EV RE-20 Repair Issues (Self Repair)

[yoink]

So I bought an RE-20 off of ebay over a year ago. I was ripped off. The mic worked only intermittently. It sounded fine when it worked but it wasn't reliable. At one session it didn't work at all. I put it away and just tried to forget about the pain. I'd learned my lesson. That was the last ebay mic purchase.

However, I decided, seeing as though EV now charges a straight $250 to fix them that I should just try myself.

Opening up the mic, it was clear that someone had simply twisted the base and one of the wires had come off the (or finally come loose) from one of the soldering points.

Then, in opening the mic both of the cables that connected to the XLR connector came off (they must have been really damaged and my inexperience with this mic didn't help.)

So all this blah blah blah-ing to say is there a wiring diagram for this mic available? While I know which two leads on the mic body to use, and which two on the XLR connector to use, I don't know how I could be sure I didn't reverse the phase of the mic or something to that effect when I re-wire it. IE, which cable connects where.

Anyway, many thanks in advance.

[emrr]

The EV site has a document with an exploded view parts drawing.

[yoink]

Originally Posted by emrr

The EV site has a document with an exploded view parts drawing.

Last time I checked it didn't however detail connections between the leads and a look today confirmed that either a) it doesn't or b) I'm looking in the wrong place.

I hope it's "b" and someone can provide a link.

[yoink]

I think I figured it out checking out the official XLR pin numbers and a wiring diagram Harvey Gerst posted on another forum.

1. High side of the transformer (typically the lead labelled 150) goes to pin 2
3. Low side of the transformer goes to pin 3.

*Crosses fingers and warms up the the iron.*

[emrr]

sounds right. good luck.

inside there are a number of other possible impedance terminations that aren't really discussed anywhere, but they don't all come out to the connector, they strap at the terminal board inside.

[yoink]

Originally Posted by emrr

sounds right. good luck.

inside there are a number of other possible impedance terminations that aren't really discussed anywhere, but they don't all come out to the connector, they strap at the terminal board inside.

I noticed that 50 + 250 (vs the 150 that seems to be the standard.)

Also, I wrote to EV and they kindly offered to send me a new HPF switch and male XLR assembly free of charge to make my own repair!

[ulysses]

Unless you have another RE20, it really doesn't matter too much if you get it wrong. Polarity is not standardized across all microphones, so in situations where it matters, you always have to listen and check polarity anyway. Relax, don't worry, have a home brew!

[close/far]

Check your PMs or e-mail.

[chris319]

http://www.coutant.org/evre20/re20.pdf

Polarity is not standardized across all microphones

Generally, positive pressure on the diaphragm results in a positive voltage on XLR pin 2.

[ulysses]

Originally Posted by chris319

Generally, positive pressure on the diaphragm results in a positive voltage on XLR pin 2.

Except for when it's pin 3. Which, globally and historically, is about half the time.

[chris319]

Originally Posted by ulysses

Except for when it's pin 3. Which, globally and historically, is about half the time.

This matter was settled in 1990:

In 1990 the AES14 Standard settled on the use of the pin 2 high convention and ended years of confusion in the marketplace.

XLR History

[ulysses]

That's funny. Did the AES go around and rewire all the microphones in the field? Did they send inspectors to Mexico and China to visit microphone factories and enforce their decision? What is the penalty for non-compliance?

Heck, at least a quarter of my microphone collection was made after 1990. Do you think I still need to listen for phase inversions when I mix several microphones on one source?

[amorris]

I think the AES can assume you can rewire an XLR/mic/anything with the right information. its not the Audio Operators Society.

and the cost of non compliance is out-of-polarity recordings.

It sure sucks they upped the flat rate. used to be $75 for anything. $250 is high for a flat rate.

[chris319]

Did the AES go around and rewire all the microphones in the field?

No, but you've had 19 years to rewire yours.

[ulysses]

I still have a polarity switch on every preamp I own, and a pair of healthy ears. The agreement of those in attendance at an AES meeting doesn't eliminate the need to listen. That's the point.

[Rick Sutton]

My experience is that 95+% off all mics made in the last 15 years are wired for positive polarity on pin 2. About half of my pre 1990 American made mics but the majority of my pre 1990 European made mics were wired pin 2 positive when I received them (Europe favored pin 2 positive, with some exceptions, long before America). There is a very easy way to check the polarity of microphones and every studio should do this to ensure you at least start with all your mics in polarity. Healthy ears aside, why not KNOW that you are starting with a level playing field?

The following is from a post in January:


As to how to get all your mics in phase with each other you don't even need to use a multimeter.
There are different methods out there but most involve the same principle where you put two mics on the same source and see if they combine or subtract when added together in a mixer.

Here's my test:

Put two mic cables into two channels of a mixer. Send both channels to the same METERED output.

Plug a mic that you KNOW is pin 2 pos into channel 1. I'd borrow a new AKG, Senn etc. Or do your clicker test to determine . (You can plug an unknown mic in first but it makes the test a little random as to how all the mics end up)

Bring the mic up close to your mouth and say AAAAAAAAAHHHHHHHHHH and keep saying it while you bring up the channel 1 fader til you get around a reading somewhere in the middle of the meter. On a needle VU meter I push it up to zero. Leave that channel at that setting.

Now plug another mic into channel 2 and hold it and mic 1 together at your mouth (both capsules as close together and the same distance as possible) repeating the AAAAAHHHH. You have become a human tone generator. Bring up channel 2 SLOWLY into the same metered output.

If mic#2 in IN PHASE with mic #1 the meter will rise continually all the way and peg.

If mic#2 is OUT OF PHASE with mic #1 the meter may start to raise but at the point the two channels are close in gain the meter will lower dramatically. It may rise again after you pass the equal gain point but it's the dramatic dip that you look for and it is very obvious.

Keep #1 mic as control and continue to test all the mics on channel two marking each mic as you go so you can rewire the out of phase ones later. If you are testing a collection of mostly new/standard mics you should find that the vast majority/all are in phase. With a collection of modified and custom mics it's anybody's guess.

I can run through an entire colection of mics with this test in about 10 minutes.

You don't have to use your voice as the tone source, many people use a speaker. And a meter isn't entirely necessary as you can use headphones and listen for the dip. The point is to get the mics close to the mouth/speaker and at an equal distance from the sound source.
Try it. It works.
Rick

[chris319]

Originally Posted by ulysses

I still have a polarity switch on every preamp I own, and a pair of healthy ears. The agreement of those in attendance at an AES meeting doesn't eliminate the need to listen. That's the point.

Say you have 20 mics in your mic locker. Once you've gone through the above procedure for every mic in there and correct any out-of-phase units (and cables), you're done with those mics and cables forever. No need to reinvent the wheel every time. They're not going to spontaneously reverse polarity at 3 in the morning when you're not looking. No need for a phasing switch on every preamp (you can always build a phase reverser into an XLR barrel). You can grab any mic out of your locker and not worry about polarity. When you buy a used mic on ebay or borrow someone else's you'll need to check phasing. I know you know how to wire a mic connector so that's not the issue.

Last year I purchased an E-V 666 off ebay and when it arrived I took a look inside. I noticed that the wiring did not comport with the color code on the EDS. Sure enough some dinkus had decided to rewire the UA connector backwards so I wired it back to factory spec and now it is hap-hap-happily in phase with everything else.

[ulysses]

You're missing the point entirely. When you put multiple microphones on a single source and mix them together, whether or not they're in phase depends on more than whether or not they're wired to the same standard. Take a top snare mike and a bottom snare mike, for example. If the two mikes are wired the same, they'll be out of phase. You have to flip one to make them work together. Now consider a mike on the beater side of a kick drum mixed with another in front of it. Same deal. These are just the most obvious examples, but the situation arises all the time. It's hard to miss when your bottom is completely gone in your kick drum, but if you're not listening for this even in less obvious multi-mike arrangements then you're probably not achieving the results you could be. Take a mike on a bass amp mixed with a DI - it's rarely entirely in phase or out of phase, due to complex reactive elements in the amplifier and speaker, among other things. Sometimes flipping polarity on the mike only gives you a shift in tonality rather than severe low-frequency cancellation, and you have to choose the polarity that works best with the music. ANY time you're using more than one microphone on a source, you need to listen to the phase relationships between them and choose the polarity that works best with that source. Once you're doing that, it really doesn't matter at all how the mike was originally wired, or whether or not you've bothered to rewire it. You're flipping the polarity switch and choosing the appropriate position. There is no inherent advantage to using one position over the other. The correct answer is contextual.

But suppose you have taken the time to rewire your microphones so they're all "pin 2 hot". Then you work with a band who brings in another engineer, and he's "solved" the same problem by memorizing the polarities of different models and vintages of microphone. He assumes your Grampion ribbon mike is wired pin 3 hot just like his, but it isn't. He throws it up over the right shoulder of the fiddler, with a 4038 out in front. He doesn't bother listening while flipping the polarity switch, because he knows they're wired in opposing polarity and he knows that's going to work with the mike positions he chose for his room full of acoustic instruments. Now he's spending half an hour trying to figure out why the timpanis sound all nasal and weird, and by the time he figures out that it's a phase issue with the fiddle mike, the musicians have gone out for a cigarette and started talking about where to eat. They decide to eat at the Thai place because it's near the liquor store, and your whole session is shot to hell. All because you and your guest engineer both thought you could assume phase coherence based on mike wiring instead of using your ears.

[yoink]

Well that turned out to be a productive discussion!

As far as the RE20 goes, I got the replacement switchcraft male XLR part (though EV sent the wrong switch for the bass rolloff). I wired it as indicated above and it's back to normal and sounds great.

At least, so far.

We'll see how this shoddy Canadian workmanship lasts.

Thanks for all the input folks.

[AmongstTheLiving]

Originally Posted by Rick Sutton

My experience is that 95+% off all mics made in the last 15 years are wired for positive polarity on pin 2. About half of my pre 1990 American made mics but the majority of my pre 1990 European made mics were wired pin 2 positive when I received them (Europe favored pin 2 positive, with some exceptions, long before America). There is a very easy way to check the polarity of microphones and every studio should do this to ensure you at least start with all your mics in polarity. Healthy ears aside, why not KNOW that you are starting with a level playing field?

The following is from a post in January:


As to how to get all your mics in phase with each other you don't even need to use a multimeter.
There are different methods out there but most involve the same principle where you put two mics on the same source and see if they combine or subtract when added together in a mixer.

Here's my test:

Put two mic cables into two channels of a mixer. Send both channels to the same METERED output.

Plug a mic that you KNOW is pin 2 pos into channel 1. I'd borrow a new AKG, Senn etc. Or do your clicker test to determine . (You can plug an unknown mic in first but it makes the test a little random as to how all the mics end up)

Bring the mic up close to your mouth and say AAAAAAAAAHHHHHHHHHH and keep saying it while you bring up the channel 1 fader til you get around a reading somewhere in the middle of the meter. On a needle VU meter I push it up to zero. Leave that channel at that setting.

Now plug another mic into channel 2 and hold it and mic 1 together at your mouth (both capsules as close together and the same distance as possible) repeating the AAAAAHHHH. You have become a human tone generator. Bring up channel 2 SLOWLY into the same metered output.

If mic#2 in IN PHASE with mic #1 the meter will rise continually all the way and peg.

If mic#2 is OUT OF PHASE with mic #1 the meter may start to raise but at the point the two channels are close in gain the meter will lower dramatically. It may rise again after you pass the equal gain point but it's the dramatic dip that you look for and it is very obvious.

Keep #1 mic as control and continue to test all the mics on channel two marking each mic as you go so you can rewire the out of phase ones later. If you are testing a collection of mostly new/standard mics you should find that the vast majority/all are in phase. With a collection of modified and custom mics it's anybody's guess.

I can run through an entire colection of mics with this test in about 10 minutes.

You don't have to use your voice as the tone source, many people use a speaker. And a meter isn't entirely necessary as you can use headphones and listen for the dip. The point is to get the mics close to the mouth/speaker and at an equal distance from the sound source.
Try it. It works.
Rick

Unless you're using tape you could just look at the waveform...

Originally Posted by ulysses

Except for when it's pin 3. Which, globally and historically, is about half the time.

I've got a Soundcraft board wired this way. No phase buttons. Just use reversed xlr barrels where needed, which is most everywhere. I'm picky about positive excursion first through monitors. Just makes me feel better.

So no, it doesn't really matter which way its wired. If it were mine it would make my life that much easier if it was wired pin 3 hot. One less stupid barrel in the chain.

[ulysses]

Originally Posted by AmongstTheLiving

Unless you're using tape you could just look at the waveform...

Why is everybody so determined to find an alternative to simply listening? Is listening difficult?

Originally Posted by AmongstTheLiving

I've got a Soundcraft board wired this way. No phase buttons. Just use reversed xlr barrels where needed, which is most everywhere. I'm picky about positive excursion first through monitors. Just makes me feel better.

So no, it doesn't really matter which way its wired. If it were mine it would make my life that much easier if it was wired pin 3 hot. One less stupid barrel in the chain.

Now, this is a very different discussion. If every channel is wired the same way, there's nothing "out of phase" with something else. If you have a neurosis about absolute polarity, that's between you and your psychiatrist but it has nothing to do with audio. We're talking about cancellations that result when you combine multiple, correlated sources with mismatched polarities.

[Rick Sutton]

You know, if we all wanted to live on the edge we could just make all our balanced cabling in the studio have random polarity. Why take all that extra time to make it uniform? All 'ya gotta do is listen and flip a few switches. Why only microphones.... let's get crackin'

obviously just kidding.

[AmongstTheLiving]

Originally Posted by ulysses

Why is everybody so determined to find an alternative to simply listening? Is listening difficult?

What?

[jakeweismann]

I just picked up an old EV Cardyne 1. It isn't working and I would like to change that. Nothing looks disconnected inside, just old and ugly. Also, how are you contacting EV? I tried there website but was referred to technicians at the same address who only work on newer equipment.

Thanks.