SOWTER AUDIO TRANSFORMERS
VINTAGE AUDIO TRANSFORMERS SUMMARY
A SERVICE for recreation or replacement or repair of vintage studio compressors, microphone amplifiers, equalizers, bridging and distribution amplifiers etc using tubes or transistors. There may be small differences in dimensions, taps and in the detailed specification but we are confident these transformers will sound as good as or better than the the "original sound"

DRIP ELECTRONICS are now selling PRINTED CIRCUIT BOARDS and other components for the equipment listed below

CUSTOM DESIGN SERVICE Our custom design service includes this type of transformer. We will not make a charge for the design provided we accept the requirement as being of general interest. We can work from circuits, actual transformers loaned to us or from specifications. We may offer the service on a "best efforts" basis if we cannot be sure of meeting a particular performance.

EQ INDUCTORS  Please see separate page

GENERIC PRODUCTS Many manufacturers used generic transformers which you may find on our Pre-Amp and Line Amp page or our Pro-Audio page. Please feel free to contact technical support for assistance.

PRICE and SHIPPING cost can be found by clicking on the "Buy" link or using SEARCH an using the type number as the search word

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TRANSFORMERS FOR VINTAGE COMPRESSORS AND LIMITING AMPLIFIERS

Quote TYPE Equipment Description Voltage
ratio
Z ratio Total DC res ref pry
ohms
Max level at 50 Hz
PACKAGE DIMENSIONS
Buy9643

Fairchild 670

Drip
Electronics

Control amp output 4:1
9:1NFB
10KCT/
600+NFB
950 75 V rms
output
I
Fits original can.
Buy 8344 Signal amp output 9+9: 1+1 60K/600 940 +30 dBu
output
M
Style e
Buy 8345 Control amp input 17+17:
1+1
600/170K 34 +16 dBu J
Style e
Buy 8346 Signal amp input 9+9:
1+1
600/50K 65 +24 dBu K
Style e
Buy 1231

Altec 436C Compressor

Drip
Electronics


Bridging input 1:1.23CT 15K/80K 1.1K Ohms +30 dBu J
Style e or i
Buy 1232 Line Output 12.4CT:1+1 23KCT/
150+150
25 Ohms (sec) +28 dBu K
Style options
Buy 9795 Mains  ww Primary E
Shrouded
Buy 0295

Teletronix
LA-2A
Compressor

More info

Mains Transformer WW primary 2 x 120,110  V. Electrostatic shield. 250-0-250 V  40 mA. 6.3V CT at 2 A.  F
Shrouded
Buy 0208Mains Transformer 240, 220, 200, 0, -10 Primary. Electrostatic shield. 250-0-250 V  40 mA. 6.3V CT at 2A.  F
Shrouded
Buy 1449 Amp input (was 1009)
UTC A10 replacement
1:9.1 600/50K 75 Ohms +12 dBu E
Style options
Buy 1010 Amp output
UTC A24 replacement
5:1 15K0/600 30 ref secy +30
dBu
output
K
Style options
Buy 1290 Amp output
UTC A24 replacement
5:1 15K0/600 30 ref secy +30
dBu
output
M
Style e
Buy 9880

Universal Audio
Urei UA175B Sta Level


Drip
Electronics

Mains transformer  WW Primary 120,110 V Twin winding.
250-0-250V at 100 mA, 6.3 V CT 2.5 A. 5V@2A.
Electrostatic shield for power line noise supression.
L
Shrouded
Buy 8650 Output 9CT:1 15K/
185 ohm
  +28 dBu A
Style options
Buy 1449 Input (was 1009)
Similar to UTC A-10
1:9.1:1 600/50K 75 Ohms +12 dBu E
Style options
Buy 1133

Interstage
Tested with Drip PCB Similar to
UTC A19

2.3:1 180K/15K 4K +40 dBu J
Style e or i
Buy 1285

Universal
UA 176

Output PP triode
with attenuator
9CT:1 50K/600 1050 +48 dBu K
Style options
Buy 1260

Universal 1176 Peak Limiter

Input 1:1.158 200/500     E
Style options
Buy 1327 Output for Rev A or D
(With feedback windings)
1:0.5+0.5:1:0.05
600/150+150
+Feedback
    C
U-Clamp
Buy 9062

Sta-Level (Micro)

Drip
Electronics version

Input 1CT:4+4 600/50K CT 103 ref pry +42 dBu J
Style e or i
Buy 9185 Output 7.3:1 8KCT/150 40 ref sec +40 dBu J
Shrouded
Buy 8345

Fairchild 666

Input
Similar to
UTC Y6431
17+17:
1+1
600/170K 34 +16 dBu J
Style e or i
Buy 1160 Output
Similar to Chicago
BO-1
10:1 or 5:1 15K/
150+150
  +30
(output)
K
Style options
Buy 1255 Side chain output 6.32 :1 20K/500 66 ref secy   K
Style options
Buy 9835

RCA BA-6A Limiting amplifier

Drip
Electronics

Input  1CT:4.08CT 600/150 
to 10K
131 +16 dBu I
Style options
Buy 9830 Interstage 1CT:1 10KCT/
10K
1680 +36
dBu
J
Style e or i
Buy 9770 Output for 6V6 PP 3.65 CT:1 8K/600 506 +30
dBu
output
K
Style options
Buy 1195

RCA 86-AL Limiting amplifier

Interstage
Suitable for RCA 86-A
1+1:1.4 10K+10K/
20K
1610 +36 dBu K
Mumetal can
Buy 8540

Gates M5167 Compressor

Line input  1:4 600/10KCT 120 +16 dBu E
Style options
Buy 9185 Line output
(PP 6V6's)
7.3:1 8KCT/150 40 ref sec +40 dBu J
Style options
Buy 9062

CCA Electronics Corp LA-1D
Limiter

Line Input 1CT:4+4 600/50K CT J
Style options
Buy 9890 Line Output 5.77CT:1 20K/
150+150
D
Shrouded
Buy 1065

Collins Peak Limiter

Interstage 3.1+3.1:
1+1
30K/60K 752 +45 dBu K
Mumetal can
Buy 1212 Line Output 3.87 900/150+150 88 ref sec +25 dBu D
Shrouded
Buy 9935

API 525C
Compressor
Limiter

Line Output 1:1+1 600/600+600 39 +26 dBu J
Style options
Buy 9905

Federal
AM864/U
Compressor

 WW Primary 120,110 V Twin winding 50/60 Hz
. 175-0-175 at 40 mA, 6.3 at 2 A 5V at 2 A. Internal electrostatic shield
See also input type 8540 , output type 9900 and choke type CB24.
I
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TRANSFORMERS FOR VINTAGE MICROPHONE AMPLIFIERS AND EQUALIZERS

Quote TYPE Equipment Description Voltage
ratio
Z ratio Total DC res ref pry
ohms
Max level at 50 Hz
PACKAGE DIMENSIONS
Buy 9970

Chandler
REDD 47

Microphone input 1:7
35%
secy tap
200/10K    

J
Style e or i

Buy 9980 Line Output 7:1+1 30K/
600+600
    J
Style e or i
Buy 9527

Pulteq
EQP-1A


Schematic

Drip
Electronics


Mains transformer for 1 or 2 units.  WW Primary. Electrostatic screen
250-0-250 at 60 mA. 6.3 V CT@ 1.5 A. 
6.3-5-0 V @ 1.0 A for rectifier and pilot light.  50/60 Hz
Larger than original but still fits on chassis with minor modification.
J
Shrouded
Buy 3603 EQ input
(Triad HS-56)
1CT:1 600/600 150 +17 dBu E
Style options
Buy 9330 Amp input
(Triad HS-29)
1:2CT 2K5/10K
112 +16 dBu E
Style options
Buy 1475 Amp input
(Triad HS-29)
1:2CT 10K/40K 1600 +34 dBu J
Style a or e
Buy 9530 Amp output
Peerless S-217-D
10CT:1+1
NFB 4% of primary<
15K/600 
15K/150
40
ref secy
+23 dBu J
Style e

Buy 9325 Passive EQ inductor 150/82/68/47/33/27 mH
15/11/10/8/6/5 ohms
E
Style options
Buy 9186

Altec 1566a

Microphone Preamp.
Circuit on request
Mains ww primary.  110 V 30 mA, 22V CT 0.5 A D
Shrouded
Buy 4935 Mic input  1CT:7 200CT/
100K
40 ohms +12 dBu E
Style options
Buy 8940 Output 3:1 5K/600 15 ohms (sec) +28 dBu K
Style options
Buy 9820

API 312

Mic Pre and Line amp
Input 1:4.37 150/600:
11.5K
149 0 dBu E
Style options
Buy 9825 Output 1+1+1+1 75:300+75 31.5 +30 dBu J
Style options
Buy 1364

EMI TDS5383

Germanium desk
Input
1tapped:1 30/300/600:
600
92 +26 dBu J
Style options
Buy 1295

EMI TG12345

Mic input 1:3.16
secondary taps
      J
Style options
Buy 1365 Output 1:1.77       J
Style options
Buy 9775

Langevin
AM 16

Input 1Ct+1CT
:4+4
50,150,600/
2K5 + 2K5
  +17 dBu F
Style options
Buy 9765 Output 1+1+1+1
:1+1
 600/
150,600
   +37 dBu J
Style options
Buy 1960

Telefunken
V72

Input 1+1:20 50/47K OR
200/47K
  +12 dBu E
Style options
Buy 1275 Output (original ratio) 11.2:1 76K/600
Ohms

20 Ohms

+14 dBu at 40 Hz J
Style options
Buy 9375 Plate choke 750H approx at 1KHz 7 ma max
DCR  18.4 Kohm  CKV72/1
ask
Style options
Buy 1120 Output (alternative ratio) 9:1 50K/600 11.5 Ohms (sec)+12 dBu at 40 Hz J
Style options
Buy 1110

Telfunken
V76

Output 9:1 50K/600 10 Ohms
ref secy
+18 dBu
at 30 Hz
K
Style options
Buy 1004 Input 0.5 + 0.5:30 200/180K 9
ohms
+12
dBu
J
Style options
Buy 1377 Plate Choke 400 mH approx. 3.6 mA BV514
DCR = 18K Ohms approx
J
Style options
Buy 1378 Plate Choke

250H approx 12 mA max BV515
DCR = 6.8 K Ohms approx

K
Style options
Buy 9129

Telfunken
V74

Output 8:1+1+0.7 2K/30ohms 584 ohms +20 dBu J
Style options
Buy 8751

Neve L01166
BA283
1073/1272

Darlington 
Line Amplifier
600 ohm line Output
P/N L01166
1:1.5
N/A 39 +30 dBu B
U-Clamp
Ask 1425 Cost reduced version of 8751 1:1.5
N/A 39 +30 dBu A
U-Clamp
Buy 9160

600 ohm line Output
P/N L01166
reduced size

1:1.5 N/A 37 +27 dBu

A
U-Clamp

Buy 9780 600 ohm line Output Ungapped for use with pin "F" only. P/N L02567/T1801 1:1.5 N/A 39 +30 dBu B
U-Clamp
Buy 9145 Input transformer
P/N 10468
1+1:2+2 300/1K2 to 1K2/4K8 190 +18 dBu E
Style options.
Buy 9165 Input transformer
P/N 31267
2+2:1+1 10K/2K4 
to 2K4/600
1K8 +24 dBu E
Style options
Buy 7490

Helios

Input transformer
Lustraphone M10 
1:10
tap for 1:1
200/20K  _9 dBu E
Style options
Buy 1478

Trident
A range
B range

Input transformer
Marinair ZUTT012a
1:5.9 600/30K 146 +20 dBu E
Style options
Buy 9930

Gyraf
Passive EQ

267 mH inductor tapped at 269,169,69,22 mH replaces separate 100,100,47.22 mH inductors shown on schematic E
Style options
Buy 9540 Input 1:1 200/200 +10 dBu E
Style options
Buy 8403 Output 1:1+1 600:
150+150
65 ohms +34 dBu J
Style options
Buy 1200

Universal 1008A

Mic
Pre amp
Output 3.42:1 7K/600 plus NFB winding 1052 +24 dBu K
Mumetal can
Buy 0640

Klein and Hummel UE-100 EQ

Mains transformer
50/60 Hz. Choice of World Wide or European primary. Secondary windings: 220V at 36 mA, 150V CT at 130 mA, 8.5V at 3.6A, 8.5 mA at 3.6A ,8.5V at 2.3A and 12V tapped at 10V at 4A.
N
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TRANSFORMERS FOR VINTAGE TAPE RECORDERS ETC

Quote TYPE Equipment Description Voltage
ratio
Z ratio Total DC res ref sewc
ohms
Max level at 50 Hz
PACKAGE DIMENSIONS
Buy 9915

Ampex 350

Single ended
Line out
10:1+1 15K/150+160 109 +70 dBu D
Shrouded
Buy 9084

Ampex 351

Push-Pull
Line out
5.55CT:
1CT+1
15K/"600"
+NFB
48 +38 dBu K
Style options
Buy 9735

Ampex
350/351

Input 1+1:32 50+50/50K 28 +12 dBu F
Style options
Buy 1100

Ferrograph

head input transformer
For series 3 etc 6:1 300/10K     E
Style options
Buy 1166

EMT 262 Reverb

Input from plate 1:35 40/50K    

C
Style options