spritzer

The SR-404 is just not a good headphone in comparison to its older siblings. The Signature does have some etch but it is fairly benign compared to the peak on the SR-404.

You can crack open the Lambda drivers but it isn't easy getting them back together. Dust issue normally presents as a static sound in the driver at all times but a bass resonance could be due to a bad seal somewhere. Are the drivers and earpads completely airtight? If you press the phones towards your head then you should hear the diaphragm flex...

It's probably a phase splitter for the SE input. We'll see when they post the internal pics...

I will but it may take a while. Be ready before CanJam XXX (2010 )

Yeah... cheap PSU caps. There is no PCB in that PSU so it is identical to my unit except with two complete, yet seperate DC filament supplies, each running off it's own transformer winding. On my unit there were two rectifiers (one for each winding) but only a single set of caps, resistors. The winding is actually hooked up to the rectifier on this one but nothing connected to the output...

Hmmm they've added a sole 12AU7....

I'm sorely tempted to pick one up.

Changing to boutique caps or leaving out the "bias adjustment" for the 3rd stage doesn't change the basic "design" which is always the same on the amps we've had a good look at. It's the same clusterfuck time and time again... The newest pics are especially entertaining in a twisted way since Mikhail actually built two filament supplies into the PSU but only used one of them. Running all those tubes off a single 6.8A winding isn't a good idea to say the least...

It's just a homage I think since this isn't Stax project. Looks like it is a variation of their other amp but with a opamp gain stage and 12FQ7's. Sure sounds like it but could also be a torn diaphragm. I was going to ask Craig to do it so thanks.

There is only one volume level that you need and it's MOAR LOUD!!!!!

Would you guys be really pissed off I'd build the new version of the KGSS then? Moar power then the BHSE with a +/-500v PSU...

Ok.... I want one of these!!!!

I sure hope they come pre-assembled.

It's what you do best, curring round holes in metal plates. Just buy one of these and some sockets... Now can anybody tell me what this is..? I want...

Ahh now I understand what you are getting at. The cap will certainly do no harm and I suspect that Stax added them when they were having issues with ripple. I know Justin also added one in the amp chassis in the BHSE, probably to make up for the long wire from the bias supply and the close proximity to the filaments on the way. All of the SRD-7's have a series resistor (I have the schematics for most of them) but it's been too long since I opened up the small Stax amps to be sure. The 313, 323, 717, 007t, T1, T1S all have them.

Can you drill some holes in a chassis and do some easy soldering? If so why not DIY one... or better yet, make Nate do it for you. You can get a 4 pole stepped attenuator on ebay for next to nothing and XLR's sockets are cheap.

One thing our crazy baby elephant should note, I'm fairly sure you prefer the more "audiophile sound" of AC-coupled amps rather then the brutal honesty of DC-coupled units such as the BHSE. You may like the extra power when listening to Umbrella remixes at silly volumes but the BHSE will show you just how much crap they are. For the HE90 that may be the case (never heard one but I should get the PCB's to build my own one day) but it lacks the sheer overkill of the BH amps i.e. larger tubes, more voltage, more current etc.

I did indeed leave the protection devices off the board but this is essentially a niche design for modded transformer boxes so I'd assume the users know better then plug it into a 400W Krell amp and listen at full output. I have the schematic for the SRD-7 Mk2 bias supply as well (which has both outputs) but frankly there isn't much need for the NB output. You also just need two resistors to drop the bias voltage so it is easy enough to accomplish. I could fit that to the PCB though... The 5M or so resistor is absolutely needed, not only for safety reasons but it also sets the constant charge mode of the diaphragm. I don't see how a cap across the bias line could work since the bias is DC and that can't pass through caps. I've at least never seen a cap in that position and even the oldest Stax schematic which I have at hand (Feb 1961 SRA-6S) shows a 5M ballast resistor.

If he did stumble onto something worthwhile then he fucked it up royally with sheer stupidity and recklessness. Almost every part is right on the limit if you are lucky or far over it as is often the case. Then we have the horrible build quality of even the "good" units. All wires on top of each other with no support at all. A single 4" wire may even have up to 3 pieces of wire connected together and then heatshrinked for some unknown reason. When you know more, please drop me a PM. A bad amp is something like the HEV70, E.90, 313 or the A-10, the rest all have some merit. In its stock form the ES-1 simply lacks the power it should have so the bass is too loose, the midrange too recessed and the top end rolled off. The soundstage suffers too and lacks a lot of the forward projection it is capable of. Removing the offset takes care of most of that but the sound is still a bit loose and when you push the amp hard, audible distortion shows its ugly head. There is a fix for that but I just have to install it.

Thanks.

Given the evidence gathered from quite a few amps (including the one Elephas has) via detailed internal pics he never strayed that far from the original schematic. The resistors used were almost never the same between two amps and a lot of series/parallel stuff going on but since he appears to have bought a lot of stuff cheap from surplus sales that makes sense. The use of filament transformers a main transformers is the result of him finding a bunch of them for next to nothing.

If you can find some of the Kimber braided cords cheap then they would be a good option. I know that Russ Andrews in the UK sold them but they present a new definition for expensive...

The fit could have been due to worn pars (which you'll never see on the outside) or the arc's have been modified to fit the owner so they don't work for you. Now for something different, I need some input. I have a SRD-7 Pro PCB all drawn up but I'd like to know if you thought it was a good idea to place jumper's on the PCB for the signal coming out of the transformers. All the input wiring is there but I'm not sure if Stax passed the output though the PCB too on the older models. A pic but it is much smaller then this to say the least, roughly 4*2.3".

There is next to no variance when it comes to the basic circuit. They are all sitting at a -100VDC offset which severely limits the output voltage. Remove it and the amp has promise. The basic Stax circuit was specced at 0-5VDC.

They are Abyssinian so no stripes. Just got word that one of them is named after me.