So I see. You have PM. I think this could be a fun long weekend project for a skilled DIYer. Unfortunately, I don't have any long weekends available. I'd approach it as a complete rebuild and would put it in a chassis with heat sinks along the sides, such as the BZ4309 available on eBay or the...

What is it that needs fixing internally? What sort of budget do you have in mind for the repair? Tom

Head-Fi doesn't have a large DIY following. You may have better luck on DIY Audio. Tom

They're parameters commonly used for driver characterization and selection. https://en.wikipedia.org/wiki/Thiele/Small_parameters Which sorta begs the question: Why bother with the repair. Unless you're just looking for a project. Tom

It's probably intended to tame the high end of the frequency response. That'd be my guess. Tom

Your best option is probably to get the headphones repaired by the manufacturer. Alternatively, contact the manufacturer to see if you can buy the drivers. If you choose to replace the drivers with something else, you'll need to find drivers that have similar Thiele-Small parameters and a...

Interesting. I've never heard of flux that just brushed off. Learn something new every day, I guess. :) Nylon tends to stretch over time and gets brittle. So it's not a good choice for a mounting screw. All the transistors need thermal pads between them and the chassis or the metal of the...

Sweet! You're welcome. Soldering grease? Are you using pipe solder or that greasy flux used for soldering copper pipe? For future reference: I have a longer article on how to choose solder for electronics here: https://neurochrome.com/pages/choosing-solder If you use solder intended for...

I'd go back and measure the AC input and DC output of the rectifier bridges. I wouldn't be too worried about the melted corner on the headphone jack. Just don't make it a habit. :) Tom

I'd redo the solder job on those wires. Especially the solder joint on the top green wire looks unhealthy. It looks like you need to give it a bit more dwell time so the solder can flow correctly. Tom

If there's no AC voltage (make sure the voltmeter is set to AC) between the two AC pins on the bridge, the connection to the transformer is the problem. It could also be the transformer itself, but that's pretty darn unlikely. Tom

That's the one. Great question. I would verify that first. No AC going in, no DC coming out. That wouldn't be the fault of the bridge. That would be a bad connection to the transformer. You need to measure AC voltage from one ~ (AC) pin to the other ~ (AC) pin. If you have AC voltage there...

There could also be two separate supplies. One for each channel. Tom

In that case I bet you have a faulty connection between the transformer and the rectifier. Tom

You should measure with the voltmeter on the AC setting. Stab one probe of the meter on one ~ pin and the other probe of the meter on the other ~ pin. That should show an AC voltage. If you get that but no DC on the output (measure from + to - with the voltmeter on the DC setting) the bridge is...

I'd check eBay/amazon/alibaba for replacement pads. As far as the headband goes, you're probably out of luck for repair unless you can glue it all together. One thought could be to take the headband from another headphone and see if you can cobble something together. Tom

Excellent!! A dead power supply cap can take out a bridge rectifier (the round, black thing with the + on it). There are two terminals on the rectifier marked with a ~ symbol. Connect an AC voltmeter to those two terminals. Do you get voltage there? If you do get AC voltage into the bridge...

First fix. Then modify. As long as you haven't touched the bias pots you should be able to get it working by swapping the dead capacitors. Just pick some decent ones from Nichicon, Panasonic, KEMET, or other good manufacturer. As you've discovered, get some that are of the same dimensions...

A transformer certainly beats the integrated solution on simplicity of assembly every time. But transformers are large, somewhat heavy, and add distortion. If the downsides of transformers don't bother you, I recommend the Jensen JT-11P-1. You can buy them directly from Jensen...

The purpose of a hobby is to consume your time. :) Rather than reverse engineering the Schiit's module, you could consider designing your own DAC. MiniDSP has some nice USB->I2S modules that could be used with a DAC chip: https://www.minidsp.com/products/usb-audio-interface/usbstreamer...

Overkill much? :) Does it still fit in its case? Tom

You may like the Nichicon UES-series. They're the bright green bipolar ones. I agree with the previous comment that blindly removing capacitors can be a recipe for trouble. Tom

Usually the manufacturer has an evaluation board that they use to characterize their parts. It doubles as a "marketing board" that allows the customers to evaluate the chip without having to develop their own board. The schematics for these tend to be available. It could be worth an email to ESS...

Let's start with the easy part: The connector looks to be a standard header. The pins should be 0.025" square and on 0.100" pitch. The mating connector could then be a Wurth 61301021821, Samtec SSQ-105-01-T-D, or Preci-dip 803-87-010-10-012101, all of which are available at Mouser Electronics...

I've noticed this with a lot of older TI parts. The LM317L is another example. There must be 6-7 'flavours' of that IC just for the TO-92 package option. Same for the OPA134. Some options were carried over from previous manufacturers (National Semiconductor or Burr-Brown). You'd think that it...