HA73JRII - 73JR II British-Spec 500-Series Preamplifier and DI
Real deal 73 sound. The 73JR II is an update to the already classic 73JR — a true 73 style mic preamp in a single 500 series slot, with some added features that will satisfy the most demanding of recording engineers.
Employing discrete circuitry and conventional components, the 73JR II is a faithful 3 stage all Class-A 73 preamp. Styroflex and tantalum capacitors have been used throughout. No corners were cut.
The all-discrete Class-A hi-pass filter is sweepable from 20 to 220 Hz — making it easier to make your low end tighter without affecting desired frequencies.
The Line mode allows for reamping of prerecorded tracks, and is a perfect solution for adding some color to lifeless recordings. The DI input (which automatically switches to DI mode when inserting a 1/4" TS cable) is an all-discrete Class-A JFET circuit in front of the microphone transformer — giving you all of the color and weight you could ask for.
Finally, special care has been taken with power handling, implementing internal +24v slow-turn-on-regulation. This is extremely healthy for your 500 series enclosure’s power supply, and keeps the 73JR II’s power independant from other slots.
Heritage quality, through and through.
There are several compromises usually made when adapting a 73 preamp for the 500 Series, but none that you will find in the 73JR II. The 73JR II uses the full 3 gain stage circuit for up to 80 dB of gain with noise of -125dBu EIN all over the gain positions. The 73JR II uses a true 24volt on board power supply for identical performace and distortion point.
The 73JR II uses only discrete, through hole traditional components and hand labor for that great 70s vibe.
The output transformer is a custom Carnhill, made for in the St Ives factory. The input transformer is a custom Carnhill, made in Carnhill´s Oxford factory — this one has a huge impact on the extra mojo of the unit, and is the same one found in our higher-end 80 Series modules.
Features
- A high-end, 3 stage 73-style microphone/DI preamplifier
- 80dB of British-style gain
- All discrete through hole components
- Class-A circuitry
- Internal +24v slow-turn-on-regulation for the very best performance
- A custom Carnhill output transformer, made at the St. Ives factory
- A custom Carnhill input transformer, made in Carnhill’s Offord factory
- Auto-switching, discrete Class-A JFET DI mode for true console-style weight and color
- Line input for reamping
- GAIN, OUTPUT, LO-Z, PAD, LINE, 48V, PHASE, HI-PASS, and HI-PASS FREQUENCY controls
- 500 series format
Technical Specifications
- High Pass Filter: 20 to 220 Hz, sweepable
- Microphone input impedance: HI, 1200 Ohm min., LO, 300 Ohm min., transformer balanced
- Line input impedance: 10KOhms bridging, transformer balanced
- DI input impedance: > 2 Megohms, unbalanced.
- Output impedance: < 75 Ohms, transformer balanced
- Output (max.): > +26dBm into 600 Ohms
- THD: < 0.025% at 1Khz, < 0.05% at 100Hz.
- Frequency response :20Hz (+0.3dB) to 20Khz (-0.2dB).
- Gain (max.): > 80dB (Mic), 50dB (Line)
- Noise: -125dBu EIN
- Power consumption: 88mA per Rail @ +-16VDC
- Dimensions (W x D x H): 3.81 x 17.5 x 13.5 cm, 1x 500 series slot
- Weight: 0.6 kg
