Zuma question

[flozki]

yes i think i can underline johns 3th point

a reliable perfect cut...

this is the most important thing.
cutting 5 times same track on stock neumann and having a overcut. you will have the overcut on 5 different places....


and thanks a lot for that info about different versions...to know that a 60hz system doesnt work on 50 hz...i guess that could save a lot of headache...haha.
i only know 1-2 zuma systems in europe..wondering if they got it right.

[Zuma Group]

[oh shit, my zuma runs with 110V and was used in the US before so I think my line frequency is wrong ( I'm in Germany) so I have to look for a frequency shifter. Or is it possible to change the line frequency setup with a jumper internally ?

The computer is locked to the turntable 'clock'. For lathes with synchronous motor turntables, the 'clock' is the line frequency. For lathes with quartz drive platters, it would be the quartz reference frequency.

To go from one 'clock' to another requires a change to the EPROM as well as the interface board.

I no longer can provide EPROM's so the simpliest thing you can do is substitute a stable 60HZ source for the computer's internal reference that is derived from your power line.

You'll find an orange or orange/white striped wire that runs from a terminal strip in the power supply to the underside of the motherboard. Detach the power supply end of this wire and connect to a TTL level 60Hz frequency source. You can Google for crystal derived 60Hz clock circuit to use for this purpose.

Although the computer will no longer be locked to the same 'clock' as the turntable, you'll be Ok with the crystal clock.

[duomo]

Thanks for the useful tips john !!
just calibrated with your Pulse testtone, works nice.

I PMed you because of the 50hz, 60hz issue.

Thanks for reading
best wishes from Germany
Moritz

[petermontg]

Some Zumas were built for 50Hz line frequency, they will not work properly on a 60 Hz line, nor will a 60 Hz Zuma work properly on a 50 Hz line. The internal timings will be wrong.

oh shit, my zuma runs with 110V and was used in the US before so I think my line frequency is wrong ( I'm in Germany) so I have to look for a frequency shifter. Or is it possible to change the line frequency setup with a jumper internally ?

so best is to use test tones. when that works fine you can not that much better.
some basic test tones we use for pitch98 can be downloaded on their ftp..

Thanks flo I already have this pitch98 testtones, I used them for calibration...
worked fine so long, I now do the pulse test too, but at first switch the frequency

With regards to frequency changing, I think you might want to try get some high end unit to regulate it. Nothing but fxxking headaches with anything but.

Hopefully you have no damage to unit but time will tell.



Edit: should have read rest of thread

[duomo]

You'll find an orange or orange/white striped wire that runs from a terminal strip in the power supply to the underside of the motherboard. Detach the power supply end of this wire and connect to a TTL level 60Hz frequency source. You can Google for crystal derived 60Hz clock circuit to use for this purpose.

OK I found this wire, I'm planning to connect this wire to one phase of my lyrec motor. This Motor also runs on 60Hz which is genarated by a siemens Motor control device. But the motor is running with 220V. Would that be a problem ? can I destroy something if I connect the orange wire with the 60HZ 220V Motor ?
Thanks for all this insight and great help !!

[concretecowboy71]

No over-cuts?

I guess that would be pretty amazing, but to me would take some of the challenge out of cutting sweet records!

I enjoy balancing pitch and volume levels until I get what seems to be right for each project.

I do not cut high level, super bass heavy cuts for the most part. I cut records destined for the consumer market.

To me, the human brain is the best "computer" for this kind of work. I see far more recuts due to plating issues than cutting issues and have been happy with how my lathe performs.

What are the design limitations of the VMS-70? I am interested to know, just because I like to understand how the machine operates.

How does the Zuma work around the design flaws of the stock system?

[Zuma Group]

You'll find an orange or orange/white striped wire that runs from a terminal strip in the power supply to the underside of the motherboard. Detach the power supply end of this wire and connect to a TTL level 60Hz frequency source. You can Google for crystal derived 60Hz clock circuit to use for this purpose.

OK I found this wire, I'm planning to connect this wire to one phase of my lyrec motor. This Motor also runs on 60Hz which is genarated by a siemens Motor control device. But the motor is running with 220V. Would that be a problem ? can I destroy something if I connect the orange wire with the 60HZ 220V Motor ?
Thanks for all this insight and great help !!

NO!. It has to be TTL level: a digital pulse 0 to +5 volts.

Wouldn't it be simpler to buy a step down transformer and run the computer off the 60HZ motor control?

[opcode66]

I guess that would be pretty amazing, but to me would take some of the challenge out of cutting sweet records!

As others have mentioned, this process of adjusting volume level and pitch takes infinitely less time using a Zuma. You would not have to do as many dry runs (or any at all). That is a big time saver.

What are the design limitations of the VMS-70? I am interested to know, just because I like to understand how the machine operates.

Better P/D systems have a higher accuracy when it comes to detecting level and frequency of the incoming audio. Also, aftermarket systems generally have more than 4 memory slots. The stock vms system only has 4. That is to say, the rotation of the platter is broken down into more than just quadrants on most aftermarket solutions. I believe the VMS80 does it in 16th's. Anything more than 16 divisions would cause modulation in the groove. However if you had more than 16 divisions and ran an algorithm to smooth the resulting plot then you can avoid modulation and gain accuracy. Something the stock system could never do.

The least accurate part of the entire system on the VMS is the determination of how fast the pitch motor is currently rotating. There is a tachometer that supplies a signal to the motor control that is used in combination with the values generated by the p/d computer to determine how change the current pitch of the motor. The tachometer gets worn out as Flo has stated a number of times. If this piece is no longer functioning accurately it doesn't matter how accurate your p/d computer is. A bad tachometer could negate any benefits gained by using an aftermarket p/d computer.

Finally, the pitch motor itself and the belts that it drives are the final place where there are inaccuracies. Replacing the pitch motor with a Servo Brushless motor would significantly increase the accuracy. If you think about it, this is the most important factor. You can have the fanciest p/d computer around but if the motor that it controls is not responding accurately and the sensor to tell how it is responding is not functioning well, then it makes no difference in the long run because there would still be inaccuracies in the response to the highly accurate signals generated by the fancy p/d computer. So, the most ideal system would not just be a p/d computer by itself. Rather, the ideal system would also include a servo pitch motor replacement, a tachometer replacement, new motor control boards, and an upgrade to pitch motor belts to ones with teeth (that can't slip).

[duomo]

NO!. It has to be TTL level: a digital pulse 0 to +5 volts.

OK, I now put a transformer between my Motor control device and the Sync input of the motherboard to get the TTL level.
But what happened now is the the white light don´t change its status every 1.8 sec ( at 33,3rpm) as it was before but every 1.2 sec. That shows me that the modification works . But does it work correct now ? because in the manual it is mentioned that it should flash every 1.8 sec ...
Do I have a 50 HZ version than or is it just a visual side effect of the Modification and the eprom is working correct ?

[Zuma Group]

NO!. It has to be TTL level: a digital pulse 0 to +5 volts.

OK, I now put a transformer between my Motor control device and the Sync input of the motherboard to get the TTL level.
But what happened now is the the white light don´t change its status every 1.8 sec ( at 33,3rpm) as it was before but every 1.2 sec. That shows me that the modification works . But does it work correct now ? because in the manual it is mentioned that it should flash every 1.8 sec ...
Do I have a 50 HZ version than or is it just a visual side effect of the Modification and the eprom is working correct ?

The light should change once every revolution - 1.8 seconds. If it was 1.8 seconds before the change, then you must have a 50Hz chip. What is the rate if the wire isn't connected to anything?

[concretecowboy71]

@ Opcode.

Thanks for the info. Much appreciated. Makes me see how much more accurate the aftermarket systems can be.

[duomo]

Ok I check the time change with no wire connected on the weekend .. Should it have the the same rate ?
Because its not so easy to set up this ZUMA correctly I now cut again with my neumann pitch.... I have to do some jobs, they couldn´t wait...
So I hope that I have news next week..

[dietrich10]

Zuma question:
My cooling fan has been dead past 4 yrs. do i need to replace etc?

[Zuma Group]

Ok I check the time change with no wire connected on the weekend .. Should it have the the same rate ?

Since I don't know how you're getting 60Hz pulse from motor controller, I want to make sure that you are actually synchronizing with it. If the rate doesn't change when you move it from your 60Hz source and leave unconnected, you're not doing it right.

[Zuma Group]

Zuma question:
My cooling fan has been dead past 4 yrs. do i need to replace etc?

If you've been running without the fan for 4 years, I would'nt worry about it now. It should be alright. The early units had memory boards that generated a little heat, but the enclosure should have adequate ventilation without the fan.

[duomo]

so..... with the wire connected to the new clock of the motor device I have a 1,2 sec change ... too fast, if I disconnect this wire I have 1,8 sec thats the correct amount.
nevertheless I went back to my internal VMS 70 pitch computer, because the ZUMA did strange things: If I callibarte everything with the 200 Hz impule testtone, I have massive overcuts if I test this settings with the sinus pitch testtones form ivo. They are some kind of worst case senario, the max and min of the sinus tones are exactly face to face from revolution to revolution. If I calibrate with that tones I have a great waste of disc space ...
Mhh I think I need more time to figure out if that ZUMA works perfect..

but many thanks to you all (especially John) for all your helpfull input..

[Zuma Group]

so..... with the wire connected to the new clock of the motor device I have a 1,2 sec change ... too fast, if I disconnect this wire I have 1,8 sec thats the correct amount.
nevertheless I went back to my internal VMS 70 pitch computer, because the ZUMA did strange things: If I callibarte everything with the 200 Hz impule testtone, I have massive overcuts if I test this settings with the sinus pitch testtones form ivo. They are some kind of worst case senario, the max and min of the sinus tones are exactly face to face from revolution to revolution. If I calibrate with that tones I have a great waste of disc space ...
Mhh I think I need more time to figure out if that ZUMA works perfect..

but many thanks to you all (especially John) for all your helpfull input..

It is critical that the Zuma be synchronized to the motor 'clock', otherwise you will not get proper results. Do you have a frequency counter available? I would not expect the timing to be correct if the wire is completely disconnected.

Also, you cannot feed tones from the rack oscillator and expect proper results unless you are delaying the modulation signal by the proper amount. It just won't work otherwise.