spritzer

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.

Couple of pics... How it was on the ground....

Well the heat isn't free but I pay about 1$ per 1m3 of 70°C water. Monthly use is about 100m3's but I'm probably running on the old estimate. We don't use this stuff sparingly at all, my entire driveway is heated and the walkway to the house. I just checked the electricity (as I plan to buy an electric car) and it costs 5cents per kWh. So filling up a Tesla is about 4$... It is a sharp learning curve for us to stay in countries without an abundance of clean energy. I'll post some pics later on...

How else are you going to do a multi bit dac? You need precision resistors and they won't be cheap. I'll find a nice house for Kevin here so he can spend the summers awake for 24 hrs. It's a month till the solstice and yet the sun barely sets...

Yup...

Yeah, think years and years.

The difference in pads is tiny assuming they are of equal quality i.e. age. My Mk2's just have the ports plugged, nothing else. I messed with the arcs a bit to get the fit just right but it was a minor adjustment.

Does the offset pot adjust at all? I mean if you can get a higher value by turning the pot the other way then you need to change the 2K series resistor. Measure the resistance value of the pot + this resistor. If it is just 2K then you need to go to say a 1.5K resistor. If it is 4K then you need a higher value.

I got a power amp from China and it was naturally ungrounded and it hummed no end. I could actually feel the current flowing when I touched it. One wire later and it was fine. Take one wire from each of the amp boards to the PSU and one from the pot to the PSU. Then one wire to the chassis, nothing else. That should fix the issue.

So the chassis is not earthed? That is very, very bad idea. All the GND pads on the boards are connected together.

No....just no....

No shoulder washer with the SiC but be careful as the gap isn't so big. With the PEEK stuff I hand tighten as when you've done it enough times you know how far to go.

Where did you read such bullshit?

My two failed units would beg to differ. I've stopped using the shoulder washers as they simply don't cut it.

I've had two arc through so I'd advice against it.

When using RCA's you only use two of the four decks on the pot. The output of those is taken to the + input of the respective channel while the - input of the each channel is connected directly to the ground tab next to it. Those diodes have to go and the board is clearly marked for the insulated units. The person who built this board doesn't have a clue what they are doing as the tabs of the transistors is indeed live. Wrong heatsinks for the bias supply and I guess the other current sources as well. Inadequate isolation as well since the tab of these sits at a very high voltage.

Ehhh why are you using a RCA to balanced converter? Bypass that crap and just ground the - input of the amp. Grounding is simple, they all go to the PSU including the chassis.