Speedball Question

gbcook2 · 1286

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Offline gbcook2

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on: January 27, 2019, 01:00:39 PM
Just finished my speedball upgrade after two months of listening to the Crack.  Loved the standard crack so was skeptical the speedball upgrade would be better, but it definitely is.  Very glad I did it.  However, have a few questions related to my Cracked Speedball:

1)  I know the instructions say it is never the LED that is bad, but I have one LED out and am within range on all my voltage checks and resistance checks.  The amp also sounds good with the exception of a low consistent buzz when not playing music.  Should I still be worrying about the LED that is out on my small circuit board (pics attached)?

2)  The low buzzing I am hearing I am assuming is due to a bad solder joint?  I noticed if I tap on the top of the Crack I can hear a muffled sound in my left channel.  The low buzz also seems to be coming from my left channel.  It is unnoticeable when listening to music for the most part but it will build to higher volumes at times.  Just wanted to see if anyone had any ideas on troubleshooting. 

Thanks in advance for the help.



Offline Paul Birkeland

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Reply #1 on: January 27, 2019, 03:28:07 PM
We certainly do appreciate the gap in time you've allowed to let your stock Crack settle in, that  helps reduce the probability of an error in the original build being disturbed during the Speedball upgrade.

1)  I know the instructions say it is never the LED that is bad, but I have one LED out and am within range on all my voltage checks and resistance checks.  The amp also sounds good with the exception of a low consistent buzz when not playing music.  Should I still be worrying about the LED that is out on my small circuit board (pics attached)?
It's not the LED, it's the backwards transistor next to it.  (You also wouldn't have passed your voltage checks on the small board, OB will be about 50V, which is too low)

« Last Edit: January 27, 2019, 03:30:45 PM by Paul Birkeland »

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline gbcook2

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Reply #2 on: January 28, 2019, 02:09:48 AM
Thanks for catching, Paul.  Not sure how I missed that.  My voltage on OB was 59v so you are correct it is in the 50s, but within the +/- 10% of 60v so I figured it was fine.  I will try and fix when I get home. 

Also, any thoughts on how if I just tap on the top of the chassis I can hear the tap albeit muffled in my left channel?  I also will occasionally get a buzzing that builds and if I tap I can get it to go away. 

Appreciate all the help and thanks again.



Offline Paul Birkeland

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Reply #3 on: January 28, 2019, 04:46:24 AM
A buzz that goes away when you tap the chassis is nearly always a loose solder joint.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man