Are there any affordable "reference" electrostatic amplifiers?
Jun 12, 2013 at 10:10 AM Thread Starter Post #1 of 9

3X0

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I would first like to mention that I subscribe to an objectivist mindset when it comes to dynamic transducer amplification. I would be comfortable running any of my headphones out of something like a Magni+Modi or O2/ODAC and have little-to-no interest in upgrading.
 
However, I have almost no experience with electrostatic transducers besides listening to them at meets. In my brief research it seems that the likes of the KGSS, BHSE, WES et al come up as "the usual suspects" for electrostatic amplifiers. I've also read good things about the SRM-007t and a few older Stax models.
 
These are all very expensive.
 
I am wondering if there is a relatively "cheap" (i.e. sub-$500 by any means, including second-hand) reference electrostatic amplifier out there, preferably of Stax Pro bias sockets. By performer I mean by the usual objectivist criterion -- low/inaudible distortion and noise throughout a flat 20Hz-20KHz output frequency response.
 
Jun 12, 2013 at 11:38 AM Post #2 of 9

jcx

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Jun 12, 2013 at 12:06 PM Post #3 of 9

3X0

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Interesting -- I know the ESP-950 is quite the performer at its price so I will have to look into the performance of the amplifier independently. I might have to ask Koss on how much they ask for the amplifier-only.
 
I have also read good things about the SRM-1/Mk2 Pro so I may have to look down there as well. Objective evaluation of electrostatic amplifiers seems to be impossible to find given you can't just plug them in for signal analysis.
 
Jun 12, 2013 at 12:11 PM Post #4 of 9

rawrster

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There aren't too many sub $500 amps that I know of.  Justin from headamp sells the SRM-252S but I haven't heard it before so don't know how good or bad it is. Also some older Stax amps shows up every now and then. I saw a modded T1 the other day going for $400 so if you go that route you have to be patient. 
 
Jun 12, 2013 at 12:23 PM Post #5 of 9

forbigger

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it all depends on what you refer to by reference. There no real reference class amp within stats headphone realm. If you refer to amp that can drive Stax reference headphone to its full potential then head over to stats thread, tons of information there......
 
Jun 12, 2013 at 3:14 PM Post #6 of 9

spritzer

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New would be the Stax SRS-252S but at just 4W of current draw there are limitations.  It struggles a bit in places with the Lambda load so a 323S would be a better candidate. 
 
Used I'd go for a Stax SRM-1 Mk2, SRM-3 or SRM-313. 
 
Jun 20, 2013 at 6:03 AM Post #7 of 9

3X0

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Where does the stock SRM-T1 stand? I picked up an older version of it that doesn't seem to have switchable input voltage (EDIT: actually newer since it's internal it seems). Decent enough pairing with the HE60?
 
Jun 20, 2013 at 11:51 AM Post #8 of 9

spritzer

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The T1 design is good but it has the wrong tubes for the job.  Just can't handle the strain but there aren't many good choices out there for high voltage dual triodes. 
 
The amp wouldn't be my first choice for the HE60 though.  They like power or they are just too thin and bright. 
 
Jun 22, 2013 at 3:28 PM Post #9 of 9

3X0

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Anything better for the job circa $500US though? This is under the presumption that the SRM-T1 will serve as a stopgap until I can afford something like a KGSS, KGST, or KGBH sometime in the (distant) future.
 
The one I purchased recently had new tubes installed and was rebiased.
 

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