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Nagra IV-SJ Reel to Reel With Accessories

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Pickup currently unavailable at SkyFi 479

Nagra Vi-Sj Reel To With Accessories Tape Deck

Nagra IV-SJ Reel to Reel With Accessories

SkyFi 479

Pickup currently unavailable

479 South Broad Street
Glen Rock NJ 07452
United States



Nagra IV-SJ is the Enhanced version of IV-S that came out in 1972.

This was an instrumentation recorder for precise noise and vibration measurement and other scientific audio analysis organisations.

Equipped with special microphone preamplifiers, modulometer, and stepped input, attenuators the IV-SJ is used for a multitude of different environmental and industrialization applications.

Customers for the IV-SJ varied from NASA to Rolls Royce and Greenpeace and was commonly used to record whales and ultrasonic waves. 

The IV-SJ also makes for a formidable audio machine with a super low noise floor and great dynamic range.

Link to a video I did a while back on a different machine of the same model:
This machine had an easy life and was well cared for. I removed the calibration stickers which indicated a healthy service interval as far as 1999, at which point the machine was retired.

To get this machine to the highest level I performed several upgrades:
• Custom high-quality input cables with RCA and DIN
Custom high-quality output cables with RCA and DIN
Custom high-quality switching power supply
Large 10.5" reel adapters made of machined aluminum which bolts to the back of the unit.

In addition you'll get the original acrylic hinged cover that's usable with the small reels.

If you've not had a Nagra piece of equipment you're for a treat.

It's by far my most favorite manufacturer, as their products are built like Swiss watches and utilize a level of precision and engineering found in only a handful of European brands.

Never mind that they look so cool!

Brand Background:

Nagra is a brand of portable audio recorders produced from 1951 in Switzerland. Beginning in 1997 a range of high-end equipment aimed at the audiophile community was introduced, and Nagra expanded the company’s product lines into new markets.

Originally a product of the Kudelski Group, Nagra recorders are now developed, produced and sold by independently-owned company Audio Technology Switzerland S.A., based in Romanel-sur-Lausanne.

The machines were initially designed by Polish inventor Stefan Kudelski,[1] and his company won numerous technical awards for their precision and reliability.[2] Nagra means "[it] will record" in Polish, Kudelski's mother language.

Nagra-brand tape recorders were the de facto standard sound recording systems for motion picture and (non-video) single-camera television production from the 1960s[3] until the 1990s.[1][4]"


Second Owner 


European DIN with included cables (See Photos)

General Sound:

Accurate to the recording

Cosmetic Condition:

7 - Some Wear and Light Scratches

Working Condition:

Working perfectly and tested in our lab.


As pictured


Will be packed using our highly developed in-house process and custom packing materials.Dimensions:

Dimensions of the box as such with the lid closed, without knobs, feet, handle or handle mounts 12.6"x 8.8" x 4.4"- 318 x 222 x 110mm

Overall dimensions without the removable handle 13.2" x 9.6" x 4.5"- 333 x 242 x 113mm

Thickness of the Anticorodal sheet used for the box .080"- 2mm

Thickness of the tape deck .120" - 3 mm


Empty weight, without batteries or tape

14 Ibs - 6.150 kg

Approximate Age:


Link to Manual:

Recommended Cables:

The included playback and record proprietary cables, and power supply.

Testing Process:

The SkyFi Testing Process for Tape Decks and Reel to Reel Machines:

First steps are performed to determine if the unit is a candidate for our full restoration process or if its just in need of a light service.

We first do a basic functionality test to ensure proper playback fast forward and rewind. We look for smooth operation of the motors, transport engagement and associated rolling parts.

We then do an internal physical inspection to ensure the belts and rubber consumable parts are up to spec.

Internal components are checked to make sure that there are no signs of heat stress or damage particularly in the power supply section. Capacitors are checked for telltale signs of predictive failure including bulging, shrunken wrappers, or physical leakage. We also inspect the PCBs for discoloration from resistors or transistors that may have been running hot. On vintage units we often spot check select capacitors for value and ESR.

A light service will involve replacement of belts and rollers, external cleaning of heads, mechanism and boards and basic record and playback tests.

A full restoration will often include disassembly of the drive system and replacement of all consumable and wearable parts including pinch rollers, belts, brakes, bearings. We then clean lubricate and re-assembly the drive and perform basic mechanical alignment to ensure proper tape path and head alignment.

Final calibration will involved adjustment of playback erase and record heads and optimization of the bias for a specific tape type. We do this with the aid of a Soundtech 1510A tape deck analyzer and a Nakamichi T100 unit and reference calibration tapes.

Final listening tests are done while monitoring with our reference Grado HP1 headphones and a variety of factory and custom reference recordings. We find that there is no better system for critical listening on tapes than the headphones specially when comparing a live feed to a recorded feed.




Admissible thickness

Maximum reel diameter with lid open


Supply voltage, direct current, positive to the

15 ips 71/2 ips 3% ips 11ips

38.1 cm/s 19.05 cm/s 9.525 cm/s 3.81 cm/s


Current consumption on Test

12 to 30 V

120mA 205mA 260mA 465mA 305mA

R 20 D and L 90

Stability of the nominal speed in relation to the temperature (from 0° to 50°C), the position of the recorder, the distribution of the tape between the reels, and the supply voltage (except for 1 1/2 ips). ±0.1%

Wow and flutter

weighted peak-to-peak value, in accordance with DIN 45 507 standard: (lEE 193-1972 ANSIS 4.03.1972)

on Line Playback on Record

on Rapid Rewind


mic. (1 BK 2619)

Type of batteries used (12 cells) CE I standard

ASA standard

Approximate autonomy with Eveready E95 man- ganese dioxide alcaline batteries

15 ips

7 1/2 ips 3314 ips

1 1/2 ips Starting time

±0.05% (0.07%) ±0.07% (0.11%) ±0.12% (0.15%) ±0.25% (0.3%)

3 seconds

Continuous use, recording direct

with mic. and 2619 preamp.

26 hours 11~ hours

161bs -

7.300 kg

Recording time at 71/ 2 ipswith35jlm (1.5 mils)tape 45 min.

Maximum reel diameter with lid closed

5"- 127mm

Recording time under the same conditions

22 min.

Rewind time with 5" reel and 35 /-lm (1.5 mils) tape 2 min.

SKU: 104010