T-Rex Room-Mate hum with Pedal Power 2 Plus

General discussion and tech talk about the industry standard Pedal Power line of power supplies.
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Andreas Näsman
Posts: 4
Joined: Wed Aug 07, 2019 11:49 am

T-Rex Room-Mate hum with Pedal Power 2 Plus

Post by Andreas Näsman » Wed Aug 07, 2019 12:08 pm

Hi!

I've read several threads on the forum about being able to power a T-Rex Room-Mate with a Pedal Power 2 Plus, by connecting a Current Doubling Adapter into outputs 5 and 6 with their DIP switches set AWAY from NORMAL. However, when I try this, a pretty audible ~50 Hz (I live in Finland were we have 230 V/50 Hz residential voltage) hum is heard from my amplifier. The hum is louder if I have the pedal turned on, although it can also be heard if it's turned off. I power a couple of other pedals with the PP2P, and I've tried disconnecting them, but it doesn't affect the hum. Also, there is no hum if I use the power cable that came with the Room-Mate.

Am I'm doing something wrong or is something not functioning correctly? Tomorrow I'll have a chance to measure the mA and V that is outputted from the Current Doubling Adapter, just to check that they are correct.

Thanks!
Andreas

Rez
Posts: 401
Joined: Thu Sep 01, 2011 10:31 am

Re: T-Rex Room-Mate hum with Pedal Power 2 Plus

Post by Rez » Wed Aug 07, 2019 2:53 pm

The expectation based on its specifications, is that powered as you suggest it should work fine. But, as confirmed by a variety of similar feedback from others too, it seems this is not always the case.

Have you tried with BOTH the DIP switches 5 and 6 set instead to the NORMAL 9VDC position?

Any better?
Cheers,
Ben Resnick
Voodoo Lab - Tech Support

Andreas Näsman
Posts: 4
Joined: Wed Aug 07, 2019 11:49 am

Re: T-Rex Room-Mate hum with Pedal Power 2 Plus

Post by Andreas Näsman » Thu Aug 08, 2019 6:42 am

I tried that no and the hum is gone...but the effect of the reverb is diminished quite heavily.

Haven't tried it out, but could a viable option be to have one of the outputs set to NORMAL and the other one set AWAY from NORMAL? What would the theoretical total voltage and ampere be in this case?

Rez
Posts: 401
Joined: Thu Sep 01, 2011 10:31 am

Re: T-Rex Room-Mate hum with Pedal Power 2 Plus

Post by Rez » Thu Aug 08, 2019 10:22 am

No. When using a current doubler the outputs must be the same voltage (both 9V or both 12V), as combining different voltage outputs with a current doubler could create problems and even risk of damage.

If neither of the previous configurations work to your satisfaction, powering it from the AC courtesy outlet with its adapter/wall-wart may be the best option.

Also/FYI, any of our supplies with a regulated 12V 400mA output would work to power the T-Rex Room-Mate without issue and no current doubler required. Here's a list: Pedal Power 4 x 4, Pedal Power ISO-5 or Pedal Power MONDO.

Hope this helps!
Cheers,
Ben Resnick
Voodoo Lab - Tech Support

Andreas Näsman
Posts: 4
Joined: Wed Aug 07, 2019 11:49 am

Re: T-Rex Room-Mate hum with Pedal Power 2 Plus

Post by Andreas Näsman » Tue Aug 13, 2019 11:12 am

Ok, thank you for the clarification!

One of these adapters should work for me right, since I'm using the European version?

Rez
Posts: 401
Joined: Thu Sep 01, 2011 10:31 am

Re: T-Rex Room-Mate hum with Pedal Power 2 Plus

Post by Rez » Wed Aug 14, 2019 10:13 am

Cheers,
Ben Resnick
Voodoo Lab - Tech Support

Andreas Näsman
Posts: 4
Joined: Wed Aug 07, 2019 11:49 am

Re: T-Rex Room-Mate hum with Pedal Power 2 Plus

Post by Andreas Näsman » Wed Aug 14, 2019 12:17 pm

Thanks for all the help, works now without any hum! 8-)

Rez
Posts: 401
Joined: Thu Sep 01, 2011 10:31 am

Re: T-Rex Room-Mate hum with Pedal Power 2 Plus

Post by Rez » Thu Aug 15, 2019 9:17 am

Thumbs up! ;)
Cheers,
Ben Resnick
Voodoo Lab - Tech Support

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