Sony C9 Betamax remembered but not forgotten. An engineer remembers.

[Mooly]

I used to be a huge Beta fan and owned two C9's, one from new, and thought some of my experiences might interest others.

This was a machine that was light years ahead of its time, and even today it still looks a classy bit kit. Mine clocked up thousands of hours use over some 18 years or so. I always felt a twinge of regret when it was brought out of service but it just wasn't economically viable to keep as a main machine and I felt pleased in a way that it lasted to the end of the analogue era and into the start of digital transmisions.

So... how reliable was it and what needed doing. So as they say "In no particular order" as I keep thinking of things.

Well the first fault occured relatively early on its life, the infamous "gear kit C", the little nylon gears on top of the carriage that split. At the time I found that the split gear could be repaired by fitting an appropriate sized washer over the flange part to hold it clamped. That worked a treat although I subsequently fitted a replacement metal gear set. I have a vague recollection that the repaired gears were then fitted 180 degrees about to accomodate the washer...

The DC/DC convertor failed... I had a new one of the modified type so that was soon fixed.
A "prismatic" Nicad battery was fitted for the clock backup and ran it for about 60 minutes I think with that.

With all the use the machine got video heads came and went along with replacement upper castings... the curse of the Beta machine.
Years later as parts became harder and more expensive to source I wondered if anything could be done to refurbish these castings and the answer is a definite yes... and it takes literally minutes. I found car valve grinding paste (mine was in a double ended metal can with coarse at one end and fine the other) worked brilliantly. A small amount of the fine paste was put on a cloth and lightly rubbed around the (removed ) casting. The result was a splended and even matt finish... no score lines or scratches... it really looked like it could be factory supplied... and these "refurbished" castings provided many hundreds of hours service. And they could always be done again too.

The tape path was another unique Beta feature, and the C9 had one of the most complex around as regards setting up. One problem that I discovered was that generic replacement pinch rollers seemed to cause tape path problems around the ACE assembly. I investigated this and found that the original Sony parts had an offset bearing whereas the others had the bearing central in the roller. The effect of this is that the original causes a slight but definite bias in the tape travel causing the tape to want to travel "up" the capstan shaft. The guides of course operated on the top edge of the tape and so countered this keeping the tape nicely up against the guides. The replacement rollers had a tendency to allow the tape to creep down the capstan causing audio problems and even tape damage in reverse search etc. Add to that the fact that the capstan angle was adjustable along with the ACE head and there was the real possibility of problems.

With all the thousands of hours use pileing on the machine, wow and flutter became noticeable. This was caused by a combination of problems.
Some electroylitics... I forget the value although 47uF comes to mind... on the capstan motor itself. These were replaced and it was much better but not perfect. Sadly I came to the conclusion that the capstan shaft was now so highly polished with all the use that it longer gripped the tape properly. Another refurbishing job loomed. The motor was rigged up to run on a PSU and I lightly held some fine wet and dry against the capstan to "refinish" it. Result, another success and all wow and flutter was banished.

Electronically it was superb... I replaced all the electros in the PSU around 1990ish... as you do... and it never suffered any PSU failures at all.

I built a Nicam decoder for it from a scrap board from a Sanyo TV. This neatly plugged into a now rewired "multichanger" socket instantly converting the machine to full off air stereo recording... it was now a Nicam VCR, illuminating the stereo light on E-E on nicam transmissions. The electronic switching on the audio board made it easy to alter such that it switched over to "line inputs" so that it could record from the outboard Nicam decoder.

I forget exactly when but the machine suffered its only true electronic failure. I switched on and the capstan motor (I think) took off at a million miles an hour accompanied by a burning smell. Looking back this was before the capstan rebuild. The problem was the TL494 ? going from memory and a reference voltage was missing from the IC. It was a one of failure, annoying in that it damaged the capstan motor. It was the driver transistors that were burning. Its a long time ago... it could have been one of the reel motors... I can't remember now.

Towards the end I experimented with splicing VHS tape into Beta cassettes with mixed results. Another discovery was that Beta tape seemed physically different to VHS. Again from memory, if you pull VHS tape it stretches into a thin thread, Beta tape just snaps. This difference had consequences... VHS tape wouldn't easily conform to the up/down nature of the Beta tape path as it traversed the guides. As I say, some tape was better than others.

What else... normal maintenance, lubrication... I even managed to get oil into the ball races of the drum assembly without totally dismantling. I think around 6 sets of heads were fitted during its lifetime. A new ACE head too around 1992.

One of the last problems to surface was a split threading ring... and I had a new one. Obviously a major job and full set up but it was fine.

I remember too an electronic mod I did early on. The carriage had that annoying habit of quickly grabbing a tape and then deciding to throw it back instantly. Maybe the timing of the microswitches or switch bounce but it was annoying. Anyway after studying the circuit I fitted a couple of diodes as a sort of discrete logic gate so that as soon as the carriage motor operated it latched the drive circuit and the operation always completed.

I'm sure there must have been more but these are the more memorable events. A Sony DVD/HDD now lives its place but two major parts of both
my C9's live on in another incarnation that is used daily... if anyone would like to see what they became I will post a picture upon request

Well thanks for reading and I hope that it may help others.

[murphyv310]

Great write up, I am an ex Sony engineer and it brought back many memories! I had a C9 for about 15 years and 500 odd tapes, all were given away to a beta collector a few years ago.
Go on post your pictures, the mind boggles!

[Red to black]

Hi,
As Trevor said, a great post, not much I can add to that list of faults (I can remember most of them!), other than replacing the two small pop up/flip up guides with modified types (as used on the later C20, C30 etc. Machines I think) ISTR cutting parts of the broken originals off, to accomodate the new parts, I think this was the official Sony policy, as ISTR a small note with the new parts explaining which bits to cut..

A trip down memory lane

Cheers,
Baz

[Mooly]

I never had the pop up guides fail on mine strange to say, particularly considering all the use it got. I had a repair kit tucked away though and yes you are right, there was a note about cutting parts with sharp cutters. The new parts had cotton thread attached too ?? I seem to remember to help fit them in some way.

Well the "major parts" that I reused are actually part of the casework/chassis... and were ideal for a nice little project

[IanNVJ35]

The C9 was of all-time laced design, but in real terms did this impact on the wear of the tape path compared to the Sanyo range?

I was thinking about this the other day and wondering by what percentage the wear was increased - if at all?

[Red to black]

@ IanNVJ,

Hi Ian,

I was thinking about this the other day and wondering by what percentage the wear was increased - if at all?

Certainly this increased the wear on the upper and lower drum, as well as the head drum (Sony C5,6 and 7 drums had three surfaces remember), just as they had done with the earlier C5,6 and 7's, and probably the ACE head.

The Sanyo 5000 series, had just the two surfaces (3, with the heads through the narrow slit), the Sanyo machines also unlaced for REW and FF modes etc., which improved reliability no end.

In fact I can remember a battery operated (and a hand operated), tape rewinder being on sale for Beta tapes in various magazines around this time, just as later on the same type of tape rewinders were offered for the various different camcorder formats, in an effort to reduce wear on the expensive deck components.

This was partly why some manufacturers (VHS as well) went to half load mechanisms, which then developed into the G-deck type mechs., to cater for the realtime counters, I feel that this (the G-Deck etal.) was the pinnacle of deck design, which sadly reverted back to type, you just have to look at all mechanisms since the K-deck to see this retrograde step (in the name of cost cutting), where the later machines of all manufacturers went back to fully laced mechanism.
It seemed that they no longer cared about excessive head wear (although the later heads may have been harder wearing), and probably because the newer machines just were not expected to last as long as their predecessors.

Cheers,
Baz

[IanNVJ35]

Thanks Baz for that informative answer. One thing I do know is that the older ex-rental Beta tapes I have show many more score lines and general wear marks than the VHS ones. The wear mainly seems to affect the sound rather than the picture (goes muffled).

I have always fancied a Sony C9 or C7 (for the striking design more than anything), but I would not get one in 2011 after years of unknown use and tinkering - it would have had to have been new from the store. I have some Sanyos and they are doing the business when I need to use the Beta format.

[julie_m]

I remember Sony machines would lace up the first time you pressed PLAY, allowing winding and rewinding "inside the cassette" (which makes sense; very often, you want to rewind a tape to the beginning, either to watch a recorded programme or before recording a new programme) at first but would not unlace again until you pressed EJECT. Once the tape was laced, pressing WIND or REWIND while already winding or rewinding would switch to visual search.

Early Sanyo machines used to lace up as soon as the cassette was inserted, so initial rewinding was always done with the tape fully-laced.

Later Sanyos worked more like VHS machines, lacing up for PLAY and unlacing on STOP. This made for a quicker eject operation, but you could not go from wind or rewind to search without first passing through PLAY. (Though, later VHS machines would eventually borrow Sony's user interface idea and lace up "on the fly" to enable a seamless transition from {re}wind to search.)

[Mooly]

Originally Posted by IanNVJ35

The C9 was of all-time laced design, but in real terms did this impact on the wear of the tape path compared to the Sanyo range?

I was thinking about this the other day and wondering by what percentage the wear was increased - if at all?

Logic says being laced all the time must increase wear on the tape path... as to a percentage, I can't say.

I suspect that the more the upper drum (casting) wears the faster the rae of wear if that makes sense. Worn castings had more friction in FF/RW. Wear on the head tips I think is minimal in FF/RW because the tension on the tips is lower.

It was always hotly debated though.

[Mooly]

Originally Posted by IanNVJ35

Thanks Baz for that informative answer. One thing I do know is that the older ex-rental Beta tapes I have show many more score lines and general wear marks than the VHS ones. The wear mainly seems to affect the sound rather than the picture (goes muffled).

The tape is very sensitive to damage and unequal tension top and bottom as it runs through the tape path will stretch the tape giving rise to the "cockleshell or scalloping" appearance on the top edge... where the audio is. In my experience this was one of the major problem points in the design. It could be got perfect by careful alignment but it was always an ever present problem to be on the lookout for as the tape path wore with use. A crease in the top edge was common and also caused by improper alignment.

[Lodgesound]

Very interesting read there - I have a C9 stored away in good order and even have the PCM adaptor for it.

It is interesting to note how the design of these transports was derived from u-matics and continued throughout the Betacam range and still exists albeit in very modern form within HDCAM SR machines made by Sony.

I found a brand new (100 hours use) Betacam SP machine in a skip a few months ago - perfect working order - and the similarities between the transport in the C9 and this machine are both interesting and noteworthy.

Many folk think that Betamax is long extinct but it's professional derivation still exists and is still manufactured as HDCAM SR.

This makes Betamax which became Betacam (the small tapes in Betacam & HDCAM SR are indentical in physical form) the world's longest surviving and most successful videotape format - nearly 35 years!

[IanNVJ35]

Out of interest what Beta tapes do you use? I have tried a few (new) ones and the Sony Dynamicron - with the red, orange and yellow striped box - seemed to have many dropouts that spoiled any recording. I tried Sanyo - in the blue and white box and they were much better. The Fuji ones I got seemed to all have mould - so in the bin they went.

I see Scotch sells well - but have not tried them.

[Mooly]

Its many many years since I bought new Beta tapes but even in the early days the cooking grade Dynamicrons weren't my favourites. I only ever had a couple of Fuji and they were by far and away the best at the time for hard use without problems. Toshiba did some too... they were OK

I did get a box of 10 L500 "Top of the range" Sony ones that had a clear full width window... they were excellent.

Are tapes available still and if so when were they made ?

[ben]

Without wanting to go toofar OT, I have had oxide shedding and dropout problems with early beta scotch cassettes. Prerecorded ones were always pretty ropey, as with VHS! maybe they used cheap tape stock.

I have a c9 stashed away, I think with either a duff audio head or some chroma problem, can't recall...been using my three HF100s quite regularly as their Hi Fi audio is amazing.

[Heatercathodeshort]

Head wear with fully laced up Beta machines was a nightmare. I was for ever replacing upper drums and heads in Sony and Toshiba machines. The C9 was no better than the C5/6/7.The delightful Sanyo VTC series that partly laced were in my opinion the best Beta machine ever produced. Maybe not as many 'features' as a Sony machine but who used all the features anyway? Excellent picture and I never replaced a single head. Incredibly reliable.
When the dreaded [and personally hated] centre decked VHS machines appeared, the later ones with full tape lacing, the short life head problem came back with a vengeance. Many later VHS machines were written off after 14 months due to the replacement heads costing more, a lot more than a new machine. Not so happy days! Regards, John.