EmRR

OK, time to let some things go so they can be put back into use.  Input, interstage, output, repeat coils, and power.  Some singles, some pairs.  In this issue:
UTC A-20
RCA BA-3 program amp input and output transformer set
(2) RCA MI-38482 nine pin plug-in transformers (McMartin MT-4) tube inputs
Kenyon T-26 600:600
Gates console panel with 3 transformers
Presto PPP 6L6/807 tube record lathe power amp output transformer and choke
Thordarson PP 6V6 to 500 ohm output transformer pair, good for Sta-Level, etc
Tube output transformer for four 6L6
Pair of IOaudio input transformers for Pultec
RCA potted power transformers 70VCT 800mA
ADC HUM-1 video humbuckers


UTC A-20
has some paint pulled off from tape, has connection labels added on side, with an original A-20 box.  Tests fine.
$50 plus shipping/insurance



RCA BA-3 program amp input and UTC output transformer set
Indeed.  Both test well.  The UTC output is NOS, very difficult to find a high level single ended output like this with good low frequency response.  The input is in great shape. 
Input is 150/600 to grid. 
Output is for single ended 6V6 or 6L6 (RCA did both with this) to 600/150/15/7.5/5 at +30dBm with less than 1% THD 30-15K as used in a BA-3.  Lots of BA-3’s in use for vintage audio speaker listening, especially with efficient horn systems. 
$600 plus shipping/insurance on 9 lbs.




(2) RCA MI-38482 nine pin plug-in transformers   
Accessory transformer for the 1970’s SA-115 transistor general use amplifier, which appears to be a rebadged McMartin unit.  A good guess would be these are rebadged McMartin MT-4’s.

https://groupdiy.com/index.php?topic=73580.msg935848;topicseen#msg935848

pins 1-3 7.5Ω DC = 125-150 pr
pins 1-4 16Ω DC - 600 pri

pins 5-6 139Ω DC = 10K bridging input

pins 8-9 91Ω DC = 10K sec
pins 2-9 349Ω DC = 60K sec

9 pin sockets frequently available NOS on ebay. 

$100 plus shipping/insurance



Kenyon T-26 600:600
NOS/NIB. +24db, hum bucking construction, typical multiple tap coil, see UTC A-20 impedance diagram as example.         
$40 plus shipping/insurance on 2 lbs.






Gates console transformer panel
All three measure 8R : 0.7DCR roughly, would appear to be 150:speaker Z.   Possibly identical, with center piece having shielding to prevent crosstalk.  Maybe perfect for Paul’s bass trick, speaker as microphone. 
$30 plus shipping/insurance on 3 lbs.




Presto tube record lathe power amp output transformer and choke
From a model 88-A power amp, using (4) 6L6/807 type power tubes.  Has plate cap attachment for use with 807 tubes, can be removed for standard wiring to 6L6’s.  Also the transformers on the later 92-A/B models, which spec within 1dB 20-17K. output impedances of 500/250/15/6 ohms at 50W output.  Choke is 10H.   The last picture shows how it was used on the 92-A amp, with plate cap attachment.
http://www.hifido.co.jp/KW/G0105/E/0-50/C05-23362-51346-00/
http://www.steveespinola.com/lathetrolls/resources/Presto_92A_Manual_Schematic_gif.pdf
$200 plus shipping/insurance on some lbs; heavy.






(2) Thordarson PP 6V6 to 500 ohm output transformers
Great for Stalevel and other tube limiters or compressors.  T-17S11.   One is on a sub-panel which has a rotary switch to choose output impedances from 500/25016/8/4.   Rated 15W, primary 8K. 
$150 plus shipping/insurance on 7 lbs.





Tube output transformer for four 6L6   
Apparently from a Baldwin organ with several references suggesting 40W power, tests fine for DCR, leads in good condition.  Nice hefty chunk of iron for a power amp build.  Part #512-14633D.  Organs have to pass some low lows, so inductance should be better than average. 
$40 plus shipping/insurance on 5 lbs




Pair of IOaudio input transformers for Pultec
As provided with his MEQ500 mid range Pultec project back in 2008 or so.  They didn’t work for me as I was trying to use them with true 600 ohm source impedances, and they are somewhat rolled off on the bottom in that case.  Feed them with a 50 ohm source such as many converters provide today, and they are full range on the bottom, with IOaudio measuring a -3dB point of 14Hz in that case. 
$20 plus shipping/insurance on 1 lb.



RCA potted power transformers 70VCT 800mA
Multiple pieces of very nice potted/shielded power transformers for SS projects.  Two are US voltage only, seven more that cover international voltage ranges. 
$25/ea plus shipping/insurance on 5 lbs.




ADC HUM-1 video humbuckers
Off the audio path, into video.  I have a number of these to sell.  New in original shipping boxes.  BNC connectors.   Pass audio too, an interesting euphonic sound, probably from the low 75Ω loading. 

Here's a typical ad for one at $160: 
http://www.markertek.com/product/hum-1/adc-by-te-connectivity-hum-1-humbucking-coil

$30 + shipping and insurance.  Slightly under 4 lbs / 1.8 kg shipping weight per piece.





---------recently sold-----------

RCA OP-6 tube mic preamp input transformer pair
RCA OP-6 input transformer pair in good shape, ready to go into your two channel tube mic preamp build.  Typical American impedance ratios of 30/250Ω to single tube grid use, center tap also available on the primary.  Great classic sound.  Tested for both resistance and inductance. 
$295 plus shipping/insurance on 2 lbs. 








(2) UTC P-16 plug in transformers
250:50K mic inputs, say pri ‘OK 150/600’, nine pin plug in equivalent of O-16.  Matching dates codes.  Same ratio, form and pinout as RCA MI-12399/A, will work well in RCA amp sockets, NOS sockets included.
$85 ea plus shipping/insurance



Altec / Peerless 15095A NOS/NIB
New in box.  Used in 1567A, 1566, blah blah blah. 
$OLD plus shipping/insurance  on 1 lb. 


Triad / Gates AI-3009      
SA series input transformer.  250/500:60K, +10dBm, 2 mu metal shields.  Perfect for mic preamp or LA-2A input.     
$OLD plus shipping/insurance


Two UTC A-20’s
1:1 Repeat coils with taps for 50/125(150)/200/333/500(600) on each side, +15dBm level rating, 10-50K response.   Great higher headroom option for 1176 with wider response.  These measure very high for inductance, averaging 20H.  10H is generally sufficient for a good 600:600. 
$OLD, plus shipping/insurance.
Buy one, shipping is 1 lb, buy two shipping is 2 lbs. 


Kenyon P-204 mic/line to tube grid transformer
Kenyon’s top line ‘P’ series tube input.  This is the input used on the Presto 88-A lathe recording system power amp, I think that one is in the tech docs section at GroupDIY (or at least the very similar 92-A). Perfect for many tube preamp builds.  Taps like a UTC HA-100, 50 through 500 input Z and a center tapped secondary that can be used to one or two grids.     
$OLD plus shipping/insurance on 2 lbs.

RCA OP-6 tube mic preamp input transformer pair
RCA OP-6 input transformer pair in good shape, ready to go into your two channel tube mic preamp build.  Typical American impedance ratios of 30/250:50K for single grid (single ended) use, center tap also available on the primary.  Great classic sound.  Tested for both resistance and inductance. 
$OLD plus shipping/insurance on 2 lbs. 


ADC RCA MI-11712 / A6278 bridging transformer
20K to 600/150, meant for bridging use.  There was awhile these were frequently appearing for sale as 20K output transformers.   Up to you what to do with these, no apparent loss of low end when fed a 20K source.   Roughly 3.5”x2.5”x2”, UTC HA size. 
$OLD plus shipping/insurance on 3 lbs.


pair UTC A-20 Gates Radio custom variation
As normal with Gates, an alternate part # and case for the UTC A-20 600:600 transformer, here found in a CG style case.  Shown with an A-20 (not part of sale) for scale comparison.  They test as same for inductance and resistance.  See A-20 listing above for more details. 
$OLD plus shipping/insurance on 2 lbs.
« Last Edit: September 10, 2020, 06:19:37 PM by EmRR »
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


okgb

Bump to say Bump, and if I bumped into him at a casino, I'd loan him a few bux
GKB Audio / Greg Boboski

EmRR

Gates input sold, thanks
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

tronan

PM sent

EmRR

ADC, UTC, RCA sold, thanks
« Last Edit: June 01, 2015, 09:34:56 AM by emrr »
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

OK, time to let some things go so they can be put back into use.  Input, interstage, output, and repeat coils.  Some singles, some pairs. 

UTC HA-108 600:600 transformer A-20 upgrade
Repeat coil like A-20 and LS-30, early shiny black type with rectangular terminal layout.
$70 plus shipping on 2lb. 
I'll take the HA-108, so long as the shipping isn't high.  Please PM me with payment instructions at your convenience.  Location; Phoenix, AZ. 85032.
Thanks!

EmRR

HA-108 and ADC 200K sold, RCA pair added. 
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

interested in the RCA 11712 pair , if still available. , since this is a bridger , would like to use as a plate to line output transformer  secondary loaded to 150 /200 impedance......   ( reference mentioned in your output trial ) similar in nature to a Triad HS52 /54  ?  if so, send me payment instructions, thanks.
« Last Edit: October 14, 2015, 03:32:04 AM by electrochronic »
curiousaudioparts at  gmail  dot  com
https://sites.google.com/site/diypartsstore/

EmRR

ADC 214J sold, thanks.
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

alexc

pm'd

and  pp'd :)

Thx emrr!
I ping therefore I am


okgb

Complimentary Bump, you have some great looking pieces!
GKB Audio / Greg Boboski

craptical

Aaargh, I give up! The OP6 inputs look perfect, time to finish that stereo RCA-style preamp. Still have them? Shipping to Sweden. :)

Best
/Dave

EmRR

emailed..   Looks like $39 insured 6-10 day shipping. 
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

craptical

Money sent!

fsalter

Hi
Chinese xfrmers still availbale?

EmRR

Chinese ribbon trans and RCA OP-6 inputs sold, thanks
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

craptical

Iron received! Thanks emrr! :)

EmRR

Thanks!  Enjoy!
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

EmRR

Pair of UTC A-20 sold, thanks!
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

iampoor1

Received the A20s today. Excellent packing and excellent condition transformers. Thanks Doug! After reading a few 100 of your posts on various message boards, its nice to put some moolah in your pocket!  ;D


 

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