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

Anyone own befaco output module?
MUFF WIGGLER Forum Index -> Music Tech DIY  
Author Anyone own befaco output module?
jamsk
Hi,
I own a befaco output module, I was wondering if anyone else out there has one and can confirm my headphone out behavior? The headphone only works with some very high ohm headphones a friend lent me. Normal headphones are unusable as ear destroyingly loud with huge noise floor. If this is not how it should be what can I do to bring it down to normal headphone levels or what have I done wrong in the build?
Thanks
Jamsk
petkost
I usually use the AIAIAI TMA-1 headphones and the level is ok.
A simple ipad drives these cans easily.
jamsk
petkost wrote:
I usually use the AIAIAI TMA-1 headphones and the level is ok.
A simple ipad drives these cans easily.

thanks
Do you use these with the befaco? if so i probably have a build issue.
thanks
Jamsk
petkost
jamsk wrote:
Do you use these with the befaco?


Yep.
petkost
Just to inform you, I am using Output Module version 1 (bananas).
jamsk
petkost wrote:
Just to inform you, I am using Output Module version 1 (bananas).

Thanks for letting me know. I have output 2 , cant see any problem with the build and was checked at the workshop when i built it. Seems strange that it doesnt work with 'normal headphones'. Will try and contact befaco.
thanks
Jamsk
custommonkey
I've got the same problem myself. Did you manage to find a solution?
jamsk
Afraid not. It has now gone to another wiggler. He will let me know if he manges a fix.
Befacosynth
This behaviour is not normal. Most likely a mismatched resistor or faulty soldering.

Take a look to schematic here:

http://befaco.org/img/Modulos/Output_module/Output_module_schematic.pd f

If problem is just with headphones output, check resistors pairs R7/R6 and R5/R14
If they are not 10K/120R then you got it.

Also, you can get this behaviour if R6 and R14 are no properly soldered. Give them a test and let us know, either here or by mail thumbs up
Befacosynth
A little heads up about this module.
Resistors R104 and R107 can be changed from 68 ohms to 120 ohms to reduce the noise.
We received a couple of mails about this and newer versions are bringing this change already.

Hope this helps!
synchromesh
Thanks for that Befacosynth, I have modded my module (which is the unit in question). I think the original problem was that the TL084 was in backwards. Or something. Certainly the unit seems to work fine now with my trusty AKG K141 headphones (which admittedly are 600Ω).

I've also modded my unit to connect the 1/4" adapter sockets as unbalanced left & right outputs, so that I can more easily connect the unit to my audio interface. Perhaps a future PCB revision could have some jumpers to allow this as an option.
freq
Befacosynth wrote:


If problem is just with headphones output, check resistors pairs R7/R6 and R5/R14
If they are not 10K/120R then you got it.


In the build guide it states the following,

R6 = 120 Ohm
R7 = 68 Ohm
R5 = 120 Ohm
R14 = 47k Ohm

Did I miss something?

asembly_eng.pdf
Befacosynth
freq wrote:


In the build guide it states the following,

R6 = 120 Ohm
R7 = 68 Ohm
R5 = 120 Ohm
R14 = 47k Ohm

Did I miss something?

asembly_eng.pdf


See updated assembly guide + schematic.
Knock
i just build the version 2.3 and the same noise on headphones out.
The same values of R104 and R107 (68 OHM) on the assembly guide.
Should i change to 120 OHM this resistors to decrease the noise?
I really need this to make this module util.
Thanks!
importjingles
I just built one and had the same issue. Switching R104 and R107 to 120ohms definitely helped. Still a bit noisy though.
Rics
Hi there, i've built an output module, board rev. 2.21, and the headphone output is noisy as hell here too.
I tried too to change the output resistors from 68R to 120R as adviced but nothing changed at all.
I've tried also different power supply, it's noisy with uZeus too.
The main L/R output, instead, is crystal clear.
KöterRanzig
I soldered the Output module two days ago and at first, the noise was way too much, like some people noticed, but after checking the suggested Resistors, the solder points were just bad, the noise problem was gone.

Much love to the Befaco people, nice job.
Graham Hinton
importjingles wrote:
I just built one and had the same issue. Switching R104 and R107 to 120ohms definitely helped. Still a bit noisy though.


Of course it's noisy. The main output is being attenuated by 40dB and then put into an amplifier with 44dB gain. That isn't a good way to drive headphones, especially high quality ones.
mutronic
I have a befaco output module, and whenever I plug in my synth voice to the left signal, and an elements into the right, there's a significant drop in volume on the right signal, and the synth voice totally overpowers it. Could this be a loose solder joint or something?
MUFF WIGGLER Forum Index -> Music Tech DIY  
Page 1 of 1
Powered by phpBB © phpBB Group