Vintage DD turntables. Are we living dangerously?

Hi Hiho, Lew and I nearly started the Dual motor adventure
but were both confused by reading more about 'it' of 'them'(?). The 'lirical report' from some 'spaceman' was nowhere else affirmed. My interest was 'awakened' some time
ago in the context of the Goldmund Studio and the problems with
the Pabst motors. The Dual motor(s?) were the hope for those how owned the 'wrong Sudio'. This story about possible 'right Dual motor' was even more confusing. I give
up my intention to buy the Studio and bought Lurnes Audiomeca J1 instead. At present I own Kuzma Stabi Reference which has many similarities with the J1.
However I am not aware that this 'effort' to replace Pabst motor was succesful. I need some 'ammunition' or arguments to convince Lew that our 'adventure' with the Dual motor
is worthwhile. Our 'division of labour' was meant that he will do the 'technical issue' while I would buy the right Duals on the German ebay. Ie one can see on the German ebay at least 6 of them each day.
Will you care to provide some 'ammunition'?

Regards,

From my understanding of the Goldmund Studio situation is that...

1) If you have nonworking motor, you need to replace it with...
____A) Stock Papst motor, if you can find one.
____B) Stock JVC motor, if you can find one.
____C) EDS-1000 motor salvaged from Dual CS-701 turntable.
____D) EDS-1000-2 motor salvaged from Dual CD-721 turntable.

2) Read quote from below:

"Dual 701/721, EDS 1000/EDS 1000-II- These motors are 5.5" in diameter, while the original Goldmund Papst is 4 3/8", so machining is required....... Further, both motors are fed via their own electronics, and MUST be used with it. It is not bulky, will fit inside. All in all, I would only recommend these if all other options are exhausted"

Personally I would prefer the 701 motor for this purpose because it was designed for a heavier platter (2.9kg) as the 721 uses a lighter platter (1.5 kg) and has less torque. Go for the 701, I say. All the electronics are underneath the motor and the power supply is in its own enclosure so that can be outboard from the table. There is an umbilical cord for the 33/45 speed switch and two pots for speed adjustment. You can eliminate the strobe light if you want.

Again, the person who did the conversion emphasize that he would "only recommend these if all other options are exhausted."

You have been warned. :)

P.S. Or you can simply buy a beater 701 and take out the motor and electronics and make a simple plinth for it and have a listen like this guy.

_______

Dear Hiho, Thanks for your contribution and explanation.
As I or 'we' (Lew included) thought there are at least two
Dual motors: 701 and 721. Lew suggested to use the Dual motor for his
Lenco. I have no idea what to do with my specimen.
Your contribution was primarily directed to the Goldmund
Studio problem. We thought that if this motor is something
very special some other applications would be interesting.
Dreaming and speculating are to my mind very similar.
However I am not sure that this 'ammunition' will convince
Lew to participate in 'some' international collaboration.

Kind regards,

There appears to be some confusions regarding Dual motors. Maybe I am the one who is confused... Let's answer each question one at a time.

Nandric: "As I or 'we' (Lew included) thought there are at least two
Dual motors: 701 and 721....... Lew suggested to use the Dual motor for his Lenco. I have no idea what to do with my specimen."

Yes, there are two Dual direct-drive motors. EDS-1000 from 701 and EDS-1000-2 from 721. 701 uses a heavier platter and 721 uses a lighter platter.

From what I read and if I understand Lew correctly, he wants to use the EDS-5000 motor from the CS-5000 belt-drive turntable and apply that to his Lenco, which is doable, and it has nothing to do with the 701/721 motors. I don't see how you can use the EDS-1000 and EDS-1000-2 motors for the Lenco since the Lenco is an idler drive design and the 701 & 721 are direct drive. I don't know what "specimen" you have or what exactly you are trying to do. Please elaborate.

"Your contribution was primarily directed to the Goldmund Studio problem."

The earlier question(s) was directed at the Goldmund issue so I answered accordingly. I must add that I would only repair the Goldmund using the Dual motor if the Goldmund platter would fit over the Dual motor with no or very minor machining. Otherwise, your Goldmund is not a Goldmund anymore and you're better off just transplanting the Dual motor onto a custom plinth and make it a stand alone arm-less direct drive turntable.

"We thought that if this motor is something very special some other applications would be interesting."

The EDS-1000 and EDS-1000-2 motors are, indeed, very special and is great for making your own direct drive turntable.

Here is a gallery of pictures of a 701 and its innards.

Have fun!

_______

Dear Hiho, Thanks again for your explanation as well for
your patience with the ignorant. As I already stated my hope was based on Lew because he seems to like to mess with all kinds of TT's in his garage(?). I also stated to have no idea what to with the Dual motor on my own. So it is not easy for me to 'elaborate' on this sade state of affair. However I am 100% sure that Lew is very inquisitive
so who knows?

Kind regards,