Gotham Audio Studer C37 60HZ 1960’s
- Thread starter RogerD
- Start date
The C37 was originally owned by RCA in NYC and they tinkered with a few things. The machine uses 4 relays for NAB and CCIR and specialized EQ. All the caps are German Roderstein / Vishay, resistors are all Low Noise metal film 2%.. I am trying to keep it as stock as possible.
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I was talking to my tech and found out some real interesting improvements that can be made to the record and playback preamps. So I told him to do his magic....exciting. There are several impediments in the signal path on all the preamp designs which are now 60 years old. So the result will be a much cleaner and more powerful signal which will enhance the sound of tube compliment, which is excellent and with the improved EQ, bias levels.
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Here's the record preamps with swapped out transformers replacing the inadequate Beyers. Just one of the upgrades Dan is doing for me. These transformers will make a overall big difference and these had excellent specs.
Which audio heads of Studer are you using, Butterfly ones or the standard heads?
Best
airbearing
https://audiocirc.com/2018/04/30/tape-is-my-love/
https://audiocirc.com/2014/05/05/the-holy-grail/
https://audiocirc.com/2015/07/05/c3...ly-head-set-as-well-as-with-the-standard-set/
Here is video I made stitching the small piece together.I over dubbed the music “Stairway to Heaven”. I currently feel that way, as I waited so long, it’s a gift from heaven.Coming home soon.
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I heard from Dan Zellman today regarding the playback on the C37 . His reply below .Nice to hear from a tech that knows these recorders.
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Hi Roger,
I'm amazed at the lack of flutter products in this transport. It sounds pretty good so far.It's closer to real NAB EQ than any other C or J37 I've seen .
Still; a few adjustments to EQ values will get that.
There's a 2+ dbboost at 32 Hz a half db drop at 500, up a half at 2K to 8K, flat at 10KHz down a half at 20KHz.15 IPS.
The Bass boost is easiest to deal with. It will be clearer when I start the record trouble shooting.
Also It's nothappy with dis-similar reel sizes.
There is also Head positioning I have yet to deal with. Next.
Dan
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Hi Roger,
I'm amazed at the lack of flutter products in this transport. It sounds pretty good so far.It's closer to real NAB EQ than any other C or J37 I've seen .
Still; a few adjustments to EQ values will get that.
There's a 2+ dbboost at 32 Hz a half db drop at 500, up a half at 2K to 8K, flat at 10KHz down a half at 20KHz.15 IPS.
The Bass boost is easiest to deal with. It will be clearer when I start the record trouble shooting.
Also It's nothappy with dis-similar reel sizes.
There is also Head positioning I have yet to deal with. Next.
Dan
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I forgot to mention the extremely low flutter...that’s why I supplied Dan with all aircraft spec ABEC 5 and 7 bearings. It does matter.
Latest report on the C37
Hi Roger,
You may have guessed I had some issues with one of the playback amps. Still do but almost done. The EQs were pretty good Left channel is flat 32 Hz to 20KHz, plus/minus .5 db. Right channel is the same up to 10Khz but rises to +3 at 20 KHz. Most of the issues were around the speed relay and the relay socket. This relay is a custom, very non standard relay. It has 4 form A contacts and 2 form B contacts. Never even heard of this before. Normally they come with only form C contacts. I was able to rebuild it using a coil from a standard relay. I had to replace the socket as well. In order to find these issues I had to make a set of extender cables, power/signal and head connections, so I could trouble shoot the amplifier on my bench under power. I will include them in the shipment back. I hope to have the right channel hi end issue solved, over the weekend.
Dan
Hi Roger,
You may have guessed I had some issues with one of the playback amps. Still do but almost done. The EQs were pretty good Left channel is flat 32 Hz to 20KHz, plus/minus .5 db. Right channel is the same up to 10Khz but rises to +3 at 20 KHz. Most of the issues were around the speed relay and the relay socket. This relay is a custom, very non standard relay. It has 4 form A contacts and 2 form B contacts. Never even heard of this before. Normally they come with only form C contacts. I was able to rebuild it using a coil from a standard relay. I had to replace the socket as well. In order to find these issues I had to make a set of extender cables, power/signal and head connections, so I could trouble shoot the amplifier on my bench under power. I will include them in the shipment back. I hope to have the right channel hi end issue solved, over the weekend.
Dan
I talked to my tech and he will be ready to resume restoration on this C37 in about 2 weeks.
I decided to ship the Capstan and reel motors off to Audio House in Switzerland. So as soon work resumes off they go. The machine is so rare, it would be a shame not to go the extra mile.
I also added a 2 track Crown to my harem...so I now have four.
Time is short and it’s only money. I doubt any of this stuff will ever go out of favor. If I find one I like and it’s been well taken care of...go for it.
I also picked up another Accuphase P300...clean too.
These amps have doubled in price in the past few years.
One of my good friends wants me to take his Dad’s Fisher 800C he bought new in the ‘60s....tube receiver...I’m thinking about it. I had a 500C in high school. Funny how memories work.
I decided to ship the Capstan and reel motors off to Audio House in Switzerland. So as soon work resumes off they go. The machine is so rare, it would be a shame not to go the extra mile.
I also added a 2 track Crown to my harem...so I now have four.
Time is short and it’s only money. I doubt any of this stuff will ever go out of favor. If I find one I like and it’s been well taken care of...go for it.
I also picked up another Accuphase P300...clean too.
These amps have doubled in price in the past few years.
One of my good friends wants me to take his Dad’s Fisher 800C he bought new in the ‘60s....tube receiver...I’m thinking about it. I had a 500C in high school. Funny how memories work.
Back in early January I sent my C37 Capstan and Spooler motors to Audiohouse.ch in Switzerland to get rebuilt. They are all finished and now I can get them shipped back to New York City to have the machine finished. I could find no one in the States who could reliably overhaul them as Jeff Gillim has retired. There is light at the end of the tunnel as Dan Zellman can now finish the restoration.
What a long trip!
It was September of 2013 when we first talked of your desire to refurbish this deck!
Looks like Dan has done a superb job of rebuilding this deck for you. Dan is as they say, good people.
I really did think Dan was going to get Jeff to rebuild your motor, oh well.
Quite ready to hear your impressions.
Cheers
Alan
It was September of 2013 when we first talked of your desire to refurbish this deck!
Looks like Dan has done a superb job of rebuilding this deck for you. Dan is as they say, good people.
I really did think Dan was going to get Jeff to rebuild your motor, oh well.
Quite ready to hear your impressions.
Cheers
Alan
i just saw the freq response of a C 37 yesterday (among others ) flat as a dodo despite being tubed , nothing rolled of with those machines if properly adjusted i assume.
The most expensive desired studer out there , good luck with the restauration its definetively worth it
The most expensive desired studer out there , good luck with the restauration its definetively worth it
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The best one he had was a calibrated A 80 to around + - O,5 db flat .
I think a very good adres for info / parts : Eternal arts audio /germany . Hannover -Isernhagen
I think a very good adres for info / parts : Eternal arts audio /germany . Hannover -Isernhagen
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