spritzer

You are always so cranky... A SS amp with 2+% distortion is just facepalm material. The problem we have is that we are stuck with 1960's mentality and transformers optimized for that age. Most amps you can use today can easily driver a 1:15 to 1:20 transformer so why use a higher ratio?

Shitload of Kiwame/Koa resistors.

That's about what Stax said back in the day. Compared to the Exstata then it isn't anything to complain about.

There isn't a whole lot of distortion in the SRD-7 but it will naturally only add to what the amp is doing. The 1:25 ratio isn't that bad but I do prefer lower ratio's as unlike 1971 when the SRD-7 was introduced, we have power to spare. Higher ratio can only mean more distortion. Transformers do have merit and I'm getting good results from the massive Lundahl irons. Not cheap by any means and about 5 times larger then the SRD-7 trafo's but this is team overkill after all. Even the small LL1630 was very nice upgrade over the WEE at CanJam even if it was struggling a bit with the lower ratio. Add a small diecast box, one of my bias boards and it's also cheaper than the WEE, at least for people who don't have to pay silly import fees. I did one WEE owner claim that it was as good as it gets which just shows how clueless people really are. The 717 was indeed changed but whetther they did it to save money or just that the neutral sound of the KGSS wasn't their cup of tea. Neutral it isn't and the 727 (after mods) is a better amp just because of that.

Happy Birthday John!!!

Nope.

I would never go back to the Mk1 pads but I haven't bought a set in a while so no idea on prices...

There is nothing to secure the driver with in a Sigma chassis. The older Lambda drivers are glued together and then attached to the baffle but here it is all loose. One could glue it together but it is far from easy to do...

Go to thread tools above the first post of the page and click on "download thread". That should do it.

Happy Birthday!!!

I for one haven't come across any headphone that has better imaging then the SR-007. Some like the HE90 are much bigger but washed out and diffused as if you were listening in a fog. What most can's do is present something larger then life and it doesn't follow what's on the recording which the SR-007 always does. That's not their greatest feature though, that's providing depth and layering to the soundstage which is truly unique. I tried the T1 at CJ and it was washed out, ditto for the HD800 which is just a poor version of the HE60.

Fake it, till' you make it...

The white sand cast bricks are resistors and you can certainly get better units such as the non-inductive Mills and the Mundorf stuff. The other white boxes (such as the one in the upper left hand corner above) are film caps. You could replace them as well and it might be worth to do so. As for choosing parts, we can help you with that. If either of you has a high res picture then that would be a great thing to have and also measure the distance between the mounting holes and how much wider a new cap could be.

Yeah, Kerry and Ray don't belong on the same forum, let alone the same thread. Kerry's amp is better than 99% of the manufacturers out there and his attention to detail is just astounding. I played a small part in the design of that amp and I do have a set of boards here waiting on a chassis (like so many of my projects). It will be fun to compare it to Justin's amp, especially with the new KGSSHV PSU unit... Speaking of the two umbilical cables, there is actually a funny story about that which I hope Kerry doesn't mind me sharing. He got zapped by the amp so he decided to design a circuit which would flash a fault sign and disengage the PSU if the umbilical cables aren't hooked up. He then sent me the circuit for me to look over and I liked the idea but was a bit puzzled why it was needed. I asked him why he didn't just have the female chassis plug on the PSU and the male plug on the amp so he could never touch exposed pins (he had it the other way around). With such small caps in the amp chassis there is no way to come into contact with the full fury of the PSU. Two solutions to the same problem...

Those are electrolytics and I for one would replace them. These are about as old as me so well past their sell by date. If you can't fit polyprop caps in there I'd recommend something like the Nichicon ES series which are non-polar. They are radials though...

Woo is guilty of the utter stupidity of using male pins on the PSU connectors as well. I was concerned enough about this that I dropped Jack and email early this year but he just gave me some BS about these being the only connectors they had access to. I use the same dirt cheap Y2M connectors and they are available as matched pairs in both configurations. Ray's real "genius" is building PSU's which eat up more power than the amp they supply and how he's cheap enough/doesn't understand tubes enough, to seriously compromise the safety of the end user. The A-10 uses a 4 pin connector for the umbilical, +300V, +600V, GND and a single wire for the filaments. This means the common ground in the amp chassis is the return for the switching DC filament supply. Now for a normal tube amp which has relatively low voltage sitting on the cathodes you can get away with using a single filament supply or if the tubes in question have a high cathode-filament voltage limit. Electrostatic amps do not qualify here, at least not the output stage. Take the ES-1 for instance, the Stax schematic clearly states the filaments for the first two stages should be grounded but the last stage should be on it's own transformer winding and left floating. Mikhail naturally didn't do that (I do think he was working off a schematic where the filaments aren't drawn but he should have known better) so all the tube issues the owners complained about came from this. Now with the A-10 this is an even bigger issue since we are dealing with small signal tubes (5687's) configured in SRPP and pushed way past their limit. With SRPP you have one tube stacked on top of the other in a bid to get a cheap push-pull circuit but most aren't used like that. In truth the A-10 should have 6 filament supplies and 8 single triodes just for the output stage. The driver stage and the "preamp" could be fed from a single, grounded supply and the first stage of the SRPP circuit could be fed of a common, floating supply. The output tubes would have to be isolated and left floating individually which isn't really an issue but requires a lot of wiring. Now what happens when the tubes are driven past their limits like this is hard to predict but the thought of high voltage DC spilling into the signal ground terrifies me no end.

You are talking about stereotypical tubes vs. solid state which is just that, a stereotype with no real meaning. With Stax equipment the sand amps aren't dry and sterile while the tube amps are overly lush and warm. In fact, SS amps like the 717 are a bit too warm while a reconditioned T1 is a bit on the dry side... As for why this happens, I'd say it is all about how the track was recorded.

I would bolt the transformer firmly to the frame as it will only dampen an vibrations. Have you tried DC blocking caps to see if that is the issue?

Is there an output relay? I can't see it but a bad connection there would account for the issues you are describing.

The one hopped up on berserker mushrooms and wielding a huge axe... It just really rubs me the wrong way when people, either knowingly or by sheer incompetence, sell gear which is basically broken or so badly designed that it will never better a much cheaper unit. Add to this high prices, some magic and fairy dust BS with very questionable engineering and I just get mad. This isn't just RSA though, Slee and Rudistor also pull the same crap. With the A-10 I do think Ray knows he's selling badly made crap as I had to force his hand to post internal pics and those were terrible quality. No pics of the inside on his site either. We do know what's in there though and it is much worse then even those tube PSU Single Power ES amps.

Ahh id did forget about the battery but there might be another explanation. The speaker is from the 80's and they did really like the white powder back in the day...

I love the date sticker on the back of the magnet. It could be some dust from the damping accumulating on the driver. Doesn't look like corrosion...

Went to the family cottage with my Dad to check out some electrical issues. This is how Iceland looks at 3pm... What you are seeing here is America on the left and Europe on the right.

Many of the B52's have issues, if Ray had sold more than two A-10's and to people who aren't clueless idiots then he'd have a massive problem and lets not forget all the cRaptor issues and the Stealth preamps. Running a low voltage regulator at high voltages will just end this way. As for being badly designed, where should I start? The A-10 is just bad over all. It drives the tubes to horrifically past their limits that they will fail and could do nasty damage to the headphones as there is nothing to protect against that. The SR-Omega for instance has the metal chassis connected to the +/- outputs off the amp so a short is possible given enough voltage. The single filament supply is also grounded into the signal ground so if something were to happen it could end very badly for the other components connected to it. Then there is the whole issue of trying to use SRPP with electrostatic drivers without trying to compensate for the major issue of SRPP. What you end up with is a 6500$ amp that is worse in every way to the Koss E/90 which you get "free" with the ESP950 system. Then we have the preamp section which has a very high output impedance which is my book isn't a very good way of doing things... As for warranty, take for instance a B52 which was less than 5 years old but Ray suddenly decided it was out of warranty and wanted 500$ to fix a 20$ part. This was in no way due to misuse or anything like that, it was Ray just not honoring his own fuckups.

Happy birthday buddy! Somebody bring the man a beer!!!