Sony C-37A questions

[dukasound]

Hi
Does anyone have some schematics for this mike.
I find one (http://www.rcrowley.com/SonyC37/index.htm) but I need some aditional data for resistor wattage,
power transformer and ratio audio transformer.
Thanks
Duka

 

[BYacey]

I think I might have it. Give me a day and I'll go through my filing cabinet. I had to repair the DC to DC converter on this some time ago.
Bill

 

[gyraf]

Here you go (if it's the C37A you're after):

http://img56.photobucket.com/albums/v172/gyraf/Sony_C-37A_schematic.gif

Jakob E.

 

[BYacey]

My apologies, It must be a C-37B that I have. It's the FET model.
Bill

 

[gyraf]

Uh.. The C-37B schematic wouldn't be bad to see either..!

You know - when it comes to schematics, I'm always interested..



Jakob E.

 

[dukasound]

[quote author="gyraf"]Here you go (if it's the C37A you're after):
Jakob E.[/quote]

Hi Jakob
I have it. I wanna know wattage of resistor and transformers (both power and audio) specification.
Thanks
Duka

 

[dukasound]

[quote author="BYacey"]My apologies, It must be a C-37B that I have. It's the FET model.
Bill[/quote]

Thanks Bill
Duka

 

[dale116dot7]

The 45 ohm resistor needs to be a 10-watt unit.
The 100 ohm resistors need to be about 3 watts.

The 10k resistors in the power supply need to be 1/2 watt but I'd use 1 watt.

All of the other resistors can be 1/2 watt, except the 100 Meg which can be the smallest one you can get - the MOX200 series seem to be popular. I think they're 1/4 watt. Also, the 3k in the mic and 10k loading the transformer can be 1/4 watt.

These aren't from Sony's documentation, but you can figure out the amount of current draw in the circuit and thus the wattage ratings needed of the various resistors.

 

[dukasound]

[quote author="dale116dot7"]The 45 ohm resistor needs to be a 10-watt unit.
The 100 ohm resistors need to be about 3 watts.

The 10k resistors in the power supply need to be 1/2 watt but I'd use 1 watt.

All of the other resistors can be 1/2 watt, except the 100 Meg which can be the smallest one you can get - the MOX200 series seem to be popular. I think they're 1/4 watt. Also, the 3k in the mic and 10k loading the transformer can be 1/4 watt.

These aren't from Sony's documentation, but you can figure out the amount of current draw in the circuit and thus the wattage ratings needed of the various resistors.[/quote]

Hi
Thanks for good explanations. If you know tell me voltages and curents of power transformer. Does output transformers have ratio 4:1 (I saw add by hand on schematics-wach firs message) Also I saw on schematics that out trans. was 10K/600ohm. Does C37A have 200ohm output?.
Best
Duka

 

[dukasound]

Hi
Excuse me for repeat!!!!!!!
Have anyone answers on below:

If you know tell me voltages and curents of power transformer. Does output transformers have ratio 4:1 (I saw add by hand on schematics-wach firs message) Also I saw on schematics that out trans. was 10K/600ohm. Does C37A have 200ohm output?.
Best
Duka

 

[gyraf]

I have updated the gyraf schematics page to include some C37/C38 schematics - courtesey of Bill Yacey..

http://www.gyraf.dk/schematics/schematics.html

Jakob E.

 

[dukasound]

[quote author="gyraf"]I have updated the gyraf schematics page to include some C37/C38 schematics - courtesey of Bill Yacey..

http://www.gyraf.dk/schematics/schematics.html

Jakob E.[/quote]

Thanks Jakob but I need some specifications of C37A.
Did you receive my message?
Best
Duka

 

[dukasound]

[quote author="dukasound"]Hi
Does anyone have some schematics for this mike.
I find one (http://www.rcrowley.com/SonyC37/index.htm) but I need some aditional data for resistor wattage,
power transformer and ratio audio transformer.
Thanks
Duka[/quote]

Hi
Does anyone have another specification except what we find.
Thanks
Duka

 

[ciminosound]

http://www.rcrowley.com/SonyC37/

Here is some additional info on the C-37 mic

Gerry

 

[dukasound]

[quote author="ciminosound"]http://www.rcrowley.com/SonyC37/

Here is some additional info on the C-37 mic

Gerry[/quote]

Thanks Gerry but I have it. See my message above.
Best
Duka

 

[volki]

i just bumped into this thread...

maybe dumb question, but - this is the first tube mic i've seen that uses a cathode follower. all other designs i know take the signal off the plate. what might be the advantages (and disadvantages) of this design here?

 

[funkydiplomat]

for a compact microphone it seems to help. you can locate the output transformer and coupling cap in the psu. altec did it for a few mics. i don't know their model numbers but the 'lipsitck' was this way with a 5840 i think. (the same one royer uses in his mod i believe). the 'coke bottle' does the same thing with a 6AU6 like the sony. i had a chance to use one of these once. it was ok. it's not worth what people are paying for them on ebay imo. both of the altecs are small diaphragms though so it it makes a little more sense. don't know what sony was thinking, though. see if you can dig up the royer mod article. it tells a little bit about it. tape op may have it still posted somewhere. and some of those articles pop up on pro sound web.

 

[Marik]

[quote author="volki"]i just bumped into this thread...

maybe dumb question, but - this is the first tube mic i've seen that uses a cathode follower. all other designs i know take the signal off the plate. what might be the advantages (and disadvantages) of this design here?[/quote]

There were quite a few mics using CF-- Bruel & Kjaer, some AKGs, in addition to aforementioned Altecs.
The CF has some advantages--very high input impedance, you can use smaller size and lower ratio transformers, very high overload handling. Many folks don't like their sonics, though. I think it is not the problem of the CF itself, but question of a right design and implementation.

 

[dale116dot7]

CF is going to be quite linear - very little 'tube' sound. The output will be lower but so will the output impedance, as mentioned earlier. Another advantage is you can self-charge the capsule using the grid bias resistor - or use grid leakage to charge the capsule without needing that big valued resistor. Check out the Altec m11 'Coke Bottle' schematic (or the Royer 5840).

I like the Altec M11 on some instruments - banjo, upright bass. The prices on evilbay are inflated IMHO. But I do like my Altec a lot - much better than most SDC's currently available.

 

[soundguy]

AKG C60, C12a and lomo 19a9 are mics I have that are cathode follower (I thnk). They tend to sit behind regular tube mics really nicely. They dont have the most presence in the world and I can see why people might think they are noisy or not the best idea, but used strategically, they can make a mix fall into place with little effort. That might be one advantage to a CF design.

dave