Toshiba OPTI: Any information?

Steerpike_jhb · Post by **Steerpike_jhb** » 15 May 2006 21:01

Today I was given this 'new' cartridge.

Does anyone know anything about it?
It's in a carved wooden tub with ground-glass lid, as shown in the pictures (I cleaned out the rotted foam that it was couched in).
The only identifying wording is on the glass lid: "Toshiba OPTI", and the number 3085 stamped into the underside of the cartridge itself. The globe is made of aluminium, and the plug assembly of hard plastic. It's a standard 4-pin headshell plug.
I'm guessing it's a moving-coil - since there is no obvious way to replace the stylus. Not sure what those two screws hold together!

Yosh · Post by **Yosh** » 16 May 2006 07:07

It looks like Toshiba C-100P

There were photoelectric type cartridges: Trio(=later Kenwood) Supreme 20 (combination of lamps/moving mask on the end of cantilever/photocells) and Toshiba (Aurex as audio brand) C-100P(combination of lamp/moving mask with slits/photo transistors).
Finial/Elp Laser Turntables have no stylus while these old types from the late 60s had stylii because laser beam was not available on public application at the time.

This type cartridge outputs linear to amplitude: sensitive to the displacement of tip. Hence compensation or circuit quite different from RIAA/IEC reproducing characteristics is required. These cannot be used without specific head amplifier.

These are very rare even in Japan and I have not seen actual products.

Regards
Yosh

Steerpike_jhb · Post by **Steerpike_jhb** » 04 Jun 2006 12:09

I have moved these posts to here from the GALLERY'S PICTURE COMMENTS to improve consistency:

Poster: Blue Angel @ Mon 15.May.2006, 23:26
Hey Steerpike
This is an icecream scoop made to look like a cart, surely?
Seriously, this is a rarity woth hearing. Have you tried it?
Blue

Poster: Steerpike_jhb @ Wed 17.May.2006, 22:35
I have not yet tried it! Yosh suggests (and I do suspect he is right) that it is an 'optical' pickup, that uses a beam of light modulated by stylus motion. I need to locate some sort of wiring diagram to know what pins take the excitation voltage etc.
Some sort of custom pre-amp is definately in order - I just need those pin descriptions!

Poster: Blue Angel @ Thu 18.May.2006, 00:36
Hello steerpike
When next I see my friend Brian Lane (who has a mountain of hifi mags and a memory second to non), I will ask him if he has anything in his archives. Have you googled for more info? What if you could contact Toshiba directly for any info? Maybe through Yosh.
Lucky man!
Blue

Poster: Steerpike_jhb @ Sat 20.May.2006, 22:24
Toshiba online seem to be only interested in NEW equipment.
No google info that i can find.
Local Toshiba agents seem to know nothing about anything old either.
I might open it up, but am a bit scared as all the bits might be TINY & i've already ruined a Philips (cheap & disposable, fortunately) pick up by being too 'big fingered' to be inside such tiny placces.

Poster: Blue Angel @ Sat 20.May.2006, 23:05
Hello steerpike
It IS sad that certain distributors want nothing to do with equipment they possibly distributed some time ago. This is sheer lazyness. Once in awhile, you still find those who care. I'm busy this weeking braaing for the CTSMEE (my engineering society's open day and will get in touch with my pal Brian re your cart to see if he has any details.
Cheers
Blue

Poster: Yosh @ Sat 03.June.2006, 05:45
Output pin connections are quite differnt since L/R/E/+B. E+B is DC electric source for lamp according to schematic for C-100P. Though I cannot allocate which pin is which for your cartridge. Toshiba cannot help you since this was produced 40 years ago. I think nobody but enginner can understand or help. Yosh-no engineer, but simple philologist of analogue

Poster: Steerpike_jhb @ Sun 04.June.2006, 03:13
Hi Yosh - thanks for that info.. its is some progress at least.
I do have a good background in electronics, so perhaps if you can give me any more information from the schematic, i will be able to figure it all out. Applying a DC voltage to the wrong pins would be very harmful to the pickup!

Yosh · Post by **Yosh** » 04 Jun 2006 12:33

Most plausible configulation of pin arrangments
as seen from SME type connectors at shell end:
R:right upper
L:left upper
E:right under (usually the earth of MM cartridge housing is connected to this channel within cartridge or by metal plate as in Shure)
+B:left under. Applicable DC voltage is unknown, hence better check resistance between E and this terminal.
I suppose the resistance between E and +B is smaller than other terminals and the rate of lamp resistance is constant even if +/- at circuit tester terminal is reversed.
The above is only my assumption. :oops:

I suspect that the lamp has burned out so the previous user might throw away this cartridge.

If you are seriously interested in schematic and performance chart and outlook, please send your personal message to me infoming your email address so that I can scan and send them with my notes.

As regards to pre-amp applicable to amplitude-sensitive cartridge
I can also introduce my friend site (Mr Boron) who are restoring Technics transistor type cartridges and buiding suitable head+equalizing amplifiers.

BTW: In your wooden candy or cool box, is there any concealed drawer?
In my reference book from 1971, Toshiba C-100P was sold at Yen 28,000
togerther with preamp. Pre-out voltage was 200mV, separation 32dB at 1kHz, VTF 1g, compliance 30cu, stylus 0.3x0.8mil, Load to line-in 10k Ohm and weight 14.8g. Expensive and high quality cartridge around 1970.

Regards
Yosh

Steerpike_jhb · Post by **Steerpike_jhb** » 04 Jun 2006 21:30

Thank you Yosh! That information is great - I will make some careful measurements this week.
The cartridge is new - never been used - so unless the lamp is damaged by physical shock or rough handling, I suspect it will work.
I imagine this is a filament lamp, since LEDs had not yet come on the market back then?
There is a small block of red translucent plastic in the front of the pickup- possibly a pilot light.
The numbers of the specifications are impressive, I do hope I can get some sound out of it! If so, then I will be asking for more advice on pre-amp designs.
No drawer in the candy box :-(

Steerpike_jhb · Post by **Steerpike_jhb** » 06 Jun 2006 22:36

Between B+ = BLUE (conventionally Left -) and E = GREEN (conventionally Right - & screen), I measured 1.5 Ohms.

Between RED (conventially R+) and GREEN I measure approx 17kOhm, as with between WHITE (conventionally L+) and GREEN.

I did find this page with more info on the cartridge (yes, Yosh, you were right about the model number it IS a C100P)
http://www.badenhausen.com/VSR1Pickups.htm

That page has a lot of interesting historical notes on the technical progress of all brands of cartridge design & is definately worth a read.

Yosh · Post by **Yosh** » 06 Jun 2006 23:40

Oh Thank you for introducing the interesting site in Germany.
What I have as schematic is almost same.
I abridge my translation from Japanese text as follows.
---------------------------------------------------------
This cartridge is displacement(amplitude) sensitive one (output -6dB/oct against constant velocity) so that special equalization is required.
RIAA has pre-emphasis (turnover 500Hz and rolloff 2122Hz and bass limit toward 50Hz).

This system required lighting source so that special head amp with DC supply was prepared.
The output from headamp was directly connected to AUX terminal of pri-amp.
The high frequency resonence was located around 18kHz but effectivedly damped.
Because photoelectric transistor had amplifying effect by itself
its output level from cartride was around 75mV and also high S/N ratio.

The features common for photoelectric types:
Merits:
1. Lower mechanical impeadance is attained since only the force to deflect the light at slit plate is required.
2. Light VTF
3. The transducer element has good linearity so that IM distortion as found in ceramic cartridge can be avoided.
Demerits:
1. Lighting source is required. The phase of one channel must be reversed - special head amp design is required.
Since only one E is commonly used for L/R, the phase reverse of one channel is not possible by connection but only by electrical process at intermediate amp.
2. small lamp and small photoelement are delicate and unstable. Moreover the heat from lamp is apt to change specifications.
3. stylus cannot be changed due to its generating system.
4. structure is much complicated

Cautions to handle:
As above said, the structure is complicated and delicate.
If cartridge is handled roughly, the wire to terminal may be down.
Lamp may cause unbalance of lux between channels.
The downforce shall not exceed the recommended VTF
otherwise the mask plate may touch the slit
causing degration such as output/separation/crosstalk etc.
-----------------------------------------------------------------
Please note "the phase reverse of one channel" is necessary.

Regards
Yosh

Steerpike_jhb · Post by **Steerpike_jhb** » 09 Jun 2006 22:20

I powered it up tonight (2V at around 200mA) and got a dim pinkish glow from out the cantilever area! The little red plastic block at the front which I thought might be a pilot lamp doesn't light up - just a decoration apparently.

Next up, I'll have to put together some sort of audio signal interface - can hardly wait to hear what it sounds like.

Yosh, you mentioned Y28000 in 1970 - I have no idea of the value of the Yen back then - what sort of value is that? What would that amount of money have bought in the 70s?

Yosh · Post by **Yosh** » 09 Jun 2006 22:48

Value of Yen 28,000 around 1970 in Japan??
The exchange rate from Yen to USD was fixed at Yen 360 per one dollar.
Yen 28,000 was around USD 78.
I remember that Yen 28,000 was more than one month salary.
For comparison I quote old price list as under:
---------
FR-1MKII Y 15,500
AT-VM35 Y 12,800
Satin New M-11 Y 15,900
---------
ADC 25 USD 100
DECCA USD 65
ELAC USD 70
EMPIRE 999VE/X USD 80, 1000ZE/X USD 100
Ortofon SL-15/T USD 75
Shure V-15 type I 62.5, II 67.5
Stanton 681EE USD60

Regards
Yosh

anar · Post by **anar** » 22 Sep 2006 07:53

I think that the cartridge you have is to be used with the Toshiba Opti SR-50 turntable.
I own one of these SR-50 but can't find the original Opti cartridge for it.

Steerpike_jhb · Post by **Steerpike_jhb** » 22 Sep 2006 13:21

How interesting that bits of these machines turn up in such far-flung conners of the world!
I still have not built an amplifier to interface to my cartridge, but the cartridge seems to be mechanically compatible with many arms & turntables. It will plug right into my Grace arm with not much adjustment needed to tracking geometry.
Have you a photo of your turntable?

anar · Post by **anar** » 22 Sep 2006 15:44

The complete name of this model is Toshiba OPTI photo cartridge player SR-50.
I just bought the unit for a few euros and was searching the web when I found your post on this forum/subject. For now I did not have the time to make photos of it but I found an old Ebay auction with good photos of a SR-50. Here is the link :

http://cgi.ebay.com/Toshiba-SR-50-Stere ... dZViewItem

It's an amazing TT with functions I have never seen before.
There is a L/R switch on the front panel.
Also a stylus gauge and a meter/phono switch on front panel.
And there is a photo/magnetic switch at the back panel.

I think this last switch might be of interest to you...

By the way, I have opened a subject on the SR-50 in the TT talk.
May be someone somewhere knows something...

Anar