Speedball Voltage issue

[HMF]

Hey all,

Just installed the speedball upgrade and have run into some discrepancies. My voltages are as follows:

Terminal/Expected/Mine
1 75 128
2 170 173
3 0 0
4 170 173
5 75 83
6 0 0
7 100 136
8 0 0
9 100 112
10 0 0
11 0 0
12 0  0
13 170 169
14 0 0
15 185 189
19 0 72
20 206 0

A1 75 81
A2 0 0
A3 1.56 1.56
A4 0 0
A5 0  0
A6 75 109
A7 0 0
A8 1.56 1.56
A9 0 0

B1 75 112
B2 170 172
B3 100 132
B4 75 81
B5 170 171
B6 100 111
B7 0 0
B8 0 0

Seems like anything related to the capacitor on terminal 1/2 is getting more voltage than it should. I've resoldered, but I will again. Not sure what else I should be looking for.

And I have no idea what's going on with 19/20. Was not an issue previously.

Any help would be appreciated!

Thanks,

EDIT: It seems that 19/20 is a typo. So no worries there.

Also, I've resoldered each connection in question. I've also reseated the 12AU7, as I thought that perhaps that was the issue. Still no change.

I suppose it could be an issue with the tube.. but as it was working this morning, I would highly doubt it.

[Paul Birkeland]

I'd reheat the center solder joints on the MJE-350's and TIP50C's.

[HMF]

Thanks for the reply. Just did that.

Now A6 seems to be around the mid 130's shortly after I power on, and slowly counts down and settles around 120. No other changes.

All LED's are nice and bright, if that helps.

[HMF]

Doing some forum digging.

Seems that this could be an issue of a bad tube from the get go? Perhaps the issue was just made more apparent with the install of the Speedball.

I might try getting a new 6080 and 12AU7 and see if new tubes makes a difference. Anyone know if there are any local dealers in Fredericton, New Brunswick, Canada?

Of course I could be barking up the wrong tree entirely. (I don't know what I'm doing)

[Paul Birkeland]

You could probably snag a 12AU7 locally from a guitar shop.  They are pretty easy to find.

You can run the amp with just the 12AU7, and look for the T1/T5 voltages to pop down in the 70-90V range. 

Actually, can you do that test anyway?  (Just post your T1 voltage with no 6080 in the socket)

[HMF]

Will do. I'll do it in a few hours and post my voltages from T1 for you.

Thanks for all of your help, btw. I appreciate it. I'd be pretty lost without the help of this forum.

[HMF]

Tested with the 6080 tube out.

The LED's on the 9 pin socket, and boards A and B were nice a bright.

T1 read 95.

I don't know what that means at all.. but it's a number!

[Acclaim]

I had a similar concern with the voltages listed for 19 and 20 under the Speedball manual:

19 0
20 206

I dismissed those voltages as a typo because the Crack manual doesn't list 19 at all and has:

20 0
21 206

Which are the voltages I maintained from standard Crack after doing the Speedball upgrade. Am I correct in assuming this was a typo? (I was planning to write it up independently as a head's up but this thread is very much on topic!)

[Paul Birkeland]

Tested with the 6080 tube out.

The LED's on the 9 pin socket, and boards A and B were nice a bright.

T1 read 95.

I don't know what that means at all.. but it's a number!

This means that the little PC boards are working fine, but there's a miswire somewhere on the big board.  I would carefully inspect the wiring, especially the feed that goes to T7.

-PB

[Paul Birkeland]

Which are the voltages I maintained from standard Crack after doing the Speedball upgrade. Am I correct in assuming this was a typo? (I was planning to write it up independently as a head's up but this thread is very much on topic!)

This is a typo, it's being fixed as I type.

-PB

[HMF]

This means that the little PC boards are working fine, but there's a miswire somewhere on the big board.  I would carefully inspect the wiring, especially the feed that goes to T7.

-PB

Hmm interesting. I'll double check the big PC board this evening then, and the feed that goes to T7.

Does this also rule out tubes being an issue, or is that still possible?

Thanks again.

HMF

[Paul Birkeland]

Your 12AU7 is working well based on this information.  We also know that your amp was working well pre-Speedball, so funky tubes are looking increasingly unlikely.

-PB

[HMF]

So, I completely removed the big PC board, reheated each solder joint, made sure that all components were where they should be, etc.

I rewired from T7U -> B3, and from T7L -> PC Board.

Currently the voltage at T1 is 105, T7 is about 128, A6 is 103, B1 and B3 are roughly the same as they were.

Oh, I even flipped the big PC board around just for fun. Didn't make any difference.

Here are a couple of pictures.. maybe you will see something that I am missing? (Although I am fairly certain I have done everything correctly. )

http://imgur.com/a/QG5Jx#0

Thanks!

[Paul Birkeland]

105 is pretty close, I believe you have a working amp now.

[HMF]

Ok. Awesome!!

Are the still high voltages at T7/A6/B1/B3 normal with Speedball? They are all still like 25-40 over what they are expected to be in the manual.

Just want to make sure I don't blow anything up. =D