LINEAR STANDARD (LS) AUDIO TRANSFORMERS

LINEAR STANDARD (LS) AUDIO TRANSFORMERS

The design of the Linear Standard(LS) transformer goes back to the1940’s, and the drawing boards of the United Transformer Company (UTC).

UTC was located at 150 Varick St. in New York City. The designs were founded in tube audio design, and have been heralded as being one of the best lines of Hi-Fi audio transformers ever designed and manufactured.

Linear Standard Audio Units Feature:

UNIFORM FREQUENCY RESPONSE… at low frequencies, is effected through the use of HIPERM-ALLOY, a stable nickel iron alloy of very high initial permeability. Uniform frequency response is the result of multiple section interleaved windings arranged in a proprietary coil structure. This, plus special winding methods and insulation’s, assures a minimum of distributed capacity and leakage reactance.
UTC LINEAR STANDARD…transformers have a guaranteed response of ±1db from 20 to 20,000 cycles. For low distortion, high level units far exceed the guaranteed response and can attain ±1db from 7 to 50,000 cycles.
MINIMUM HUM PICKUP…is accomplished through the use of hum balanced coil structure which affords maximum neutralization of external fields. For very low level applications, units whose part numbers end with an X employ multiple alloy shielding, making possible a transformer with extremely low inductive pickup.
DEPENDABILITY…is a function of external and internal structure. Linear Standard units are housed in rugged steel cases of precise dimension. The solid terminal posts are arranged in a circular layout so that a round chassis hole will clear all terminals. There are four standard mounting inserts placed on the terminal face of the transformer for easy installation. Coils are vacuum baked and impregnated. Semi-Hermetic sealing is accomplished through the use of a high adhesion compound introduced through large pour holes opposite the terminal board after controlled preheating of the unit for full compound penetration.

Case No.	A(+/-.060)	B(+/-.060)	C(+/-.060)	D(+/-.031)	E(+/-.031)	INSERTS
LS-1	2.56	2.99	3.13	2.38	2.00	4 X #6-32
LS-2	3.31	3.88	4.13	2.49	3.00	4 X #8-32

High Fidelity
Low Distortion
High Efficiency
Output, Interstage, Mixing & Matching Transformers
Ideal for Vacuum Tube Audio

Low Impedance to Grid And Mixing & Matching Transformers

Type Number	Application	Primary Impedance	Secondary Impedance	Response 2db (Hz)	Max Level dbm	Rel. Hum	Unbal DC in Pri.	Case
LS10X	Low impedance mike, pickup or multiple line to PP grids	50, 125/150, 200/250, 333, 500/600 Ohms	60,000 Ohms in two sections	20-20,000	+17	-92 db-Q	.5 ma	LS-1
LS12X	Low impedance mike, pickup or multiple line to PP grids	50, 125/150, 200/250, 333, 500/600 Ohms	80,000 Ohms overall, split	20-20,000	+17	-92 db-Q	.5 ma	LS-1
LS14X	Low impedance mike, pickup or parallel mixer to grid	2.5, 5.5, 10, 15, 22, 30, 38, 60 Ohms	50,000 Ohms	20-20,000	+17	-92 db-Q	.5 ma	LS-1

Interstage Transformers

Type Number	Application	Primary Impedance	Secondary Impedance	Response 2db (Hz)	Max Level (mw)	Rel. Hum	Unbal DC in Pri.	Case No.
LS21	Plate to PP grids Split Primary & Secondary	15,000 Ohms	135,000 Ohms 3:1 Overall	10-20,000	100	-74 db	0 ma	LS-1
LS25	PP plates to PP grids, Med. level split Pri & Sec	30,000 Ohms	50,000 Ohms Turns Raio 1.3:1 Overall	20-20,000	200mw	-74 db	1 ma	LS-1
LS40	Plate to PP grids Split Secondary	15,000 Ohms	135,000 Ohms 3:1 Overall	30-18,000	100mw	-74db	8 ma	LS-1

Output Transformers to Line & Voice Coil

Type Number	Primary Will Match Typical Tubes	Primary Impedance	Secondary Impedance	Response 2db (Hz)	Max Level (W)	Rel. Hum	Unbal DC in Pri.	Case No.
LS55	PP 300B, 6L6's, 6AS7G, 6080, 7027, 7581, 7355, 786B	5,000 Ohms P to P 3,000 Ohms P to P	500,333,250/200,125,50,30,20,15,10,7.5,5, 2.5,1.2	7-50,000	20	-	-	LS-2
LS63	PP triode: 6AS7G, 6080, 6L6, 5881, KT-66, 807, 1614	10,000 Ohms P to P 6,000 ohms P to P	30,20,15,10,7.5,5,2.5,1.2	7-50,000	20	-	-	LS-2