Amperes in a power supply

[vendettav]

hey guys. I recently read some stuff and whatnot and finalyl got to the idea... could a 1000mAh power supply cause hum/buzz?? if used with one pedal only or two...

may be this is stupid question but let's see how the thing goes and then if it's not making any sense i'll explain the reason i thought of this

[R.G.]

hey guys. I recently read some stuff and whatnot and finalyl got to the idea... could a 1000mAh power supply cause hum/buzz?? if used with one pedal only or two...

may be this is stupid question but let's see how the thing goes and then if it's not making any sense i'll explain the reason i thought of this

Well, **a** 1000ma (not ma-hr, that's a battery rating) of unspecified type **could** cause hum/buzz. Or it could not. Depends on the power supply and in particular on things which are not related at all to the current rating.

A car battery is capable of hundreds of amperes, and causes no hum at all. A Visual Sound 1Spot (just because I have looked into this one in depth and know it) causes hum too low to be detected even in studio situations in most cases. A no-brand 9V power supply may or may not cause hum, depending on the internals.

Mostly it's unrelated to the power capability. Could be bum diodes, lack of filtering, poor or no regulation, lots of things. They're not related.

[vendettav]

Thanx RG
just found some confusing articles and thought i'll better ask to make sure

[drhulsey]

The power rating of the PS is the total power it can supply. Your pedal only uses as much as it needs. If it needs 20 mA, your 1000 mA PS might power 50 of them daisy chained. As R.G. said, that says nothing about the quality of the power.

[R.G.]

If it needs 20 mA, your 1000 mA PS might power 50 of them daisy chained.

We hand test pedals in bulk to verify designs. I got a call one day that we were only getting 7.2V our of one of our power supplies. I told them to measure the voltage at the power supply itself - it measured 9.6V. What had happened was that there was a large daisy chain tree supplying pedals and they had inadvertently powered 200 pedals from the same adapter.   

The adapter was handling it fine, but they were losing over 2V in the drop in the wires and connectors in the daisy chain from the large amount of current. 

[vendettav]

If it needs 20 mA, your 1000 mA PS might power 50 of them daisy chained.

We hand test pedals in bulk to verify designs. I got a call one day that we were only getting 7.2V our of one of our power supplies. I told them to measure the voltage at the power supply itself - it measured 9.6V. What had happened was that there was a large daisy chain tree supplying pedals and they had inadvertently powered 200 pedals from the same adapter.   

The adapter was handling it fine, but they were losing over 2V in the drop in the wires and connectors in the daisy chain from the large amount of current. 

ouch! haha... 200 pedals with one supply??

still thanx everybody.. just what got me confusing is some review in Guitarcenter on 1spot saying it was too noisy, may be it wouldn't be if he'd power more than few pedals. and then "max 300mAh" on my danelectro EQ so i thought to ask you know

[R.G.]

just what got me confusing is some review in Guitarcenter on 1spot saying it was too noisy, may be it wouldn't be if he'd power more than few pedals.

I'd very much like to read that review. Do you have a link?

[Mark Hammer]

If it needs 20 mA, your 1000 mA PS might power 50 of them daisy chained.

We hand test pedals in bulk to verify designs. I got a call one day that we were only getting 7.2V our of one of our power supplies. I told them to measure the voltage at the power supply itself - it measured 9.6V. What had happened was that there was a large daisy chain tree supplying pedals and they had inadvertently powered 200 pedals from the same adapter.   

The adapter was handling it fine, but they were losing over 2V in the drop in the wires and connectors in the daisy chain from the large amount of current. 

And at 7.2V I bet those pedals sounded bitchin'!! 

[R.G.]

And at 7.2V I bet those pedals sounded bitchin'!! 

Yeah... I'm thinking of releasing a mod package: 200 pedals, 27 daisy chains, and, as they say on late night TV, MORE!!

You can get a variety of sounds by where in the daisy chain you plug the one pedal you're actually using, instead of the 199 drone pedals. Hmmm... you know, I bet that the collective signal emissions from the 199 drone pedals make a sitar-like tone, with slight hints of oak and a touch of turnips on the finish of notes.

[defaced]

just what got me confusing is some review in Guitarcenter on 1spot saying it was too noisy, may be it wouldn't be if he'd power more than few pedals.

I'd very much like to read that review. Do you have a link?

This?
http://www.guitarcenter.com/Visual-Sound-1-SPOT---Space-Saving-9V-DC-Adapter-101999308-i1124557.gc#customer-reviews

[R.G.]

This?
http://www.guitarcenter.com/Visual-Sound-1-SPOT---Space-Saving-9V-DC-Adapter-101999308-i1124557.gc#customer-reviews

Looks like it.

I thought it was a Guitar Center official review, not necessarily an open reviews page where anyone can write anything. Of course, people are free to think whatever they want; I wish the people with the units they thought were failing would take them back for replacement. It's simple and easy. I'm struck by how different the reviews are, mostly either "best thing ever" or "pure junk". But I should have guessed, given my experience with reviews on other commercial pages.

I was tempted to write commentary on the reviews, but upon reflection, I think it's not necessary. I got a good laugh out of a couple of them.

[vendettav]

yeah lol .. that was the one... well whatever you'll see online huh?

anyways thanx guys. i just plan on getting my hands on a 1spot so it kinda got me wondering...