Ortofon Network

[Serif]

I could have used the vintage Ortofon Dummy Load box, but its test condition resistance, invoked via pushbutton, was too low to trip the bi-stable switch that tries to save the coils from profound heat. One can goose the settings on the front panel trimmers, but I wanted the temperature reading to start at the 25C mark and reach full scale at the actual test load which is based on the 200 C heat of the designated newer stereo cutters. (There is circuit reaction time and meter ballistics which makes the 200 C coil need the temperature sensing circuit really to swing out more than just 200 on the needle.) The resistance of cherry picked resistors, alone, is adequate for the test condition, even though the Dummy Load box has large coil inductors and capacitors to mimic the reactive impedance. Furthermore, the TEST pushbutton allows the output drivers to be bypassed minimizing the available power, so this is invoked for these tests.

(3rd order 2 Hz Low Pass filter inside...)




- Serif

[Serif]

I find it helpful to photograph a circuit and place component i. d. numbers on the photo (using Paint or Graphic Converter, etc...) because most of the time a schematic is drawn only for the convenience of showing the connections, but the actual tracks of the circuit on the board will have to be arranged quite differently.






The benefit of mercury-wetting the contact reed is that its inevitable momentary "bounce-back" upon contact will not break the electrical contact desired as the capillary action of the liquid metal rises to the occasion and won't let go as soon as the first slap of the reed hits the target. Thanks to ITI Audio for this and many other electronic details explained.

- Serif

[Serif]

By the way, *L* I recommend any who have loud fans to look into Thermaltake. The model I got of theirs blows a little harder CFM than the original P_bs_ 4800X, and they are 16 dB instead of 32. Over 2 1/2 times quieter. Whether one, or all three (two amps plus one dual-psu = 3 fans...). Now on all three units of the main drive package. Plus, with a couple of fat rubber bands, I was somehow allowed to position another of these 120 mm hydrorotor fans right under card cage beneath the warmest-running card, which has a small grill heat sink on it the size of a sandwich, for one MJE 3055, but not the TO-220, version. Rather, the TO-126, or with the e-c-b legging, such that the metal back touches the heat sink but the heat sink can't work with the through holes of the board for the stand offs of the heat sink and also do this with an MJE 3055 which has the TO-220 pin configuration, b-c-e... It is very easy to find an MJE 3055. It is almost impossible to find the same part number in the TO-126 version... A mod is in order, but, for now, I'll try wind-chill for slower ageing?



- Serif

[mossboss]

Lovely Monologue
Great photos
Cheers

[Serif]

Thanks, MossBoss. Not many use Ortofon, here, but they are quite easy to work on. Everything tidily assembled with plenty of space for hands. I was glad I took the time to calibrate the safety circuits, myself, even though I ordered the back-up system "already checked out and serviced, as needed, by a tech." The original fan was replaced by someone backwards, so that it was trying to pull air out where it should have been pushing air in. Hard to blame much since they had the wrong part, so the only label was turned to the outside, even though that model was for out-draft, rather than in-... Might have been less effective over time. Also, the parallel tuning-resistance on the cutter off relay circuit was too high.

Non-Grundy-guaranteed lathe equipment can turn on and look to be functional but actually be sort-of booby-trapped. Some guys in Canada early on warned me about how a tech can repair a cutter head cable and not do something right and cause the next person who uses it to have to call George A. for a recoiling session...

By the way, I really appreciate lathe troll's own, tubefan, for showing me how to read a schemo and go ahead and unmodify gear which has no documentation of the mods. Also, how to discharge a large cap. To use no-clean flux. Etc... I have no official electronics training, so I invited him to visit last year for some tech talk after Len H. suggested it.

Since then I have been reading the Navy .pdfs called, N. E. E. T. S. Quite easy reading and recommended for all auto-didact trolls. Lathe Trolls' THD also gave me many good tips and links to videos on how properly to solder (it's the dwell time, principally, then the tip mass, and least of all the actual heat... no more than 2 seconds' dwell, once the solder starts to melt).


servus humilimus,
Domine spectabilis,
Andrew the Serif at Dingbat L. S. D.

[Serif]

More photos now available. The box resistor is a God send for its ability to allow the user to sweep through a broad range of values while fine-tuning a circuit. The Ortofon Safety Circuit, and many other cards, have tuning resistors that have to have the values determined for the amp the card is in. The extra resistors are in parallel with ones that are factory-specified (and packed). Nice posts stand off from the board which allow alligator clips from a box resistor to be used. I got this one on eBay, and it was calibrated. I verified with a new Fluke and it is spot on. What's more, the name Shallcross is the same family responsible for Shallco switches. These are used in things ranging from Sontec Mastering equalizers to nuclear power stations. The old ones seem to be the best. These switches have a satisfying "snick" as they find their respective steps.






- Serif

[Serif]

New pictures of the process. On the last of the four cutting amps' Safety Circuit fine tuning. By now, I ran across an Ortofon 31-pin edge connector which makes for a much more convenient Impedance Board bypass connector. Someone had already jumpered two of the connections and had almost done that correctly (gotta peep every solder when bringing back these relics). I corrected the jumper pin which was wrong and added the extra (jacketed) jumpers, following the instructions in the field bulletin that came with my Ortofon manual. The bulletin reminds the clerk who is doing the work that resistors take "some time" to stabilize after soldering. This was definitely evidenced, when the decade resistance box would be able to sweep and find the right value, I'd carefully cherry pick a resistor (or two-part network, as shown in the photo --- how to make 1,55k R out of two higher value resistors, since they're all's I had...), pack it, and then power on and see a different behavior (at first) than I did with the calibrated box resistor. After waiting a few minutes and repowering, the resistors I had just packed suddenly started to behave correctly - just like the box resistor did... (check out the model number of the mercury relay.)




servus,
Serif

[Serif]

While using the camera, I nabbed this one of my dog, Meynard, resting next to the newly purposed lacquer blank humidor. I took the huge Iso-Box out of the cutting room after I replaced the chassis fans in the Ortofon amps with the high blowing Thermaltake DC fans that have a hydro-rotor. Having attenuated the chassis noise by 250%, I no longer needed the Iso-Box, which has racks, but also inside has its own fans. Those fans are still audible when the door is closed, so the Iso-Box was always more of an Eye-Sore box.

Once I read in Mr. Boden's Compendium about how Audiodiscs were supposed to be stored at 50 % relative humidity until use, I decided not to sell the Iso-Box but turn it into a lacquer blank humidor. I got some RH60 silica bead sticks from Heartfelt cigar supplies and a battery-operated hygrometer and run the Iso-Box humidor on no wall power. Just the passive thermo electric weather system of a low variance evap and condensation loop.




...and a cel phone picture of the cutting room with the simplified furniture allowing me to access the meters and pushbutton for Cutter On/Off from The Lathe and console without remotes. (Have moved the N bottle behind the new cutting rack, but these bottles with round gauges look like droids to me.



servus,
Serif

[JayDC]

wow... didn't realize you used "the lathe", do you cut dubs as well? I'd like to hear what that lathe sounds like...

[Serif]

Although the computer designed platter and furniture for the aluminum table and the well known high quality manufacturing (e.g., feedscrew that gets lapped for 40 hours by machine after the threads are cut) all contribute to the precision and lack of rumble, the sound is really the sound of the Ortofon drive package. It has a ruler flat response to above 20 kHz at full speed cutting. The amps have 550 Watts each, so there is a truly audiophile capability. I use no extra audio relay for cutter off, other than the one in the cutting amps. My cutter key is an NKK mechanical kill switch (without mercury or current), recommended by SALT. Sherwood Sax indicated in his notes that it is desirable to minimize the amount of mercury relays to one per channel.

I am using a solid state STL 732 treble limiter with the control signal (RIAA pre-emphasized) output from the GO 741 amp (and have another as a spare, but it's being unmodified from the Gray mod which was for using it without pre-emphasis). I also have a tube STL 631 in my shop that I got from Dietrich. Might invoke at some later time. I have stocked up on three DSS heads (green, blue, and red), since they are delicate precision cutters which are notorious for being easily abused, and two The Lathes (Criteria/Fullersound and also Eva Tone history). Both The Lathes are appointed with Island Audio chip tube nozzles which work with the DSS heads, since they have no captive tubes, the way the SX Georg's do.

I'm about to start work restoring an MCI JH110-B with preview for 1/4" and 1/2" tapes, because only the MCI has the full revolution threading for preview which is required by The Lathe (as well as Compudisc and Zuma, although those systems' delay requirements are changeable, whereas The Lathe's isn't...).

These The Lathes have the most advanced Scully pitch and depth system developed, which appears to be based largely on the last Capps automation. It only goes up to 600 LPI (while the Capps goes to 1000), but the feedscrew and tt are driven by mylar belts, so there is extremely little rumble. My two The Lathes, unlike those of my colleagues, who have the original turntable oscillator cards, use the latest turntable servo drive boards (PLL) with a 432 kHz crystal providing the master clock for the turntable motor speeds and also the feedscrew tt speed compensation math. Records played back on it which I have heard on other systems have a satisfying time base precision. This is basically an all-American Technics SP-02 (which also uses a quartz). Even though both The Lathes have working turntables at present, I like having redundant backup components in stock. I was worried that I might have an end of life system when I realized that almost every vendor of crystals refuses to cut one slower than 1 MHz. But a company in Pennsylvania, named Basers Engineering, specialize in cutting crystals to resonate at specific fundamentals between 100kHz and 900kHz, so it appears I'm working with a net on that circuit. Florian Kaufmann, who sold me the other The Lathe, did offer to make me a circuit to use a higher frequency crystal with chips to divide its output down to whatever I need, but I think it would be fun to keep the original design wherever possible, since it worked fine for Criteria and Fullersound and several others. I also found some rare as hen's teeth MJE 3055 transistors that are in the TO-127 package needed by the turntable servo drive board (due to its unique large heatsink that precludes one substituting with a conventional TO-220 package for the MJE 3055. They were sourced from England's Little Diode Shop).

The day before yesterday, while driving to work, I saw a white car in the park I drive through that had a license plate which read, LJS 5. That struck me as odd, since it had the initials of the son of the founder of Scully lathes: Lawrence Jeremiah Scully, as well as having the exact number of known The Lathes still in existence (5). There were possibly ten ever made, based on the serial numbers we know of. But only half of them have been accounted for since the invention of the internets.

Pete Lyman (#651), Tor Degerstrøm (#653 + a vintage Scully), Deroy (from Rhythm Shack) (#65?), and yours truly, Andrew Hamilton (#656 and 660). It is believed that one of The Lathes was owned for a while by Kim G., but he doesn't appear to be using it, now, and it might be an urban legend.

I'd like to cut your sides, if you're game. It can even happen this year (: I've been developing the cutting room and restoring the old and field-repaired gear since April 2011. However, I have finished most of the work, now, and the test cuts sound beautiful. I recorded some tracks to CD a few years ago and did nothing with them (Drum and Bass). But once I transferred them to Apollo, the sound was finally what I had been "going for." 808 on lacquer is sweet, and as you know, there's almost no surface noise on a dub plate...

I'm working out of a two-building studio facility where my own band's music was cut to disc and pressed to vinyl in the early '80's (Sluggo/Contradiction and Nickolas Elissia/Slippers and Pistols). I've been their tape op since the Millenium began. This place (QCA) has been in business in vinyl so long that they were once hired to make extra pressings for regional sales of The Beatles and Elvis while in original circulation. The building where the cutting room and premastering studio are used to belong to The Vocal Style Music Company. They made player piano scrolls (the original "records") and, at their earlier 4th Street Cincinnati location, they recorded to scroll some of the playing of Jelly Roll Morton, prior to his moving to Chicago to record his first gramophone records.

The extra cool part about my main The Lathe is the following: It was bought by Criteria (yea, Tom Dowd!) and used pricipally by Mike Fuller. Mike Fuller, of Miami, is originally from Cincinnati. He learned disc cutting while in High School at my studio, taught by my landlord's father. The room in which he learned cutting is the same room where his once future (and now past) lathe now sits. He learned on an AM32B, from what the landlord remembers. But he used Scully #656 for 33 1/3 years, using it to cut Rod Stewart's "Sexy," among others, and he did it with the Ortofon GO 741/DSS drive package, so, you have already heard this very The Lathe. Mike has accepted my LinkedIn request, and I've invited him to see his Scully any time.

- Andrew

[Serif]

Here's a more irie picture of it, using the Kodak*. 2,5 mil deep grooves at 190 LPI going to lock-out.

(Don't worry about all that Armstrong shag carpet. I have a freshly charged fire extinguisher on the wall.)

(The [He] bottle (not shown) is strapped to the steel weldment of The Lathe using a high tech bicycle chain and combo lock. The [N] bottle is more of a shorty and is wedged closely without yet touching between the amp rack and side wood curtain of The Lathe. If it falls backwards, it would rest on the shag wall without losing much verticality. Might get a bike chain for it, too...)

Of course, The Lathe is using a Nikon microscope and Ikegami video camera/monitor combo. I don't have it on most of the time...
(Nikon, Nippon, Nihon, etc... are Romanizations of the word in Japanese for Japan.)

A cable connecting the amps' remote control connectors together makes the pushbutton controls of either amp control the related function on both. I can therefore run The Lathe single-handedly using its pushbuttons for Banding and Finish and have my other hand ready to hit the pushbutton on the top amp for Cutter Off. I play traps so this is not a problem. I have recently switched to using only brushes and soft mallets, though, since I want to preserve my hearing and not always wear musician's ear plugs. Stick-struck drums are a weapon.

The stacked black racks now have a thick wooden shoe rail going from the bottom of the lower box to the top of the top box on each side. This is for strength and stability since the Ortofon amps and dual psu chassis are very heavy - giant heat sinks inside.




* notice how on both the cel phone picture and the higher res Kodak picture, the light bends the appearance of the control panel metal trim? It's not warped at all, but both pictures lie that it is. \"
Cel phone sees warp nearest second switch from the left, and Kodak sees warp mostly near third switch from the left...

- Serif

[Serif]

Finally re-installed the original head connector per several of you folks' advice(s). Last year or so, I had to replace the old head connector cables whose jackets had somehow become dried out and cracked open in a few places. Coils survived, but repairing the cables was not possible since the gauge was so small that all my jacket removing cutters removed too many strands along with the jacket, and I didn't have a proper thermal jacket-stripper... It was very small gauge wires - smaller than most lavalier, portable headphone, or similar mini-flex twisted pair. I had this nice, Mogami 3080 (AES/EBU 14 pF/foot twisted pair with shield and drain), but its o.d. was too big for the small holes in the top of the Phonotech-badged Ortofon head connector. So, I had been using until the other day a home made head connector slip cover made from hand-cut Gorilla Tape. It looked like a triangle-shaped witch's hat (though I thought of it as more of its dred cap). But it protected the solder posts for the drive and feedback coils, as well as stylus heat supply lines, so, I deferred cosmetic upgrade until I'd fixed some other stuff.

Solution (for return to aesthetic normalcy while keeping added permittivity (of larger diameter wires) and/or having the convenience of not having to replace the cables to the carriage terminal (inside it) in situ): Use Dremel bit to increase the bore* of the cover's holes for the coil lines while leaving the heater cable holes the same (since the same wires would be used, and they were already small enough for the original hole size). Then flux-daubbing with Kester pen and soldering (again, in situ - with the alligator clip vise sitting on the turntable) with a Radio Shack cordless soldering iron (running on four AA Voltaic piles), unsolder the cables after unpeeling the Gorilla Tape (which was surprisingly easily unpeeled after a year of curing), and then unsoldering each of the cutter's electrical wires, threading them through the newly enlarged head connector holes, and then resoldering each of the cutter's electrical wires and battening down the cover.

You will find many lengths of kite string used as cable bundling lace, here at Dingbat L. S. D. Originally a temporary measure, it has been resilient in its function and vanishingly low in cost - ergo - since NASA say we must bundle our cables and lace them, I have done just that. No rats' nests in trolls harnesses. At least no untidy rats' nests?

I used to wax the the string, but that was a messy job and not really necessary.

The lace shown is a Marlin hitch, using a modified surgical knot on each end, and also a daub of Liquid Tape for the aglets. My standard power and data cables with moulded on or proprietary-crimp connectors are all bundled using a Sheepshank with a sword for any slack and laced with a kite string Marlin hitch. Audio lines are cut short as convenient and have connectors put on in house. Our favorites are Mogami 3080 and Belden Mediatwist.



servus,
Serif





* I have also a spare DSS head connctor with no cover.

[Serif]

...let us know if ye search parts for GE/GO 741 or DSS cutter or L. J. Scully "The Lathe" parts hard to find. We have some inventory, now, so can at least consult on locating/cloning some items and have good partners in searching for parts in China, USA, and Lithuania. Have a great session!

serif

[Serif]

...speaking of "The Lathe," Here's a photo I hope Flo will like. I have at last located the correct Brooks-Mite flow reduction valve/meter (showing 0,05 - 0,4 SCFH legends) for LS-76 #660 that he sent me last Fall as a back up machine for #656. What a one-man army FloKa has been for lathe trolls! Big Ups to Solothurn for having this guy.


{I think a lot of lathe operators are seeing the benefits of having two of the same model for cherry picking parts or to have spares of any type when needed, since there are no more lathe factories running. I actually got the idea of doubling up on The Lathe from my uncle, an E. E. and former studio musician at King Records in the fifties. When in college he bought two teletype machines at a yard sale and managed to use the parts of one to make the other one work. A family tradition now has been established of doing something dingbat, sure, but doing it twice... He was able to print out the AP story of the assassination of JFK before it made it to the newspapers. Original internet.}

[Serif]

...and it's all sewed up. DSS 731 mounted in Ortofon head connector. Now to make some kind of Lexan screw on pointer for the disc diameter scale (inches counted every half inch of travel)... For now, a daub of White Out indicates the carriage position. 0:






- Serif

[Serif]

1 kHz finally at 3.54 cm/sec/channel/RMS, on the backup Ortofon amps. This is a 400 LPI feed having only a ~1,25 mil depth.




Just noticed it was time to order some more [H], but my account at Praxair was not given any word on when their current shortage will allow for new recharges, and AirGas says no new accounts. Finally, the balloon room at Weiler Welding Supply, in Fairfield, to the rescue with a new H bottle.


-Stylus Wigglesworth

[tubefan]

Make sure you buy [He] and not [H] .

[Serif]

Hi TubeFan,
Actually, Ortofon recommend [H] over [He].


From the Ortofon GE/GO 741 instruction manual, p. 3:

"Cooling

During recording, the cutterhead [sic] may be filled with a good thermal conducting gas. Hydrogen is best suited but for safety reasons, helium is often preferred. About twice the power can be handled when cooling by this method."


[H] won't ignite in the absence of air. So, if you're out of [He] and need good cooling, crack some [H], but only after evacuating the cutting room of all air.

- Serif

[boogievan]

I read that [H] is only 1/20 as combustible as automobile engine petrol. Also, it's lighter than air, so it tends quickly to rise to the ceiling. I reckon with proper ventilation, as well as an eaves which is constructed in a way to be easily blown clear of the room. might make acceptable working environs for the Ortofon recommendation for coil coolant. If you could replace the room atmosphere with something other than [O] in the air, you might be ok doing SCUBA whilst cutting using [H].

- Tim E.

[Serif]

Hi Tim E., No worries, Mate, I'm checked out for SCUBA since 1979 . The local instructor was also a professional photographer who would take photos while leaning out the window of a single-propeller airplane (while others piloted...). Buddy system with a Daredevil?

@Tubefan- I did find [He] at the Balloon Room through the auspices of Weiler Welding Supply. They were courteous and all pro. But it was weird to think of helium being only available through party supply stores and not through welding suppliers, directly, right now... Or so is the situation at my locals (whether existing client or not).

The other weird thing is that the [He] this time came in what they called an "H" bottle, whereas Praxair call theirs a "K." (Didn't try compressed gas Potassium, yet)....


..so, we're putting Talcum powder down the hose, and party balloon gas in our head, and fluid in our wells, and heat on our wire, and tension on our spring, and trip switches whilst gyrating and expanding? It has to be grandmothering.... (: Cuz, that's how your Fathers get made...

- Chuck Spindle