Kerry

Possibly Q18, but most likely Q19 or the regulator circuitry itself. You could check the voltage across D12. Should be around 30V.

If the -560v is correct, then the 300v supply coming off of it must be the problem. The -560 + 300 voltages gives -260v.

Wow, interesting

Having a great time so far. My granddaughter is coming soon. Can’t wait

No. The CCS has the potential to exceed the -400V rating of the 1156. Bad things could happen if it does. The batteries might be possible though I don't recommend it. It's cutting it close if something goes wrong or while you are doing the initial adjustment on the batteries. I'm pretty sure Q1, Q2, Q3, Q28 & Q29 are on the heat sinks. I'm confused by your statement above.

Back in the day (for various builds) we used 2SA1156 (-400V) and 2SA1486 (-600V) pretty interchangeably provided the voltages were in spec. K2SA1156 is a direct replacement for 2SA1156. I would recommend using K2SA1156 where it works. It is proven and better not to jury-rig something if not needed.

At full voltages you can use K2SA1156 (as JoMat suggested) for Q1, Q2, Q3, Q28 & Q29. It's what I've been using in my builds and is a good substitution. I also use STN9360 as a replacement in some areas, but I've redesigned the boards specifically for them. I don't recall which of the remaining 2SA1486 (batteries & CCS) are mounted on the heat sinks, but if they aren't, it seems like you could use 2SA1413 though I never have.

^ this

Condolences to you and your family Todd. Cherish her memory

That looks like a bad spec sheet. 2SAxxx transistors are always PNP and 2SCxxx are NPN

Happy Birthday Brent!

Initial testing on the balancer is looking good. I’ll need more testing to confirm, but the batteries are much closer than before. This should help to extend battery life.

Happy Birthday!

Here are the part numbers for the 8 pin connectors and pins... 1-794065-0 770579-1 770988-1

I got the board and parts in for the battery protection/balancer and was able to get one built. I’ll try to get some testing in tomorrow.

Happy Birthday Chris

I'm doing a trial on Qobuz just to see the difference. From Roon they look pretty much the same. Metadata, etc. is identical. You can click on Tidal or Qobuz on the left side menu of Roon and they highlight different songs, but that's the only difference I noticed. PS Also, the catalogs are slightly different

They are the Phoenix Mate-N-Lok-2 connectors. They are rated at 600V which is nice.

They're just Nylon R Type Cable Clamp Fasteners. I got my last batch from Amazon. I tend to use 1/8, 3/16 & 1/4" sizes.

In other news, I just got back the analog input board and assembled the amp. The sandwich is 6.2mm thick + bottom components for a total of about 9mm thick. Batteries are about 10mm on top of the input board. Back plate on and plugged into USB-C (charging LED on) Why we did this... Portable music Just analog from my phone at the moment. DAC is up next PS The Weight is 12oz or 340g

Here's the final board I just sent out to get manufactured... I added some more optional parts that help stabilize the current sense circuitry. The board is now 10mm x 58.4mm x 1mm. Parts are ordered, so it's a race to see if Mouser can ship my order before the boards arrive.

Happy Birthday Shelly

The USB-C and battery management chips are crazy insane. It would not be possible to solder with an iron. They both have one or more exposed pads underneath the chips. Here's the USB-C PD controller... Those giant looking resistors on the left of the chip are 0402

The TI chips I'm using for the USB-C and protection/balancer already have a mechanism built in, so I just followed their recommendations. I found some 0603 parts (RT1, RT2 one the board). They are 10K resistance to start and about 4.3K at 50 C. I found new batteries that are 2400mAH that should give a little over 8 hours playing time. Over voltage is 4.2 and minimum discharge voltage is 2.75V. I'm using 4.2V for OV and 3.0V for UV.

I just finished designing this battery protector board. It has a built in balancer to try and keep the cells at the same voltage. I added a thermistor that gets fed up to the battery management on the amp board. This also has it's own thermistor in the middle of the board. I'll set this to about 50 C for both and do some testing once I get this built. The board is 10mm x 56mm.