EmRR

Re: DCR and Impedance - modern audio transformers New
« Reply #20 on: January 14, 2021, 10:45:51 AM »
It's economics, surely to large degree. 

Note I didn't say there was a flaw in functionality, on the face of it.  There's a difference in method, the majority of modern offerings are not 'same as'.  It leads in to the same morass as any discussion about the realism of clones. 

Some data I did write down, not a lot directly apples to apples, but enough to make general trend observations and supported by all the other measurements I've taken but not written down. All of these are averages of multiple units, so not unconfirmed single outliers.

I've noted various things at 120Hz, L, sometimes ACΩ, sometimes DCR, quoted Z.  In general, higher L and DCR equates to lighter ACΩ loading.    None of it says anything definite about bandwidth or frequency linearity. 

One example, it's extremely rare to see a modern mic/line to grid transformer with a secondary DCR over 3K, in old stuff it's normal to see 4K-7K. 

some outputs of various types

Sowter 8344E - Fairchild signal output 60K:600
32h, 90k ACΩ, 510 DCR - you would expect 5-10x these numbers in an older transformer
1040mh, 320 ACΩ, 5R5 DCR
 - not the H is still a fraction of the lowest below, the lowly Peerless 15095. 

UTC LS-50 (SE)
15K 645h 328k ACΩ, : 500 20.3h 13k9 ACΩ

UTC LS-51 (PP)
30K 2487h 856k ACΩ : 500 34.57h 13k9 ACΩ

Gates SA-70
15k 477h 186k ACΩ : 500 16.38h 11k ACΩ

Collins 6Q-1
15k 287h 156kACΩ : 500 13.58h 9k9 ACΩ

Peerless 15095
179h 55k ACΩ : 9.5h 4k75 ACΩ

Various RCA single ended DC coupled outputs 30-50K : 250-500
240-250H : 3-5H5


Some interstages note the Hammond 850Q test, source and load Z of 40K with full bandwidth

Sowter 9830 BA-6 interstage DCR 1680Ω, recall approx 200H  +36 rating!  Why?!?!

Hammond 835  10K/40K:” +/- 0.5db 50-15K +15dbm, 0mA unbal DC, 980:982H

Hammond 850Q  10K/40K:” +/- 0.5db 20-20K +15dbm, 0mA unbal DC, 1400-1685:1400-1685H (40K:40K) 480K AC Ω 5K DCR
   looks the same connected either side to ground, 40K source and load yields
   +/-1dB 10.9-29K4Hz rising 34K9 peak +1.5dB
   +/-0.5dB 16.8-26K5Hz

RCA 86-A limiter interstage 5K2ct:, 2029Hct:1023H

UTC A-18 grey badged era
1070 : 2948 DCR
246H : 1301H
321K :  greater than 1M AC impedance at 120Hz

RCA 76 console program amp interstage
258H : 1605H
875 DCR : 3K08 DCR


a couple 600:600

Edcor WSM600/600
10H3 3k6 ACΩ

WE 111C
51H 19K ACΩ

Hammond 850G
12H9 10K ACΩ

UTC A-20
23H  14K AC Ω
« Last Edit: Today at 04:12:03 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


shabtek

Re: DCR and Impedance - modern audio transformers
« Reply #21 on: Today at 11:56:03 AM »
CJ has done dissections that show a variety of techniques used in winding

The methods to interleaving and different ways of controlling distributed capacitance is really interesting

I imagine it would not be economically feasible to replicate some of those techniques today
"really fine players do not use stomp boxes or master volume, they match the amp to the room and turn it up to 11.  Stevie Ray, BB King, Albert King, Duane Allman, Dicky Betts, Louis Armstrong"
   -CJ

abbey road d enfer

Re: DCR and Impedance - modern audio transformers
« Reply #22 on: Today at 12:03:19 PM »
CJ has done dissections that show a variety of techniques used in winding

The methods to interleaving and different ways of controlling distributed capacitance is really interesting

I imagine it would not be economically feasible to replicate some of those techniques today
CNC winding machines can do it economically.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.


 

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