No sound on right channel (AKA: Apparently I must be a total newbie)

[bigfatpaulie]

Yes.  YouTube is maxed and laptop volume is maxed.  If I plug in headphones I can clearly hear it.

Both sides of the RCA cable measure the same.  Here's a video of what I am doing:

htt p://wri stshot wed.com/per sonal/IMG_12 46.MOV

(remove the spaces, as the forum isn't posting it correctly)

[Paul Birkeland]

You'll want the volume all the way up on your source (phone) when you're doing that test.  You should see about 0.3V of AC between the center pin and shell of the RCA plug.

Did your voltages change with that resoldering?

[bigfatpaulie]

AC!  Okay...  I was thinking DC.  I am getting 0.473 at the cable then.  Let me test.

RCA R:  0.473
RCA L:  0.473

A2: 0.473
A7: 0.473

[Paul Birkeland]

OK, that clears your input wiring.  Next you can run the amp and check AC voltage between ground and 1, then ground and 5.  Your meter may not return a reading since there's DC present, but some will be able to resolve the AC measurement there.

Did your OB voltage on the big board drop after resoldering?

[bigfatpaulie]

Okay.  Thank you.

1: 9.12 (AC)  77.7 (dc)
5: 8.94 (AC)  70.8 (dc)

OB: 167.7v  ()

[Paul Birkeland]

Yeah, half the big PC board just isn't conducting.  Can you post photos of the top and bottom of the board?  99% of the time, this is just a cold solder joint, I suppose 1% of the time the wire from the "O" terminal is broken or not landing on the correct terminal.

[bigfatpaulie]

Thanks!  Hopefully we (you) are getting closer

I really appreciate all your effort and patience on this.

PS. Sorry for the crummy photos, it is hard to get a photo of it attached.

PPS. I also tested the continuity of the connections to board again.

PPPS. I've since re-flowed every point on the big board.  No change.



EDIT:  Here's something interesting.  If I put my headphones on with the amp powered up (but nothing playing) and I measure the voltages at OA and OB I hear static ONLY in my left channel, never in the right.

[fullheadofnothing]

You can go longer than 2 seconds, and especially on the center of the TIP-50, probably should.

[bigfatpaulie]

Please keep in mind I've re-flowed ALL these solders AT LEAST three times.  At this point, no, they don't look perfect...

[fullheadofnothing]

I know they do not look perfect. That is why I posted a video showing what good solder joints look like and clearly showing the process to get good looking solder joints.

[bigfatpaulie]

I get that.  It's really the best I can get them to look at this point, however.  As I said, this didn't start out looking this way...  Keep in mind this isn't my first Crack/SB.  I've also built a Mainline and several ANK kits including the level 5 (https://www.head-fi.org/threads/audio-note-kit-dac-5-1-signature-nos-r-2r.793641/).

I may not have the knowledge to diagnose, but I have a good amount of soldering in my day and I have been working with electronics for 15 years.  I'm certainly no professional, but I really suspect there is something else going on in this case.

Is there any possibility, at all, that one of the transistors isn't functioning correctly?

[Paul Birkeland]

At least one of the center legs of a TIP50 transistor does not have a solid looking joint on it.  Try putting your iron on the pad/center lead, then count to 20, then pull it off.

-PB

[Jimb0]

I usually desolder my joints with a desoldering pump if I noticed anything that didn't look good. When I tried reflowing my joints sometimes they looked the same or worse so I always made a habit of doing them over. I just never knew you could reflow them by reheating it that's why I always did it like that. Not sure if it will help in your case, but I'd give it a try on the Speedball board if nothing else works.

[bigfatpaulie]

Thanks, guys.

Okay, I completely removed the big board from the amp and did the 20 second soldering iron 'hold' on every joint, not just the ones on the TIP50.  No change.

Here is an odd symptom.  I don't know if the amp was doing this before or just started as I didn't try it prior to today.

If there is music playing at the source and I power up the amp with headphones on, I hear the music FIRST come in on the right side then it quickly shifts to the left fully as the amp powers up, leaving the right side dead.  The best way I can articulate it is if someone was on the right of my then quickly moved to my left.

I don't know if that helps but that's what I am experiencing.

[Paul Birkeland]

It's a really, really bad idea to listen to an amp that doesn't pass its voltage tests.  You may end up being in the market for new headphones.

Can you post new photos of the top and bottom side of the big PC board?