Crack-Speedball V1.0, No right Channel, A8 LED Not Lighting [resolved]

jmineart · 1207

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Offline jmineart

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Hello,

After a year of no issues with the crack amp w/ speedball, turning the amp on one day resulted in with less than whisper quiet sound in the right channel. I noticed that the A8 led was not lighting. After checking many wires and finding some that needed re-soldered due to joints that dislocated with a slight nudge I have not solved the problem. I have replaced the A8 Led due to what looked to be a bad connection from the wire to the light housing. I checked the led before soldering and it lit up with my multi-meter. Here are the voltages readings. (Reading are right number)

1   75   (176.5)
2   170   (181.5)
3   0   (0)
4   170   (180.7)
5   75   (71.6)
6   0   (0)
7   100   (175)
8   0   (0)
9   100   (105.4)
10   0   (0)
11   0   (0)
12   0   (0)
13   170   (181)
14   0   (0)
15   185   (201)
     
19   0   (90)
20   206   (0)
     
A1   75   (71.2)
A2   0   (0)
A3   1.56   (1.56)
A4   0   (0)
A5   0   (0)
A6   75   (176)
A7   0   (0)
A8   1.56   (watched it raise from 0 to 200 mV)
A9   0   (0)
     
B1   5   (175.6)
B2   170   (180)
B3   100   (174)
B4   75   (71)
B5   170   (180)
B6   100   (105.1)
B7   0   (0)
B8   0   (0)

Also note, when re-soldering I did not have the speedball manual but I dont believe that I misplaced any wires. When I went to download the file from my account my browser crashed and I had lost the file! Google Chrome wasn't working so I used internet explorer to download it, serves me right. It would be fantastic if I could have another file so I can double check the wiring if there does not seem to be a clear fix.

With great thanks,

Jacob


« Last Edit: December 15, 2016, 08:40:17 AM by Caucasian Blackplate »



Offline fullheadofnothing

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Reply #1 on: December 13, 2016, 06:35:00 AM
1) Try another 12AU7
2) Your download count can be increased if I know what order it is. Post your order number or full name.

Joshua Harris

I Write the Manuals That Make The Whole World Sing
Kit Packer Emeritus


Offline jmineart

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Reply #2 on: December 13, 2016, 06:42:51 AM
I will give that a try.

11997 is the order number.

Thank you.



Offline Paul Birkeland

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Reply #3 on: December 14, 2016, 07:41:05 AM
It's also possible that the solder joint on the center leg of the MJE350 feeding that channel could use some reheating.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline jmineart

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Reply #4 on: December 15, 2016, 07:11:56 AM
Looks like the new tube was the answer, thank you for the help!