[notverriegod49]

also seems like the cheap amazon multimeters are decent enough for low voltage testing, think it should suffice?

 

[HiGHFLYiN9]

Should do the trick for your purposes.

 

[notverriegod49]

thanks for help, ill update if I have any more issues

 

[Jmoy]

thanks for help, ill update if I have any more issues

I’ve been building the Sangaku amp and have hit a snag. There are locations on the PCB labeled “CN1” and “CN2.” I can’t figure out what is supposed to go in these locations. Can anyone help?

 

[Yukon888]

I’ve been building the Sangaku amp and have hit a snag. There are locations on the PCB labeled “CN1” and “CN2.” I can’t figure out what is supposed to go in these locations. Can anyone help?

Nothing, as far as I know. There's nothing listed in the BOM. From looking at the pictures on Pete's website and in this thread, they are all blank in everyone's build. I recently built the amp without anything in those locations and the amp works great. Not sure why Pete put those locations there.

I've been trying to post pictures of my own build, but I can't find the option for attaching pictures to my post.

 

[Jmoy]

Nothing, as far as I know. There's nothing listed in the BOM. From looking at the pictures on Pete's website and in this thread, they are all blank in everyone's build. I recently built the amp without anything in those locations and the amp works great. Not sure why Pete put those locations there.

I've been trying to post pictures of my own build, but I can't find the option for attaching pictures to my post.

Thank you. That was my thought - leave it blank. I think as new-comers we have to post a certain number of posts to get access to all the features, like posting photos.

 

[Yukon888]

Thank you. That was my thought - leave it blank. I think as new-comers we have to post a certain number of posts to get access to all the features, like posting photos.

No problem, glad to help.

Bummer, I'm only an occasional headphone user, so I don't have much to post about, but I wanted to show off my build. Oh well.

 

[BeyondStupid]

Hello everyone,
I tried building a Sangaku the last two days, but I think I took the wrong turn someway. It turns on, it plays music, but I have a horrible high frequent pitch on the unbalanced headphone out (I couldn't test the other outs for the moment). The pitch gets louder when using the gain switch and is independent of the volume switch. It is also present if no source is connected.

I did check the voltages and most are in a few percent range as the schematic describes. Except for the supposed 32-38v plate voltage, which sits around 42,7V for reasons I cannot grasp right now.

Does maybe anyone have an Idea where a high pitch (like a tinnitus video from youtube) could come from? I am absolutely lost right now and am grateful for any help.

 

[Yukon888]

Hello everyone,
I tried building a Sangaku the last two days, but I think I took the wrong turn someway. It turns on, it plays music, but I have a horrible high frequent pitch on the unbalanced headphone out (I couldn't test the other outs for the moment). The pitch gets louder when using the gain switch and is independent of the volume switch. It is also present if no source is connected.

I did check the voltages and most are in a few percent range as the schematic describes. Except for the supposed 32-38v plate voltage, which sits around 42,7V for reasons I cannot grasp right now.

Does maybe anyone have an Idea where a high pitch (like a tinnitus video from youtube) could come from? I am absolutely lost right now and am grateful for any help.

Is there a solder bridge here:

It looks like you need more solder here:

Looks like there is a lot of solder flux on the back of the board. I would trim back the leads more and then give the board a good cleaning with Isopropyl alcohol (90% pure or more, if you can get it) with a brush.

 

[BeyondStupid]

Is there a solder bridge here:

There is, I left it because the riser connects those to points as the first thing. So I thought it shouldn't matter. I cleaned it up, but it didn't help.

It looks like you need more solder here:

I fixed that too, though that was the heatsink connection.

I also replaced the orange drops with the default wima coupling caps, but that didn't help. (Breaking the pcb at the easy one to the right side too, so I had to jumper. I know I am stupid) If I remove the coupling caps the noise is gone.

I cleaned everything up properly, but will do again. Any more ideas? :/


Edit:
I wanted to verify that I am not listening something that isn't there, so I connected it to rma. Apparently the annoying pitch is at 13,6k

 

[Whitigir]

That is a lot of noises you have there

 

[BeyondStupid]

That's true, also odd imbalance I didn't notice. I changed to my mainboard line in, my old STX line in is somewhat fishy sometimes.
Looks more balanced already quieter.

Edit:
Stupid question, but I am becoming desperate with trying things out, since I don't want to wait to until I am old enough not to hear 13k anymore to listen to the sangaku.

Do I need to insulate the To-220 regulators?

 

[Yukon888]

Do I need to insulate the To-220 regulators?

I didn't insulate mine, just put thermal grease on them. I looked over your board, checking for obvious issues such as reversed diodes, transistors, and capacitors, or other issues, but nothing stands out, beside what I mentioned previously. I'm not the most knowledgeable on the circuit theory, so hopefully other people can help.

 

[BeyondStupid]

I hope so too, as a last effort I wrote Pete an email, hoping he answers and can give me a pointer in the right direction. Otherwise I have learnt an expensive valuable lesson. I am not even entirely new to DIY, but this issue is so out of scope of everything I had until now that I don't even know how to trace it properly.

 

[BeyondStupid]

You won't believe it.

I used some 8 Pin dip sockets out of my stash, I don't know how old but probably one of my aliexpress 100 piece orders years ago.

I wanted to replace those and trimmed the leads down to absolute bare minimum. That was it. The pitch is gone, even with the crap sockets.

Edit: Pete answered, what an awesome guy.