MUFF WIGGLER Forum Index
 FAQ & Terms of UseFAQ & Terms Of Use   Wiggler RadioMW Radio   Muff Wiggler TwitterTwitter   Support the site @ PatreonPatreon 
 SearchSearch   RegisterSign up   Log inLog in 
WIGGLING 'LITE' IN GUEST MODE

Help needed: Silent Journeyman Issue 1
MUFF WIGGLER Forum Index -> Oakley Sound Systems  
Author Help needed: Silent Journeyman Issue 1
e-grad
Some time ago I've built Journeyman Iss. 1. Unfortunately I did something wrong since it was silent on the first testing. I was not able to troubleshoot the board.

Today I'm working on it again. However still my knowledge on circuits is not sufficient to find the culprit. ATM the board is populated except for the THAT300 chips which I've pulled out.

Up to now I've checked the following:

- Wiring for the 2U-version seems to be correct.
- Soldering work just seems fine.
- Used a continuity tester to check whether Input 1 jacks ends up at the appropriate pin of the Input 1 pot and leaves at the wiper etc. Anything seems to be fine.
- All caps are correct. (I'd assume the same for the resistors but haven't double checked ATM.)
- Switch wiring seems to correct.
- Meassured the ICs/sockets not sure whether the results are fine:

U1: Pin 1 = 3,62V; P4 = -12V; P7 = 3,61V-8,68V (varies with Freq Pot); P8 = 12V

U2 and U3: Pin 4 = -12V; Pin 8 = 12V

U4: Pin 1 = 12V; P2 = 1,2V; P4 + P11; P6 + P7; P8 + P 9; P13 = 1,55V; P14= 12V.

U5: Pin1 + P2 + P13 + P14; P4 + P11; P5 + P10; P6 + P7; P8 + P9.

Whereas PX + PY denotes that they're connected.

Any idea where to investigate further? Will it be safe to place the THAT300 chips into their sockets?
e-grad
Just realized that my Balance trimmer is 500k instead of 470/500 as per BOM. Does this might have silenced my Journeyman?
Synthbuilder
What is your supply voltage? It should be +/-15V. From your readings it looks like you are using +/-12V. I don't known for sure whether the Journeyman will run from +/-12V without problems.

e-grad wrote:
Just realized that my Balance trimmer is 500k instead of 470/500 as per BOM. Does this might have silenced my Journeyman?


Not sure it would silence it but it won't work properly with the trimmer value that large.

Usually complete silence will mean that the output connector has been wired incorrectly. If you can hear a faint hiss and hum, and that hiss and hum changes in sound with the frequency and resonance pots then the problem is a fault with the input wiring - or the LP/HP switch.

Tony
e-grad
Thanks for the swift reply.

Synthbuilder wrote:
What is your supply voltage? It should be +/-15V.


My PSU for testing is +/-12V.

Please let me know whether +12V on Pin 1 and 14 of U4 are fine. Having looked at the datasheet I think it is fine yet I'm far from understanding these sheets.

If the 12V at pin 1 and 14 are fine I'll place two THAT300 chips into their sockets and will mount the module in it's frame with +/-15V.

Synthbuilder wrote:
Usually complete silence will mean that the output connector has been wired incorrectly. If you can hear a faint hiss and hum, and that hiss and hum changes in sound with the frequency and resonance pots then the problem is a fault with the input wiring - or the LP/HP switch


I'll happily re-investigate this if the fully populated board is powered up. Today I've checked these connection by eye and they seem fine to me. But then I recall that I was experiencing some hiss in powering the module up for the first time.
e-grad
I think I've got up and running. The culprit seems to be the way to huge Balance trimmer. Final testing will be done when I managed to get a trimmer to the specs.

BTW I had huge problems to get a trimmer which fits the board's pin spacing. During my long search I obviously even confused the value I was hunting for.
MUFF WIGGLER Forum Index -> Oakley Sound Systems  
Page 1 of 1
Powered by phpBB © phpBB Group