Power supply query

tbm

Hey kids.

I have a very compact pedal board for a band that I play in. It goes:
Boss TU2 > Stone Deaf PDF-1 > MXR Carbon Copy 

The PDF-1 is picky about power, but I've found that it likes the One Spot. What I had wanted to do was power the tuner, and then use one of those 2 into 1 cable adaptors - that allows you to sum two 9 volts into a single 18 volt pedal - reversed, coming out of the tuner into the two pedals. It does work, but introduces noise into PDF-1 when its engaged. Is there any reason why that might be happening? I can just daisy chain of the One Spot, but that's messy as all those daisy chain things have at least 5 plugs attached. Powering each of the tuner in isolation is perfectly silent. 

 Thoughts? 

MattBanshee

Unsure exactly what Y-cable you're using, but it's clearly not the right tool for the job and is probably creating ground loops or something.

Similarly, using the tuner's power output is physically identical to using a daisy chain cable - it simply splits off the power input, there is no isolation or 'independence' there at all.

I recommend buying either a 2 or a 3-way daisy chain (you can buy them cheaply on ebay/amazon with virtually any number of plugs), or alternatively use something like a Gigrig Distributor. Another option would be to use one of the new low-profile Harley Benton ISO isolated power supplies, which may fit underneath your pedalboard, and will offer fully isolated power to each pedal.

steamabacus

A voltage doubler (2x9V > 18V) cable is the wrong type of cable as it is wired in series.

What you need is a current doubler (2x9V > 9V) cable which has the sockets wired in parallel. In reverse, that becomes a splitter cable (a 2-way version of the common 5-way daisy chain cable).

If all you can find is a normal daisy chain, you can simply snip off any un-needed plugs to make a 2-, 3- or 4-way daisy chain, making sure the screen doesn't touch the core where it's snipped and with a bit of electrical tap over the end to avoid shorts.

tbm

steamabacus said:

If all you can find is a normal daisy chain, you can simply snip off any un-needed plugs to make a 2-, 3- or 4-way daisy chain, making sure the screen doesn't touch the core where it's snipped and with a bit of electrical tap over the end to avoid shorts.

Will this actually work? Because I've picked up a bunch of these daisy chain cables down the years. I recall doing this before though, and it just stopped working. If I can just mangle an old then that'll be perfect. 

tbm

MattBanshee said:

Unsure exactly what Y-cable you're using, but it's clearly not the right tool for the job and is probably creating ground loops or something.

Similarly, using the tuner's power output is physically identical to using a daisy chain cable - it simply splits off the power input, there is no isolation or 'independence' there at all.

I recommend buying either a 2 or a 3-way daisy chain (you can buy them cheaply on ebay/amazon with virtually any number of plugs), or alternatively use something like a Gigrig Distributor. Another option would be to use one of the new low-profile Harley Benton ISO isolated power supplies, which may fit underneath your pedalboard, and will offer fully isolated power to each pedal.

Thanks Matt. I'll try snipping a 5 ways daisy chain as per @steamabacus ;suggestion. Otherwise I'll source a 3 way daisy chain thingy. 

steamabacus

tbm said:

steamabacus said:

If all you can find is a normal daisy chain, you can simply snip off any un-needed plugs to make a 2-, 3- or 4-way daisy chain, making sure the screen doesn't touch the core where it's snipped and with a bit of electrical tap over the end to avoid shorts.

Will this actually work? Because I've picked up a bunch of these daisy chain cables down the years. I recall doing this before though, and it just stopped working. If I can just mangle an old then that'll be perfect. 

Yes, I've done it myself many times over the years. Just make sure it's a clean cut and the centre and screen wires don't touch and cover with a bit of electrical tape (or heat shrink if you want to be a bit more robust).

A daisy chain has all the connections in parallel (all the positives joined together, all the negatives joined together) so removing a few plugs off the end doesn't affect those that remain.

tbm

So daisy chaining didn't work. Well it worked, but the PDF-1 was noisy in the same way so I'm just running the Tuner and MXR orr a Boss power supply, and dedicating the One Spot to the Stone Deaf pedal. Had wanted to avoid two plugs, but he-ho, it's still neat enough... 

Anybody else found Stone Deaf pedals need clean isolated power? 

TimmyO

A single gigrig isolator should Cope with those 

TateFX

tbm said:

So daisy chaining didn't work. Well it worked, but the PDF-1 was noisy in the same way so I'm just running the Tuner and MXR orr a Boss power supply, and dedicating the One Spot to the Stone Deaf pedal. Had wanted to avoid two plugs, but he-ho, it's still neat enough... 

Anybody else found Stone Deaf pedals need clean isolated power? 

I remember something about the PDF needing exactly 9V to work

ICBM

Maybe get a better distortion pedal that isn't stupidly fussy about power supplies...

downbytheriver

Get an isolated power supply - fuel tank junior, iso brick, One Spot pro. Also you can buy daisy chains with fewer (and more) plugs (eBay). 

tbm

ICBM said:

Maybe get a better distortion pedal that isn't stupidly fussy about power supplies...

Well quite. It is a bit annoying. But I don't use it for distortion. The amp is high gain and this yoke lets me boost certain frequencies so i can distinguish myself over the other noisy guitarist in our noisy band, and it does a good job. 

downbytheriver said:

Get an isolated power supply - fuel tank junior, iso brick, One Spot pro. Also you can buy daisy chains with fewer (and more) plugs (eBay). 

I might well pick something up. I have these three pedals on a Pedaltrain Nano so there sod all clearance underneath, and little space on top. 

ICBM

tbm said:

It is a bit annoying. But I don't use it for distortion. The amp is high gain and this yoke lets me boost certain frequencies so i can distinguish myself over the other noisy guitarist in our noisy band, and it does a good job. 

Graphic or parametric EQ?

tbm

Parametric - https://www.premierguitar.com/articles/Stone_Deaf_FX_PDF_1_Parametric_Distortion_Filter_Pedal_Review

ICBM

tbm said:

Parametric - https://www.premierguitar.com/articles/Stone_Deaf_FX_PDF_1_Parametric_Distortion_Filter_Pedal_Review

That's what I meant. If you're not using it as a distortion, just get a better parametric (or graphic if it will do the job) EQ.

Makers will only stop building poorly-designed pedals which won't run properly on power supplies when people stop putting up with it. There's really no excuse.

tbm

Noted @ ;
I actually contacted the Manufacturer and they had no idea why I was getting the additional noise. Maybe I got a duff one. 

Wazmeister

I honestly believe that you cannot overspend on power supplies. Yes, they are expensive but money saved down the line. I used the Strymon Zuma and Ojai/Expansion and they are faultless and silent. Gigrig are also very good.

robinbowes

Wazmeister said:

I honestly believe that you cannot overspend on power supplies. Yes, they are expensive but money saved down the line. I used the Strymon Zuma and Ojai/Expansion and they are faultless and silent. Gigrig are also very good.

I agree with this.

I used to have a Gigrig G2, and went all-in with the GigRig power supply system (isolators, high-current supplies). I sold the G2 so no longer have the Generator, but I kept all the other stuff and use it with a couple of Johnny Shredfreak switching PSUs on my smaller boards. I simply don't ever worry about noise from the power supply.

R.