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Seeking listening help in Austin area

I live in Austin and have built an amplifier that I designed for magneto-static loudspeakers, specifically Magnepans.

I am looking for listeners to critique the sound of the amp. It is physically it is built on a wood board and is meant for 'first-ear' listening evaluation and learning only, it will not survive shipping so I have to hand deliver it and pick it up, thus Austin and the immediate area.

If you have a basic Maggie system the you know well I would like to bring the amp over and have you change it out with your amp, you listen, and tell me what you think it did to the system. This is how I learn to improve a design.

The is a Concept Amplifier, to my knowledge there is nothing like it. Class-A, no feedback, current mode gain, very high bandwidth and most uniquely, the distortion does not change with frequency and that is uses over 700 transistors to accomplish 50 watts per channel.  Results so far have been exceptional and I want to learn more. 

If you would be interested in listening and telling me what you hear, I would be glad to bring it over to audition.

Thank you,

Barry Thornton 512-266-7142

barryaudiophile
12 responses Add your response
sbank's avatar
sbank
3,379 posts
 
@geoffkait @audiokinesis Thanks for the comments, but there's no trouble getting proper volume at normal distance in my setup. What I meant is that my speakers probably would not be a great candidate for the OP to use to test his 50w amp. 
In fact, I don't think there are many electrostatics that are a great match for a 50w amp; perhaps smaller Quads, but certainly not larger Maggies, Sound Labs, nor Analysis Audios. Barry, even if your amp sounds inherently terrific, it will mate well with a pretty darn narrow slice of the speakers in the market IMHO. Bridgeable monos? A bigger brother? Cheers,
Spencer
tomic601's avatar
tomic601
12,969 posts
 
700 x probability of failure.....make mine tubes....
but what a cool experiment 
ignore anything I wrote....
audiokinesis
2,747 posts
 

@geoffkait , It looks like I misunderstood what you meant by "twice the volume".  

It can mean "subjectively twice as loud", which is generally considered to be +10 dB.   That's now I'd normally use the term.

But it can also mean "equivalent to doubling the amplifier power", which would be +3 dB, which is indeed what we'd get from sitting half as far away from a line source.

Duke

geoffkait's avatar
geoffkait
23,365 posts
 
Eggs ackley! That’s what I said.

PS I kinda doubt anyone sits one inch from his speakers. Or one foot. Hel-loo!
audiokinesis
2,747 posts
 

Hi Spencer,

I'm afraid that you do not get as much SPL increase from moving closer to the SoundLabs as you do with conventional speakers.  Likewise you do not get as much SPL decrease as you move further away.

The reason is, the big SoundLabs do a good job of approximating a line source, while most conventional speakers approximate a point source.  SPL falls off by only 3 dB for each doubling of distance from a line source, as compared with 6 dB for each doubling of distance from a point source.  Likewise SPL increases by only 3 dB for each halving of distance from a line source, versus 6 dB for each halving of distance from a point source.  These numbers don't take the contribution of room reflections into account, but these trends hold up well in a home listening room.  

In fact, at very close range, the SoundLabs approximate a planar source, with virtually ZERO change in SPL as distance changes!  The difference in SPL in going from 1 foot down to 1 inch is negligible. 

Duke

geoffkait's avatar
geoffkait
23,365 posts
 

sbank
Too bad my Sound Lab full electrostatics need more power. 86db on a good day. Good luck Barry, it’s gonna be tough. If you just want to borrow my ears, I am happy to come listen to them anywhere around Austin. Cheers,

Have you tried sitting closer? If you can sit half as far away you should get twice the volume, no?
audiokinesis
2,747 posts
 

"What in the Hell is "electroscopic" and "mangetostatic" operation?!"

Insight that Barry is more of an amp guy than a speaker guy.

"Class-A, no feedback, current mode gain, very high bandwidth and most uniquely, the distortion does not change with frequency"

It sounds to me like Barry is solving problems that really matter to the ears, even if they don’t necessarily result in the most impressive traditional specs.

Duke

I’m a speaker guy, not an amp guy



bdp24's avatar
bdp24
9,868 posts
 
What in the Hell is "electroscopic" and "mangetostatic" operation?!
sbank's avatar
sbank
3,379 posts
 
Too bad my Sound Lab full electrostatics need more power. 86db on a good day. Good luck Barry, it's gonna be tough. If you just want to borrow my ears, I am happy to come listen to them anywhere around Austin. Cheers,
Spencer
barryaudiophile OP
57 posts
 
Thank you Gentlemen for the information but my request was and is -

Looking for some one in the HOT area with a stable listening system based on or including a pair of planar speakers, either electroscopic or mangetostatic operation, and knows the sound of the system, to put my concept amp design prototype in the system and tell me what changes are heard,

whart's avatar
whart
3,052 posts
 
Do you know the guys at the Sound Gallery in Austin? They are dealers of used equipment, mostly older dynamic speakers, but they have tech chops and are pretty cool~ I can't really help you b/c I'm running a pair of vintage Quad electrostats and very high efficiency horns. Those Sound Gallery guys might play, though- give 'em a call. The one fellow's name is....wait for it....
Robert Johnson. 
good luck,
bill hart
bdp24's avatar
bdp24
9,868 posts
 
Barry, Magneplanars (and Eminent Technology LFT’s) are actually called magnetic-planar loudspeakers. The term "static" is appropriate for electrostatic speakers, but not magnetic-planars.
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