73JR II

THE REAL DEAL:

The 73JRII  is the 2021 update to the already classic 73JR, a true 73 style mic preamp in a single 500 series slot with some added features that will cover all the recording needs for engineers and musicians that don´t find the need to track with eq.

Employing only discrete circuitry and conventional components, the 73JRII is a faithful 3 stage all class A 73 preamp. Styroflex and tantalum capacitors have been used throughout.  No corners were cut.

The useful all discrete class A hi pass filter has been updated, making it sweepable from 20 to 220 Hz. Now it is even easier to make your low end tighter without affecting desired frequencies.

The Line mode allows for reamping of prerecorded tracks and it´s perfect for adding some class A color to lifeless recordings.

The smart switched DI (automatically switches from MIC to DI mode when inserting a MONO ¼” jack) is an all discrete class A JFET circuit ahead of the MIC transformer, so all the juice is there. Since its introduction in 2013, it has become a classic DI for bass.

Finally, special care has been taken with power handling, implementing internal +24v slow turn on regulation (about 20 seconds to reach full voltage).This makes your 500 series enclosure´s power supply healthier and makes the 73JR independent of the rest of the slots.

WHAT TO LOOK FOR IN A 500 SERIES 73 PREAMP:

There are several compromises usually made when adapting a 73 preamp for the 500 Series, especially the following 3. You won´t find any of these in the 73JRII:

  • Eliminate one gain stage and run only up to 70dB of gain. A “real deal” 73 mic pre must have 3 gain stages for a total of 80dB of gain. Taking the first gain stage out and maxing out the other 2 allows for up to 70 dB of gain, but noise figure and low end at high gain are seriously compromised. 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.
  • Use the readily available +- 16v power from the 500 Series protocol. By doing this, the magic distortion of a 73 amp is compromised. The 73JR II uses a true 24volt on board power supply for identical performace and distortion point.
  • Use of surface mount technology. Although there is no actual drawback in using SMD components, it should be reflected in the price, not merely to enlarge the manufacturer´s profit. No 500 Series 73 mic pre using SMD should cost more than $500. The 73JR II uses only discrete, through hole traditional components and hand labor for that great 70s vibe.

When looking for the ultimate 73 500 Series preamp, always make this fact check.

THE 73JR II TRANSFORMERS:

No 73 preamp is such without the correct transformers. For the 73JR II (and its predecessor the 73JR), Heritage Audio went a step further the competition. The output transformer, the same used all along the Heritage´s line of products, is a  Carnhill gapped one made exclusively for us in the St Ives factory. The input one, again exclusive to our company, is made in Carnhill´s Oxord factory, and has a big impact on the extra mojo of the unit. It is the same one found in our higher end 80 Series modules and sets one of the main sonically differences in between the 73JR II and the competitors.

When looking for an exclusive sound, do not settle for non-exclusive transformers.

• Microphone input impedance: HI, 1200 Ohm minimum, LO, 300 Ohm minimum. Higher gain positions gradually have greater impedances, optimum for lo gain ribbon mics. Input is transformer balanced and floating.
• Line input impedance: 10K Ohms bridging, transformer balanced and floating.
• DI input impedance: Greater than 2 Megohms, unbalanced.
• Output impedance: Less than 75 Ohms, transformer balanced and floating, to drive a load of 600 ohms (factory terminated).
• Maximum output: Greater than +26dBu into 600 ohms.
• THD: Less than 0.025% at 1 Khz, less than 0.05% at 100Hz.
• Frequency response: 20Hz ( +0.3dB ) to 20Khz (-0.2dB)
• Maximum gain: Slightly greater than 80dB
• Noise: Less than -125dBu EIN.
• Power consumption: 86 mA per rail @+-16VDC.

Can’t go wrong with a Heritage Audio 73 Jr

Well, I´ve finally gotten around to writing a review for this absolutely stellar preamp… it only took me three years! At least you know that I actually had time to give it some use before writing my review. Since, winning my 73Jr in an online writing contest, it has made valuable contributions to all of my recordings. Everything about the 73Jr is well made and I can’t say enough about its build quality. It´s based on the vintage 1073 preamp and it adds a warm, creamy clarity to vocals and it makes digital keyboards/synthesizers sound less digital before hitting the DAW. My 73Jr does what it is meant to do and it does it flawlessly. BONUS: when pushed it adds some really sweet breakup to clean guitar. I never imagined that a mic preamp could actually contribute to a recording… I mean, all they do is raise the volume of a signal, right? Hahaha! I was wrong and I’m glad I was wrong! Had I not won my 73 Jr in a contest, I would have never found out how truly necessary a good preamp is to making a quality recording. I have to admit that, my first thought was to sell it for some quick cash – I didn’t own a Lunch Box and my prize was going to require the purchase of a Series 500 chassis. But, ha! I’m a gear freak and the 73Jr now sits next to an harmonic exciter and a compressor. I’m glad I spent the money on a Lunch Box because the 73Jr is a keeper!!!! If you are in the market for a 500 Series preamp, the Heritage Audio 73Jr will make you a very happy camper.

Ajax Lepinski from Long Island, NY on February 24, 2017Music background: Musician / Audio Engineer
Awesome!
It´s a truly special unit. It´s a best in class considering its price, having ahpf, and line in onboard. Without all of those things it still wins, as it´s exactly what you´re looking for sound-wise. I´ve tried several other sub 1k iterations of this circuit. Up until now, nothing has gotten me this close. Shines on vocals, and synths. I´m frantically trying to save to get another unit, and will eventually add the eq’s as well. This is the real deal folks. My Sweetwater Rep, Brian Loney was dead-on with this one!
Chris from SoCal on February 6, 2017
Incredible Classic Piece
It’s the real deal… been tracking vocals on this thing with an SM7b and Warm Audio 1176 after in the chain before printing in Protools… excellent. Just recently tracked a kick drum with it and it was surprising very transient and punchy accompanied with API 550A/560 EQ within the Protools DAW. Incredible piece that is a MUST in your U-rack.
Jason Damico from Raleigh, NC on March 30, 2016Music background: Rock, Blues, Metal
Saturation
I’m completely loving this preamp after a couple of weeks of ownership. Dialing in a good sound is straightforward. I have gotten thickly saturated sounds from a DI improving tone on my Fender P bass and allowing the bass to be heard easily in a mix. Playback on my iPhone speakers still produced the clear sound of the bass recordings. With a cheap mic I was able to dial in a clean sound by keeping the input transformer subdued and cranking the squeaky clean output transformer. By the way, the pad is in the chain before the input transformer so engaged you can crank the input harder. Also lots of success with my Alpha Juno 2 analog synth. It sounds huge. I will likely invest in the 73eq down the line. Tone galore.
James from Phoenix, AZ on March 14, 2016
Absolutely Gorgeous Sound
Can´t go wrong with this Pre. The amount of tonal variation the gain knob provides will make it easy to fit any source you throw at it. Great on Vocals – just sounds simply expensive. I usually record guitars direct and this thing gave my Axe Fx 2 a new life. ( Never thought the sound of the Axe fx needed any more but this preamp just gives the sound an extra level of clarity ) Can’t wait to get at least another one of these units for a stereo pair.
Eduard on January 26, 2016Music background: Professional Musician/Producer/Mixer

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