Crack not functioning - guidance requested

[Deke609]

It seems like these issues arise once the unit has been used for multiple hours. Any advice?

I have to wonder whether this might be heat related. Do you have the rubber feet installed so that there is at least a 1/4" gap between the wood frame and the table? Are the vent holes on the metal chassis open and clear? I'd also check that the heatsinks are properly and tightly mounted with the supplied mica insulator.

Just some shots in the dark.

cheers, Derek

 

[DenverDude]

Thanks for the ideas, Derek. The rubber feet were installed to spec, so there is the 1/4 inch gap between the unit and the table. The vent holes are clear  (though I can view a couple of wires when looking inside ... I assume this is normal). The heatsinks are firmly attached too.

To be honest, the unit has always run hot to the touch ... I can keep my fingers on it so it's not as hot as the cylinders on my Triumph when riding for a while, but it's much more than warm.

 

[Paul Birkeland]

It seems like these issues arise once the unit has been used for multiple hours. Any advice?

Do the voltages change if you leave the amp on for a few hours and recheck them? 

Can you let me know what soldering products you used on the amp?  (solder, flux, etc)

 

[DenverDude]

Hello Paul -

Here are the measurements as follows:
First reading = Just after turning unit on
Second reading = 6 hours after turning unit on- slight tinny noise in mostly left channel and when I tap on metal base I hear tinny tapping in mostly left channel - unit hot to the touch
Third reading - 2 hours after last reading, unit still on - now low but audible buzz in both channels - when I tap on metal base I still hear tinny tapping in mostly left channel - unit hot to the touch

1 84.3 - 84.2 - 83.4
2 182.8 - 176 - 179.2
3 0 - 0 - 0
4 182.8 - 175.8 - 179.4
5 83 - 83.1 - 82.2
6 0 - 0 - 0
7 112.2 -110.1  - 110.9
8 0 - 0 - 0
9 112.4 - 110.4 - 111.3
10 0 - 0 - 0
11 0 - 0 - 0
12 NA - NA - NA
13 182 - 178.4 - 179.4
14 0 - 0 - 0
15 201.2 - 195 - 198.6
20 0 - 0 - 0
21 220.8 - 214 - 217.9
A1 82.6 - 83.2 - 82.3
A2 0 - 0 - 0
A4 0 - 0 - 0
A5 0 - 0 - 0
A6 83.5 - 83.8 - 83.5
A7 0 - 0 - 0
A9 0 - 0 - 0
B1 83.5 - 83.7 - 83.6
B2 182.2 - 178 - 179
B3 112 - 110.6 - 110.9
B4 82.4 - 82.5 - 82.4
B5 182.2 - 178 - 179.3
B6 112 - 110.8 - 111.2
B7 0 - 0 - 0
B8 0 - 0 - 0

I am using Alphametals 60% tin 40% lead solder with fastacting flux.

Also, since my last soldering job, neither channel plays unless I pull the headphones out slighly and then I can bring the right and left channel in, but it's not perfect.

At this point, I want to send this unit into you to take a look at it. I am at the point where I need help, so let me know where to send in and how you need payment. Thanks for your help...

 

[Paul Birkeland]

Sure, we can set that up.  It would be helpful to see some build photos before we go down the repair road.

 

[DenverDude]

Just let me know what you need pics of and I will supply them.

 

[DenverDude]

Here are several pics of the assembly....

 

[Paul Birkeland]

OK, you can give Eileen a call on Monday to setup the flat rate repair. 

Thank you for providing the photos, it's helpful to be able to visually confirm that the amp is stock and doesn't have something super obvious going on.