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

[Paul Birkeland]

Those solder joints look a lot better, let us know what voltages you get with the board in that condition.

Using a pair of film resistors in place of the large Speedball board is possible, but you'd need a pair of 3K/3W parts.  These will get insanely hot, but they shouldn't self destruct too quickly.  Anything under this power rating is going to smolder rather quickly.

 

[bigfatpaulie]

Thanks.  Okay, no dice.  So I desoldered the TIP50's again and re-soldered.  Again, no dice.

So I took some of the kit wire and bridged from each of the three pins to their locations on the PCB and HAZZAH!  Sound!  I don't know if the wire is helping the connection, or if there is a brake on the board or whatever, but I am getting sound now.

That said, the sound on the right side is quite a bit quieter than it is on the left...  IE, the challenges aren't balanced now.

Is there anything I can do to fix this?

 

[Paul Birkeland]

Post your new voltage measurements.

 

[bigfatpaulie]

OA: 102.3
OB: 112.5
G: 0
B+:  189.8

 

[Paul Birkeland]

Now test to see if the volume balance is due to the volume pot.  To do this, plug your phone into the Crack with the phone level very low and the Crack's volume pot nice and high.

 

[bigfatpaulie]

No change.  I tried with the volume on the Crack all the way and stepped down to see if there was a change in balance and there isn't. 

I even jumped from the RCA in to past the volume pot (IE, eliminated the volume pot from the chain) to make sure.

 

[bigfatpaulie]

No suggestions at all?

We've come so far! 

 

[adydula]

Have you thought of sending it to BH for resolution?

Alex

 

[fullheadofnothing]

With the amp on and the 60Hz tone playing at the input, what is the AC voltage at 6 & 10?

 

[bigfatpaulie]

Thank you.

6: 0.410 VAC
10: 1.378 VAC

 

[fullheadofnothing]

With the amp on and the 60Hz tone playing at the input, what is the AC voltage at 1 & 5?

 

[bigfatpaulie]

1: 20.86v
5: 20.26v

 

[fullheadofnothing]

The only suggestion that makes sense with these measurements would be to try another 6080. If that doesn't solve your issue, we are approaching the end of what can be done without having the amplifier on the bench. The repair service exists for these kinds of cases.

 

[bigfatpaulie]

Okay - I swapped out the 6080 for a NOS 5998 tested and sold by Brent Jesse (ie, it's perfect) and there still is a balance issue, and sadly, the voltages test the same...

Part of me feels good that it isn't an obvious issue.

Part of me is really disappointed as clearly is something going on here.

To pay $165 to diagnose a $199 doesn't make sense: I would just as soon throw it out and buy a new kit, frankly.  Don't get me wrong, I'm not knocking the service, I get that it's a flat rate on a $199 and on a $1999 amp.  I also really appreciate all the time and effort everyone has put into this.

Out of interest, what's all between the 1 & 6 and 5 & 10?  The big board and the 6080: is there anything else?  I am considering rebuilding the big board and replacing all the parts with new as it's really only about $5 worth of stuff on it.  I just want to know if there anything else I should be swapping out.

 

[Doc B]

It's possible (but I can't say certain, without having the amp on the bench) that the big board might have some fault on it and it may be a damaged semiconductor. If you found a damaged trace (where you laid the piece of wire over it) that should be considered an omen that trying to rework a board with new parts is potentially asking for trouble. If you decide that replacing the board will fix the amp you might be playing it more safe to start with a fresh PC board, and we can sell you the board and parts. Before you go there double check that the output cap on the bad side didn't get brushed by a hot iron and burned. You can contact Eileen at queen at bottlehead dot com to order the parts. We are pretty much out of other ideas without being able to put the amp on our bench and go through it.