spritzer

You can remove the elastic mountings and shorten it a bit. Just two screws on each side.

http://www.ebay.com/itm/Alps-Brass-RK50-Quad-Pot-/200990813525?pt=US_Amplifier_Parts_Components&hash=item2ecbfc6d55 That is some funny shit. The "alps folk of Switzerland"? What the hell are they smoking. Plus the quad was used in a lot of high end equipment in Japan.

The 6P1 amp is even cheaper (less than 200$) so yeah, great to learn from. You could also modify it to take EL90's which are pretty good. I picked the bigger amp as it had a better PSU setup and I have a pile of nice 807's that will work perfectly. My only problem is with the chassis height as it simply might not be enough for all the film PSU caps I want to put in there. The 100uf/500V aren't exactly small... I'll also probably add DC heaters for the front end, maybe a CCS on it too.

Happy Birthday John!!!

Mosfets are fine for a CCS...

On this subject take a look at this: http://www.siliconray.com/audio-amateur/amplifiers-w-case/low-price-6p3p-single-ended-tube-amplifier-kit.html So this is a fully featured tube amp kit for 241$ shipped. It uses 6P3P which is a Chinese version of the 6L6 and 6N1 driver. It is trivial to use 807, 6BG6, 6L6 or indeed 6V6 and swap the driver for 6N1P-EV or indeed 6CG7 (aka 6SN7). Now all the components included are probably crap so it's just the chassis, sockets and transformers that are usable. Good excuse to get some Koa SPR's and rework the circuit to perform better. The PSU needs work but the small Wima 10uf caps are cheap so make for an excellent input cap after the tube. Add another choke, some new caps and we are in business. All in something like this could cost 500$ with very nice parts and crush the Alo piece of crap. Hell there is plenty of space on that front panel for six TRS sockets if you think that helps... The Edcor output transformers are only 50$ and should fit the top plate perfectly. I just bought one but I'll do it a bit differently. I'll fit some Lundahl iron and turn this into a Stax amp. Might even add some input transformers and balanced inputs. XLR in, then single ended to balanced output.

Yeah, it should have been done right in the first place. They really need to fix the amps though as some idiots might buy them and think they are good.... until they try the SRS-2170

Don't mess with the drivers. 90% chance that you will damage at least one of them. As for King Sound, just saw this.

Yeah, we tend to build a lot of stuff. Today I've been working on ways of making a very complicated singled ended triode Stax amp.

Done

Yup, we need higher resolution. It's certain though that the voltage can be changed.

They are absolutely worthless but I think everybody knew that going in. It's funny that people don't even want them on loan...

Can you post a high resolution picture of the labels on the transformer and where the wires are soldered into the PCB? It's quite clear what needs to be done but I want to make sure that there is nothing hidden. When configuring a component for 230V you need to wire the primaries in series but for 117V they are in parallel. For this the picture from 6moons makes sense but I just want to make sure that it is the case.

If the diaphragm is intact then there is no reason to swap it out. Just recoat it and replace the dust cover. Given that the first one was pretty crappy it was expected but I'm not sure these are an improvement. Same cavernous earpads which were the worst offenders...

I wouldn't look blindly at the jumpers as there are clearly two ways for them connect the transformer primaries. Those are also not the same transformers. Is the picture you posted of the 117V setup your own unit? If so, look all around the transformer for any writing as to which wire is which. Then remove the jumpers and ohm out the connections to the jumpers. Then you will know how to connect them.

Mine is still out of commission but then again, I haven't touched it in months. Too many projects, not enough time.

They were always Stax compatible and intended to be run off Stax Pro bias. The "manual" even states they should be run at the Pro standard. Well that and the bias supplies in the amps were ca. 580V. I was talking more about the entire setup rather than the headphone stand. That is the HPS-1 though. I also have that exact same version of SR-1 and it sounds bloody good... Yeah, the ones which reached retailers in August last year. That product cycle even has Cavalli beat...

I really like the Stax stand at CES2014... http://speaker.yesky.com/105/35737605.shtml Nice to add the SR-Lambda and SR-1. Also, King Sound are at it again: http://kingsaudio.com.hk/headphone.html Might either of this suck less than the H1?

There is a source in Japan (linked somewhere in thread) that has most, if not all the semis and we know they are legit. There is a PM function but it might be limited at first.

All the audiophools need are pilot lights that can be rolled for piece of mind. If somebody wants to read about the proper use of caps with tube rectified PSU's I recommend the EML datasheets. These will die an early death in the Woo amps and this shows exactly why.

This was years back but somebody simulated the ideal vinyl playback setup and figured out that it was the equivalent of 14bits. Sampling rate was something close to 80kHz if my memory doesn't fail me. This is naturally never going to happen in real life as the records wear, so do the pickups, the tables are never 100% accurate, the RIAA eq never 100% correct etc.

150mA is overkill so the problem is just with SumR. All the other ones I've had made had no issues.

It would be funny to try and explain that on the tax return. "Sure I should get the VAT back on this... it's a new way of slicing bread... honest...."

Seem to be going after the SR-Omega style driver... Nice of them to use a Gilmore derived amp too. The VAW TA-8PS is just a slightly modified GES with Pentode outputs.

That's the same BS Woo are up to. In the WES it's the tube, followed by one of those ultra cheap Chinese bridges and into a 100uf cap. Makes less sense than usual...