Stax SRM-Xh Review (Electrostatic Headphone Amp)

[amadeuswus]

Yes, with XLR. It works great.

Your volume pot is logarithmic, won’t be surprised if you are outputting way less than 5 watts at 9’oclock setting

The bias voltage goes into the membrane the signal voltage goes into the plates. Higher bias voltage higher sensitivity.

I have a SRD-7 (original version, not the "Pro" model) and I sometimes use it to drive Lambda Pros since the connectors are compatible. It sounds fine to me that way, but am I sacrificing anything other than ultimate output level? Thanks for your thoughts.

 

[brimble]

I have a SRD-7 (original version, not the "Pro" model) and I sometimes use it to drive Lambda Pros since the connectors are compatible. It sounds fine to me that way, but am I sacrificing anything other than ultimate output level? Thanks for your thoughts.

Good question. If you don't get an answer here, I suggest you ask on head-fi:

https://www.head-fi.org/threads/the-stax-thread-new.223263

 

[the_brunx]

I have a SRD-7 (original version, not the "Pro" model) and I sometimes use it to drive Lambda Pros since the connectors are compatible. It sounds fine to me that way, but am I sacrificing anything other than ultimate output level? Thanks for your thoughts.

I think I once heard a louder ground noise or hum level, cant remember on a normal bias transformer I am guessing since you have to amplify more to get the same loudness compared to pro bias. So I am guessing the SNR level and SINAD can also be different compared with pro bias depending on the characteristic curves of the amp being used and maybe also other factors. but I am interested to know the definitive answer myself.

 

[billqs]

Way late to this party, but the SR-007's are much harder to drive than the Lambdas (also harder to drive than the SR-009). I believe the mini amp reviewed here is only meant to power the "L" series.

 

[vintageaxeman]

The A90 is a Headphone amplifier / preamplifier, although powerful for a head amp, it wasn't designed, nor would it have enough power to drive speakers, (it has no speaker terminals).

The SRD-7Mk2, SRD-7Pro were designed to connect to the speaker outputs of a poweramplifier or integrated Amplifier, I think somewhere between 15 to 50 watts RMS per Channel, into 8 ohms would be required for adequate drive and headroom, when connecting to an SRD transformer box and Stax electrostatics.

If Toppings JohnYang designed an amp at a reasonable cost, say $700 to $800 or there abouts, I'm sure there would be a market for it, as Stax headphones are reasonably priced when compared to similar quality Dynamic / plannar headphones, it's the expensive amps / energisers that discourages people from trying Stax headphones.
But I personally would love to see a well designed modern version of the old SRD transformer boxes, for about $350 max, then make my own choice of desktop amp to drive it.

Topping does now do a STax Pro headphone amp.... Just spotted it yesterday. For less than 400 Euros (about 450USD?)

 

[milosz]

Head-Fi reviews by Dr. Gilmore of the Topping EHA5 amp are not complimentary, it doesn't swing enough voltage to really bring out the best in electrostatic 'phones.

There IS an improved "transformer interface" made by Mjolnir audio, the SRD-1 and an upgraded model with transformers by Lundahl, the SRD-1 Lundahl.

The original Stax SRD-7 can be found used. I had one and used it with a number of amplifiers, it was OK (it produced sound through the electrostatic headphones) but it was nowhere near as good sounding as the KGSSHV amp I had or the Carbon amp I now use. In fact, the Stax SRM-T1 or SRM-1 mk II that had both sounded better than the SRD-7, but again neither was anywhere near as good as the KGSSHV amp I had or the Carbon.

 

[A.West]

Seems like everyone who actually listens to the EHA5 for music at normal volumes thinks its fine. But it clearly wasn't designed to amplify square waves at high volumes, and it sounds like it might shut down if you try to do too much 20Hz boost at high levels. Seems like everyone who sells $3000 plus EStat headphone amps says that all Stax amps are bad, and nearly everything else under $3000 is bad and dangerous. Thus it would be a perfect situation for Amir to investigate, if he could get the products for a showdown. Maybe paired also with Stax's sub $600 SR-X1 headphones to see if one can one upgrade one's headphone experience with $1,100 of electrostatic kit and a bit of equalization.