Help with Speedball Voltages off [resolved]

d79cjm · 1564

« previous next »
Pages: 1   Go Down

0 Members and 1 Guest are viewing this topic.

Offline d79cjm

  • Newbie
  • *
    • Posts: 5
on: September 13, 2021, 08:51:08 AM
I am trying to complete my Speedball upgrade on my 2 year old crack.  Got to the voltage check on the small board and my readings are off.

They are:
OA 30
IA 54
B-A/B 90
IB 54
OB 30

Particularly worried about the B-A?B since that one should be 0.  Any thoughts on what could be my issue?  I'm very much an armature here.
« Last Edit: September 13, 2021, 01:38:04 PM by Paul Birkeland »


Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19694
Reply #1 on: September 13, 2021, 09:06:07 AM
Can you post some photos of your build?

B-A/B wires to terminal 3, which wires to the chassis.  If you have your black meter probe on terminal 12 and you see 90V at B-A/B, then you have a very bad solder joint between terminal 12 and terminal 3.  The one we encounter frequently is where the black wires meet on the headphone jack, and if one of those isn't captured by solder, you'll run into an issue like this.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline d79cjm

  • Newbie
  • *
    • Posts: 5
Reply #2 on: September 13, 2021, 09:20:18 AM
I’ll post some pics in a bit after I finish walking my dog. And I’ll check the section you mentioned.


Offline d79cjm

  • Newbie
  • *
    • Posts: 5
Reply #3 on: September 13, 2021, 11:29:26 AM
Ok. Now I’ve got another issue.  Got my small board sorted. Installed the large board. But I’m failing my resistance check on OB. I’m getting 9.6 m ohm. OA is reading infinite.


Offline d79cjm

  • Newbie
  • *
    • Posts: 5
Reply #4 on: September 13, 2021, 12:05:03 PM
Further update. Removed large board to try and reflow the joints and now I fail resistance checks on both OA and OB. I think I’m done for today but would love some guidance and how to troubleshoot this issue.


Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19694
Reply #5 on: September 13, 2021, 12:54:30 PM
What's wrong with those resistance readings?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline d79cjm

  • Newbie
  • *
    • Posts: 5
Reply #6 on: September 13, 2021, 01:33:39 PM
Ok. Maybe someone will get a kick out of this. When you add a newb and a poorly documented multi-meter you get confusion between milli and mega ohms.

So once I figured out I was being a dumb ass I released I was getting appropriate resistance readings.

Moved on to voltage tests. And everyone is good.

Listening to my beloved crack now and it sounds better than ever.

Feel free to mark as resolved. And I hope someone gets a laugh at my stupidity.


Offline kGlerup

  • Jr. Member
  • **
    • Posts: 26
Reply #7 on: September 13, 2021, 08:10:27 PM
Great you got it sorted and enjoy the "tightness" and energy the SB upgrade brings  ;)
You surely made it a very funny read! I can't find stupidity anywhere, just a guy learning as he goes along  8)


Pages: 1   Go Up
« previous next »