spritzer

The T1 is not equal to a 007t!! What you would do is feed -350V straight to the cathode and do a lot of crazy things.

If you check the 007t schematic (which is out there) you see that the cathode goes through two low value resistors and the pot so you need to bypass those.

Something is wrong with the either of the last two stages. Also look for shorts to the ground plane.

Internally connected pins means you can use either one so no worries. Otherwise it is just grid to grid, anode to anode but with the cathode I always bypass the balancing circuit next to each tube.

It's not dust proof.

It's some type of PVC film but no idea where to get it.

If you've changed all the transistors, all the diodes and the voltage reference then it could be a short on the board. I would also change the resistors which set the voltage too as if you used Xicon's they might age badly. I always used the CMF60's due to their higher voltage rating.

The A1831 does work just fine within the voltage limitations and the A1967 too if you can find any.

First off, why is this in the LCD-2 thread? Second, the 727 has 350V rails so it can't really produce enough voltage to kill the drivers. Now there are two main ways to destroy electrostatic drivers, over voltage on the stators which shorts out the D/S gap and causes an arc and then there is simply destroying the high resistance coating on the diaphragm. Now the first one is simple, keep the max voltage swing below bias*2 and you should be good. This is voltage peak to peak so roughly 1200V for Stax pro bias. This is insanely loud but the BHSE, Carbon and KGSSHV will easily reach those peaks but you also need a very high input voltage. The second part is a bit more complicated. Now for all intents and purposes, there should never be any current flow on the diaphragm. It should hold a charge but said charge should be a constant and never change. Now we live in the real world and it simply doesn't work like that but the charge has to be carefully controlled as little current flow as is possible. When we design amps we account for these things so none of our amps should ever damage the headphones if they are built correctly. We can't control what others do but if follow our lead then they should be safe. This brings us to the people who really don't know what they are doing aka Woo Audio, Cavalli and RSA. Those amps aren't safe and in some cases are guaranteed to destroy your headphones.

You could use a 4 pin with a grounding tale and connect it to something like the RCA shield on the back. But yeah, 4 pin is just stupid but somehow the standard.

There has never been any evidence that the A or II units differ in any way besides color. It also wouldn't make a lot of sense for Stax to do that and defeat the whole purpose of the A and II system. So yeah, they are most likely identical. In other news I managed to save those 4070's. One set of SR-303 drivers and leather earpads and they are good as new...

Indeed, works wonders on this stuff.

He could put a steel plate in the lid of the PSU, that should take care of the transformers.

Just stick with proper caps without attempting to add to the clusterfuck. Just because it has a Mundorf sticker on doesn't mean it is any better than the Japanese stuff and probably inferior.

Or some Quad ESL...

Yes that could very well be the case.

Exactly!! The ears are a sucky measurement tool but do some things really well.

Rather take them with a hefty grain of salt. The 207 and 507 sound nothing alike so something is rotten. There seems to be this movement now that measurements are king but they only tell part of the picture. Do amps sound the same based on THD, frequency response and noise? No!!

Just spent a couple of hours comparing a SR-303 which is about to give its life for the 4070 and a brand new SR-407. For my collection I decided to collect all of the TOTL Lambdas so I had to get a 407. The 507 is a steaming pile of shit and they are all dead to me... Anyway, the 303's were is pretty great condition and sound their usual self. Naturally both were run off a Carbon as that's the only way to roll.. The 303's are very neutral with no real issues, bass is strong but lacks depth, midrange is a tad laid back and the highs are just right for a Lambda. Not too piercing and none of the etching of the old days. These were fitted with the newer "cloth" earpads which did fix a lot of the old x0x problems. Now enter the 407 fresh out of the box. From the get-go they are far more energetic, the midrange has real presence, the bass has more foundation and the top end might be even bit too alive. This is not as tiresome as the 009's top end, here they just go over the edge from time to time but the Carbon keep them in check. Over all a truly impressive set of headphones and goes to show what Stax can do without creating the mess that is the 507's.

Google that!!!

Sure, that's not a problem. Also isolate all the winding's and check for continuity. Shorting though the barrier between primary and secondary is no easy task so I'd call it unlikely.

Also not single ended...

I think driving with headphones is illegal but yeah, I could cram an amp in there. There is no official reseller for Tesla here and the guy selling them is the scum of the earth so I' d buy directly from the factory. The view from the porch is pretty boring but there are some nice spots around the house. I'm about 200m from the see so far enough away...

Yeah, it is a special kind of hell. I was the first and only one to view my house as I just jumped on it. That was after quite a few other ones which I missed out on.

Yeah, it is a large portion of our lives. Well it isn't as we don't let it control us but it's always there.