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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => AC Power and Grounding => Topic started by: Bob Stone on October 01, 2023, 08:28:52 PM

Title: Paying for Air
Post by: Bob Stone on October 01, 2023, 08:28:52 PM
https://www.youtube.com/watch?v=VqeOcD7zba4

Grabbed a used Furman Merit M-8 for dirt cheap the other day, popped it open to have a look inside just to make sure it's all in good order (I usually do this with used equipment just to be sure, and well...having never opened one of these up, was pretty funny to see that it's 90% empty. Figured I'd share :)
Title: Re: Paying for Air
Post by: Jeff Lelko on October 01, 2023, 09:10:35 PM
I wonder if the NEC(?) volumetric requirements for an outlet box come into play here.

Either way, based on my pull-out rack light topic from last week I’ll soon be in the market for two of these.  Extra air not required!
Title: Re: Paying for Air
Post by: Steve-White on October 01, 2023, 10:00:29 PM
The Furman Merit Series M-8Dx is worth $100 for my needs and what I use in processing racks and wireless receiver racks.  Remove the dimming circuitry and  replace the incandescent lamps with non-dimmable LED type and they are pretty nice.  Tape the front panel and fill dimmer control know hole wiht RTV and let it set up before pulling tape.

DJ System Wedding Ceremony rack pictured with the modified Furman in it.  Rack has a Behringer XR12 behind the blank covers, and 2x XLR IO patch bays in the rear., and BNC inputs for antenna coax + BNC RF cascade outputs from UA844+V for adding receivers when needed.  They don't just light up the face of the rack, but give a little ambient on the floor which is nice.
Title: Re: Paying for Air
Post by: Brian Jojade on October 01, 2023, 10:11:48 PM
These don't do anything to 'clean up' the power.  MOVs and audio can be problematic as they age and actually cause more noise and ground loops.

The size of the box is for convenience. Being deeper means access to the outlets is closer to the depth of the rest of your gear.  Thinner/smaller units are available if that's what you're looking for.
Title: Re: Paying for Air
Post by: Steve-White on October 01, 2023, 10:14:23 PM
^  Yep the "Conditioning" is pure Snake Oil.  The depth on the Furman's is about right and also hides the light tubes allowing for them to extend out a bit.
Title: Re: Paying for Air
Post by: Bob Stone on October 01, 2023, 10:54:32 PM
These don't do anything to 'clean up' the power.  MOVs and audio can be problematic as they age and actually cause more noise and ground loops.

The size of the box is for convenience. Being deeper means access to the outlets is closer to the depth of the rest of your gear.  Thinner/smaller units are available if that's what you're looking for.

I was just surprised how much empty space was in there when I popped the cover off. The access part makes sense, but talk about paying for a glorified power bar lol

Of course, when you get a used one for $20, there's not much to complain about. It'll suffice for the little wireless rack I'm putting together.
Title: Re: Paying for Air
Post by: John L Nobile on October 02, 2023, 11:06:35 AM
I started laughing when the guy pooped the lid off. I expected empty space but mice would think it was a mansion.
Title: Re: Paying for Air
Post by: Steve-White on October 02, 2023, 11:42:33 AM
I was just surprised how much empty space was in there when I popped the cover off. The access part makes sense, but talk about paying for a glorified power bar lol

Of course, when you get a used one for $20, there's not much to complain about. It'll suffice for the little wireless rack I'm putting together.

Not defending here.  The Furman stuff is in large part, at least the one's I've looked inside and yes I do open them all up - well built.

Circuit card construction for the outlets is nice and they are good quality outlets and such.  All the "Conditioning" snake oil aside, racks need multiply outlets and the Furman stuff is a good solution.
Title: Re: Paying for Air
Post by: Daniel Levi on October 03, 2023, 02:05:34 PM
Just think, what goes into these boxes will be similar to what goes into a surge protected extension lead, and there isn't a lot of room for circuitry in there.
Some of the Behringer rackmount effects are just two PCB's, one on the front panel and one on the back panel plus a transformer,  a fair bit of air!
It's when they put a lump of metal in the device to give it more weight that I start to get worried!
Title: Re: Paying for Air
Post by: doug johnson2 on October 03, 2023, 02:45:04 PM
Not knocking the product but, yes, it is not much more than a glorified surge protector. Pretty much plugs, a switch, and MOVs.  As other have said MOVs can cause problems as they age.  The most common problem I have found is they can cause GFCIs to trip.  You use to be able to get replacement from Furman, very reasonably.   I also recall many years ago, opening up a Behringer 16 channel mixer that was also mostly empty chassis.  I just chalked it up to the "Invisible Pre-amps" they were marketing at the time.
Title: Re: Paying for Air
Post by: Tim Weaver on October 03, 2023, 02:45:20 PM
This is what I usually buy for rack power lately.

LINK (https://www.bhphotovideo.com/c/product/865803-REG/tripp_lite_rs1215_ra_1u_rack_mount_power.html/?ap=y&ap=y&smp=y&smp=y&lsft=BI%3A514&gclid=CjwKCAjw9-6oBhBaEiwAHv1QvKk161Ilo7O2W3bMCuwAvs9UuUCrPYZN1lw5wvqERtd_FcICeeqOdhoCdL0QAvD_BwE)

Nothing in it but a circuit breaker and a bunch of outlets. I personally love having convenience outlets on my racks and these give me a bunch.
Title: Re: Paying for Air
Post by: Brian Jojade on October 03, 2023, 03:04:45 PM
Nothing in it but a circuit breaker and a bunch of outlets. I personally love having convenience outlets on my racks and these give me a bunch.

Looks awesome. If they added a voltage meter to the front, it would be even better. I'm so used to now being able to double check line voltage before flipping the switch, I don't know that I could go without.  Add a current meter too, and it would be epic!
Title: Re: Paying for Air
Post by: Steve-White on October 03, 2023, 04:29:51 PM
^  I have a front face voltmeter in all processing racks as well.
Title: Re: Paying for Air
Post by: Scott Hofmann on October 03, 2023, 06:18:51 PM
mpja.com has a real good selection of panel-mount digital AC voltmeters, amp meters, and combination volt/amp meters at really good prices:
https://www.mpja.com/AC-Digital-Panel-Meters/products/620/
A few examples....
Title: Re: Paying for Air
Post by: Tim Weaver on October 03, 2023, 07:24:27 PM
mpja.com has a real good selection of panel-mount digital AC voltmeters, amp meters, and combination volt/amp meters at really good prices:
https://www.mpja.com/AC-Digital-Panel-Meters/products/620/
A few examples....

Wouldn't be hard to put a voltmeter or three in a single space blank. Could do all kinds of other displays too. Temp, fan speed, amperage, etc.
Title: Re: Paying for Air
Post by: Brian Jojade on October 03, 2023, 09:00:33 PM
Of course it's not hard to add a meter, but factoring in labor to do it, it would be much cheaper if the manufacturer just did it when it was being made!
Title: Re: Paying for Air
Post by: Bob Stone on May 12, 2024, 10:08:40 PM
At least QSC puts stuff inside their amps :)

https://youtu.be/N4jYkyDM_qE

Figured better to share this here than starting a new thread, but opened up a CX254 for some cleaning the other day and took a smidge of video.