Wollensak Reel to Reel Tape Recorder Stereo Recording Demo 1
- Phonograph Record -

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This page provides a demo of the Wollensak 5750 reel to reel tape recorder stereo recording from a phonograph record. This piece of vintage audio equipment was restored/rebuilt after a purchase on E-Bay and it arrived as a complete "DOA" (Dead On Arrival).

 

Music File Should Start Automatically When Loaded.
If it doesn't, use the controller.

For a real tape recorder challenge - an all digital master selection demonstrating the Wollensak 5750's ability to record material from a CD, please click here.

For a video of playback performance, please click here.

For a sample of stereo playback performance of a commercial tape, please click here.

The whole point of a tape recorder is, obviously, it's ability to faithfully record sound. To demonstrate the recording ability of the Wollensak 5750 that matches historical usage, a stereo phonograph record was used.

The music is a selection from Pavane by Gabriel Faure, Op. 80. It was recorded from the album titled: "The French Touch", performed by the National Philharmonic Orchestra, conducted by Charles Gerhardt - dated 1978 on RCA Red Seal records. Number ARL 1-2783 Stereo.

 

Procedure:

The line output of a Marantz Stereo system (with a Technics Direct Drive Turntable) was plugged into the line inputs of the Wollensak 5750 and a recording was made. For maximum fidelity, the Wollensak 5750 was set to record at 7-1/2 ips on a vintage Scotch® brand - 150 formulation recording tape. This is the tape most users of the Wollensak 5750 would have had available in 1967, when the machine was in production.

The recording on the Wollensak 5750 was then digitized into a raw WAV file sampled at 44Khz on a Pentium-4 computer running Windows XP. It was then converted to MP3 format using Apple's iTunes.

It is important to note that MP3 compression actually lowers sound quality by removing some of the audio information from the original "raw" - WAV - file. This is unavoidable due to bandwidth needs.

There is a popular misconception that because MP3 is so widely used, it actually improves sound, which is not the case. So what you are hearing here is somewhat less than the actual performance of the Wollensak 5750 reel to reel tape recorder!

 

Results:

To understand the recording results it is important to note the operating specifications of the Wollensak 5750:

• Frequency Response: 40 - 17,000 Hz
• Wow and Flutter - .25% RMS
• THD (Total Harmonic Distortion) - 5%

Commercial recordings usually exceed these specifications, and the Marantz Stereo system (as well as the Technics turntable) have a broader frequency response - 30 - 20,000 Hz and lower THD  - 1%. All turntables have some degree of wow and flutter, but the Techniques turntable has a direct drive motor (no belts or idler wheels in the transmission), reducing it to below detectable levels.

The Wollensak 5750 did a very good job with the recording. The most noticeable defect is tape hiss (which is natural to all reel to reel tape recorders) and some "gurgling" - similar to the problem of trying to talk when you need to "clear your throat."

The amplifier circuitry can contribute to this type of flutter or "gurgling" as is heard on the recording. The Wollensak 5750 uses a number of electrolytic capacitors to filter the line (sometimes these are called "filter caps") and smooth out the electrical signal being processed in the amplifier. I was able to identify them (all 14) thanks to a SAMs Photofact book, which I ws able to purchase from Stereo Manuals.com.

Electrolytic capacitors have a dielectric and electrolyte which over time can fail due to dryness or other conditions brought about by age (much as a battery chemical will become exhausted even if the battery is stored on a shelf and not used). The only solution is to replace the capacitor, a time consuming and potentially expensive process. To accomplish this on the Wollensak 5750 requires "major surgery", as the amplifier board is located deep within the machine, and most of the frame must be removed to free the board for alterations. The author has chosen to delay this procedure as long as possible, for obvious reasons.

The issue does not occur when the machine is in playback mode of a commercially produced tape, and a careful check using sensitive headphones reveals the source. There is a hum when the recording function is engaged, but the hum is different on each channel. That hum (or pair of hums) is a giveaway of one or more failing electrolytic capacitors in the recording circuit. Since there are two circuits, one for each channel in the stereo mix, with different low frequency hums, harmonic distortion is introduced, which accounts for the "gurgling".

Mechanical wow and flutter seem negligible, certainly within the specs of the machine (.25%)

Bass frequency response in the recording matches the output of the turntable and stereo system fairly closely.

Stereo separation is quite good.

  

Summary:

The Wollensak 5750 restored/rebuilt tape recorder does an acceptable job of tape recording from a phonograph record, preserving the quality of the original while introducing some level of tape hiss.

But the story doesn't end here. After approximately 40 years of being abandoned in an attic or basement or who-knows-where, how well does the Wollensak 5750, even "resurrected" deal with the future that is now? What can it do when recording from modern digital equipment, especially virtual music created on a computer, with its wide frequency response and high sampling rate of 44Khz?

For a real challenge - an all digital master selection demonstrating the Wollensak 5750's ability to record material from a CD, please click here.

For a video of playback performance, please click here.

For a sample of stereo playback performance of a commercial tape, please click here.

Please DO NOT ASK US how to sell your old machine or tapes or records. We will NOT respond to selling or value estimate inquiries.

Do YOU need a tape recorder restored? Contact us TODAY and tell us YOUR story! We're happy to help! Call: 781 322-4430 or use our Contact page on this website!

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