Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: [email protected] on May 18, 2019, 06:55:19 AM
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I have installed the Speedball and caps with poor results.
The caps are
Dayton Audio DMPC-100 100uF 250V Polypropylene Capacitor
tubes
6AS7 Russian 6H13C tube is also known as 6N13S and 6AS7G.
Genalex - Gold Lion ECC82 / B749
Results
No audio on left side and voltages are off.
Term correct My results
1 75 178
2 17 183
3 0 0
4 170 183
5 75 90
6 0 0
7 100 177
8 0 0
9 100 116
10 0 0
11 0 0
12 0 0
13 170 183
14 0 0
15 185 203
29
19 0 95
20 206 0
A1 75 96
A2 0 0
A3 1.56 1.58
A4 0 0
A5 0 0
A6 75 178
A7 0 0
A8 1.56 0 (led not lit: replaced to no effect)
A9 0 0
B1 75 178
B2 170 183
B3 100 176
B4 75 90
B5 170 183
B6 100 116
B7 0 0
B8 0 0
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Can you post some photos of your amp? (preferably with the stock caps in and not the big monsters that will obscure our view of everything)
In the manual we provide instructions to install the small board then test it before moving on. Did you pass this test and then run into issues when installing the large PC board?
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hope this helps
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Ah, it's an old Speedball!
I would suggest reflowing the solder joints on the MJE350 on the small board feeding terminal 1, especially the center leg.
-PB
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reflowed as instructed. no effect yet
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Can you post some new photos? What wattage rating is your iron?
For the MJE350s, your soldering iron is very unlikely to be able to heat them up enough to damage them. You need to see solder flow through the hole that the lead passes through and wick up a little bit on the other side. From the original photos you posted, there's no solder coming through on the other end. For the center lead of the MJE350, it takes a lot of heat to get this going, and without allowing that to happen, the flux inside the solder will create an insulating barrier between the solder joint at the lead of the MJE350. Once it is hot enough, that flux will be displaced and you will get a proper joint.
This is also consistent with the high voltage you are seeing, and I would bet that one LED on the 9 pin socket isn't glowing anymore either.
-PB
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Hotter is better it seems. Thank you!
i got my crack back. Both sides now.
current(hehe) voltages Unsure about 19, and 20 (21 is 207v)
Term correct 1st 2nd
1 75 178 91
2 170 183 180
3 0 0 0
4 170 183 186
5 75 90 95
6 0 0 0
7 100 177 114
8 0 0 0
9 100 116 117
10 0 0 0
11 0 0
12 0 0
13 170 183 185
14 0 0
15 185 203 182
19 0 95 96
20 206 0 0
A1 75 96 93
A2 0 0 0
A3 1.56 1.58 1.56
A4 0 0 0
A5 0 0
A6 75 178 92
A7 0 0 0
A8 1.56 0 1.54
A9 0 0 0
B1 75 178 89
B2 170 183 182
B3 100 176 114
B4 75 90 93
B5 170 183 181
B6 100 116 116
B7 0 0 0
B8 0 0 0
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I spoke too soon.
the left channel is in both ears. time to do some digging. do any of the above voltages indicate where I should start?
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Your voltages now are looking better. Having the left channel in both ears is most likely a miswire that will require us looking over some photos to understand what's gone wrong.
-PB