electrostat amp.

[GoRedwings19]

I have read a lot of good things about the Es-1, aristaeus and of course the hev90. All 3 are obtainable and in the case of the hev90 if you know where to ask.

But I wonder what are the differences between the three?

I currently use a 007t to drive my electrostat headphone and am looking for something which improves on it.

I am looking for something which tightens up the bass over the 007t and if possible goes lower. Also I find the 007t and phone has a kind of even tonal balance. I prefer things a little on the warmer side. Also I hear this metallic ringing or sheen to notes. This is distracting to say the least.

So any amp which does not have any of these flaws is worthwhile checking out.

[Rob N]

I would also like to know this.

Also how does it perform with Omega 2's?

[hungrych]

Check out the impressions on the ES-1, apparently it's amazing. Jason told me that it not only got you up there, but down there too..

[hirsch]

I've heard two ES1's so far, and the next one I hear better be mine

The key word I'd use to describe the amp is transparent. In NJ, the owner requested that it be connected to a Leonardo CD player. The amp sounded confused, and detail was missing. Mikhail couldn't figure it out. Finally, he connected it to a Meridian G08, and everything came back. Not the amp at all, but the thing is extraordinarily sensitive to input, and was magnifying the flaws of the player (I'm not recommending the Leonardo ). The ES1 doesn't sound like any other electrostatic amp currently marketed, nor does it sound like HEV90 (based on recollection as an HEV90 was not present). It's cleaner, without sounding analytical. ES1/HE90 may be as close as you can get to the source in headphones. I've had less listening time with ES1/Omega II, but so far I'm almost as enthusiastic about that combo as I am with HE90. I may even buy an Omega II, and I've never really been a fan of that headphone before. It should be possible to alter tonal balance of ES1 a bit by tube rolling. The outputs are EL34's, but you can use a LOT of different tube types on the gain positions (Almost anything from 6SN7 to 5687 to 12A?7 to 6922 types, using Mikhail's socket adapters, and that covers a lot of tubes). It's likely that a tube set that can do what you want can be found.

The HEV90 is warmer and laid back. It does not have the transparency or detail of the ES1. It does have a warm lush signature that is almost the hallmark of the HE90 sound, but is not a great Stax driver IMO. Bias voltage of Stax headphones is 580v, while bias voltage of HE90 is 500v. Since HEV90 is designed for HE90, bias voltage is a bit low for Omega II. HEV90 does drive Omega II, and sounds OK, but it's not the best amp for the headphone. Further, the Omega II wants a 5 megaohm loading resistor in the bias line, while the HE90 wants 10 megaohms. ES1 has separate bias voltages and impedance loading optimized for HE90 and Stax on the respective jacks, so each headphone sees its correct optimal electrical parameters.

Aristaeus sounds like the HEV90 with a bit more definition. It's based on the HEV90 circuit, but with a different power supply. The version I heard was a prototype, as I don't think the production model has been completed yet.

IMO ES1 is a breakthrough product that has the potential to redefine what an electrostatic amp should be. The advantage of an electrostatic headphone should be speed and transparency. To date, the ES1 is the best amp I've heard for hearing the unique characteristics of electrostatic headphones. In comparison, other electrostatic amps now sound to me as though they are hiding the full potential of electrostatic cans.

Sorry if I sound a bit overenthusiastic. The ES1 is something new to me, and I like it. A lot.

You should be able to get rid of the metallic sheen and ringing you hear on the 007t, however. Decent tubes, properly biased, should not produce that effect on that amp. The ringing could be due to tube microphonics, but the metallic sheen could be the tube type. I heard something like that using Mazda-Brimar 6CG7's, but got rid of it with Toshiba 6FQ7's.

[tkam]

Any thoughts on how the Blue Hawaii compares to the ES-1?

[kevin gilmore]

Time for my 2 cents.

The SR-007 does in fact go to dc. But the sound is severly limited by the choice of output tube, you can tube roll the thing night and day

and you still can't get away from the fact that a 450 volt (max) tube is being pushed to 700 volts. The Rp of the tube limits what it can

do at low frequencys.

Coming some time in the future is the KGST which has 6s4 output tubes which have about half the impedance of 6cg7's. And are rated

for the voltage. Fully DC coupled.

The ES-1 and BH share the same output tubes. About 4 times the power of a sr-007. The ES1 is based on my ac coupled design.

The BH is fully dc coupled. They sound much more similar than you might think.

No one is currently making BH's. So if you want one, you would either have to build it, which is a significant amount of work, or pry one

out of someone who already has one.

I should also mention that i own an aristaeus, and i very much like the sound of that too.

[PATB]

Time for my 2 cents.

The SR-007 does in fact go to dc. But the sound is severly limited by the choice of output tube, you can tube roll the thing night and day

and you still can't get away from the fact that a 450 volt (max) tube is being pushed to 700 volts. The Rp of the tube limits what it can

do at low frequencys.

Coming some time in the future is the KGST which has 6s4 output tubes which have about half the impedance of 6cg7's. And are rated

for the voltage. Fully DC coupled.

The ES-1 and BH share the same output tubes. About 4 times the power of a sr-007. The ES1 is based on my ac coupled design.

The BH is fully dc coupled. They sound much more similar than you might think.

No one is currently making BH's. So if you want one, you would either have to build it, which is a significant amount of work, or pry one

out of someone who already has one.

I should also mention that i own an aristaeus, and i very much like the sound of that too.

Dr. Gimore:

Could you please give us your 2 cents on the upcoming Woo Audio Tube Amp (which is based on your design)? A tube amp for $1250 seems too cheap to pass up. The build quality looks amazing too.

Pat

[hirsch]

The ES1 is based on my ac coupled design.

Just a note, the ES1 is not based on your ac coupled design, according to Mikhail. It's actually much more closely related to the older Stax designs, such as SRM T-2. There are only two capacitors in the signal path.

Sonically, there is little similarity between the sound of the ES1 and the sound of your designs that I have heard (mostly implemented by Justin).

[neilvg]

I would love to hear the ES-1. I have been listening to the HEV90 all weekend and to me, Hirsh's descriptions seem right on. Warm, smooth, articulate, but a little ethereal. It doesn't have the bass impact or 'etched out' high's that it could. I like the laid back sound, and I have had the pleasure of noticing the burn in effect. I have NOS Siemens, and it took a good 100 hours to start to really feel that signature liquid sound. It's like cream.

The ES-1 makes me very curious.

[kevin gilmore]

Mikhail just called me and told me what the schematic is. It is certainly NOT a T2 as that is a solid state/tube hybrid.

The BH is much more like a T2 in this respect. Mikhail's amplifier is a single tube differential amplifier, with the second tube

as a direct coupled cathode follower, which is ac coupled to the output tubes. The output tubes are directly coupled

to the load. I assume there is some feedback. Multiple plate resistors and lots of standing power for the output section.

Something like 15 watts per tube. Similar to the BH in power consumption. (i.e. great for cold winter nights)

So in this respect its more like a SRA3S except with a drive tube in the middle.

As far as the woo audio amp, who can argue with quality like this. At that price it is a bargain.

Edit: not the sra3s, as that is also a solid state/tube hybrid.

More like this

http://www.bonavolta.ch/hobby/en/audio/hdgsta.htm

[GoRedwings19]

From the replies it seems that the hev90 would be more my cup of tea. I don;t need outright transparency and resoulution although the Es-1 being able to tube roll with the varying sockets also sounds intriguing.

[philodox]

Just a note, the ES1 is not based on your ac coupled design, according to Mikhail. It's actually much more closely related to the older Stax designs, such as SRM T-2.

Wait a sec... isn't the Blue Hawaii based on the SRM T-2?

EDIT - Looks like the Doctor beat me to it.

[PsychoZX]

Dr. Gimore:

Could you please give us your 2 cents on the upcoming Woo Audio Tube Amp (which is based on your design)? A tube amp for $1250 seems too cheap to pass up. The build quality looks amazing too.

Pat

Wow that amp looks fantastic. Almost makes me want to get an Electrostatic rig.

[GoRedwings19]

So does the base model Es-1 start at 4k? How would I know what kind of options I wanted? you hear about these solen stages and all this kind of stuff etc but I don;t have a clue what they do. Can someone draw up a list of options and what they do? I am not interested in technical aspects of the amp I just want to know I pick the right goodies for my preferences and taste's.

[PsychoZX]

So does the base model Es-1 start at 4k? How would I know what kind of options I wanted? you hear about these solen stages and all this kind of stuff etc but I don;t have a clue what they do. Can someone draw up a list of options and what they do? I am not interested in technical aspects of the amp I just want to know I pick the right goodies for my preferences and taste's.

Mikhail would probably be the best person to help you with that.

[GoRedwings19]

Well if he has time then maybe he can post as I think most people would find it helpful.

[Dusty Chalk]

I would also add the KG SS electrostatic amp (as implemented by Justin), as I have heard that several times now and've been impressed.

I have yet to hear an ES-1. I suspect I will be able to shortly after Hirsch receives his. If he lets me. I may have to bribe him. With pretzels.

[hirsch]

I would also add the KG SS electrostatic amp (as implemented by Justin), as I have heard that several times now and've been impressed.

I have yet to hear an ES-1. I suspect I will be able to shortly after Hirsch receives his. If he lets me. I may have to bribe him. With pretzels.

I've let Dusty listen to the ES1, but did not exact the pretzel toll. Good thing I saw this, as he may want to hear it again

[Dusty Chalk]

I brought pretzels! The first time I heard it, anyway. Those Newman's Own Bavarian pretzels? Of course I didn't call them a bribe at the time (one doesn't do that), I just said, "you have to try these".

And yes, I do want to hear it again, once you fix it/it burns in/whatever.

[tkam]

How about the McAlister EA-4? I've been thinking about getting a pair of Stax O2's and the EA-4 and the new amp McAlister has coming out look like pretty good options.

[philodox]

How about the McAlister EA-4? I've been thinking about getting a pair of Stax O2's and the EA-4 and the new amp McAlister has coming out look like pretty good options.

Seconded.

[GoRedwings19]

The Mcallister is a worthy consideration. I don't think I could do the wait time for something like the aristaeus or the es-1.

I certainly need to hear it against what I am currently using to drive my headphone. Although 007t sound is adequate I find it versatility is very much appealing with it's inputs and loop thru circuitry.

[pabbi1]

There is yet another McAlister not yet on the web site - POST EA-4 ( EA-X?), which is in the ~$1700 range (refer to McAlister for pricing). Peter is building mine this week, and I hope to see it by Labor Day weekend. I'll be doing a mini-shootout with Rob (bahamaman) and his ES-1 with OII, and Alex (AKZip) with our respective HE60 shortly thereafter just to see where we all are.

Now, if only I could find a panel mount HE60 jack...

[philodox]

Now, if only I could find a panel mount HE60 jack.

You should just get them recabled with a HE90 connector... You know... Larry woodied his.

[thrice]

Anyone have info on that Woo electrostatic amp? There's some info at their website, but that pic is not there....looks like a different amp. They do not list a price for the amp either.