spritzer

I like the whole "minimal lighting for dramatic effect" thing you've got going on.

Do you know if the large sub-board is included which was designed for the 3 channel amp? That makes wiring a lot easier and much neater. As for testing the amp, always start off with the PSU without anything connected to it.

Is it SE or balanced and have the boards been tested? If they are all functional then there isn't much to wiring it up but it is better to know which wire goes where.

Now we all know that Ray's an idiot but this is just too much. Why on earth did he turn the drivers around when they are dipoles? If he wanted to run them out of phase he only had to switch the + and - wires. It may even be worse then that (I'm going from memory here) but the HE60 has slots on the back of the driver which is where the rubber o-ring sits which seals the baffle. I'm not sure the front piece has those same slots so there could be massive baffle leak i.e. no wonder the He60 didn't compare well to the He90.

There are some pics of the A-10 in the Detroit impressions thread and amongst those a picture of the amp section with no tubes. It appears that Ray is using the same sockets as I'm using in the Warthog (PoorMan) which were the cheapest ones I could find.

For all the AC wiring you should use 300v rated wire but since the rest is all low voltage stuff you can use pretty much any wire you like, given that it can handle the current. 16-18AWG is plenty for anything this amp can dish out and 20AWG could even be enough. For the input wiring you can even use 30AWG or smaller but stick with 22-24AWG since they are easier to work with. As for the insulation, teflon has the extra benefit of not melting and thus not potentially contaminating the solder joints.

That's why I would never own a stock Esoteric machine. \ It's the same deal with a lot of headphones too.

I did it to let the bass breath just a bit. The housing presses the felt close to the drivers at the back and there is a 4mm or so gap to the front of the headphones.

Here are the pictures I promised I would upload yesterday. Anyway here are the earpads with the front damping material. I take one sheet of the damping paper, break it in half and then iron in nice and flat. The dustcover is upside down in all of these pictures and should have the plastic rings facing towards the ears. In the second picture you can see the "pocket" which is on the new Lambda pads. This makes installing the damping sheets far easier and has allowed me to use only minimal amount of double sided adhesive to secure the pads for testing. Next up are the drivers permanently mounted to the baffles with polyurethane glue. If somebody reading this is crazy enough to do this, please use as little of the stuff as you can and let it cure for 12+ hours. The drivers are wired and ready to go in the second pic. The Lambda drivers are always wired in phase (the wire with the stripe on it is connected to the front stator) but this isn't the rule with all Stax headphones. Some of the SR-1,3 and 5 units were wired out of phase and the Sigmas are all wired out of phase. Here is the back damping layer. This felt is called craft felt by the ortho crowd, is 1005 polyester and of lowish density. The part numbers can be found in the massive ortho thread over on HF but I'm sure most types of felt would give an acceptable result and the same goes for medium density foam. Finally here are all the parts need for assembly (minus the screws and the glue for the earpads). I'll probably try a few different materials for damping the backwave but I'm rather happy with how this configuration sounds. I've accomplished what I set out to do, tame the damn midrange peak. Now when damping one can't have his cake and eat it too and when damping the midrange there will be consequences elsewhere. The top end is dulled a bit (a good thing to my ears) and the bass isn't as quick as it is on the stock cans. There is also a hint of edginess from time to time but I can live with it.

Stax did change out the elastic on the Mk2/A's for a stronger material but my O2's have been on a stand every day since 2003 and the elastic isn't loose in any way, even in comparison to the new sets which I've bought over the years. Still it wouldn't hurt to use the arc's to support them.

I blame it on ape's doing the soldering as by the same reasoning the Stax drivers should never even be touched with a soldering iron. With the Lambda drivers you are soldering directly to the brass rings which clamp the diaphragm in place or directly to the stator plates which are held in place by small plastic bits which could easily melt.

I'm thinking about using an old IBM PC case for the Warthog with wood front and rear panels. This is meant to be cheap and cheerful but I'm still debating whether it should be SE or balanced....

I though I was meant to bury them in some lave for a week? It says 105

For a great Stax amp on the cheap there is really only the 717 but the Warthog (PoorMan) could have what it takes. Time will only tell...

There is certainly a few ways to go from here though I may end up building that DC coupled DHT amp Kevin designed. Let's get these two BH, the Vulcan, Warthog and ES-1 up and first though. I'm more then ready to be impressed by the cheap pile-o-parts. I've got the PSU working here without the 10uf output caps (which are on the way) but I'm having the same massive AC issues as with the KGSS psu in the Egmont. There really shouldn't be 830VAC riding on the + side of the supply but I can't figure out what the fuck is wrong... I thought it was Marc-E-Marc? Us dissing Ray for selling overpriced crap to people that believe the BS he spews? No...no... you are mistaken sir.

Just get XF2's and the chase is over. It's a very expensive retirement though... The WKZ Black-Gates are unobtainable now except used at very high prices so we have to settle for Mundorf, Jensen etc. I'd love to get some Elna Cerafines but they have been long out of production. The PSU works after some issues (mine is just about ready for testing) but there are some issues with the amp sections. Alex is on it though. You can just get a set of Quad II monoblocks, a pair of KT66 in each. The EL34 and the 6CA7 are the same tube more or less. The 6CA7 is slightly beefed up version but they are identical in every way but not called the same name due to copyright issues at the time. This is not to be confused with the 6AC7 tube...

Given a good nights sleep the change from using tape to permanent glue isn't so bad and mostly the fault of me jacking up the volume too much. Any damping scheme will be dependent of the intended volume setting since it changes the sheer amount of air the drivers are shifting. Now that makes more sense. The thinner diaphragm needs more power to behave as it lacks mass to damp it self. Put those phones on the budget amps and it isn't pretty... You need to damp the back as well to get the bass back but I'm struggling to get back some of the presence in the upper bass/lower midrange. Foam might be the ideal material here but I don't have any of the good open cell stuff. Nobody will ever accuse the L-Sigs of being dull that's for sure. It will be hard to give them more separation since they are diffused by nature and the bass is also hard to fix.

I used polyurethane so not excessively hard like epoxy but very strong. I'm thinking about adding a layer of the paper material to the back to the drivers and see if it makes a positive difference.

I am way too tired but I managed to bring back most of the sound that I had before I stripped the phones down. It turns out that I had mounted the dustcovers for the earpads the wrong way around so they pushed the drivers away from my ears just a bit. I may have only been a couple of millimeters but that was enough to add some etch to the midrange.

Ooohhh CDE and Panasonic, fancy!!! I'll just have to be content with my brown Nichicon's... The heaters are probably driven off a single switcher supply which is grounded into the amp's signal ground (and thus dumping all the noise into the amp) as that's how the B-52 is built. I do hope that Ray's using at least two supplies in this amps or there is going to be trouble... I would buy anything based on Darth Nuts reviews. He's nailed down completely how the SR-007 sounds and how it is different from the SR-Omega. I'd really like to read his take on the Mk2/A's...

Those tubes would be only too cool on a black BHSE.

The Lambda Sigs have never struck me as being shrill so there might be something else at play here. I'm very sensitive to exaggerated HF response and even with my sole use of silver wire they have never presented like that. That's about 10-15 sets in total so have you checked that the set still has the stock drivers? There are plenty of them out there with SR-404 drivers... I've just rebuilt the phones after permanently gluing the drivers to the baffle and it seems that I may have to revisit my damping. \ The bass is much more even but there appears to be more treble energy as well which I'd like to tame. I'm taking this with a grain of salt as I'm way too tired for any coherent thinking. It's 6pm here now and I've been working since 4am so I'm slightly loosing it...

I really like the part about all the different PSU's and that he uses Panasonic caps in the PSU. They are pretty much our standard go-to caps for these PSU's and far from special in any way.

I've heard a few of them but I still vastly prefer electrostatics. That shouldn't be too surprising though...