Speedball Help

[Blkout]

So I just got the Speedball installed, vacuum tubes light up fine, however I don't have sound in the right channel or if I do, its very low volume compared to the left. I noticed that one of the smaller PCB's next to the headphone input jack which has two LED's, only one of the LED's is lighting up, I removed it to make sure it was installed in the right direction which it was and reflowed all of the solder joints on that PCB just for good measure. It still doesn't light up. Could this be the cause of my right channel problem or should I look deeper? I also checked the 2N2222A and 2N2907A transistors and they're installed in their correct positions, so there's no mix-up there if that helps. Any suggestions from your guys or PB on this would be greatly appreciated.

Thanks.

FYI, my Crack has been running fine for the last 2-3 months now before I installed the Speedball.

 

[Paul Birkeland]

Start by taking voltage measurements and posting those that are out of specification.

 

[Blkout]

Start by taking voltage measurements and posting those that are out of specification.

OK Paul,

T1. 168v - supposed to be 75-90v

T7. 165v - supposed to be 100v

T21. 217v - should be within tolerance but noted anyway

A1. 73v - supposed to be 90v

A6. 168v - supposed to be 90v

B1. 168v - supposed to be 90v

B3. 165v - supposed to be 100v

B4. 73v - supposed to be 90V



All of the others are either dead-on or very close.


Thank you.

 

[Paul Birkeland]

Do both LED's on the 9 pin socket light?  (If one doesn't it's probably not the LED, so no need to resolder it necessarily)

 

[Blkout]

Do both LED's on the 9 pin socket light?  (If one doesn't it's probably not the LED, so no need to resolder it necessarily)

Paul, both LED's light on the 9 pin socket and all of the Speedball LED's are lit except one of the two on the small PCB nearest the headphone input jack.

My biggest concern is that when I was installing the Speedball, I didn't have a lot of room for the nylon stand-offs around the tube sockets so I had to move some wiring around to make room for them and I'm concerned that I may have weakened or broken a solder joint even though visually they look ok.

But I still have no idea what could be causing the voltages to be so far off on the terminals and tube terminals I listed above.

 

[Paul Birkeland]

Check that you haven't swapped your R1's accidentally. 

(One LED on the 9 pin socket would be quite a bit brighter if this was the case)

-PB

 

[Blkout]

Check that you haven't swapped your R1's accidentally. 

(One LED on the 9 pin socket would be quite a bit brighter if this was the case)

-PB

Paul, feel free to call me a moron but what part is R1? Yes one LED on the 9 pin socket is much brighter than the other.

 

[Paul Birkeland]

Paul, feel free to call me a moron but what part is R1? Yes one LED on the 9 pin socket is much brighter than the other.

Check the Speedball manual and resistor installation.

 

[Blkout]

Check the Speedball manual and resistor installation.

Paul if you're talking about the R1's on the small PCB's for the Speedball mod, then both are correct, 237ohm resistors at R1 positions. Both read 237ohm resistance with the meter.

 

[Blkout]

And pictures, just in case this helps.

 

[Grainger49]

Can you see if the LED that is not lighted is in the proper orientation.  That is, the silver band toward the flat side of the painted circle? 

This is the reason that the manual instructs you to mount them upside down.  It was a popular mistake till the upside down mounting was suggested.  This allows you to easily see the orientation.

 

[Doc B]

Flip that A board over and inspect the solder joints. In particular look for missing solder or solder bridged pads around the 2N2907 transistor and the LED

 

[Paul Birkeland]

I would suspect a solder bridge on the bottom side of the board if the R1's are correct.

Also, FWIW, the instructions say to put the LED's in with the stripe facing up so it's easy to see that they are all properly oriented.

-PB

 

[Blkout]

Can you see if the LED that is not lighted is in the proper orientation.  That is, the silver band toward the flat side of the painted circle? 

This is the reason that the manual instructs you to mount them upside down.  It was a popular mistake till the upside down mounting was suggested.  This allows you to easily see the orientation.

I've already removed that LED that isn't lighting and checked its orientation and its correct. I double checked and triple checked them before installing them.

Flip that A board over and inspect the solder joints. In particular look for missing solder or solder bridged pads around the 2N2907 transistor and the LED

Will do and report back.

I would suspect a solder bridge on the bottom side of the board if the R1's are correct.

Also, FWIW, the instructions say to put the LED's in with the stripe facing up so it's easy to see that they are all properly oriented.

-PB

I will check the R1's from the bottom again. And I knew I would probably catch Hell for installing those LED's the other way. I know the instructions said to install them face down but I wanted it to be a bit prettier and I figured if I was absolutely sure they were orientated right, it should be fine. However, I didn't count on having a problem with the installation. I can guarantee that the LED's are orientated correctly though.

 

[Blkout]

Reflowed all solder joints on the A board. Didn't see any bridges and the R1 looks fine to me. Here's a backside picture of the A board.

 

[Paul Birkeland]

Next I would double check the "I" and "O" pad wiring.  The "I" pad should be fed from T2 or T4, the "O" pads on each board will go to T1 or T5.  Swapping these can cause some issues.

 

[Blkout]

Next I would double check the "I" and "O" pad wiring.  The "I" pad should be fed from T2 or T4, the "O" pads on each board will go to T1 or T5.  Swapping these can cause some issues.

Check and check, all 4 are correct.

 

[Paul Birkeland]

Try reheating the center leg of the MJE-350 on the offending board.  Put your soldering iron tip on both the center leg and the PCB at the same time, then count to ten.

-PB

 

[Blkout]

Try reheating the center leg of the MJE-350 on the offending board.  Put your soldering iron tip on both the center leg and the PCB at the same time, then count to ten.

-PB

Thanks Paul but no-go. I'm pretty sure the center leg is soldered well, there's just a dab of solder coming through the board on the top side touching the middle leg. If I may ask, would this offending "A" board also be the problem with my voltages reading so high at the tube terminals too?

 

[Paul Birkeland]

You can try swapping the small PC boards side to side to see if the high voltage follows a board (I suspect it will).

-PB