Taperssection.com

Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: Matt Quinn on August 19, 2008, 10:01:25 AM

Title: V3 & Schoeps CMC4's question - parallel power?
Post by: Matt Quinn on August 19, 2008, 10:01:25 AM
Hello all,

Couldn't decide if this belonged in Microphones or Preamps/AD, mods feel free to move if you want....

Anyway, I am getting a V3. I run the CMC4's, which run on parallel power:

http://www.schoeps.de/E-2004/cmc.html

 "The CMC 4 works only with 12 Volt parallel powering"


Normally I use a pair of adapters (one for power, from 48v to 12v, and one for reversing polarity) to run the mics off of standard 48v power. So perusing the V3 manual this mornng, I notice this on page 3-

"Alternatively, the V3 can be configured to provide 12V Parallel power."

So of course, I am wondering if I can send the V3 in, get it set for 12v power, ditch the adapters, and maybe save some power in the process? Would I still need to use the polarity adapters even after setting the V3 for 12v?

Thanks all...
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: lino on August 19, 2008, 10:48:00 AM
...you just try and see, you can not hurt anything
but what do you mean by reverse polarity? you have regular CMC4`s right?
the schoeps with reversed polarity are marked with a "p" and I know of no CMC4"p"
or am I missing something here?
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: Matt Quinn on August 19, 2008, 10:53:52 AM
...you just try and see, you can not hurt anything
but what do you mean by reverse polarity? you have regular CMC4`s right?
the schoeps with reversed polarity are marked with a "p" and I know of no CMC4"p"
or am I missing something here?


Well, there are 2 adapters for each mic. One is for power, and one reverses polarity. I'm not sure on specifics, I bought the adapters with the bodies, and just figured I'd never run across a box that could provide parallel power.

I believe they are 'regular'- oh, just found the original PM from ShawnF, who I bought them from:

"let me dig into this in detail...

The schoeps cmc4-uk is a very unique mic body because it requires one of the most unique forms of power of any mic currently available. It requires what is known as red-dot t-power.  Standard T-power sends 12V of current to the mics. Red dotted t-power is basically the same as standard t-power except the positive and negative signals are swapped. So the XLR barrels you are getting serve two different tasks. One pair of barrels (the phantom adapters) step 48v power down to 12v and the other pair (polarity cross adapters) swap the positive and negative signals which are sent on pins 2 and 3 of a standard XLR cable. The Phantom adapters are easy to tell apart from the polarity cross adapters. What you'll need to do is plug one phantom adapter into the polarity cross adapter and put it in the chain for one mic. then plug the other phantom adapter into the other polarity cross adapter and put them in the chain for the other mic.

The good news is that you won't blow anything up even if you don't use them. The mics won't work, but it won't break them. Now that being said It's still not a good idea to hook them up without the adapters. You'll see once you have them in your hands, but it's pretty self explanatory. I understand your questions though. I was totally confused when I bought them and the guy I bought them from didn't know a dambn thing about them so I had to read all kinds of crap on the internet and call schoeps retailers for information. It was not fun. Don't worry though I'm happy to answer any questions you have about them.

I'll ship the adapters in the correct configuration. all you'll need to do is put them on the end of your mic cables and plug the cables into the mics.

As far as the miodification I mentioned earilier goes... Basically all you need to do is open up the phantom adpaters and swap the wires for pins 2 and 3 and resolder them. Then you could remove the Polarity cross adapters from the chain. If you are decent with a soldering iron or you know anyone that is it would take less than 5 minutes to do. Truth be told it's about as simple an electronics job gets, but I just have no confidence in my abilities with a soldering iron. I'd highly recommend doing it though just to reduce the amount of crap in your signal chain (and crap you have to carry in your bag/deal with at a show)."
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: lino on August 19, 2008, 11:05:37 AM
if is a red dotted one then it has reveresed polarity indeed, same applies to red dodded sennheisers
but back to your question.. well ,then no, it will not work without the polarity cables
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: Matt Quinn on August 19, 2008, 11:15:58 AM
Boo. I was all excited. I wonder if Grace can reverse the polarity at the factory too.
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: lino on August 19, 2008, 11:20:44 AM
how about you resolder the mic connector internally and get done with it?
2 minute job

Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: Matt Quinn on August 19, 2008, 11:23:38 AM
how about you resolder the mic connector internally and get done with it?
2 minute job




1) I have no idea how to solder.

2) Even if I did, I'd probably leave ANY fucking around with the internals of the mics to the factory.


That said- anyone know if this is a service the factory could provide, and how much it would cost?
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: Brian Skalinder on August 19, 2008, 12:19:00 PM
Here's what I'd consider, if I didn't want to dork around with re-wiring the connector in the mic:


$0.02

I think the real issue here is what do you need to do to the V3 (and the associated interconnects) so it will work with the mics, so I'm moving the thread to the Pre & ADC forum.
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: Matt Quinn on August 19, 2008, 12:46:01 PM
Here's what I'd consider, if I didn't want to dork around with re-wiring the connector in the mic:

  • Have Grace enable 12V parallel power and leave P48 enabled.  That way you can choose which powering option you want with the jumpers.  If you sell the V3, you don't have to send it back to Grace to convert it back to P48, you just have to make sure you set the jumpers for P48.
  • Make / buy a pair of reversed polarity interconnects.  No more adapters = fewer potential points of failure.  Just make sure you label the interconnects so you don't use them with other mics.

$0.02

I think the real issue here is what do you need to do to the V3 (and the associated interconnects) so it will work with the mics, so I'm moving the thread to the Pre & ADC forum.



Thanks Brian, +t (and Lino too!).

I did not realize you could leave both powering options intact & change them by the jumpers. Good to know. That said, I am not planning on running any other boxes any time soon (famous last words, I know), so I think I may just set it for 12v & if I ever decide to part with it, send it back to the factory. I will think about it before making a final decision though. 

Regarding the reverse polarity interconnects - I had no idea it was possible/ would work. I have no skill with soldering (as previously mentioned), so I'd have to buy. I assume any of the cable makin' gentleman here on the board would be capable of building them?

This is sweet. I will be psyched if I can dump the adapters from the chain. :) :) :)
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: Brian Skalinder on August 19, 2008, 12:54:42 PM
I did not realize you could leave both powering options intact & change them by the jumpers. Good to know.

That's how I read the manual, anyway - and no point in jumpers to switch from 12V to P48 unless it's possible for both to be enabled.

That said, I am not planning on running any other boxes any time soon (famous last words, I know), so I think I may just set it for 12v & if I ever decide to part with it, send it back to the factory. I will think about it before making a final decision though.

Nothing to lose if both are enabled - I figure why limit yourself and/or future owners of the V3.

I assume any of the cable makin' gentleman here on the board would be capable of building them?

Yup.
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: lino on August 20, 2008, 08:41:26 AM
..not sure if the follow is allowed in this forum section but here it comes any way

I asked a "handy" friend about this and he says he can fix cables with reversed polarity AND P48-T12V power converter @ the labor cost of $25 each + parts (of your choice)

these cables will look like straight normal cables and will have the convertor electronics build inside the connectors

which means that you can omit the adaptor pieces and  leave your V3 as it is set at p48 , 
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: Matt Quinn on August 20, 2008, 10:01:28 AM
..not sure if the follow is allowed in this forum section but here it comes any way

I asked a "handy" friend about this and he says he can fix cables with reversed polarity AND P48-T12V power converter @ the labor cost of $25 each + parts (of your choice)

these cables will look like straight normal cables and will have the convertor electronics build inside the connectors

which means that you can omit the adaptor pieces and  leave your V3 as it is set at p48 , 



Hmmm. That sounds awfully tempting. Does your friend have an email address? I'd only need the cables to be about 1'-2'.


If you'd prefer to email me, it's mk4kc5cmc4@gmail.com. Thanks!
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: jerryfreak on August 20, 2008, 04:27:14 PM
polarity swap aside,why would you convert from 48 to 12v in the cable when you can easily jumper the v3 to 12v in like 5 minutes? am i missing something here?

..not sure if the follow is allowed in this forum section but here it comes any way

I asked a "handy" friend about this and he says he can fix cables with reversed polarity AND P48-T12V power converter @ the labor cost of $25 each + parts (of your choice)

these cables will look like straight normal cables and will have the convertor electronics build inside the connectors

which means that you can omit the adaptor pieces and  leave your V3 as it is set at p48 , 



Hmmm. That sounds awfully tempting. Does your friend have an email address? I'd only need the cables to be about 1'-2'.


If you'd prefer to email me, it's mk4kc5cmc4@gmail.com. Thanks!
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: Matt Quinn on August 20, 2008, 04:47:02 PM

polarity swap aside,why would you convert from 48 to 12v in the cable when you can easily jumper the v3 to 12v in like 5 minutes? am i missing something here?



V3 has to go to the factory to be set up for 12v initially - after that it's just a matter of jumpers.

From the manual-

MICROPHONE POWER JUMPERS The V3 can supply +48V Phantom power as well as 12V Parallel power. Jumpers J1 and J5 select the mic power for channel 1. Jumpers J13 and J18 select the mic power for channel 2. The V3 ships from the factory with the jumpers in the +48V setting. To avoid possible microphone damage the V3 is shipped with the 12V setting disabled. The 12V setting must be enabled at the factory. Please contact us if you need 12V microphone power.
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: JasonSobel on August 20, 2008, 05:36:25 PM
I think your best bet is to just contact Grace Design.  Their customer service is top notch, and even if you do have to send it in, it's always a very quick turn-around.  There's no sense in having the internal DC-DC converters convert the voltage up to 48V if you're only going to drop it down to 12V immediately.  it's inefficient and a waste of battery power.
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: Matt Quinn on August 20, 2008, 08:40:27 PM
I think your best bet is to just contact Grace Design.  Their customer service is top notch, and even if you do have to send it in, it's always a very quick turn-around.  There's no sense in having the internal DC-DC converters convert the voltage up to 48V if you're only going to drop it down to 12V immediately.  it's inefficient and a waste of battery power.



Already emailed them, and was quoted $45/hr for shop time (estimated 2 hour max job), and a 3-5 day turnaround time. It's the route that I will most likely go, then get a pair of reverse polarity cables made up to run with the CMC4s.
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: Brian Skalinder on August 20, 2008, 10:23:35 PM
Already emailed them, and was quoted $45/hr for shop time (estimated 2 hour max job), and a 3-5 day turnaround time. It's the route that I will most likely go, then get a pair of reverse polarity cables made up to run with the CMC4s.

They want to charge you to enable a function they intentionally disabled prior to shipping for the purpose of protecting a very small number of people who might switch the jumpers and damage their gear?  Interesting policy.  You might ask nicely if they'll do it for free, since it seems odd they don't just enable both P48 and T12 on every shipped unit and allow users to select their mic power of choice.
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: stevetoney on August 21, 2008, 05:24:23 AM
^^ Not only that, but they haven't done this enough or know enough what to do that they can't quote you a firm price?
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: lino on August 21, 2008, 07:12:05 AM
After my last comment linking to my cable friend I thought lets not post anything else since it will look biased but I just cant help it….How about some common sense here?

- (dis)invest in enable the T12  mode and disable the P48 means:
 a)you will not be able to run any P48 mic in the future
 b)if you ever want to sell the unit you will have hard time getting a fair price because 9 out of 10 mic users out there have P48 mics
- you will still have to use reverse polarity adaptors or cables

But!
If you get a pair of those custom made converter cables
- you will be able to use the V3 with your T12 or any other P48 mic
- you will need no extra polarity cables
- you will loose no money if you decide at some point to sell the V3
- you can always resell these custom cables
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: SmokinJoe on November 08, 2011, 07:32:43 AM
Follow up in case anyone else runs across this thread... I bought Matt's CMC4's.

I called Grace about converting my V3 and they were really hesitant about doing the T12 mod.  They have only done a couple of them, and it sounds like it was more hassle than they expected.  If I had pushed the issue they probably would have done it.  I've decided to leave my V3 stock because I have other P48 mics that run well with the V3.
 
I have a Littlebox which sounds great with the Schoeps (I prefer it to the V3 with these mics) and I'm having that converted to 12T.  I bought the Littlebox from the yard sale for a reasonable price and having that dedicated to those mics is fine with me.  Jon is doing the P48 to T12 mod for $40 plus shipping, which is a lot cheaper than Grace.
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: F.O.Bean on November 08, 2011, 11:13:09 PM
Follow up in case anyone else runs across this thread... I bought Matt's CMC4's.

I called Grace about converting my V3 and they were really hesitant about doing the T12 mod.  They have only done a couple of them, and it sounds like it was more hassle than they expected.  If I had pushed the issue they probably would have done it.  I've decided to leave my V3 stock because I have other P48 mics that run well with the V3.
 
I have a Littlebox which sounds great with the Schoeps (I prefer it to the V3 with these mics) and I'm having that converted to 12T.  I bought the Littlebox from the yard sale for a reasonable price and having that dedicated to those mics is fine with me.  Jon is doing the P48 to T12 mod for $40 plus shipping, which is a lot cheaper than Grace.

Enjoy my old LB. I was going to get one within the next month w/ Jensen xformers and a KCY input, but now thats impossible :(
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: DSatz on November 11, 2011, 09:23:42 AM
People, please don't jump on Grace about this. Parallel ("T") powering had its day in the film and video industry; it was the only powering method supported by the earliest Nagra recorders and Sennheiser shotguns in the 1960s. But all other professional sound engineers were using phantom powered microphones, which have big advantages especially when multiple microphones are being used. Both Nagra and Sennheiser saw the light and began to support phantom powering in the early 1970s. By the mid- to late-1980s the changeover was essentially complete, and nowadays new T-powered microphones are hardly sold any more if at all.

The fact that a V3 can be configured to support this system, in the rare cases where it may be needed, is a plus. The fact that the preamp can't easily be switched over to parallel powering by people who don't understand microphone powering is an even bigger plus in my opinion because parallel powering can instantly damage or destroy certain types of dynamic microphones. It's not like phantom powering, where both signal leads are charged relative to ground; in parallel powering, the two signal leads are charged relative to each other. The DC is directly superimposed on the audio. It is, in some respects, like putting your fingers into a (low-voltage) light socket.

(You all do know that that's why "phantom" powering is called what it's called, don't you? The idea was that the power would appear when a condenser microphone was plugged in, but a dynamic microphone with a balanced output wouldn't "see" any powering, and could be used safely even if the phantom power switch was left on by mistake.)

--best regards
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: F.O.Bean on November 11, 2011, 06:13:04 PM
People, please don't jump on Grace about this. Parallel ("T") powering had its day in the film and video industry; it was the only powering method supported by the earliest Nagra recorders and Sennheiser shotguns in the 1960s. But all other professional sound engineers were using phantom powered microphones, which have big advantages especially when multiple microphones are being used. Both Nagra and Sennheiser saw the light and began to support phantom powering in the early 1970s. By the mid- to late-1980s the changeover was essentially complete, and nowadays new T-powered microphones are hardly sold any more if at all.

The fact that a V3 can be configured to support this system, in the rare cases where it may be needed, is a plus. The fact that the preamp can't easily be switched over to parallel powering by people who don't understand microphone powering is an even bigger plus in my opinion because parallel powering can instantly damage or destroy certain types of dynamic microphones. It's not like phantom powering, where both signal leads are charged relative to ground; in parallel powering, the two signal leads are charged relative to each other. The DC is directly superimposed on the audio. It is, in some respects, like putting your fingers into a (low-voltage) light socket.

(You all do know that that's why "phantom" powering is called what it's called, don't you? The idea was that the power would appear when a condenser microphone was plugged in, but a dynamic microphone with a balanced output wouldn't "see" any powering, and could be used safely even if the phantom power switch was left on by mistake.)

--best regards

I learn something new everyday from you Mr. Satz. Thanks for the read :)
Title: Re: V3 & Schoeps CMC4's question - parallel power?
Post by: SmokinJoe on November 13, 2011, 10:23:01 PM
DSatz, you are correct.  I didn't mean to bad mouth Grace.  I was just trying to make the point that if someone buys some CMC4's or other T-powered mics ASSUMING that converting a V3 was no big deal, that's not necessarily a good plan.