Otari MX-5050 Review (Reel to Reel Tape Deck)

[Billy Budapest]

Dolby SR (Spectral Recording) was pretty good. Involved multiple bands. The prototype shows how complex it was. I can't find any spec. for S/N except that it improved as much as 25db. Probably because there were many factors like tape types on different machines etc.

Dolby SR became the standard for noise reduction for analog magnetic and optical film audio tracks. It’s still used today in theaters with analog optical decoding hardware. The consumer implementation (developed years later) was the relatively short lived Dolby S noise reduction.

 

[garbulky]

The digital releases have been heavily processed and screwed up. If what is on tape was released in digital, it would sound even better. But such is not available.

Can you do a test? A/B the tape player vs a digital recording of your favorite master tape. I feel like that would be a good data point in the age old debate of analog playback vs digital playback.
I've heard this whole "it's mastered" better thing all the time. I wonder if that's really true.

 

[DanTheMan]

I have a very old Nakamichi Deck and just wondering if anyone knows someone who can work on them in the Bay Area? It still works well, but it’s nearly 30 years old and never had any work done on it.

 

[c1ferrari]

Thanks, Amir, for the review! To obtain optimal record/repro performance requires attention, if not devotion. The reel-to-reel device applies mechanical, electrical, and magnetic principles...I love it!

 

[musicforcities]

I’m getting an image in my head of an Amir listening room filed with cool reel to reel decks, turntables, old huge amps with massive vu meters dancing, but right in the middle is a tiny topping dac with 115db+ snaid and a little ncore connected to an exquisite pair of Revel speakers. Or maybe the reel to reel is plugged directly into a pair of Genlecs

 

[Urib]

Needed a change of pace so decided to go after a project I planned almost five years ago, namely measuring my Otari MX-5050 BIII-2 Reel to Reel take deck! Otari was the last company in the world making Reel to Reel tape recorders and sadly, ceased production a few years ago. I got my sample from the Reel to Reel master, Ki Choi. I think it cost something like $5,000 to $6,000 new. Used ones go from a range of prices from $2K to $4K from what I see. As always, it is a risky thing to buy one online as conditions of these decks is all over the place and service is not cheap. Mine is extremely clean and as the sub-model indicates, is a more recently sample

Here is a shot of the beast as best as I could fit it in my lightbox:

View attachment 155831

What makes this model unique and valuable among tape heads these days is that it comes with both NAB and IEC equalization. The latter is what is used for a lot of tape production today (what little of it there is). A lot of consumer decks don't support it and require a hack or outboard equalization/amplifier. The fancy red spool is aftermarket which I bought at an audio show. Costs a couple hundred dollars just for that! Blank tapes are $60 from what I recall. And pre-recorded ones like the one on it are $290 but go way up to something like $600. Each! For some 30 minutes of music as these are recorded at 15 inches/second. So not a practical format for most people. But for those of us who wished we had such a nice unit when young and poor, it brings bag fond memories and good listening as you watch the spools turn and meters dance.

Being rather old, there is hardly an measurements of them by today's standards. There is also chicken and egg problem of how to get an accurate test tape. The de-factor ruler in that world is MRL and that is the tape I used for my testing. It has just a set of test tones and it too is very expensive. How good it is, I don't know. The measurements in the box come from a chart recorder! Let's say it is a few generations behind my Audio Precision analyzer.

Otari MX-5050III-2 Measurements
1 kHz tone has been the standard forever in audio and hence it naturally came on the MRL tape so I used it to run our usual dashboard:

View attachment 155832

Distortion is at -57 dB or so but add a bunch of them and some noise and we land at SINAD of 46 dB. It is strange to see the elevated low frequency noise. Subtracting FFT measurement gain gives us a noise floor that is in the 40s! I wanted to see how much of it was the tape format and how much was the machine so I stopped the playback and measured the noise out of the unit:

View attachment 155833

Yuck. There is that rising low frequency noise floor but also a bunch of solid tones. What on earth is the 1 kHz and its harmonics coming from? No wonder folks get outboard electronics for these decks (although who knows how good they are).

BTW, the convention for measuring these older electronics is a-weighting so I thought I turn on that filter and see if SINAD gets better:

View attachment 155834

It goes up 3 dB so that low frequency noise is hurting it some. BTW, this is why I don't use a-weighting in my measurements. It really hides a lot of sins in equipment performance at lower frequencies.

There are skirts around the main tone if you look carefully which indicates jitter/speed variations. Watching the dashboard in real time showed a ton of variations. It is a jarring experience coming from today's systems. At 20 kHz, I measured 19.8 kHz frequency so we have about a 1% speed error.

There is not a whole lot more on the tape than a set of fixed frequencies to measure frequency response. My old Audio Precision analyzer could run a sweep against external sources like this by detecting the frequency and then plotting its level. The new APx555 I have now can't do that. It expect you to record its own sequence on the unit and play that to get asynchronous measurements. So I had to resort to the real-time recorder to plot the frequency on the right, and level on the left:

View attachment 155835

The first frequency is 32 Hz and highest is 19.8 kHz. I set reference at 1 kHz to 0 dB. We see a bass boost at 32 Hz by 1.6 dB or so. And a massive droop at 16 and 20 kHz. Not sure if this is a fault of this unit or in general. It might be this unit as the other channel took a nose dive above 1 kHz! I had cleaned the heads and could see nothing obvious that could cause this externally. Worse yet, I don't know if the tape is bad this way (I assume not but it is possible). I loaned out my last blank tape so need to buy another to record and playback and see how that behaves.

Conclusions
I sort of assumed SINAD would land in 40s and it did. I didn't expect the rest of the garbage this deck produces, nor the one bad channel. Need to find the time to tear it open and see what could be done to improve it. I have not listened to it in months. When I did, my favorite second generation master tape from rock music of 1970s is superb. It easily outperforms the digital ones which have been remastered to death. It is eye and ear popping how much nicer they sound than digital. I often play that tape when people come over first and their jaw drops on the floor in how good it sounds. Tape hiss is there during gaps between tracks and the highs sound a bit distorted to me but neither takes away from enjoyment of that tape. It makes me grin thinking about it as I type this!

Tape gives me the experience of the analog recording without loudness wars and remastering without the limitations and aggravation of LP. I also find the format so much more gorgeous to look at as it plays than anything out there, digital or analog. It is a shame that its popularity has pushed the price of used decks so high.

Anyway, we have first super hard set of measurements of any tape deck now. Gives us some anchoring as far as objective results are concerned.

-----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

I think this is really interesting. Objective measurments are so poor, and yet, Amiram it sounds so good to you. So what is the essence of all these sophisticated measurments? And what is really the thing that makes sound good?

 

[aj625]

Problem with digital is post processing. If you record at 32bit 768khz and play that "unprocessed recording" with a capable dac, it will sound like analog format. But when you convert it down to 48khz with a bad src algorithm, then no dac or upsampler can make it sound as original 32bit 768khz recording. So using a long filter src algorithm with sharp cut off, linear phase filter for down sampling to 48khz/44.1khz from original dxd recording is the way to go. But sadly nobody cares about this most important aspect of mastering.

 

[amirm]

I think this is really interesting. Objective measurments are so poor, and yet, Amiram it sounds so good to you. So what is the essence of all these sophisticated measurments? And what is really the thing that makes sound good?

I explained earlier that what sounds good is proper mastered music. It is not the format that is making it sound good. It is the old recordings that were not subjected to horrible mastering that goes on in digital. The format itself has noise and distortion. I hear both but the quality of the recorded material is so superior to digital versions that in balance it is a wonderful experience. Think of LP which has even worse response yet folks enjoy listening to them (for similar reasons).

 

[ayane]

That seems like a ridiculous claim. I believe there's more to analog recoding than can be defined using a number of bits.

It's not ridiculous at all. Analog media are far worse than digital media.

 

[DSJR]

Regarding digitising old recordings. I was told in the 90's by people who worked with said tapes that it was a race against time as many tapes from the 60's onewards were beginning to shed - and this is before the Ampex (and others) thing about tapes needing to be baked first before the one safe playing to digitise them... My pal then showed me a tape from 1954 (so then forty years old) with a one-sided 'open' spool (I don't know how they're referred to but the engineers here will know) and said tape was in perfect playable condition... Less so a popular UK recording artist where the recordings as originally released on a twin CD in the early 90's 'sound' superb, but the tapes were shedding badly and needed to be preserved digitally. I believe the first transfers (done 'flat' and I think then on Sony 1630 A-D units) were also kept, so hopefully a frame of reference (I think by then an optical large yellow?disc format was beginning to be used for archiving, but I'm sketchy here). Hope I've got that right from a major UK label subsidiary of Polygram point of view (not sure if EMI were similar?)

As for mastering old recordings (classical mostly I can comment on), do you do a 'flat transfer' with only clean-ups of edits and so on, so the listener hears it as the producer signed it off, or do you tweak it to 'sound good' on modern squeaky domestic stereos with one-note boom for bass?

 

[tomtoo]

That seems like a ridiculous claim. I believe there's more to analog recoding than can be defined using a number of bits.

And why should we believe what you believe?

 

[Frank Dernie]

That seems like a ridiculous claim. I believe there's more to analog recoding than can be defined using a number of bits.

You are quite correct.
The number of bits only gives an easy to understand way of showing the noise performance equivalence.

To get the full picture one needs the frequency response and speed (ie pitch) stability.

The frequency response is influenced by lots of factors but IME on a properly aligned machine the big ones are bass uneven-ness due to the tape head shape effect and inability to record high frequency at high level due to tape limitations.

Speed stability can be very variable from "audible on everything" to "only noticeable on sustained notes".

 

[MCH]

Regarding digitising old recordings. I was told in the 90's by people who worked with said tapes that it was a race against time as many tapes from the 60's onewards were beginning to shed - and this is before the Ampex (and others) thing about tapes needing to be baked first before the one safe playing to digitise them... My pal then showed me a tape from 1954 (so then forty years old) with a one-sided 'open' spool (I don't know how they're referred to but the engineers here will know) and said tape was in perfect playable condition... Less so a popular UK recording artist where the recordings as originally released on a twin CD in the early 90's 'sound' superb, but the tapes were shedding badly and needed to be preserved digitally. I believe the first transfers (done 'flat' and I think then on Sony 1630 A-D units) were also kept, so hopefully a frame of reference (I think by then an optical large yellow?disc format was beginning to be used for archiving, but I'm sketchy here). Hope I've got that right from a major UK label subsidiary of Polygram point of view (not sure if EMI were similar?)

As for mastering old recordings (classical mostly I can comment on), do you do a 'flat transfer' with only clean-ups of edits and so on, so the listener hears it as the producer signed it off, or do you tweak it to 'sound good' on modern squeaky domestic stereos with one-note boom for bass?

I hope the musical industry is addressing the problem before it is too late, i would like my grandgrandchildren to keep on rocking to the music that we love nowadays if they want to.
However, seems that going digital may not be the ideal solution.... Take as example the records of the nuclear waste facilities in France and other countries. After long studies they decided that the best available technology to keep the information in the long term was.... to write it on paper... they don't trust digital media will last more than a few decades

https://www.neimagazine.com/features/featurefor-the-record/

 

[PeteL]

I explained earlier that what sounds good is proper mastered music. It is not the format that is making it sound good. It is the old recordings that were not subjected to horrible mastering that goes on in digital. The format itself has noise and distortion. I hear both but the quality of the recorded material is so superior to digital versions that in balance it is a wonderful experience. Think of LP which has even worse response yet folks enjoy listening to them (for similar reasons).

But why listen to these masters on this tough? Would it not sound exactly the same if you where to transfer these master to digital with a good ADC once and play this file moving forward? Seem to me you would get the best of both world? You make sure the machine is fully calibrated for the moment of the transfer but since you only play the tape once, degradation would be minimal and after that the same experience is repeatable and the same every time?

 

[sergeauckland]

Something that has exercised my mind in the small hours of the morning is just how ephemeral our records of life are.
We have reasonably accurate portraits of the famous and of the rich and powerful showing what they looked like and what clothes were considered fashionable going back some 500 years or more, but we have no idea what their voices sounded like, or what the music they made sounded like.
Since the middle of the 19th century we have had photographs showing what 'ordinary' people looked like and what life was like, but it was only at the very end of the 19th century that we had any idea what people or their music sounded like. For about 100 years we have had this available in a form that would stand very long term storage, in that a photographic print will still be viewable after centuries if stored benignly, and a gramophone record will still be able to be 'decoded' by a future civilisation as would presumably a CD or DVD.

My concern is that since few digital photographs are ever printed out on archival paper, and music and increasingly films and TV are streamed, before too long there won't be any physical artefacts for future archaeologists to decode, and human history and culture will return to being that of the rich and powerful for whom I expect there would be enough records remaining to provide some information. As to all the music being produced today, how much will be available in 100 years time let alone 1000? It would be sad, I think, if original recorded music and original records of daily life available in the long term future should be limited essentially just to the 20th century.

S.

 

[Frank Dernie]

It has always certainly and obviously been the case that the quality of recordings makes more difference than the quality of the equipment we play them on.
It is also the case, IME, that the potential accuracy needed for enjoying high quality music sound is way less than people bang on about, the mere fact that tapes played on this device don't sound excruciatingly awful is clear evidence of this.
It is therefore evident that we don't need anything like the accuracy readily available from modestly priced digital playback devices to enjoy old recordings which in no way even begin to approach their capability.

IMO the problem with moden mastering is it is too easy to mess the sound about.
When there were just a limited number of channels and simple signal conditioning and the kit was rare and expensive only a few people could do it and they concentrated on getting the basics right - microphone position for example - before making the recording.
Nowadays anybody can buy a super cheap multi track recorder, dick about massively with the channels, don't notice they got a poor recording on a track in the first place then mix together multiple manipulated possibly mediocre tracks completely losing any credible dynamic range or balance information.

 

[peniku8]

I have a Tandberg 10XD. Anyone interested in measurements? I just moved and am pretty busy still, but I guess I could add it to my to-do list

 

[MediumRare]

Something that has exercised my mind in the small hours of the morning is just how ephemeral our records of life are.
We have reasonably accurate portraits of the famous and of the rich and powerful showing what they looked like and what clothes were considered fashionable going back some 500 years or more, but we have no idea what their voices sounded like, or what the music they made sounded like.
Since the middle of the 19th century we have had photographs showing what 'ordinary' people looked like and what life was like, but it was only at the very end of the 19th century that we had any idea what people or their music sounded like. For about 100 years we have had this available in a form that would stand very long term storage, in that a photographic print will still be viewable after centuries if stored benignly, and a gramophone record will still be able to be 'decoded' by a future civilisation as would presumably a CD or DVD.

My concern is that since few digital photographs are ever printed out on archival paper, and music and increasingly films and TV are streamed, before too long there won't be any physical artefacts for future archaeologists to decode, and human history and culture will return to being that of the rich and powerful for whom I expect there would be enough records remaining to provide some information. As to all the music being produced today, how much will be available in 100 years time let alone 1000? It would be sad, I think, if original recorded music and original records of daily life available in the long term future should be limited essentially just to the 20th century.

S.

I have a big tub of photos of me and my wife before we had kids. Anyone can discover those and flick through them. Everything in the past 20 years is digital on a "crappy old laptop" or NAS. Who will ever take the time to lovingly look through them to find the 5,000 photos there?

 

[sarumbear]

Were the machines using 200 mil wide tracks or the American 70 mil?

All machines were looked after by tape technicians. Engineers had no say on the calibration. Tape techies checked every machine before any recording session and if the session last longer than a day, then every three days. They were European manufactured recorders used in UK. I wouldn't expect an American standard to be used. In any case, our machines have always matched or superseded Studer's specs.

 

[iraweiss]

I have a very old Nakamichi Deck and just wondering if anyone knows someone who can work on them in the Bay Area? It still works well, but it’s nearly 30 years old and never had any work done on it.

I suggest you contact Charalampos Armakolas who goes by Bobby. He is a former Nakamichi technician who has immigrated from Greece to Chicago. He can be reached at eBay at https://www.ebay.com/usr/babis8086

He has done great work on my Yamaha cassette decks for me.