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Double Bass Raven Labs PMB wall wart alternative

Jeff Bonny

Jeff Bonny

Inactive
Nov 20, 2000
6,852
4,585
Vancouver BC
#1
I know power supplies for these are hard to find so I figured this may be of interest to some. I've got a couple of stock wall warts but I wanted to put the PMB on a pedalboard with a tuner and compressor and use the multi outlet PSU already on the board. The Raven Labs is looking for 9v 300mA x2 that the T-Rex (or any number of other PSUs) can provide. A simple custom cable that feeds two of the PSU outlets into the back of the preamp is all it took. Works well.
PMBPScable.jpg
 
#2
Thanks for the info! Where did you get the cable for this? The RL power supply was hard to find as an aftermarket version, the ones I got didn't work as well as the original issue. Raven Labs built really good products, I was bummed when they went out of business. Back in the day, Raven Labs told me this couldn't be done with the Voodoo Labs power supply (similar to the T-rex) I own.
 
#3
MR PC said:
Thanks for the info! Where did you get the cable for this? The RL power supply was hard to find as an aftermarket version, the ones I got didn't work as well as the original issue. Raven Labs built really good products, I was bummed when they went out of business. Back in the day, Raven Labs told me this couldn't be done with the Voodoo Labs power supply (similar to the T-rex) I own.
Click to expand...

I have to confess I didn't build it myself. I had it done at Backline Services in Vancouver. They tried to use a nicer 1/8" stereo plug but had a hard time getting the two cables from the two power jacks stuffed into it. They ended up just using a cheap molded 1/8" stereo cable with the two barrel jacks added. If you had a dead Raven Labs PSU you could use the cable from it. In retrospect it was so simple I wish I'd just built it myself. I might have a go at building one with better parts someday.

I haven't tried it with my Voodoo Labs PSU but I have an Eventide hamonizer that similarly uses two 9v outputs in lieu of the provided wall wart. It works with the T-Rex but not the Voodoo Labs. The T-Rex puts out more amperage (400mA as opposed to 300mA) and I always assumed that was the difference. Dunno really though...I'm kinda stupid with this stuff when it comes right down to it.
 
#4
I was told the problem was in achieving the right tip polarity.....but alas, I'm dumb at these things as well. It's nice to know that there is an option for a quality Raven Labs power supply available, again thanks for posting.:)
 
#5
Thanks for your post. I also have a Raven Labs PMB-III preamp that I bought back in 2004. I somehow shorted the PSU several years ago and the unit will only work on batteries. I had called Raven Labs about it but they had shut down operations. I also went to Radio Shack to look for a replacement adapter but they don't sell switching adapters like the one that the Raven Labs requires so I have just used it on battery power. It's a shame that Raven Labs went out of business. The PMB-III is a great preamp.
 
#6
I may have gotten lucky having a power supply that works. Seems like not all will....I have yet to try it with my Voodoo Labs ISO 5. The cable itself was dead easy to make but paying a pro repair shop to check the output of the T-Rex against the stock wall wart may have been $50 well spent. I'd be curious to get better informed opinions about whether or not connecting to a wrong PSU could be potentially damaging. All of them are 9v and in the same 300mA to 500mA ballpark. Even tip polarity seems like you could build the cable to make that correct. Like I say though I'm not the sharpest when it comes to this stuff.
 
#7
That's one of the reasons I didn't buy a replacement adapter at Radio Shack. I was afraid that I may damage the Raven Labs preamp since it does require a switching adapter. At least the preamp works on batteries.
 
#8
cbach said:
That's one of the reasons I didn't buy a replacement adapter at Radio Shack. I was afraid that I may damage the Raven Labs preamp since it does require a switching adapter. At least the preamp works on batteries.
Click to expand...

I'm doing some more research but I wonder if Steve Rabe's concern was not only correct tip polarity but whether or not the power supply was regulated or unregulated. I'm going to get to the bottom of this......

As far as I can gather right now you have to have:
Correct voltage (established as 9v x2)
Correct amperage (established as 300mA x2)
Correct polarity...Ok, I just put a meter on the cable I had made and from the RTS (ring/tip/sleeve) plug to the stereo barrel plugs I'm getting hot sleeve/ground ring from one and hot tip/ground sleeve on the other...I'm now officially confused.
Regulated or Unregulated? I'd suspect regulated because I believe the T-Rex PSU is regulated based on the fact that an old Boss OC-2 octave pedal that doesn't work with a new Boss regulated wall wart also doesn't work with the T-rex. (and also to correct myself i said the T-rex was 400mA per outlet and it's 300mA)
 
#9
I'm curious what the difference is between the PMB-1, PMB-II and PMB-III Raven Labs Master Blenders?

I have an original power supply that came with my Raven Labs head phone amp. next time I use it, I will post the voltages and current rating for future reference to anyone searching for an aftermarket solution to Steve's +/- 9v (18 total) wall wart.
 
#10
Have been using this Raven Labs blender for a while, doing a stereo blend , sunrise pickup with a piezo, works well, this is a good unit.

I have the same problem, looking for a power supply. I was wondering if anyone here had run across a certain Mario Rebollero, who is supposed to carry these ? Very strange. I emailed him, heard back right away, yes in stock, then silence. Tried again months later, he emails again, says he has them, just post $35 to his email address at paypal, no other info.

I just can't make this leap of trust, no address, no phone, nothing, concerned my $ will just disappear into the black hole of paypal.

Anyone buy the Raven PMB 2 PSU from Mario Rebollero ?

And thanks for the T-Rex tip, sounds like a good solution.
How's that working out for you so far, cooked your Raven yet ?

Peace
 
#12
scrambldy said:
And thanks for the T-Rex tip, sounds like a good solution.
How's that working out for you so far, cooked your Raven yet ?
Click to expand...

Honestly haven't used it much but I've played it a couple of hours at a time with no ill effects. It was more a project just to see if it could be done. I have the stock wall wart and a spare (and a Euro plug one) I got from Steve Barr when it was becoming obvious they were gonna be hard to come by in the future. Following the specs on the OEM PSU though there's no reason it shouldn't work with any multi outlet PSU like a T-Rex or Voodoo Labs. I don't know what the difference would be between more expensive isolated units and the cheaper un-isolated daisy chain types but that might be something to consider too...less money and easier to shlep.
 
#13
Okay boys and girls. The polarity for the mini stereo plug is
-9V Tip
+9V ring
ground sleeve
Wire accordingly.
Could pull two independent 9V supplies via brick or 2 physical supplies. The supplies have to be independent and getting there via daisy chain cable of a 9volt supply will not get you there.
Could do a bit with a pair of 1% 1K resistors to give the appearance of a +-9Vdc supply using an 18Vdc supply.
I am going to look at the 18 Vdc power supply approach and report back when I have built and tested my idea.
 
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#14
scrambldy said:
Have been using this Raven Labs blender for a while, doing a stereo blend , sunrise pickup with a piezo, works well, this is a good unit.

I have the same problem, looking for a power supply. I was wondering if anyone here had run across a certain Mario Rebollero, who is supposed to carry these ? Very strange. I emailed him, heard back right away, yes in stock, then silence. Tried again months later, he emails again, says he has them, just post $35 to his email address at paypal, no other info.

I just can't make this leap of trust, no address, no phone, nothing, concerned my $ will just disappear into the black hole of paypal.

Anyone buy the Raven PMB 2 PSU from Mario Rebollero ?

And thanks for the T-Rex tip, sounds like a good solution.
How's that working out for you so far, cooked your Raven yet ?

Peace
Click to expand...

It's only $35. For a very hard to find item. I'd just do it. If the power supply doesn't materialize you can always file a dispute with Paypal. A hassle maybe, but worth it if it ends up working out smoothly.
 
#15
DaZombieWoof said:
Okay boys and girls. The polarity for the mini stereo plug is
-9V Tip
+9V ring
ground sleeve
Wire accordingly.
Could pull two independent 9V supplies via brick or 2 physical supplies. The supplies have to be independent and getting there via daisy chain cable of a 9volt supply will not get you there.
Could do a bit with a pair of 1% 1K resistors to give the appearance of a +-9Vdc supply using an 18Vdc supply.
I am going to look at the 18 Vdc power supply approach and report back when I have built and tested my idea.
Click to expand...

Thanks for this info!

Earlier this year I had the guy who built the cable I posted above plumb a 2x9V battery only Aguilar DB924 preamp for a single 18V source. Based on the $30 he charged it was a pretty simple job and it works well. Seems the BMP could be rewired the same way with the same ease?

I wonder why Steve Rabe chose to use the TRS twin 9V system? What would be the advantage?
 
#16
The ICs used typically are setup in circuits running a bipolar supply. He may have then thought a bipolar supply would make sense. That indeed is 18Vdc rail to supply rail so doing the tweak to set it up to run with an 18V supply would be pretty trivial. You would want to change up the jack I think. Dunlop makes a nice supply for less than $20 that is a 1000mA regulated 18V unit that would be a better supply than what came with it. You could if you modded all your Raven Labs stuff daisy chain the whole lot off that supply. I am planning on building a box for the Dunlop supply to plug into that I would then plug a mini TRS cable into that would feed it unmodified. Parts are ordered. I will report on testing once built.
 
#19
With the T-Rex, is the wiring essentially taking two independent supply lines and making the following connections?

Supply 1:-9V line to stereo plug tip
Supply 2: +9 line to stereo plug ring
Supplies 1 & 2 unused lines to stereo plug ground sleeve

I've got a T-Rex Chameleon and if I can use it using the wiring I've just listed to power my Raven, it would be a welcome respite from waiting for dead 9V batteries during a gig.......and it'd be dead easy to wire up.
 

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