mypasswordis

I can't seem to stay away. I'm in for 2 sets.

I wouldn't remove the 2n3904s unless they're fried. You do need to change the current sense resistors to 10 ohms. Get a new transformer with lower secondaries, replace all fqp8n80c with new ones, and you should off-board them to a large heatsink like eggil did. Don't forget the thermal paste. Edit: Oops, typed too slowly. KG has spoken. Do what he says

The melting point of nylon 6,6 is about 250 degrees C or 500 degrees F, which was apparently reached outside of the transistor case. The max junction (internal) temperature is usually 150 C.

Might as well replace all the pass FETs while you exchange the heatsinks for the right ones, remove the thermal washers, use metal screws and nuts, and put some thermal paste on. Also 420VAC secondaries is way too high for 450VDC output.

Thanks! That was fast. Was looking into buying a drill press anyway.

Speaking of power supplies, I tried firing up the BATE power supply (should be same as KGSSHV power supply but without the error amplifier and with an additional fixed bias line [edit: instead of the front end supplies]) for the first time. Fried a 2k resistor because the trace went to the cathode of the 10m90s instead of the gate, so I cut the trace and re-routed that and now the +400V rail and bias works fine but I'm measuring that at some point GND is tied to -430V so the negative supplies don't work. Any of you know where exactly this point is? I looked through all the other traces after the 2k resistor mishap and everything else seems to be right.

The 4070 would beg to differ. The older Koss ESPs have bass, too. Both have their own solutions to managing the backwave and tuning the enclosure.

This. Once I finish my first KGST I'm going to gift it to my parents, which is also a good excuse to build another one.

No bass distortion at all. Confirmed with such future classics as Rae Sremmurd's No Type and Tyga Ft. Young Thug's Hookah. These are bassy cans, no doubt, and are very clean and euphonic in the low end. The treble is kind of disjointed but I'm thinking there might be a comb filter effect or something going on. At least it isn't piercing in any way. Will investigate at some point in the distant future.

No, the ECR500 I bought did not come with an adaptor. Recabled with a Stax Lambda signature cable and it works fine for me. What Birgir said, but I also replaced the cable because I had to (see above).

The ECR500 has absolutely no problems being driven from a SRM212 without clipping. I would just ditch the transformer box and plug into your favorite Stax/stat amp.

Almost all of the sand in the T2 can be replaced by modern parts. Look into JoaMat's updated T2 a few pages back. I plan to build something similar but fully solid state at some point, since there are now 1000V+ FETs with low enough capacitance available.

Tried soldering up the adapters, quick and painless. Also tested a few ksa1156 Vbr on dy294. Out of the 6 I tried, only one tested under 600V. YMMV

sot223 adapter boards really cheap http://www.ebay.com/itm/5pcs-Double-Side-SMD-SOT223-SOT89-to-DIP-SIP3-Adapter-PCB-Board-Converter-F63-/181328677192?pt=LH_DefaultDomain_0&hash=item2a38080948 Would not recommend ksa1156, though I should remember to test actual Vbr at some point

If you don't need them heatsinked you can use a stn9360 mounted to an adapter, or if you can make do with a 400V part there's the ksa1156.

The darlington pairs of q32, q33 and q34, q35/q36 servo have emitter degeneration which dictates the gain and more or less stabilizes it with regard to temperature and base current. FJPF2145 has much lower beta compared to the original 2sc3675 but it's still adequate in this situation. I think the choice of heatsinking is mainly from deciding how much heat you're comfortable with. On the original DIY T2, Q35 and Q36 are heatsinked. It wouldn't hurt to heatsink Q32, too. Q33 Q34 don't need them.

Asking for help? All I see from your post is a diary entry. I would recommend your next one be on churros. Make sure you post it on head-fi.org.

Been listening to my SR-5 and SR-5NB the past few days, forgot how good they sounded. I haven't heard any of the latest gen Lambdas but it's pretty hard to go wrong with vintage Stax.

Wow amazing job as always! Looking forward to the finished result. Could you list parts numbers for those connectors?

Checking this place is not good for my wallet. I ordered some as well; thanks for letting us know, UFN. Currently Mouser still has enough to go around.

If you're interested, have the KG or similar digital attenuator boards, and are willing to wait a couple more months (really sorry about that, I'm pretty busy these days and don't have enough time to do much except sleep by the time I get home), I'll hopefully have finished the microprocessor and touchscreen code, and the android app code to implement in the KGITSOCH so you can build the full version. I aim to finish soldering most if not all the amp hardware this weekend but not sure about the next time I'll have some free time. My Nexus 4 should be getting the Lollipop update sometime next week and I think I'm planning on getting the Nexus 6 anyway (verdict still out on whether or not it's too big) so I can use them to test the app. The only dynamic headphones I still have are a couple of vintage orthos.

Nexus 6 supposedly wil be available in 2 days on T Mobile. Will probably buy at the end of November or early December, will be interesting to see Band 12 coverage increase over the next year. Never had a phablet before, might as well start with the biggest one available.

This is the one true portable ortho: Runner up the YHD series. There are plenty of orthos small enough to be considered portable. They just haven't been produced for > 20 years.

Hint: the trafo box is unipolar but the drivers are not http://www.head-fi.org/t/157539/sony-electrets/30#post_2062726

By ohm it out I don't mean the drivers, but the cable. Should have specified, I find the continuity beeps annoying.