The Stax Thread III

[Rawdawg3234]

Hey there,
I'm looking for a decent speaker amp to pair with my sr3/srd-5.
I'd like it to be relatively small for my desktop and under $200
So far the only good candidate is the emotiva mini x .

Also could use any advise about stax products as I plan I upgrading down the line.

 

[realmassy]

Especially on the STAX thread? Is this thread immune from logic and reason? I was simply stating the facts. Just like the fact that e stats are the best headphones. It's a fact not a debate.

You were not stating any fact, but your opinion, and we are OT

 

[davidsh]

Hey there,
I'm looking for a decent speaker amp to pair with my sr3/srd-5.
I'd like it to be relatively small for my desktop and under $200
So far the only good candidate is the emotiva mini x .

Also could use any advise about stax products as I plan I upgrading down the line.

Well, the emo works fine with the energizers.. Can't really tell you much more than that.

 

[FrankCooter]

  But if you look at it, he is using NOS capacitors, those back ones are mean looking Russian NOS cap's, I'm sure you can substitute all those big caps for regular modern Panasonics or alike and the amp footprint will be much smaller. 
 
What tubes is he running?

 
Those are Eimac 35T's (or Russian copies). They have a mu of about 40, take a minimum of about 700V on the plate, and have a very high rp . Since there is only one per channel, I'm assuming they're loaded with some sort of  center-tapped choke (it would have to be a "beast" both in terms of inductance and voltage/current ability ) and then capacitor-coupled to the headphones. Not the most practical approach to a DHT electrostatic amp, but If you don't mind the caps in the signal path, or the extreme power requirements, no reason it shouldn't work.
 
I have a  transformer-coupled 845 electrostatic amp in development. It's  a huge project, but  a bit more "real world" than this one.

 

[eric65]

  Ok, I just realised those two big tubes are used for rectifying in the PS with all the transformers, I'm more interested in what tube his running for the amp part, the two brightly glowing ones sure as hell not 845's as they don't have leads coming out from the top, I think the Stax mafia are interested in any tubes out there able to be pushed through 700vdc+ on the plates for there next project without going to complicated, last I read that is till either KG or Birgir can chime in.
 
What's Dimitry's website? If he has one.

 
Try to contact by PM Oingo Boingo = Alex (Alexander) (the owner of the Demograf as well as a beautiful collection of headphones) ; Alex seems well know Dimitri and his past achievements; Maybe can you it inquire about all these tubes (much more than me)
 
Here some links on Alex (Oingo Boingo) and Dimitry
http://www.head-fi.org/t/677809/the-stax-thread-iii/60#post_9737391
http://www.head-fi.org/t/677809/the-stax-thread-iii/75#post_9737962

 

[FrankCooter]

  
 
As long as we're discussing "home-brew" DHT electrostatic amps, here's my 845 based amp. It's a single-ended 3 stage design. 1st stage is a CCS loaded 6N7 direct-coupled to a 45. 2nd stage is a 45 driving an interstage transformer connected to the 845 grid. The 845 output drives a custom high level Electra-Print phase-splitting transformer.Running the 845 with fixed-bias at 650V@60mA. Power supply was originally based on mercury rectifiers, but am currently working on a hybrid solid-state/tube regulated supply. Not the most practical project, but definitely a lot of fun and a completely different presentation from most other electrostatic amps.

 

[kevin gilmore]

a thing of beauty for sure.
 
frank has retro down to a science.

 

[Lornecherry]

That thing looks like a classic 30's radio. Very art deco. Refreshing to see something that doesn't try to like like the latest smartphone.

 

[DefQon]

@eric and frank: thanks for the clarification.

Yeh Franks builds are really something I've seen those pics takeb at Canjam years ago which he brought his homebrew creations to. Is the 845 a PITA to work with I've read that it does take quite some considerations into the design to have 845 done right, also what do you mean by DHT?

 

[arnaud]

Directly Heated Triode, don't ask me anything else!!

 

[DefQon]

Lol google.

What I meant is when would you need it, why would you need it and what are things to consider when you using it.

 

[arnaud]

I figured it was bizarre you'd know about the tube and not the principle of operation . Talking about googling, for the inepts like myself: http://www.diy-audio-guide.com/direct-heated-triodes.html

 

[DefQon]

I didn't say I know about the tube till Frank said what it was?

 

[kothganesh]

Well, the emo works fine with the energizers.. Can't really tell you much more than that.

+1. I use the Emotiva with the SR5. Good but not great. I heard the SR5 with a vintage Luxman receiver. That was great.

 

[milosz]

Hey there,
I'm looking for a decent speaker amp to pair with my sr3/srd-5.
I'd like it to be relatively small for my desktop and under $200
So far the only good candidate is the emotiva mini x .

Also could use any advise about stax products as I plan I upgrading down the line.

A lot of people like the T- amp stuff- based on the Tripath chips.  For the price ($90) , the Dayton Audio DTA-100 is a damned good 50 watt/ channel amp.  Really you don't need that much power for an SRD-5  so you might try the Lepai LP-2020A+  20 watt/ channel tripath amp from Parts Express for $24 (!!)  These are switching amps, and I think they sound better than many of the solid state amps out there; not quite as nice as the better class-A amps but better than almost all mid-fi receivers, integrated amps etc. For $24  you can hardly go wrong.  If you don't like it on your SRD-5, you can use it as a spare / troubleshooting / utility amp. (The Lepai is the amp I would use if I wanted to stick to a budget.)  Many listeners have said that the Tripath amps have a "class A-like"  sound.  I have a DTA-100, and I agree.  Sounds better than it has a right to at the price.
 
If you are capable of some light D-I-Y, another route would be to use a pair of the 10-watt class A solid state amp boards from eBay seller jims_audio, the amp boards sell for about $57 a pair and you'll need   +  and - 12-to-18 volt supplies at 5 amps or so per rail.  These are VERY nice sounding amps, I have a bunch. For $150 all-in (amp boards, power supply, casework from Par-Metal etc) you could have a high-end 10 watt/ channel amp, along with the satisfaction of building something yourself.  I use 5 of these for L/R/C/LR/RR speakers for my surround speaker setup in my "computer office." (They also help heat the room- class A amps always run hot.)
 
AS far as a dedicated electrostatic-only amp for a future upgrade, I can highly recommend the Stax SRM-T1. It's a VERY GOOD sounding amp, has both low- and high-bias output jacks, and there are many of them around so they come on the market fairly regularly. I think it sounds just about as good as ANY Stax brand amp, save the rare T2.  The newer Stax tube based amps sound a LITTLE better, but not really THAT MUCH better, and given the price, the SRM-T1  is a clear winner in terms of sound per dollar.
 
Upgrading from the SRM-T1  is an expensive proposition. To get a MARKED increase in sound quality, you need to go to a KGSS or KGSSHV amp, Blue Hawaii, etc.  $$$$$$$$