Microphone Question

This is where record cutters raise questions about cutting, and trade wisdom and experiment results. We love Scully, Neumann, Presto, & Rek-O-Kut lathes and Wilcox-Gay Recordios (among others). We are excited by the various modern pro and semi-pro systems, too, in production and development. We use strange, extinct disc-based dictation machines. And other stuff, too.

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YooperMichigan
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Joined: Thu Apr 13, 2017 2:25 pm

Microphone Question

Post: # 46636Unread post YooperMichigan
Thu Apr 13, 2017 3:28 pm

Hello Folks,

This is my first post ... I am in the middle of restoring a Wilcox-Gay Recordio 6B 10 that belonged to my great-grandfather, 1946-47 I believe. I’ve replaced all the capacitors, some resistors and I have had the turntable playback and cutting heads refurbished. It is coming along nicely but I have some microphone questions for the group.

I do not have the original microphone, but I did get a microphone jack from the gentleman that restored the crystal heads for me, see attached pic. So, I have tried to wire a new microphone to this jack, both a dynamic mic and a condenser mic (I have several that I use on my digital recorder) but none of them work. I have not put the unit back together yet but the radio works, the turnable plays records but when I set the unit to the public address and plug in the mic ... nothing. Certainly there could be many issues here but I am wondering if there is something I am missing with regard to the microphone requirements?

Thanks for any help folks!!

YooperMichigan
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emorritt
Posts: 517
Joined: Thu Nov 09, 2006 2:03 pm
Location: Tennessee

Re: Microphone Question

Post: # 46642Unread post emorritt
Fri Apr 14, 2017 9:19 am

Dynamic and condenser mics don't have the output necessary for this unit. These were shipped stock with a crystal mic. Any model will work (Astatic, Argonne, Turner, etc.). You'll most likely have to go to ebay or some other retro vendor as I scoured the web and couldn't find any new production crystal mics out there. Most harp mics now are either dynamic or condenser. Also, if you find a vintage crystal mic, it will most likely have to be repaired as well, as the elements were the same as used in pickups and cutterheads (prior to ceramic piezo elements).

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tragwag
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Re: Microphone Question

Post: # 46643Unread post tragwag
Fri Apr 14, 2017 12:53 pm

you might have to do some modification, but I've seen folks update the hi Z 1/4" input to take a modern microphone.
making lathe cuts on a Presto 6N, HIFI stereo cuts on vinylrecorder
at Audio Geography Studios, Providence, RI USA
http://www.audiogeography.com

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YooperMichigan
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Joined: Thu Apr 13, 2017 2:25 pm

Re: Microphone Question

Post: # 46658Unread post YooperMichigan
Sat Apr 15, 2017 5:03 pm

Thank you folks for taking the time to respond! I don't know enough about this to understand why a modern microphone will not work with this unit, I am spending some time reading about it but if you have some references you found helpful over the years I would appreciate it. The gentleman who refurbished the crystal heads said he had some refurbished crystal mic for sale, I may reach out to him for more info or perhaps a purchase of one of these mics. I realize I am not going to be producing stellar quality recording here, I just want to make some records with my kids as my great-grandfather and grandfather did. At the same time though, are the quality of these old mics that good?

Thanks again!

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emorritt
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Location: Tennessee

Re: Microphone Question

Post: # 46660Unread post emorritt
Sun Apr 16, 2017 9:10 am

You generally have to use a matching transformer to get a low z mic to work with a hi z input. Or, there are circuits out there that you can build to modify the hi z input to low z. I've used the matching transformer trick to make a crystal cutting head work with a modern solid state amp. Crystal cutters usually run off the plate output of the amp, since they require around 180 VRMS to work. In my opinion, a crystal mic with a properly restored Recordio (or other unit using a crystal cutter) yields a crisper sounding recording than if modified for a modern mic. Radio Shack used to make a dual impedance mic (I had one years ago I used to drive vintage cutting equipment). I don't recall the model number, but all you did was flip the four pin cable at the base of the mic, which changed it from one impedance to the other. It was a dynamic mic and sounded about as good as an original crystal in hi z mode.

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YooperMichigan
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Re: Microphone Question

Post: # 46663Unread post YooperMichigan
Sun Apr 16, 2017 10:27 pm

Thanks emorritt, great stuff.

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bigive8203
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Joined: Mon Apr 24, 2017 9:30 pm

Re: Microphone Question

Post: # 46751Unread post bigive8203
Tue Apr 25, 2017 1:09 am

Hi yoopermichigan who did your Crystal head repair. I just came across a recordio 6A10 and I believe it needs repairs as well. The mic I have is clean and works.! But the cutter doesn't seem to work. Any help is appreciated. Im pretty new to this.

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YooperMichigan
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Joined: Thu Apr 13, 2017 2:25 pm

Re: Microphone Question

Post: # 46765Unread post YooperMichigan
Tue Apr 25, 2017 6:39 pm

Hello,

West tech services did my crystal head repair.

http://www.west-techservices.com/p13.htm

I spoke with a gentleman named Gib, it's a rather old school shop, I sent him my two heads and a check for the services. He had them about a week and returned them, the record head works great now, I have not tested the cutter head yet as I don't have a compatible mic or any blank vinyl.

I'd recommend him, he's a very helpful guy! He also sold me a mic plug for $5 and I may be buying a crystal mic from him.

YooperMichigan

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