Pre/Line amps – Sowter Transformers

Sowter 9745E Output Transformer

adminsowtertest — Fri, 04 Jul 2025 10:02:18 +0000

For use in a high performance valve compressor/amplifier etc where high output level and exceptional bandwidth are required. Designed for use with Push-Pull output stage or an ac coupled cathode follower or SRPP circuit driving a nominal 600 ohm line. Can be configured for low output impedance (10:1) or high level output (5:1) by connecting the twin secondary windings in parallel or series. 15kCT/150+150 ohm output transformer for driving a balanced line from push-pull triodes. 100% M6 core for high level capability and low distortion. Twin secondaries for 600/150 ohm outputs. Voltage ratio 10CT:1+1 Max dc per side of primary 30 mA. Colour coded leads. Size A Supplied with end frames for vertical or horizontal mounting. Fully shrouded style “S” option.

Sowter 9745 Output Transformer

adminsowtertest — Fri, 04 Jul 2025 10:02:17 +0000

15kCT/150+150 ohm output transformer for driving a balanced line from push-pull triodes. 100% M6 core for high level capability and low distortion. Twin secondaries for 600/150 ohm outputs. Voltage ratio 10CT:1+1 Max dc per side of primary 30 mA. Colour coded leads. Size A Supplied with end frames for vertical or horizontal mounting. Fully shrouded style “S” option.

Sowter 1461 Input/Output Transformer

adminsowtertest — Fri, 04 Jul 2025 10:01:42 +0000

Sowter 1461 Input/Output Transformer. Similar to 1460 but with 2 separate primary windings. May be configured as 600 or 2400 Ohms primary.. Input level +24 dBu at 50 Hz. Combination Mumetal Radiometal core. THD 0.01 % at 1KHz.

Sowter 1367 Output Transformer

adminsowtertest — Fri, 04 Jul 2025 10:01:41 +0000

Sowter 1367 Output Transformer. 15k/150+150 ohm output transformer for driving a balanced ohm line from single ended triode or pentode stage. Very high primary inductance for driving from a valve with a high plate resistance (rp). 100% M6 core for high level capability, primary Inductance 100H. Can be configured for 5:1 or 10:1 ratio. Max output level at 30 Hz +26 dBu. Multiple interleaved winding sections. for high bandwidth. Max primary dc 15 mA. Total dc resistance ref secondary 131 ohms. Size “D” Package options. Replacement for UTC A-25.

Sowter 9062 Line Input Transformer

adminsowtertest — Thu, 23 May 2024 09:50:50 +0000

High level, very high performance Line Input Transformer. Two chamber bobbin ensures 100% accurate phase splitting over full bandwidth. Suitable for Gates STA level compressor. Suitable for the Drip Drip M5167 STA PCB. Mumetal can with threaded grommet and colour coded leads.

Sowter 9063 Line Input Transformer

adminsowtertest — Thu, 23 May 2024 09:50:50 +0000

High level, very high performance Line Input Transformer. Two chamber bobbin ensures 100% accurate phase splitting over full bandwidth. Mumetal can with threaded grommet and colour coded leads.

Sowter 1290 Output Transformer

adminsowtertest — Thu, 23 May 2024 09:50:08 +0000

Ratio 5:1. 15k/600 ohms output transformer for driving balanced line from ac coupled cathode follower or SRPP circuit. Total dc resistance ref secondary 31 ohms. Colour coded leads and threaded grommet mounting. Max output level +30 dBu. 30% Mumetal core for exceptional bandwidth and dynamic range. Similar to UTC A24 and Triad HS-50 (in overall 5:1 configuration) but with improved bandwidth. Suitable for PCB. Also suitable for UE-100 Output.
This transformer is very similar to type 1010 and is essentially a size and cost reduced version achieved by using a smaller lamiination size and a smaller proportion of Mumetal laminations. The can size is also smaller and less expensive. The performance is unaffected except at very high level low frequencies where the THD measures somewhat higher.

Sowter 1285 Output Transformer

adminsowtertest — Thu, 23 May 2024 09:50:07 +0000

15k/185 ohm output transformer for driving a balanced ohm line from push-pull 6SN7, ECC83 etc. 50% Mumetal core for high bandwidth and dynamic range, Max output level at 50 Hz +28 dBu (19 volts). Includes primary taps for UA 176. Total dc resistance ref secondary 14 ohms. Colour coded leads. Pro Audio size K
.

Sowter 1160 Output Transformer

adminsowtertest — Thu, 23 May 2024 09:50:05 +0000

15k/150+150 ohm output transformer for driving a balanced ohm line from single ended triode stage. 100% M6 core for high level capability, Can be configured for 5:1 or 10:1 ratio. Max output level at 30 Hz +26 dBu. Multiple interleaved winding sections. for high bandwidth. Max primary dc 30 mA. Total dc resistance ref secondary 76 ohms.
Size “D” Package options. Replacement for Chicago BO-1 in Fairchild 666. Suitable for Drip 666 board.