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

[restorer-john]

My Akai GX75 MIK2 is still ready to play on the press of a button - but I have to admit that I no longer prefer its warm, slightly noisy sound with reduced dynamics.

Record carefully on better tape, Akai used TDK as reference tapes for type 1, II and IV if IIRC.

(AD/SA/MA/MA-R)

D, AD, ADX/ARX- (less bias for the better tapes)
SA (more bias) SAX (less)
MA, MA-R, MAX-G, (tweak it as you need)

 

[andymok]

has this unit been aligned and calibrated already?

 

[Hiten]

That looks a bit optimistic to me, as it depends on what level the 'signal' part of S/N ratio is taken, and whether that's a record/playback S/N ratio or playback only, and then what tape was used. Possible certainly, but I doubt whether those would be 'real-world' numbers or stay like that for long.

S.

I posted NAB but the link also has IEC specifications. My knowledge is weak, so cant say confidently but aren't NAB/IEC standard having specific guidelines to test equipments ?

 

[MediumRare]

Is there any way to determine the wear on the heads or if the alignment is correct? From my years in radio I recall this was a real maintenance issue. Also, it goes without saying (but worth checking) the bias/etc. settings which affect FR dramatically.

 

[sergeauckland]

I posted NAB but the link also has IEC specifications. My knowledge is weak, so cant say confidently but aren't NAB/IEC standard having specific guidelines to test equipments ?

Standards are good, that's why we have so many of them!
The NAB/IEC initials refer to the tape playback equalisation standard that allows tapes recorded on one machine to play back properly on another. The idea is that one sets up the replay part to the appropriate standard, then adjusts the record side to match it. It has very little if anything to do with the overall frequency response, noise or distortion.
For example, noise is usually measured relative to the 3% distortion point, and distortion measured at 0VU, which can be pretty much all over the place. Have a look at this https://www.reeltoreel.nl/wiki/index.php/Flux_Level_Standards .
As to frequency response, that is never measured at 0VU, as hardly any tape machine won't saturate at high frequencies at those levels, so frequency response is normally measured at -10dB or -20dB depending on tape speed as the amount of HF boost on record depends heavily on tape speed.
Consequently, unless one knows exactly how a machine is specified, any measurements taken could be misleading. Most studios used to set their own standards so they could have consistency between different machines.

S.

 

[sergeauckland]

Is there any way to determine the wear on the heads or if the alignment is correct? From my years in radio I recall this was a real maintenance issue. Also, it goes without saying (but worth checking) the bias/etc. settings which affect FR dramatically.

Tape head alignment is relatively! easy using a specialist test tape where the track widths on the tape are carefully defined, and one adjusts head height for lowest crosstalk. Azimuth adjustments need a test tape with a high frequency tone and one adjusts for a peak. Front to back tilt on the head can be done optically using something like engineer's blue and looking for wear patterns, or if the head block allows it, a straight edge and a light. Bias and EQ settings need adjusting for every tape type, and some studios would even adjust individually for each tape reel if the recording was sufficiently important (i.e. major artist).

S.

 

[Herbert]

A nice story about the "benefits" of anlog tape, it starts at 12:00,
Don't forget to turn on closed captions/subtitles, it is in German:

 

[Remlab]

This would be an almost perfect match for the Pass ACA that was tested earlier

 

[Labjr]

With a few exceptions mastering is terrible these days. Beatles, Stones and Led Zeppelin, aka the big three, seem to get the royal treatment. But so much of it is terrible. I don't understand why they don't care about the quality of releases. Even original CD releases were terrible when they were trying to showcase a brand new format with supposed "Perfect Sound Forever".

 

[LTig]

Record carefully on better tape, Akai used TDK as reference tapes for type 1, II and IV if IIRC.

(AD/SA/MA/MA-R)

D, AD, ADX/ARX- (less bias for the better tapes)
SA (more bias) SAX (less)
MA, MA-R, MAX-G, (tweak it as you need)

I used only TDK (SA, SAXS, MA) and Maxell (XL2). I no longer use the GX75 for recording, only for playback of old tapes.

 

[mhardy6647]

My hifi friend Kevin Kennedy has become an Otari guru in recent years (FWIW).
I have on MX5050-II here but it is (still) as found. These are good (not great), radio/studio workhorse decks and 1) tend to show their age and 2) have often been subjected to years of abuse.

The electronics in them can, apparently, be much improved.
@amirm -- you really need to get a big boy Studer, if you don't have one already.
I would go that route -- but I'd have to sell a kidney.

 

[MediumRare]

Tape head alignment is relatively! easy using a specialist test tape where the track widths on the tape are carefully defined, and one adjusts head height for lowest crosstalk. Azimuth adjustments need a test tape with a high frequency tone and one adjusts for a peak. Front to back tilt on the head can be done optically using something like engineer's blue and looking for wear patterns, or if the head block allows it, a straight edge and a light. Bias and EQ settings need adjusting for every tape type, and some studios would even adjust individually for each tape reel if the recording was sufficiently important (i.e. major artist).

S.

Excellent, thanks. And how about wear on the heads? I recall them actually developing a groove over time but I don't recall how the engineering dept. evaluated the need for replacement heads.

Edit: Interesting resource, doesn't explain how the measurements would change over time. http://www.analogrules.com/badheads.html

 

[DSJR]

Totally unrelated, I was reading an old HiFi Choice book authored by the once fearsome Angus McKenzie (r.i.p.). At the end,, there was a section on open reel machines which broadly measured better than cassette decks. Four which I did work with in a retail environment were the Tandberg TD20A, Sony TC 756, Technics RS1500 and the (too?) well known Revox B77.

Now, on the forums, the 'lookers' would win it automatically, the Technics with its complex head block probably winning it. The Sony weighs a ton I remember and the loud 'clack' of each function being engaged inspires confidence. My pal who eventually became a mastering engineer used the Tandberg for a simple amateur recording session and loved it. I was put off by the TD20A after it shredded an edit when spooling one of our master-copy dem tapes but the 'sound' was fine I remember. The 'best' machine was the anonymous looking Revox B77, used in one form or another in pro circles for many years (basic chassis as a PR99 as well) and I can vouch for the longevity of this chassis. (for good or ill, MY Bling-Deck was the Ferrograph Logic 7...)

Thing is, I sold my B77HSmk2 (IEC eq) decades ago because my 15IPS master tape copies didn't sound as 'clean' as CD issues of same tracks (too many tape generations to my copy and I don't miss it). I've been through the 'wow!' period with such machines decades ago and I do still feel that as a tool to record on, such prosumer models as these are easily bettered today. Maybe I'm too old and jaded now, but I could never now own one of these purely for the visuals!

 

[KEFCarver]

Why is it that I can't remember that I bought my wife of 35years a ring 10 years ago for her birthday, but I can remember the make and model of the 1st calculator I ever purchased (Unisonic 739sq) in 1975 or the make and model of the only Reel to Reel deck I purchased in 1981 (Teac X10R)..?

 

[sergeauckland]

Excellent, thanks. And how about wear on the heads? I recall them actually developing a groove over time but I don't recall how the engineering dept. evaluated the need for replacement heads.

Edit: Interesting resource, doesn't explain how the measurements would change over time. http://www.analogrules.com/badheads.html

Laminated mu-metal heads did wear a groove, but they could be relapped once or twice before they had to be scrapped. Later ferrite or ferrite in glass heads hardly wore at all, but when they did, they had to be scrapped. One issue with ferrite heads (those without glass) was that with wear, they could shed very sharp splinters, which could shred a tape, so very few studios would risk using those, and preferred to stick with laminated mu-metal heads that couldn't damage tapes.

As for deciding when a head needed relapping, I don't recall any particular standard, just down to the maintenance engineer's experience. When a groove got bad, it usually wore more at the top or the bottom as both tape tension across the tape and tilt are never exactly right, and after a time, and especially on 2" multitrack machines, the tracks at the worse end were more difficult to align than at the better end, so it was time to get the heads relapped.

Studio machines had the heads on a removable head-block, and the maintenance department kept an aligned spare ready to be substituted, and the whole headblock then sent off for refurbishment.

S

 

[ayane]

I remember Monty from Xiph.org commenting once that 10 bits was par for the better open-reel tape decks, but most consumer grade stuff (cassette tapes) struggles to do more than 6 bits...

It's shocking how we now take our 20-bit SINAD measurements for granted. There might have once been a time when the sound of the equipment mattered and subjective reviews maybe (maybe) had some merit, but today it's all hogwash without a doubt.

 

[Labjr]

I remember Monty from Xiph.org commenting once that 10 bits was par for the better tape decks, but most consumer grade stuff struggles to do more than 6 bits...

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

 

[Joe Smith]

I've always loved the look of reel to reel, as I grew up with them (my father was in film post-production work back in the 70s and 80s) but never owned one, as I was a child of the cassette era for tape...and some pretty decent decks were in market by about 1973, when I was putting my first system together. One of two formats I've never owned, the other being 8-track, thank mother nature. But the format still wins the cool award, hands down. Now the maintenance and tape costs you mention, condition of the older tapes etc...just seems like a bridge too far.

 

[iraweiss]

I got my first reel to reel tape deck in 1965, a Sony and over the years I had another Sony and a Tandberg. My current set up includes two Pioneer decks: an RT-1020L with the 10" reels and RT-707 with 7" reels. The 1020L I bought new in 1974 and the 707 I purchased from a widow across the street after her husband passed away. Both are used with Advent Model 100 Dolby Noise Reduction units. The Advents can be very finicky but really reduce the tape hiss. I've had to replace belts and a pinch roller over the years but both sound great, better at the faster 7.5 inches per second speed. I still have a Marantz Dolby adjustment tape to calibrate the recorder to the Advents and use Maxell UD-XL tape.

I was never as well off as my voice teacher who had a Uher 9000 and Tandberg 64 (both stolen!) and later a Revox A77.

BTW I keep the silver components on one rack and the black ones on the other.

This also satisfies my lust for VU meters!

 

[Cuniberti]

I spent 30 years of my professional engineering career aligning tape recorders until digital took over in the late '90s. 2-16 and 24 track machines by Studer, Ampeg, and the Otari professional MTR-90 and 12 machines. We considered the MX 5050 prosumer and only used it for tape-slap (echo). A fresh MRL is necessary for proper setup. The three-room studio I ran in San Francisco would buy 2" / 1/2" and 1/4" versions once a year. We would clone them on perfectly set-up machines so they would last a year because we did full set-ups every day on all the machines. Regarding commercially available 1/4" tapes of albums from the 70s'. Without exception, they are all high-speed duplications from third or fourth-generation clones of the master that ran at 15ips and, in some cases, 30ips for 7.5ips or 3/34 playback! Needless to say, the high frequency takes a big hit because what was once 15K is now 30K or 60K and unless the machine is biased and tweaked, including head azimuth, the top rolls of fast. Because of head bumps, the low end is also problematic and compromised. These tapes were a marketing gimmick that was wiped out by the cassette. Not an "audiophile" product and shouldn't be taken seriously. There is an exception. The Tape Project offers real-time duplications of a limited catalog of artists. Here is a link: https://tapeproject.com/ FYI, it's still the third generation.