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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 20th Jan 2020, 10:51 am   #1
TRADEMARK-X
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Default Ferrograph studio 8 heads & screening flap

Hi,
I am new to this forum (or any forum), but am having trouble finding some information & parts for a recently purchased Ferrograph ‘Studio 8’ tape recorder – I hoped someone may be able to help or point me in the right direction.

I have been using my Revox G36 for some time with superb results, it’s a factory high speed version (7.5 & 15 IPS) in an unusual wooden Copper screened cabinet with BBC transformer balanced inputs & outputs.

Recently I was offered a huge & ugly console version of the Ferrograph ‘Studio 8’ tape recorder for £200, in good condition (aside from the wood veneered panels could do with some fettling) – including a big box of spares, service manual, most deck parts, motors, deck PCB’s, power supply, control panel/board etc. & even a spare full track head block!

I thought it was a good price, but now not so sure as I am now finding it has a few issues that I am finding difficult to rectify due to the seeming lack of information & parts.

Initially I assumed it to be a standard stereo machine as it has two PPM meters (which seems unusual), but I now find out it is in fact a two track machine – which is different….

The tracks are much narrower than standard with a much larger guard-band (as can be seen in the pictures). Standard stereo heads have a guard-band of 0.75mm as against these ‘NAB’ 2-track heads with a 2mm one – thus resulting in less headroom / level too & from the tape + poorer S/N ratio. I assume this format allows working with tapes with a centre track of time-code or a sync. pilot tone etc?

Anyway, it is causing incompatibility issues as the machine does not erase all of a previous stereo recording, leaving a bit in the large guard-band, thus when the new recording is played back on a stereo machine again, some of the original recording can obviously still be heard!

So the long & the short of it is that I can replace the erase head from the full-track block, but need to buy replacements for the record & playback head. Trouble is I can’t source any.
I am told they are the same as ones used in the Series-7 (MK2), Super-7 & Logic-7 machines.

Does anybody have any heads for sale?
Also the play head ‘flip-up’ screening plate plastic hinge has broken – are these available anywhere?

I am also after a circuit diagram / calibration procedure for the PPM meter boards as they are not included in the service manual for some unknown reason – so anyone having any info regarding the PPM’s would be extra useful.

Thanks in advance,

Mark Barry…
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Old 20th Jan 2020, 11:50 am   #2
Ted Kendall
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Default Re: Ferrograph studio 8 heads & screening flap

With the best will in the world, sir, if you want a machine to use rather than fix, move it on or out before it's cost you too much time and money - it's a turkey. The G36, as you have found, is indecently good when running as intended...
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Old 20th Jan 2020, 5:01 pm   #3
TRADEMARK-X
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Default Re: Ferrograph studio 8 heads & screening flap

Hi Ted,

Yes, a fettled G36 high speed 1/2 track has excellent sound quality - I just don't know how they got this out of such a small 'domestic' machine. Mine sat in a cupboard for 50 years & still came out working, though I have serviced it since.
I have attached printout of frequency response etc. which is unbelievable really!
A bit of a peek in the bass department - probably due to head design?

Could you please elaborate as to why the Rustograph Studio 8 is a 'Turkey' please as it doesn't sound too bad even with the incorrect head format + it's not been aligned & calibrated as yet?

It was manufactured by Wayne Kerr who made superb instruments & is built like a tank - though admittedly is an ugly brute....

Cheers,
Mark...
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Old 20th Jan 2020, 6:06 pm   #4
barrymagrec
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Default Re: Ferrograph studio 8 heads & screening flap

At least one of the engineers who worked on the Studio 8 was formerly at Leevers Rich - he told me that they were being allowed to "do it properly" but I suspect it was too late to a market that was B62 dominated by that time.

As it was effectively a Wayne Kerr product I`m surprised it had any Ferrograph components and anyway I would have thought that most Ferrographs were twin track rather than true stereo.
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Old 20th Jan 2020, 10:53 pm   #5
Ted Kendall
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Default Re: Ferrograph studio 8 heads & screening flap

Quote:
Originally Posted by TRADEMARK-X View Post
Couuld you please elaborate as to why the Rustograph Studio 8 is a 'Turkey' please as it doesn't sound too bad even with the incorrect head format
The major flaws of the design are over-complexity leading to unreliability, excessive size and weight, awkward tape path making editing difficult and inferior performance to the Studers against which it was pitched. They sold in penny pieces and vanished from the market in little more than a year. Barry's point is well made - with a concern like Studer dominating the market, any other manufacturer was going to have an uphill struggle displacing them as far as studio machines were concerned. Scopetronics, Leevers Rich, Bias Electronics, even Unitrack had a go at cracking the BBC requirement for stereo machines, and all failed. It is at best a curiosity, in my view.

With regard to track widths, if your Revox has a .75mm guard band, it has been modified - the reference to a wooden case makes me wonder. John Boyden, one time manager of the LSO and later founder of Enigma Records, made recordings for EMI in the 60s on a hot-rodded G36 which sounds like yours. The standard domestic track width for stereo machines is 2mm, and all Revoxes were so fitted, but it was at least physically possible to fit C37 heads, which were available with 2.75mm tracks. Ampex standard, incidentally, is 1.9mm across the board.

Both the Revox G36 and A77 were notorious among studio engineers for sounding better than they had any right to at the price. I think it was a case of spending the money where it mattered - on a solid chassis, partly or entirely made of castings rather then bent tin, a formidably stable capstan motor and head assembly, and well thought-out electronics. Other makes (particularly Japanese) may have had greater perceived value, with flashier styling and more metal on show, but when it came to actually doing the job, the Revox was supreme.

Granted, the Ferrograph 8 had little to do with other machines of the same brand, but it seems to me a pity that Ferrograph didn't start with a clean sheet of paper when the A77 appeared and set the new benchmark. The Seven was a rushed and flawed lurch into the transistor age, retaining all the foibles and few of the virtues of the earlier machines.
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Old 21st Jan 2020, 6:10 pm   #6
TRADEMARK-X
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Default Re: Ferrograph studio 8 heads & screening flap

Hi Ted / Barry,

Sorry, didn't attach the response graphs of the G36HS properly last post.

I am getting conflicting reports on the Rustograph Studio 8 head configuration, mine has an unusually large guard band, the first thing I noticed over other stereo machines I've had. I presume it was used in film/video production as to not erase or disturb the time-code or pilot tone track. Looking at the chart attached it looks like mine has the NAB style heads fitted instead of the Euro ones normally fitted. I was also lead to believe that I could use heads from the Logic 7, but Geoff (from ServiceSound) said:-
"First of all the heads for a Studio 8 are not the same as for the S7 and Logic machines, they are mechanically identical but electronically totally different.
The heads on yours are indeed for a 2 channel with centre time code track."
I will check the head part numbers between the Logic & Studio manuals to see, but if they are not the same the chances of getting replacements for a reasonable cost is unlikely....

Cheers,
Mark...
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Old 22nd Jan 2020, 10:40 am   #7
TRADEMARK-X
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Default Re: Ferrograph studio 8 heads & screening flap

Hi Chaps,

In response to the quality of the machine;
The further I get into the machine I am quite impressed with the build quality & easy access to everything. The Studio-8 appears to be built like a piece of military equipment - I suppose the designer / builder 'Wayne-Kerr' had indeed built a lot of test equipment etc. for the military, so it's no wonder.
A few folk on here appear to doubt its ability to perform & remain reliable - again I'm getting conflicting reports, i.e., Geoff @ ServiceSound (Ferrograph / Brenell specialists) reported:-
"In terms of sound quality Ferrograph are pretty much the holy grail of outright sound performance and will blow the doors off any Revox or Studer.
I have customers in Germany and Holland who use only Ferrograph to master tape on even though they also have the big Studer machines."
So I think I will give it a good service, alignment & calibration to see how it performs. I think I will fit the full track erase head & look out for some replacement stereo record & replay heads to increase the recorded track width. Once done I will post the Lindos LA100 audio analyser print outs here....
Anyone got any Studio-8 Stereo heads out there

Cheers,
Mark....
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Old 22nd Jan 2020, 12:36 pm   #8
Ted Kendall
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Default Re: Ferrograph studio 8 heads & screening flap

There are two standard track configurations for two track heads, depending on whether separation or signal to noise ratio is paramount. The "two track" layout has a 2mm guard band and 2mm track width. This is the same whether or not there is a timecode or pilot track. It is also the standard for domestic machines, so that either track can be used individually with negiligible crosstalk. It is heads of this standard which will originally have been fitted to your G36.

The "stereo" standard has a .75mm guard band and 2.75mm tracks, giving about 2dB better signal-to-noise ratio but degrading crosstalk to typically -50dB, which is too great for satisfactory mono use, hence the common use of a full-track erase head. Because space is limited with such a narrow guard band, the polepieces are often tapered back away from the gap to give more room for windings and screening - this is known as a "butterfly" head. Some manufacturers, notably Telefunken, did this with wide guard band heads as well.

Some two track professional machines solved the problem of unerased stripes of mod by using "separate overlapping track" erase heads, which erased up to the edge of the opposite track.

Ampex went their own way and used 1.9mm tracks for everything.

If you are keeping the machine, I wouldn't worry overmuch about the heads - they appear to be in good state, and in any case I fancy they will be the least of your worries...

Last edited by Ted Kendall; 22nd Jan 2020 at 12:42 pm.
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Old 22nd Jan 2020, 2:15 pm   #9
TRADEMARK-X
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Default Re: Ferrograph studio 8 heads & screening flap

Hi Ted,

Thanks for the info, it's as I thought but the Revox G36 appears to have a smaller guard band than the Studio-8 I have here.

I will leave the heads alone for the time being & spend some time servicing the machine first. I am currently stripping it down, cleaning & lubricating everything that need to be - concentrating on getting the transport spot-on before moving to the electronics. It seems to be working okay, though when in re-wind there is no electrical back tension on the take up motor - this appears to be a fault as when in forward wind the supply motor gives a little electrical back tension so will have to have a look into this. Some of the motor capacitors look a bit iffy, so will look at replacing those which may rectify the issue, if not I have a spare set of cards & motor controllers to play about with.

I would like any comments from folk who own or have used / worked on the Studio-8 to see what quality I should be expecting from the machine & whether I should keep it or not - it is a bit of an oddity & the aesthetics could quite easily be improved by having the horrible wood veneer replaced with some black or grey laminate - can't make it any smaller though, a very deep deck!

Any comments welcome & also let me know if anyone out there has any spare heads and/or PB head hum screening flap hinge (I still have the flap)....

Also I could do with any information on the PPM meter adjustments, circuits etc. as these are not covered in the manual.

Cheers,
Mark....
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Old 22nd Jan 2020, 2:44 pm   #10
TIMTAPE
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Default Re: Ferrograph studio 8 heads & screening flap

Quote:
Originally Posted by TRADEMARK-X View Post
Hi Chaps,

... Geoff @ ServiceSound (Ferrograph / Brenell specialists) reported:-
"In terms of sound quality Ferrograph are pretty much the holy grail of outright sound performance and will blow the doors off any Revox or Studer.
I have customers in Germany and Holland who use only Ferrograph to master tape on even though they also have the big Studer machines."
...
Any comparisons of machine sound quality are only valid if everything else is the same including tape type, machine condition and alignment to the tape, eg: same overbias, identical track format, playback standard eg: IEC or NAB etc.
I'm not familiar with the machine but it may be that in a fair test there is little if any difference in sound quality but sound quality is but one aspect of a machine though a very important one.
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Old 22nd Jan 2020, 2:50 pm   #11
barrymagrec
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Default Re: Ferrograph studio 8 heads & screening flap

Genuine narrow guard band heads were not that common in the early days, Leevers Rich did not produce such heads until 1973, I still have my test results for the prototype record head though for some reason I didn`t do a crosstalk test.

A few machineswould have gone out before that with stereo Philips ferrite heads but mostly a "Stereo" machine would have had twin track record and play heads with a full track erase - I think a number of valve machines were supplied to the BBC like this though the post 1973 E200s were true stereo.

The Philips ferrite heads were excellent for replay but less well suited to the Leevers electronics for record. Needless to say as soon as it was decided to go with Philips heads as standard for replay they stopped making them...
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