First Time Crack Builder Need Assistance [solved]

[prtuc2]

Also heard noises like blowing wind rushing or blowing into the headphone causing noise like static.

[Paul Birkeland]

This sounds a lot like a cold solder joint or a loose wire.

[prtuc2]

I got everything up and running for a few days.  Eventually got the speedball upgrade install as well.  The first two days the amplifier sounds great, however today as I turn on the amp I noticed the sounds so weak on the left channel and no sound on the right channel.

I measure the VDC voltages and the reading:

Terminal                      Voltage
1                                 2.8
2                                 45
3                                 0
4                                 45
5                                 40
6                                 0
7                                 0?
8                                 0
9                                 37
10                               0
11                               0
12                               0
13                               44
14                               0
15                               116
20                               0
21                               186

All the values are below the range, the capacitor between terminal 14 and 15 feels much hotter than all the other parts of the amp.  I noticed the heat generate between the two terminals actually melt the solder iron on terminal 15 and the 270k Ohms resistor connecting to terminal 15 is loose in the process.  Also saw a burn mark around terminal 14 and 15, the capacitor

Which is an appropriate step to go from here?

Appreciate any input.

[Paul Birkeland]

Something in the circuit is sucking down a crapton of current.

Start by running the amp without the 6080, then remeasure the voltages.

If they are all still low, remove the red wire from terminal 13, then run the amp and measure the voltages on the two 6 lug switches.

If you have a cap that's getting really hot, that generally happens when they are in backwards. 

Do also be aware that without tubes in the amp, the power supply will take an unusually long time to discharge.

I suspect you have a loose part shorting two adjacent terminals, but the tests above will help narrow down where the issue is.

[prtuc2]

Here is my reading without the 6080 tube:

Terminal                 Voltage
1                            63
2                            224
3                            0
4                            224
5                            64
6                            0
7                            0 <<--- should be around 100 still got no voltage here
8                            0
9                           1.5 <<-- should be 100, voltage very low
10                         0
11                         0
12                         0
13                         224
14                         0
15                         230
20                         0
21                         236

I noticed two thing when I was taken the voltage, there is a big spark when I was taking reading on terminal 3 not sure if I was touching something else is little tight in the area.  There is heat is normal this time on terminal 15 where the soldering iron didn't melt.  The capacitor is facing the right direction, striped side on terminal 14 and non-striped side on terminal 15.

Thanks again for the help.

[Paul Birkeland]

OK, these voltages are correct, and indicate that there is an issue present with the 6080 tube installed.

Can you shoot a picture of the octal socket wiring?

-PB

[prtuc2]

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi828.photobucket.com%2Falbums%2Fzz208%2Fprtuc2%2FP1000258_zpscaac891f.jpg&hash=7446370606af2902cbe89d4be5884180295cbc0c)

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi828.photobucket.com%2Falbums%2Fzz208%2Fprtuc2%2FP1000248_zps84814f12.jpg&hash=c1c661b1bbc8727af887f7ea48493b4a9e4a4f42)

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi828.photobucket.com%2Falbums%2Fzz208%2Fprtuc2%2FP1000247_zps5b2915a0.jpg&hash=1d6919c24d242d4611eadd5766702e34f6a224bd)

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[JamieMcC]

Are both the upper and lower black wires on B7 soldered the lower one is hard to see?

[prtuc2]

They are not solder together, sorry I always having trouble taking pictures with my camera not sure if that is skill related or need to get a better camera.  My pictures always come out darker than expected.

[Paul Birkeland]

Ah, I had forgotten that you have the Speedball installed.

Can you measure the resistance between the chassis plate and each TIP-50 metal tab?

[prtuc2]

I just take the top of the TIP50, the underside is a little hard to take.

TIP 50 closer to the octa-socket:
Top resistor          OL
Mid resistor          0 ohms
Low resistor         600k ohms

TIP 50 closer to the A-socket
Top resistor         500k ohms         
Mid resistor          >1000k ohms
Low resistor        OL

[Paul Birkeland]

I'd snap a photo of the bottom of the larger PCB.

For some reason, when activated, that board is allowing excessive current draw.

[prtuc2]

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi828.photobucket.com%2Falbums%2Fzz208%2Fprtuc2%2FP1000260_zpsaa7c1928.jpg&hash=0972a545e4c90d2c7b352377598ea959711f4336)

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi828.photobucket.com%2Falbums%2Fzz208%2Fprtuc2%2FP1000261_zpse7501137.jpg&hash=223f05ff8ff76799d0c5f33b41175405511904f3)

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi828.photobucket.com%2Falbums%2Fzz208%2Fprtuc2%2FP1000262_zps2533bda1.jpg&hash=4beae88881f14178f5bd62578c17bb9861d1f256)

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi828.photobucket.com%2Falbums%2Fzz208%2Fprtuc2%2Fdownload_zpseb4b06aa.jpg&hash=e09ca67afd0185373bd0a899330b290dc1f9e3d1)

Sorry I know is hard to see with that pictures, that is the best I got for now.  I will upload some more if I get get better pictures.

[Paul Birkeland]

There's a fair amount of extra solder on the bottom there.  It wouldn't be surprising if one of the 2N2222A's had two pins sorted together.

[prtuc2]

I resolder the 2N2222A on both side

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi828.photobucket.com%2Falbums%2Fzz208%2Fprtuc2%2FP1000265_zps6502cf33.jpg&hash=bae8ed6bbc09546a9ac3caf7270c2cc33c751fbe)

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi828.photobucket.com%2Falbums%2Fzz208%2Fprtuc2%2Fphoto_zps9c6f4815.jpg&hash=1267d1b3348e5cd40688af8a6618bdf151be3679)

I got the same resistance value as before.