Noise from Godlyke Powerall?

eyvindwa · #1 10-09-2007, 10:17 PM

I have a Godlyke Powerall power supply (http://www.musiciansfriend.com/produ...ply?sku=155051) that I use to power all of my pedals. Lately, I have been hearing a sort of oscilating, high pitched sound when using it with several pedals. It never occurs if it is powering just one pedal, but if I for instance hook up both the Sansamp and the Boss CE-5, it is very audible at loud volumes. When running on batteries, the pedals are (more or less) dead silent. Now, I'm wondering, is this (most likely) due to
- faulty pedals
- faulty power supply
- the fact that the godlyke powers all of my pedals from a single daisy chain, and hence it is not 'isolated'.

Any experinces or opinions on this would be greatly appreciated.

JanusZarate · #2 10-09-2007, 10:43 PM

I'm almost 100% sure it's the last one. I'm just a bit surprised that you'd get noise from just having only two pedals on the daisy chain - especially a SansAmp and a CE-5.

But yeah, I suspect it's the nature of the power supply, because it's not an isolated-output supply. We've had people on TB report noise issues with 1 Spots and Poweralls numerous times in the past when powering multiple pedals.

niftydog · #3 10-09-2007, 10:46 PM

Yeah, two pedals is a bit odd. These types of supplies use very high frequency switching circuits to regulate the voltage - when the supply is nearing it's maximum current load the switching ripple tends to get worse and may manifest as audible noise. But two pedals shouldn't be a heavy load for the supply.

eyvindwa · #4 10-10-2007, 12:24 PM

Well, it certainely increases with the number of pedals powered, and attaching the Godlyke Power Pump (to bring it up to 18V for the Blowtorch) ups the noise significantly. I guess it is a realtively safe assumption to say that I need a new power supply... So; the question is: which one should I get? I've got 7 pedals on the board at the moment, all 9V except the blowtorch, but I'd like the ability to add more down the road. Any suggestions?

musicelectronix · #5 10-10-2007, 12:49 PM

as matter of fact, power supplies make noise when they are not properly regulated and/or not regulated at all. Some pedals do require voltage regulation and in some rare cases current regulation. However, I suspect neither is the case.

Considering the sansamp and CE-5 (which is known to need a regulated power supply), I would say sansamp amplifies the humming noise coming from CE-5 and inverts the signal, hence meet the high freq oscilation. Those said, IMHO the issue seems more like a filtering issue. If you manage the filter AC voltage creeping into the DC line, it might be an easy solution for the problem (I can not be 100% sure though)

Before going into a power supply research, I would suggest a simple circuit (that you can buy the parts from radioshack) I use when problems like that happens. For 5 dollars, you have a shot on that. Here it is:

AC filter.txt

one resistor, one electrolytic capacitor, a perfboard and one female and one male 2.1mm barrel power jacks, that's all there is. You will build this on a perfboard and put it after the power supply, before the daisy chain. I am not saying, this is the solution and can not guarantee if this works, but I would try this before shopping for power supplies.

Edit: I have reason to believe even 1-spot and godlyke has the same form factor, they are not same inside.

niftydog · #6 10-10-2007, 04:37 PM

Quote:

Originally Posted by musicelectronix

as matter of fact, power supplies make noise when they are not properly regulated and/or not regulated at all.

The Godlyke is a regulated switch mode supply of decent quality - it should be fine.

Quote:

Originally Posted by musicelectronix

I would say sansamp amplifies the humming noise coming from CE-5 and inverts the signal, hence meet the high freq oscilation... filter AC voltage creeping into the DC line

I'm struggling to see how inverted hum makes (meets?) high frequency oscillations.

The noise is high pitched hiss not hum, the AC mains frequency is not the issue here, your suggestion of a low pass filter might not do anything at all. Besides, the Godlyke is a reputable supply and should not need any external filtering.

eyvindwa · #7 10-10-2007, 11:54 PM

Quote:

Originally Posted by niftydog

The Godlyke is a regulated switch mode supply of decent quality - it should be fine.

I'm struggling to see how inverted hum makes (meets?) high frequency oscillations.

The noise is high pitched hiss not hum, the AC mains frequency is not the issue here, your suggestion of a low pass filter might not do anything at all. Besides, the Godlyke is a reputable supply and should not need any external filtering.

So, would your guess be that either the power supplly or the pedal is faulty?

sk8 · #8 10-11-2007, 12:20 AM

diago power supply can power up to 30 pedals and has the ability to provide an 18 volt.

I've got one and its excelelent, plus its not a wall wart!

eyvindwa · #9 10-11-2007, 12:30 AM

The Diago looks very similar to the Godlyke, have you tried both?

sk8 · #10 10-11-2007, 12:34 AM

i haven't a/b them. Got the diago and that was that, very pleased with it

niftydog · #11 10-11-2007, 12:41 AM

Quote:

Originally Posted by eyvindwa

So, would your guess be that either the power supplly or the pedal is faulty?

The power supply is most likely causing the hiss - whether it's faulty or not is a whole other debate. If I were you I'd be trying a different wall wart just to make sure the Godlyke is the cause.

Quote:

Originally Posted by sk8

diago power supply... provide an 18 volt.

No it can't - You need another device in order to do that, and a similar device is available from Godlyke. It's also more than twice the price of the Godlyke.

sk8 · #12 10-11-2007, 12:44 AM

Quote:

Originally Posted by niftydog

No it can't.

You can get an 18 volt adaptor

http://www.diago.co.uk/component/pag...rt/Itemid,206/

niftydog · #13 10-11-2007, 12:47 AM

I was getting to that, just a bit slow on the edit!

sk8 · #14 10-11-2007, 12:51 AM

fair enough.

i don't dispute what it costs but for me its performing well. I accept that if you have a powerall set up just replacing the power supply is a cost effective option

musicelectronix · #15 10-11-2007, 01:53 AM

Quote:

Originally Posted by niftydog

The Godlyke is a regulated switch mode supply of decent quality - it should be fine.

I'm struggling to see how inverted hum makes (meets?) high frequency oscillations.

The noise is high pitched hiss not hum, the AC mains frequency is not the issue here, your suggestion of a low pass filter might not do anything at all. Besides, the Godlyke is a reputable supply and should not need any external filtering.

Sorry to bother you, I am sure you will find your own way just fine.

For the record, it was an AC filter, not a low pass filter. If you put a circuit like that on the signal path, you have to be an elephant* to hear that sound. You should listen to Disturbed. It is a really good band.

Edit: didn't catch the (meet?) part the first time. it was we who met with the high Freq oscilation, not the consequences. It was like that:
- Dog, meet the high freq Osc.
- Nice to meet you, HFO
- You too, niftydog

*elephants are known to hear extra extra low frequencies.

eyvindwa · #16 10-11-2007, 12:22 PM

So, I'm almost positive it is the Godlyke now. Both my CE-5 and my new B:ASSMASTER (yehaa!) make high pitched oscilating noises when either one is the only pedal in the chain. I guess its time to look for other options (I guess your suggestion, musicelectronix, would not be valid in this case, since there's only one pedal?).

The Diago has been suggested, other options? (Must be available in Europe.)

sk8: Have you tried the Diago with a CE-5?

edit: On the other hand, both my Blowtorch and the Weeping Demon Wah are dead silent...

niftydog · #17 10-11-2007, 05:19 PM

Quote:

Originally Posted by musicelectronix

For the record, it was an AC filter, not a low pass filter. If you put a circuit like that on the signal path, you have to be an elephant* to hear that sound.

What you posted was absolutely, unequivocally, by definition a low pass filter. Just because the frequency knee is very low doesn't change the definition.

Quote:

Originally Posted by musicelectronix

Edit: didn't catch the (meet?) part the first time. it was we who met with the high Freq oscilation, not the consequences. It was like that:
- Dog, meet the high freq Osc.
- Nice to meet you, HFO
- You too, niftydog

Indubitably!

Quote:

Originally Posted by eyvindwa

The Diago has been suggested, other options? (Must be available in Europe.)

Don't know about availability, but by far the most popular multi-supply on this forum is the VooDoo Labs Pedal Power.

But, if you're having issues like I suspect with switch mode supplies, then you're best bet is to avoid them and get a "linear" supply. Remember how old wall warts were big and heavy compared to things like the Godlyke? You want a big heavy one - linear power supplies don't generate high frequency noise like some switch mode supplies can.

eyvindwa · #18 10-12-2007, 12:06 AM

Quote:

Originally Posted by niftydog

But, if you're having issues like I suspect with switch mode supplies, then you're best bet is to avoid them and get a "linear" supply.

Pardon my ignorance, but what would a 'linear' supply be? Would for instance the T-Rex Fuel Tank meet the requirements? Thanks.

musicelectronix · #19 10-12-2007, 02:27 AM

Quote:

Originally Posted by niftydog

What you posted was absolutely, unequivocally, by definition a low pass filter. Just because the frequency knee is very low doesn't change the definition.

You know a lot, don't ya. My prior 4+4+2 years of education (not talking about the high school

) didn't teach me enough, so please enlighten me more.

You should really really listen to disturbed, I bet you would find a lot in common. As of now, I am done with you.

eyvindwa, check this out. You shouldn't be punished from all these. When I was looking out for the noise issue, I found this. Jack Orman, the DIY guru, has some remarks about noise problems with the pedals.

http://www.muzique.com/lab/hum.htm

Edit: God.. I read the whole thing after writing this. So I guess my story about the AC leakage checks out.

eyvindwa · #20 10-12-2007, 08:10 AM

So, today I tried another adapter from my local radio shack equivalent here in Norway. The unit cost me about 20$, and has been lying in my drawer for a few years. It has "regulated power supply" written on it, and guess what - both the CE-5 and the B:ASSMASTER are now dead silent. So, I guess the culprit may be regulated/non-regulated supply, like you suggested, musicelectronix.