0

Filter warble? Check your power input.
Moderators: altitude, adafruit_support_bill, adafruit, phono, hamburgers

Please be positive and constructive with your questions and comments.

Filter warble? Check your power input.

by hamburgers on Mon May 29, 2006 2:08 am

I'd been having terrible, terrible, and absolutely wretched and horrible problems with a crazy wobble at high resonance. As it turns out, the wall wart I was using was at the heart of all my woes.

There have been several threads about this filter warble/wobble/tomfoolery.
I'd even gone to the lengths of replacing my jumpers with single insulated wires...

It was the wall wart. Try another one if you're having similar problems.

(smacks head)
Image

hamburgers
 
Posts: 1056
Joined: Wed Dec 21, 2005 8:25 pm
Location: DC metro

by adafruit on Mon May 29, 2006 11:04 am

was this w/the one we stock with the x0xb0x or a different one?

adafruit
 
Posts: 12151
Joined: Thu Apr 06, 2006 4:21 pm
Location: nyc

by hamburgers on Tue May 30, 2006 1:41 am

When I first started having the problem it was a US robotics, but I can't be sure if it was the one that came with the kit. I used the wall wart from my new kit and it solved the problem.

btw you don't have any extra 16-position rotary switches do you? 8)
Image

hamburgers
 
Posts: 1056
Joined: Wed Dec 21, 2005 8:25 pm
Location: DC metro

by phono on Tue Dec 04, 2007 3:48 am

ive had this a couple of times recently, ill have to source a new wallwart and see if that helps out, it seems to come and go at times, its only recently i noticed that when it happens all knobs are at 100%
phono
 
Posts: 1502
Joined: Wed May 02, 2007 4:01 pm
Location: forum whore aka 2Cv

by phono on Wed Dec 05, 2007 4:13 pm

i tried a new wallwart but unfortunately its the same brand (cant get any other brand locally) and the problem still exists, ill have to mail order one :S
phono
 
Posts: 1502
Joined: Wed May 02, 2007 4:01 pm
Location: forum whore aka 2Cv

by hamburgers on Wed Dec 05, 2007 8:27 pm

phono wrote:i tried a new wallwart but unfortunately its the same brand (cant get any other brand locally) and the problem still exists, ill have to mail order one :S


you don't have the one that came with the kit?
Image

hamburgers
 
Posts: 1056
Joined: Wed Dec 21, 2005 8:25 pm
Location: DC metro

by phono on Thu Dec 06, 2007 2:02 am

mome rath wrote:
phono wrote:i tried a new wallwart but unfortunately its the same brand (cant get any other brand locally) and the problem still exists, ill have to mail order one :S


you don't have the one that came with the kit?


no im in europe so had to skip the kit one
phono
 
Posts: 1502
Joined: Wed May 02, 2007 4:01 pm
Location: forum whore aka 2Cv

by phono on Mon Dec 17, 2007 8:59 am

i've tried 2 other wallwarts now, one 500ma and the other 800ma, the warble problem still exists sometimes. Lucklily it only seems rather intermittant so im still able to use the x0x. It may be that its only happening when the x0x hasn't been on long (i will try to verify this) Any ideas what i could check? I also have a somewhat rather scratchy res pot already, dont suppose this could have any bearing on it?

anyone got any ideas?

heres a recording of the problem in action

http://www.bahnhof.se/wb447909/phono/x0 ... oblems.mp3
Last edited by phono on Mon Dec 17, 2007 9:04 am, edited 2 times in total.
phono
 
Posts: 1502
Joined: Wed May 02, 2007 4:01 pm
Location: forum whore aka 2Cv

by guest on Wed Jan 02, 2008 10:23 pm

ive actually modded my x0x to get the warble
i like the watery sound
my 303 has it when i turn the resonance way up

you can verify that its a powersupply problem
by measureing the voltage across c8
this shouldnt drop below 15v or so
a quick fix for the warble if its intermittent
is to increase c8 to 1000uF
or get rid of r1
although eliminating r1 might put some 120hz in your powersupply
guest
 
Posts: 3155
Joined: Fri Feb 17, 2006 5:35 am

by phono on Thu Jan 03, 2008 7:06 am

guest wrote:ive actually modded my x0x to get the warble
i like the watery sound
my 303 has it when i turn the resonance way up

you can verify that its a powersupply problem
by measureing the voltage across c8
this shouldnt drop below 15v or so
a quick fix for the warble if its intermittent
is to increase c8 to 1000uF
or get rid of r1
although eliminating r1 might put some 120hz in your powersupply


thanks for the tips guest, are you implying that the warble im getting occasionally is the same one as mentioned about the real 303? (if youve got time to listen to my clip to verify this that would be great)

It definately only happens when resonance is on full, and its not related to warm up or anything. I'll check out c8 next time in inside.
Image
x0x #733 Image SH-101 MC-202 TB-303 TR-606 TR-808 TR-909 MKS-50 Juno-106 A-100 Virus-B E-6400 SX-150 Monotron
phono
 
Posts: 1502
Joined: Wed May 02, 2007 4:01 pm
Location: forum whore aka 2Cv

by guest on Thu Jan 03, 2008 6:01 pm

yeah it sounds like the warble in my 303
although i havent pinned down exactly when it warbles
as it doesnt do it often
although i have verified that it is the powersupply doing it
guest
 
Posts: 3155
Joined: Fri Feb 17, 2006 5:35 am

by phono on Thu Jan 03, 2008 6:11 pm

guest wrote:yeah it sounds like the warble in my 303
although i havent pinned down exactly when it warbles
as it doesnt do it often
although i have verified that it is the powersupply doing it


thanks for checking, i guess i got a 100% replica then, bugs and all :lol:

i figured out finally how to trigger it, make a pattern with no or very little slides, set all knobs to maximum then slowly turn cutoff down a touch. It starts then (but not always).
Image
x0x #733 Image SH-101 MC-202 TB-303 TR-606 TR-808 TR-909 MKS-50 Juno-106 A-100 Virus-B E-6400 SX-150 Monotron
phono
 
Posts: 1502
Joined: Wed May 02, 2007 4:01 pm
Location: forum whore aka 2Cv

by phono on Thu May 22, 2008 7:22 am

guest wrote:ive actually modded my x0x to get the warble
i like the watery sound
my 303 has it when i turn the resonance way up

you can verify that its a powersupply problem
by measureing the voltage across c8
this shouldnt drop below 15v or so
a quick fix for the warble if its intermittent
is to increase c8 to 1000uF
or get rid of r1
although eliminating r1 might put some 120hz in your powersupply


so i got around to testing this today, c8 read 24.7 with zero resonance and no warble, and with max res and warble going it read the same, so i tested all the radial capacitors in the power section, with and without warble and there seems to be no differnece in voltages at all. Testing the ceramic caps the only one that showed any difference was c4, and only when the seq was running (thats on the 12v line) but didnt move more than ~.03 which didnt seem to be tied to the warble. I even tried swapping the 6562 since its socketed and i have a spare, no difference again. Finally i tried shorting R1 to see if that would help, again no difference. Finally i reflowed the joints in the power section.

Incidently i also tested j4 with and without warble and the was no change there also. I do have a 1000uf radial i could swap c8 out with, but will that make any difference?
Image
x0x #733 Image SH-101 MC-202 TB-303 TR-606 TR-808 TR-909 MKS-50 Juno-106 A-100 Virus-B E-6400 SX-150 Monotron
phono
 
Posts: 1502
Joined: Wed May 02, 2007 4:01 pm
Location: forum whore aka 2Cv

by guest on Sat May 24, 2008 4:27 pm

if c8 is up at 24v
the warble isnt coming from the powersupply

the only other thing that comes to mind
is to check if r95 and c28 are soldered in well
guest
 
Posts: 3155
Joined: Fri Feb 17, 2006 5:35 am

by phono on Sat May 24, 2008 4:32 pm

guest wrote:if c8 is up at 24v
the warble isnt coming from the powersupply

the only other thing that comes to mind
is to check if r95 and c28 are soldered in well


thanks, ill give them a check soon, i can live with it either way, since its only when the power is under duress it happens, much like the silverbox
Image
x0x #733 Image SH-101 MC-202 TB-303 TR-606 TR-808 TR-909 MKS-50 Juno-106 A-100 Virus-B E-6400 SX-150 Monotron
phono
 
Posts: 1502
Joined: Wed May 02, 2007 4:01 pm
Location: forum whore aka 2Cv

Please be positive and constructive with your questions and comments.