[Rick Ruskin]

Anyone here know what the polarizing voltage is on this microphone?


Rick Ruskin
Lion Dog Music- Seattle WA
http://liondogmusic.com

[Scott Dorsey]

Rick Ruskin wrote:
Anyone here know what the polarizing voltage is on this microphone?

Check the circuit out! It is cool! The cathode sits at 131V or so, on top
of a voltage divider made with a 1K and 100K resistor (unless you have
an early model with a 3K resistor). The center point of those two resistors
should be right at 130V, and there's a 100M resistor from that 130V point
to the control grid.

So... control grid is only a volt or so below the cathode so it's just
barely turned on, but it's held 130V above ground to provide the polarization
voltage. No blocking capacitor needed anywhere. It's a rather ingenious
design. I believe the 800G also uses the same capsule and also at 130V.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[JackA]

On Monday, October 3, 2016 at 2:41:14 PM UTC-4, Rick Ruskin wrote:
Anyone here know what the polarizing voltage is on this microphone?


Rick Ruskin
Lion Dog Music- Seattle WA
http://liondogmusic.com

http://www.rcrowley.com/sonyc37/index.htm

[JackA]

On Monday, October 3, 2016 at 2:41:14 PM UTC-4, Rick Ruskin wrote:
Anyone here know what the polarizing voltage is on this microphone?


Rick Ruskin
Lion Dog Music- Seattle WA
http://liondogmusic.com

Wow, not cheap!....

"I paid $ 3000 for mine [C37-A] and that was e-bay and the knowledge that I had to spend a few hundred on servicing on top of that. So with shipping and servicing, tube tryouts, etc it came to at least $3600 or more. I love the mic though".

[JackA]

On Monday, October 3, 2016 at 2:41:14 PM UTC-4, Rick Ruskin wrote:
Anyone here know what the polarizing voltage is on this microphone?


Rick Ruskin
Lion Dog Music- Seattle WA
http://liondogmusic.com

Bipolar +/-250VDC

[John Williamson]

On 03/10/2016 20:40, JackA wrote:
Wow, not cheap!....

"I paid $ 3000 for mine [C37-A] and that was e-bay and the knowledge that I had to spend a few hundred on servicing on top of that. So with shipping and servicing, tube tryouts, etc it came to at least $3600 or more. I love the mic though".

Cheap does not always mean good value. In fact cheap very rarely means
good value.

--
Tciao for Now!

John.

[JackA]

On Monday, October 3, 2016 at 4:51:29 PM UTC-4, John Williamson wrote:
On 03/10/2016 20:40, JackA wrote:
Wow, not cheap!....

"I paid $ 3000 for mine [C37-A] and that was e-bay and the knowledge that I had to spend a few hundred on servicing on top of that. So with shipping and servicing, tube tryouts, etc it came to at least $3600 or more. I love the mic though".

Cheap does not always mean good value. In fact cheap very rarely means
good value.

I wish my Sony headphones were made of metal!! :-)

Jack


--
Tciao for Now!

John.

[geoff]

On 4/10/2016 10:06 a.m., JackA wrote:
On Monday, October 3, 2016 at 4:51:29 PM UTC-4, John Williamson wrote:
On 03/10/2016 20:40, JackA wrote:
Wow, not cheap!....

"I paid $ 3000 for mine [C37-A] and that was e-bay and the knowledge that I had to spend a few hundred on servicing on top of that. So with shipping and servicing, tube tryouts, etc it came to at least $3600 or more. I love the mic though".

Cheap does not always mean good value. In fact cheap very rarely means
good value.
I wish my Sony headphones were made of metal!! :-)

Jack

To match your tin ears ?

geoff

[JackA]

On Monday, October 3, 2016 at 5:42:28 PM UTC-4, geoff wrote:
On 4/10/2016 10:06 a.m., JackA wrote:
On Monday, October 3, 2016 at 4:51:29 PM UTC-4, John Williamson wrote:
On 03/10/2016 20:40, JackA wrote:
Wow, not cheap!....

"I paid $ 3000 for mine [C37-A] and that was e-bay and the knowledge that I had to spend a few hundred on servicing on top of that. So with shipping and servicing, tube tryouts, etc it came to at least $3600 or more. I love the mic though".

Cheap does not always mean good value. In fact cheap very rarely means
good value.
I wish my Sony headphones were made of metal!! :-)

Jack

To match your tin ears ?

geoff

I may have Tin Ears,
but you have no Heart!!!...
https://www.youtube.com/watch?v=T-RHfXZkT1g

Jack

[Phil Allison[_4_]]

Scott Dorsey wrote:


Check the circuit out! It is cool! The cathode sits at 131V or so, on top
of a voltage divider made with a 1K and 100K resistor (unless you have
an early model with a 3K resistor). The center point of those two resistors
should be right at 130V, and there's a 100M resistor from that 130V point
to the control grid.




** FYI:

The C-37A microphone was released in Japan in 1955, same year as their very first 5 transistor radio, the TR-55. Both products were prominently labelled SONY and it appears the C-37A was only the second to carry the famous brand.

It was also the first condenser mic to use a gold spattered, Mylar diaphragm as used in most such mics today.

Sony built the mic to compete with the then industry standard Neumann U47 tube model, firstly in the Japanese market and then world wide. It was a good deal cheaper than the U-47 and in several respects outperformed it.

Must have given Neumann a heck of a fright.



..... Phil

[JackA]

On Tuesday, October 4, 2016 at 8:32:07 AM UTC-4, Phil Allison wrote:
Scott Dorsey wrote:


Check the circuit out! It is cool! The cathode sits at 131V or so, on top
of a voltage divider made with a 1K and 100K resistor (unless you have
an early model with a 3K resistor). The center point of those two resistors
should be right at 130V, and there's a 100M resistor from that 130V point
to the control grid.




** FYI:

The C-37A microphone was released in Japan in 1955, same year as their very first 5 transistor radio, the TR-55. Both products were prominently labelled SONY and it appears the C-37A was only the second to carry the famous brand.

It was also the first condenser mic to use a gold spattered, Mylar diaphragm as used in most such mics today.

Sony built the mic to compete with the then industry standard Neumann U47 tube model, firstly in the Japanese market and then world wide. It was a good deal cheaper than the U-47 and in several respects outperformed it.

Must have given Neumann a heck of a fright.



.... Phil

Talking about "transistor" pocket radios, as my Dad and I discovered, since more transistors meant a better radio, some used defective transistors as diodes, just to claim X amount of transistors!!

Jack

[Phil Allison[_4_]]

JackA wrote:



Talking about "transistor" pocket radios, as my Dad and I discovered,
since more transistors meant a better radio, some used defective
transistors as diodes, just to claim X amount of transistors!!



** Sony's first radio only had 5 transistors, but they became more valuable over time. So much so that in the early 70s, Sony offered to buy them back for $100 each.

https://c1.staticflickr.com/3/2261/2...a00533d4_b.jpg


..... Phil

[JackA]

On Tuesday, October 4, 2016 at 8:29:18 PM UTC-4, Phil Allison wrote:
JackA wrote:



Talking about "transistor" pocket radios, as my Dad and I discovered,
since more transistors meant a better radio, some used defective
transistors as diodes, just to claim X amount of transistors!!



** Sony's first radio only had 5 transistors, but they became more valuable over time. So much so that in the early 70s, Sony offered to buy them back for $100 each.

https://c1.staticflickr.com/3/2261/2...a00533d4_b.jpg


.... Phil

Ouch!! Near $70 in the 50's! Yikes.

Early radios, you know, that looked like furniture, cost a fortune in early 1900's, but speaker and tubes were optional!

Thanks, Phil!

Jack