Jensen Transformers Products

Jensen Transformers CI-RJ2R Stereo CAT-5 Audio Balun Set

Jensen Transformers CI-RJ2R-T / CI-RJ2R-R Stereo CAT-5 Audio Balun Sets provides an elegant way to extend audiophile-quality analog stereo audio signals up to 350 using twisted-pair cabling such as Cat-5 or Cat-6.

Jensen Transformers CI-1RR Single-Channel Audio Isolator

This audiophile-quality device not only eliminates hum and buzz, but also enhances audio quality by reducing spectral contamination due to ultrasonic and RF interference.

Jensen Transformers CI-2RR Stereo Audio Isolator

All of the advantages of the CI-1RR (above), but with two channels.  Perfect for stereo applications.

Jensen Transformers CI-2MINI Stereo Audio Isolator

Eliminates hum and buzz when connecting computers, laptops, iPods, MP3 players and other 3.5mm mini-phone equipped sources to stereo and A/V systems.

Jensen Transformers ISO-MAX MEDIA-2 Two-Channel Direct Box

This isolator interfaces unbalanced instrument and line-level audio signals to balanced XLR inputs  AKA "DI Box".

Jensen Transformers MC-2RR Moving Coil Audio Step-Up Transformer

Jensen's audiophile-quality transformer provides essential gain while isolating noise. Use to interconnect moving-Coil phono cartridges in the finest audio systems.

Jensen Transformers SUB-1RR Subwoofer/LFE Audio Isolator

Eliminates sub-woofer hum caused by ground differences between equipment.  Designed specifically for sub-woofer amplifier isolation in Home Theater and Automotive applications

Jensen Transformers SUB-2RR 2-Channel Subwoofer/LFE Audio Isolator

Similar to the model above except that it can handle two audio channels, the SUB-2RR eliminates sub-woofer hum caused by ground differences between equipment.  Designed specifically for sub-woofer amplifier isolation in Home Theater and Automotive applications

Jensen Transformers PO-2XX Stereo Line Output Isolator, 1:1 Output Ratio

Allows any type of output driver to be connected to either balanced or unbalanced inputs without causing loading or instability problems.  Standard configuration is XLR / XLR, but you may also choose any combination of XLR, RCA, BNC, or Phone connectors.
(formerly DM2-2XX)

Jensen Transformers PO-XX Mono Line Output Isolator, 1:1 Output Ratio

Single-channel version of PO-2XX with (1) XLR and (1) XLR output connector
(order via PO-2XX page)

Jensen Transformers PO-2RP Stereo Line Output Isolator, 1:1 Output Ratio

Electrically identical to the PO-2XX above, but with RCA input connectors / 1/4-inch TRS phone output connectors.
(formerly DM2-2RP)

Jensen Transformers PO-2RX Stereo Line Output Isolator, 1:1 Output Ratio

Electrically identical to the PO-2XX above, but with RCA input connectors / XLR output connectors.
(formerly DM2-2RX)

Jensen Transformers PB-2XX Balanced XLR Stereo Audio Input / Output Isolator

Powerful 100 dB ground isolation and Faraday shielded windings eliminate hum and noise in XLR to XLR balanced audio connections!

Jensen Transformers PC-2XR Balanced to Unbalanced Audio Converter - XLR to RCA

This "Pro to Consumer" converter facilitates a proper connection from balanced audio sources to unbalanced audio equipment, while also providing isolation to eliminate ground loops that can cause hum and noise.

Jensen Transformers PI-2XX Stereo Audio Input Isolator

Recommended for most all 2-channel applications where a high-impedance line input, such as the line input of a power amp or crossover needs to be isolated.  XLR input connectors / XLR output connectors.

Jensen Transformers PI-2RX Stereo Audio Input Isolator

Electrically identical to the PI-2XX, but with RCA input connectors / XLR output connectors. Please choose RCA input connectors from the "Select Input Connectors" "drop-down.

Jensen Transformers SC-2NR Stereo Speaker to Line Audio Converter

Jensen Transformers' SC-2NR Stereo Speaker to Line Audio Converter is audiophile-grade device that provides an elegant way to convert speaker-level audio to line-level audio.  Terminal strips inputs and RCA output connectors.

Jensen Transformers SS-2RR Stereo Speaker to Line Audio Converter, tuned specifically for subwoofer inputs

Same physical specs as the SC-2NR, but the SS-2NR Stereo Speaker to Line Audio Converter is tuned specifically for subwoofer inputs.  RCA inputs and RCA output connectors.  (available on the SC-2NR product page)

Jensen Transformers SP-2SX Stereo Speaker to Line Audio Converter

Jensen Transformers' SP-2SX Stereo Speaker to Line Audio Converter provides audiophile-grade conversion of speaker-level audio to Pro-style XLR balanced line-level audio outputs.

Jensen Transformers SS-2SX Stereo Speaker to Line Audio Converter, tuned specifically for subwoofer inputs

Same physical specs as the SP-2SX, but the SS-2SX is tuned specifically for subwoofer inputs.  Terminal strip, SpeakON inputs, and RCA output connectors.

Jensen Transformers SUB-2XX Stereo Balanced Audio Input Isolator

This ISO-MAX is specially designed for low-frequency applications.  It offers common mode rejection of 105 dB at 60 Hz while also helping to eliminate RF interference...features extended low frequency down to 1 Hz and virtually non-existent distortion for hum-free subwoofer hookups.

Jensen Transformers SUB-XX Single-Channel Balanced Audio Input Isolator

Same specs as the subwoofer isolator above, but in a single-channel version with extra-heavy-duty extruded aluminum case.

Jensen Transformers PI-XX Single Channel Mono Audio Input Isolator

Recommended for most all single-channel applications where a high-impedance line input, such as the line input of a power amp or crossover needs to be isolated.

Jensen Transformers VB-1BB Baseband-Composite Video Isolator with BNC Connectors

Eliminates noise bars caused by ground differences between equipment.  Perfect for video surveillance systems!

Jensen Transformers VB-1RR Baseband-Composite Video Isolator with RCA Connectors

Eliminates ground-loop-induced hum and noise bars caused by ground differences between equipment.  Great for video surveillance systems!

Jensen Transformers VRD-1FF Cable TV Ground Loop Isolator - Improved Model

Eliminates hum and noise bars caused by ground differences between equipment. Analog.  Digital and Cable Modem Compatible.

Jensen Transformers JT-DB-E - 12:1 "Direct Box" Transformer with Wire Leads

Perfect for coupling guitar pickups, musical instruments and other line level outputs to low impedance microphone inputs. Excellent results when used as an output transformer for tube-type condenser microphones as well.

Jensen Transformers JT-DB-EPC - 12:1 "Direct Box" Transformer, PCB Mount

Same transformer as the item above, but for PB Board mounting.  Perfect for coupling guitar pickups, musical instruments and other line level outputs to low impedance microphone inputs. Excellent results when used as an output transformer for tube-type condenser microphones as well.

Jensen Transformers JT-MB-CA 1:1 Microphone Input Transformer, wire leads

Ffor Ultra-low Noise Amplifiers, provides transformer isolation to a transformerless mic preamp input

Jensen Transformers JT-123-BMCF Line Output Transformer

Line output transformer, with bifilar windings, 80% nickel laminations, +27dBu @ 20Hz

Jensen Transformers JT-123-FLPCH Line Output Transformer

Line output transformer, 1:1 or 1:2 ratio with quadfilar windings, 50% nickel laminations, +21dBu @ 20Hz. PC board mount

Jensen Transformers JT-13K7-A 1:5 Microphone Input Step-Up Transformer

4.1 kΩ secondary source impedance, not only optimizes noise performance of many IC or discrete amplifiers but also offers excellent CMRR as well.  Clamp-style Mount and Wire Leads

Jensen Transformers JT-13K7-ATB 1:5 Microphone Input Step-Up Transformer

With its 4.1 kΩ secondary source impedance, this transformer optimizes noise performance of many IC or discrete amplifiers while offering an excellent Common Mode Rejection Ratio as well.  Threaded Bushing-style Mount and Wire Leads

Jensen Transformers JT-11P-1 "Balanced Bridging" Line input transformer with 1:1 ratio

Ideal for balancing any high-impedance unbalanced input.  Screw-style Mount and Wire Leads.

Also available with Threaded Bushing mounting style as JT-11P-1TB, by special order.

Jensen Transformers JT-11P-1HPC "Balanced Bridging" Line input transformer with 1:1 ratio, PCB Mount

Electrically identical to the item above, but in a PCB mounting style. (available on the JT-11P-1 page)

Datasheet

Jensen Transformers JT-11SSP-6M 1:1 ratio split winding "repeat coil" Line Input Transformer

Ideal for balancing any low impedance input circuit.  Clamp-style Mount and Wire Leads.

Jensen Transformers JT-16-A • High-Performance Microphone Input Transformer with 1:2 step-up ratio

Ideal for use with ultra low noise input amplifiers such as the discrete 990 op amp

Additional Models Listed Below are available by "Special Order", although some are now In Stock (as noted)

• Convenient DIN Rail Mounting System
• World Famous Quality Jensen Transformers
• Removable Screw Terminal Connectors
• Reliable Gold Plated Connector Pins
• Built-in Pad and Termination Options
• Up To 12 Modules on a 3RU Rack Panel
• Quick Disconnect for Easy Replacement

Line Input Modules

Jensen Transformers DIN-LI • 10k to 10k 1:1 Line Input Module

Single channel unit provides isolation at professional line inputs. May be used with any combination of balanced or unbalanced sources and/or inputs.

Datasheet

Jensen Transformers DIN-2LI • Dual 10k to 10k 1:1 Line Input Module

Two channel unit provides isolation at professional line inputs. May be used with any combination of balanced or unbalanced sources and/or inputs.

Datasheet

Jensen Transformers DIN-LOD • 600 to 600 1:1 Line Output Module
(formerly DIN-LO-11DM)

Single channel unit provides ground isolation at professional line outputs operating at maximum levels up to +22 dBu @ 20 Hz or +26 dBu @ 30 Hz.

Datasheet

Jensen Transformers DIN-LO-11FL • 600 to 600 1:1 Line Output Module
(formerly DIN-LOF)

Single channel unit provides ground isolation at professional line outputs operating at maximum levels up to +21 dBu @ 20 Hz or +25 dBu @ 30 Hz.

Datasheet

Jensen Transformers DIN-2LO-11FL • Dual 600 to 600 1:1 Line Output Module
(formerly DIN-2LOF)

Two channel unit provides ground isolation at professional line outputs operating at maximum levels up to +21 dBu @ 20 Hz or +25 dBu @ 30 Hz.

Datasheet

Jensen Transformers DIN-PB • Line Input/Output or Patchbay Module

Single channel unit provides ground isolation at inputs or outputs. Designed especially for patch bay and long line applications.

Datasheet

Jensen Transformers DIN-PC • "Pro" to "Consumer" 4:1 Line Input Module

Single channel unit provides isolation and +4dBu to -10dBV signal level conversion for “Pro” to “Consumer” applications.

Datasheet

Jensen Transformers DIN-DB • Direct Box Interface Module

Single channel unit provides ground isolation and converts electric guitars, synthesizers, or other line level sources to microphone level low impedance signals.

Datasheet

Jensen Transformers DIN-MS-2P • 2 Way Microphone Splitter Module w/Phantom Power

Single channel, two way microphone splitter, including circuitry required to implement phantom powering of microphones.

Datasheet

Jensen Transformers DIN-MS-3P • 3 Way Microphone Splitter Module w/Phantom Power

Single channel, three way microphone splitter, including circuitry required to implement phantom powering of microphones.

Datasheet

Jensen Transformers DIN-MS-4P • 4 Way Microphone Splitter Module w/Phantom Power

Single channel, four way microphone splitter, including circuitry required to implement phantom powering of microphones.

Datasheet

Jensen Transformers DIN-2MS-2P • Dual 2 Way Microphone Splitter Module w/Phantom Power

Two channel, two way microphone splitter, including circuitry required to implement phantom powering of microphones.

Datasheet

Jensen Transformers DIN-MRP • 3RU Rack Panel Mounting Adaptor

3U rack panel accessory for mounting up to 12 modules.

Wire Lead – Standard Wire Termination with Retainer Clamp

Mounting clamp shown here:

Spec Sheet for included VR mounting clamp

PC Mount  – For Direct Soldering to Printed Circuit Board

Threaded Bushing – Mounts using 3/8" Threaded Bushing with nut

Common Features for all mounting styles

Microphone preamp designs incorporating Jensen Input Transformers offer several advantages over the more commonly used, inexpensive "transformerless" designs:

1. Superior Common Mode Interference Rejection
2. Superior Radio Frequency Interference Rejection
3. Ideal impedance matching of source to amplifier
4. Elimination of input coupling capacitor distortion

Jensen manufactures Microphone Input Transformers in many step-up ratios in order to provide the best possible noise performance with any type of active amplifier device.  All have a 30dB Magnetic Shield can and a single Faraday Shield (except * which have two shields)

Transformer Selection

To determine the proper ratio transformer for your application, you will need to know the Voltage Noise and Current Noise of the active amplifier device to which the secondary of the transformer will be connected. If you divide the Voltage Noise by the Current Noise of the device you will get a value in Ohms. This value is the Optimum Source Impedance for best noise performance using that particular amplifier device. Select the transformer whose secondary impedance most closely matches the calculated value.

Turns ratio is generally selected for lowest total noise. Lowest noise will come from matching the “optimum source impedance” of the amplifier to the transformer’s “secondary source impedance” – shown in the table above to the right of the colon under “Impedance Ratio.”  The optimum source impedance for any amplifier can be calculated by dividing the amplifier’s voltage noise spectral density in V/ √ Hz , such as 1.2 nV/ √ Hz  (1.2 nano-volts per root-Hz) by its current noise spectral density in A/ √ Hz  , such as 2 pA/ √ Hz (2 pico-amps per root-Hertz). In this example, using figures for the AD797 low-noise op-amp, the answer is 600 Ω, making our JT-16A with its 600 Ω source impedance the best choice.  This matching is not critical and mismatches of ±50% generally make less than 1 dB change in total noise. For vacuum tubes, voltage and current noise numbers are difficult to find. However, when they are available, the calculation will generally indicate an optimum source impedance higher than 15 k Ω. Due to the complex tradeoffs in transformer design, our JT-115K-E is the highest ratio (and secondary source impedance) we can produce and stay within Jensen performance criteria. The JT-115K-E gives outstanding results and we recommend it for all vacuum-tube applications.

Example: An AD797 has an input Noise Voltage of 1.2nV per root Hertz Max. @ 1kHz and an input Current Noise of 2.0pA per root Hertz. This gives an Optimum Source Impedance of 600 Ohms. The proper choice of transformers for this device would be either the JT-16-A or the JT-16-B.

Special Note for Vacuum Tube Applications

If the above calculation is performed for Vacuum Tubes, the value obtained will normally be much higher than the secondary impedance of even our JT-115K-E transformer. We do not manufacture Microphone Input Transformers with ratios higher than 1:10 due to the limited bandwidth that is possible in designs of this type. The JT-115K-E will work very well in most Vacuum Tube applications.

Jensen Transformers JT-16-A • Microphone input transformer with 1:2 step-up ratio

for use with ultra low noise input amplifiers. Ideal for the discrete 990 op amp

Datasheet

Jensen Transformers JT-115K-E • Microphone input transformer with 1:10 step-up ratio

for use with low noise FET or vacuum tube input amplifiers, Standard Wire Lead style w/clamp Mount

Datasheet

Jensen Transformers JT-115K-EPC • Microphone input transformer with 1:10 step-up ratio

for use with low noise FET or vacuum tube input amplifiers, PC Board Mount

Datasheet

Jensen Transformers JT-MB-CA • Microphone input transformer with 1:1 ratio w/wire lead

provides transformer isolation to a transformerless mic preamp input

Datasheet

Jensen Transformers JT-MB-CPCA • Microphone input transformer with 1:1 ratio w/PC Board Mount

provides transformer isolation to a transformerless mic preamp input

Datasheet

Jensen Transformers JT-MB-C • Microphone split transformer with 1:1 ratio w/Wire Leads

Provide transformer isolation to 2nd console. Dual Faraday shields.

Datasheet

Jensen Transformers JT-MB-CPC • Microphone split transformer with 1:1 ratio w/PC Board Mount

Provide transformer isolation to 2nd console. Dual Faraday shields.

Datasheet

Jensen Transformers JT10KB-D

Line input transformer, 4:1 step-down ratio, ideal for "balanced bridging" inputs or "Pro to Consumer" level conversion.. Wire leads.

JT10KB-D Datasheet

Jensen Transformers JT-10KB-DPC

Line input transformer, 4:1 step-down ratio, ideal for "balanced bridging" inputs or "Pro to Consumer" level conversion.  PC Board mount.

Datasheet

600 Ohm to 600 Ohm Repeat Coil Transformer

Jensen Transformers JT-11SSP-6M

Line input transformer, 1:1 ratio split winding "repeat coil", ideal for balancing any low impedance input circuit.

Datasheet

Wire Lead – Standard wire termination with retainer clamp

PC Mount  – For Direct Soldering to Printed Circuit Board

Load Isolators - for decoupling capacitive loads at high frequencies 

Jensen Transformers JT-10K61-1M

Line Line output transformer, 4:1 CT or 8:1 step-down ratio with Faraday shield, for vacuum tube line outputs

Datasheet

Jensen Transformers JT-11-BMCF

Line output transformer, 1:1 ratio with bifilar windings, 80% nickel laminations, +27dBu@ 20Hz. Channel frame mount, wire leads

Datasheet

Jensen Transformers JT-11-DMPC

Line output transformer, 1:1 ratio with bifilar windings, 80% nickel laminations, +22dBm @ 20Hz. PC board mount.

Datasheet

Jensen Transformers JT-11-FLPCH

Line output transformer, 1:1 ratio with bifilar windings, 50% nickel laminations, , +21dBu @ 20Hz, PC board mount.

Datasheet

Jensen Transformers JT-11-HFMPC

Line output transformer, 1:1 ratio with bifilar windings, 80% nickel laminations, +18dBm @ 20Hz. PC board mount.

Datasheet

Jensen Transformers JT-123-BMCF

Line output transformer, 1:1 or 1:2 ratio with quadfilar windings, 80% nickel laminations, +27dBu @ 20Hz

Datasheet

Jensen Transformers JT-123-DBX

Line output transformer, for use as optional transformer in some dBx compressors, 50% nickel laminations, +21dBu @ 20Hz. PC board mount.

Datasheet

Jensen Transformers JT-123-FLCF ( aka JT-123-ELCF, formerly JT-112-LCF )

Line output transformer, 1:1 or 1:2 ratio with quadfilar windings, 50% nickel laminations, +21dBu @ 20Hz.
Wire Lead - Standard wire termination with retainer clamp.
Exactly the same transformer and specs as the JT-123-ELCF and JT-112-LCF.

Datasheet

Jensen Transformers JT-123-FLPCH

Line output transformer, 1:1 or 1:2 ratio with quadfilar windings, 50% nickel laminations, +21dBu @ 20Hz. PC board mount.

Datasheet

Step-up transformers match moving-coil phono cartridges to the inputs of standard pre-amps and receivers. Experience legendary sonic transparency, made possible by Jensen's extended frequency response and time accuracy. Hum and RF interference immunity is ensured by dual magnetic shields as well as Faraday shielding. Models ranging from 3 to 45 Ohms are available, for compatibility with a wide range of pick-ups.

Notes:

• Standard wire-lead termination with retainer clamp
• The JT-346-AX is now a 346-AXT to match the 347.
• The JT-346-AXT is NOT suitable for a stand alone application. It is designed to be integrated into a moving coil preamp design and requires a 6.8kOhm load. As it will not work properly into a standard 47kOhm phono preamp.

Jensen Transformers JT-34K-DX

1:37 ratio, provides 31 dB of gain for low output cartridges. Ideal for many of the Ortofon cartridges

Datasheet

Jensen Transformers JT-44K-DX

Provides 20 dB of gain for medium to high output cartridges. Ideal for cartridges such as the Denon DL-103

Datasheet

Jensen Transformers JT-346-AXT-14

Provides 11.7 dB of gain. Requires additional gain stage added in between this transformer and the phono preamp.

Datasheet

Jensen Transformers JT-346-AXT-112

Provides 21.45 dB of gain. *Must have an additional gain stage added in between this transformer and the phono preamp.

Datasheet

Jensen Transformers JT-347-AXT-18

1:8 ratio configuration provides 17.5 dB of gain. Works with a wide range of high impedance, high output cartridges.

Datasheet

Jensen Transformers JT-347-AXT-112

1:12 ratio configuration provides 21 dB of gain. Works with a wide range of medium impedance, medium output cartridges.

Datasheet

Jensen Transformers JT-347-AXT-124

1:24 ratio configuration provides 27 dB of gain. Works with a wide range of low impedance, low output cartridges.

Datasheet