of balanced operation, good efficiency, good PSRR, etc.

That's a hard question. I'd love to hear them all, side by side. If I personally had to choose only one, I'd go with an Aleph, a proven design.

I don't think you can really go wrong with any of these amps. The benefits of Class A bias are in them all.

[carpenter]

I'm all for the ZV7-T.

Nelson describes a configuration that works with ESLs, in that it is stepped up with a center tapped, ESL transformer. Someday, I'll try that approach. For now, I love the ZV7-T with my horns.

John

[Nelson Pass]

If you want to drive electrostats more difficult than the Quads,
I suggest some version of the A75, which can deliver high
wattage if asked and high current with lower distortion than
most of the other (Pass) DIY designs. You can find the two-part
article at www.passdiy.com

[PixelPlay]

from the photo they look like Rob MacKinlay's Acorns????

They are indeed a type of Acorns. Rob hed suggested a pair of aleph 4, however with all the posts of the Aleph x, the decision becomes farmore difficuilt.

[Alain Dupont]

PixelPlay,

And YES The A75 can give you power in the 1 to 2 ohms range.

My Martin Logan Aerius' i Electrostatic's got a dip as low as 1.7 Ohms
in the impedance curve.

The A75 is one of Nelson best design for Electrostatic's!
But you need a beefy power supply, I did use a 750 VA toroid

I did listen to these electrostats through Audio Research Transistor and Tubed
amplifiers {100watts} ; and the A75 is one the best !!!

Look at my web page...
And if I had to do it again, I would do a A75!
{The electrostatic friendly Amplifier}

Regards.

Alain.

[PixelPlay]

Thank you for your suggestions. I have spent some time looking through all the treads.
The A75 looks very interesting.
I am also interested in a ste of high power Aleph-X / Aleph 100 X.
Any thoughts on these?

[Alain Dupont]

PixelPlay,

With a Aleph-X / Aleph 100 X You will need huge heatsinks....
And consider that the impedance will be higher than with the A75

I bought 4 heatsinks to build 2 monoblocs Aleph-X
4 * KL-271 (12" x 8", 0.18c/w, black anodize) or 0.09 for 2 pieces
gives about 70 watts for each mono

And on the toroid side 100 watts class A needs a 500 VA for each channel
Or a 1000 VA for a stereo...
And go for the KL-273 and 4 pieces for a 2 * 100 watts Aleph-X

http://www.diyaudio.com/wiki/index.p...+and+KL-273+GP

The advantage of the A75 is that I did use all the 4 * 12 {75 watts each) Mosfets
and so got the most low impedance possible...
Use the xcell spreadsheet to do your calculations, and use as much as possible
Mosfets, considering that they need to be biased high to get better sound!!

Regards.

PS: I am moving back to France next week and The A75 is already in his casing
3/4" plywood ; ready for shipping!!
Hope to build the Aleph-X monoblocs during 2007 !!! and be able then to compare!

Alain.