Help with mid 50's Gates Dynamote PSU
« on: March 13, 2018, 05:23:05 PM »
Hi I have this unit: https://reverb.com/item/7222987-very-early-1950-gates-dynamote-tube-microphone-pre-amplifier-from-rca-nyc-studio and it needs a PSU. Does anyone have a schematic for this unit or know what PSU is correct? Thanks in advance


rackmonkey

Re: Help with mid 50's Gates Dynamote PSU
« Reply #1 on: March 16, 2018, 01:37:18 PM »
Does the model you have use a 5879, 12AY7, 12AU7 and a 6X4? The 1952 Gates catalog doesn't have PS details (the 1947 catalog does, but that model uses octals), but it does specify that the unit draws 35W.  Assuming the tube compliment above, heaters at 6.3V draw 1.2A = ~7.6W. 35W - 7.6W = 27.4W. B+ isn't specified in the '52 catalog. The octal version in the '47 catalog has B+ at 180V. Assuming your version used 180V, 15mA puts you at about 27.4W. That's assuming you're trying to get close to the original. I don't have a schematic so I can't check that for accuracy.

You'll have more clean headroom at higher B+, and you're not strictly limited by the original power spec as long as all components are adequately rated. You may or may not want to adjust bias on the tubes if you go with higher B+. It's not absolutely necessary, but it all depends on what you're after.

You could get a used or NOS Power One HB200 or HB250 power supply for B+ and a 2A filament transformer and pretty much be off and running if you're not concerned with getting it as close as possible to original operating conditions (assuming original used 180V). HB200 would be close enough to call it original and be done with it.

BT
Whether you think you can or you think you can't, you're probably right.

EmRR

Re: Help with mid 50's Gates Dynamote PSU
« Reply #2 on: March 16, 2018, 01:41:29 PM »
that unit has been hand drawn and posted on this site somewhere. 
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

Re: Help with mid 50's Gates Dynamote PSU
« Reply #3 on: March 22, 2019, 04:28:17 AM »
So here I am over a year later and it's now up on Stephen Sanks table (designer of cloud microphones in AZ). He said it's such a hot mess with all the wiores disconnected he can't do anything without a schematic. I've looked everywhere, facebook broadcast forums, gearslutz, internet forums everywhere to no avail.

Can anyone help us find the schematic to this Dynamote MO-3777? THANKS IN ADVANCE FOR ANY HELP AT ALL!!!!

Dmichel123

Re: Help with mid 50's Gates Dynamote PSU
« Reply #4 on: April 10, 2019, 03:39:35 PM »
I've searched the site and can't locate the hand drawn schematic. It looks like the OT is switched in series with the cathode follower cathode resistor when the CUE switch is in the talk position? This one was modified quite a bit, a long time ago.

EmRR

Re: Help with mid 50's Gates Dynamote PSU
« Reply #5 on: April 10, 2019, 03:55:35 PM »
http://fixthatmix.com/Gates_mixer.php

that was here at one point
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

Dmichel123

Re: Help with mid 50's Gates Dynamote PSU
« Reply #6 on: April 10, 2019, 04:34:23 PM »
Thanks, Doug!