TT 1000 Power Supply

[Trucker1964]

I can’t beleive I actually have this deck but it arrived from Russia today ! It’s actually in amazing shape and it seems like most cosmetic flaws are minor and can be fixed.

For those who don’t know, the table was manufactured by Micro Seiki for Marantz starting around 1979/1980. This example is the first iteration which some refer to as Mk I. What seems unusual is that it has the original Micro Seiki tonearm (branded Marantz) which I beleive is an MA-707.

I think it’s really great looking and I understand it can be made to sound pretty good. I have read that Ken Ishiwata indicated that the weakness of the Mk I is in the power supply and the glass platter which I believe he corrected in Mk ll which has a suede mat and I suppose a different power supply.

So… my first job is to sort the power supply. The power supply is 100 volts, output is 24 volts; I’m really not interested in running a separate transformer so my only option would be to find someone to reengineer the power supply to work at 120 volts.

Anyone have any suggestions ?

 

[Trucker1964]

The wooden power supply cover was poorly refinished and will need to be re-veneered. I’m going to desolder the power switch and the LED from the board so that I can separate the cover and restore it as original. The PS looks fairly simple and configureable. I’ll need to get more info on the “upgraded” Mk II PS for ideas on how to improve upon the design.

 

[Trucker1964]

BTW, there was a guy in England who built a custom power supply for the unit but my understanding is that he flamed out and cannot be found. Supposedly this is a picture of the guy with a TT 1000.

 

[Trucker1964]

Schematic. Can anyone point me in the right direction ? I figured I’d post this in the Marantz section and get a recommendation for someone to talk to. Maybe I should post in the turntable section ?

 

[Steven Tate]

I’m not sure from your post — is the power supply non-working, or are you just looking to upgrade to a later design?

 

[Trucker1964]

The unit was for use in Japan and is 100 volts. The first thing I’d like to accomplish is convert the power supply to 120 volts as I am in North America. Additionally, as I mentioned, Ken Ishiwata https://www.marantz.co.uk/uk/aboutus/pages/kenishiwata.aspx who is the “Brand Ambassador” for Marantz said that one of the weakness of the Mk I TT 1000 was the power supply; it is my understanding that Mr. Ishiwata supervised the reenginnering the Mk II (suede platter mat and upgraded power supply) as seen below in his listening room in Marantz European headquarters. I believe the MK I power supply was manufactured by Micro Seiki or at least sourced from them, not sure about MK II. Maybe VAC, the company that manufactured some of the Marantz reissues would have insight. I doubt if I could get help from from any of these people (Micro Seiki is long since out of business) but you never know…

 

[Steven Tate]

Wow. Beautiful setup. That turntable looks amazing. Hope you can get the PS thing worked out.

 

[Trucker1964]

Thanks, wish it were my room…

I found an image of the Mk II power supply (not very impressive).

 

[Trucker1964]

Thanks, wish it were my room…

I found an image of the Mk II power supply.

View attachment 1203381

I also found this about the Mk II power supply on the vintage knob: “the external power supply of the Tt 1000 mkII, is a straight rebadge of Micro's ultimate AP-M1”

 

[Trucker1964]

Also from the Vintage Knob:

“The external PS of the Tt 1000 mkII (which uses uses the casing of the Micro PS-M1, as made for the AP-M1's optional EQ-M1 external EQ) bears the "SAILOR" tag which you can see below.

Sailor comes from Sailor Pen, a brand owned by an LP replay addict who funded Micro when the latter was already going down in the late 1980s and in need of urgent cash. After this welcome funding, all of Micro's output was tagged in one way or another with that "Sailor".”

 

[txturbo]

You may be able to move the incoming power to a different tap on the transformer.

Can you tale some detailed pictures and post them or your power supply with the cover off?

 

[restorer-john]

You may be able to move the incoming power to a different tap on the transformer.

Nothing sold in Japan (home market) back then had multi-tapped primaries- it was a requirement to get electrical approval.

It's a super basic PSU, even on the Mk2. All he needs are voltages and it'd be a piece of cake to make a way better PSU than he has.

 

[jstang]

One thing to note is that a good step down transformer could actually be a benefit for the stock PS and your systems vinyl play back in general.

Beyond the obvious need for the 100V AC step down from 120V ... A correctly selected transformer can be used as an "isolation transformer".

Which can reduce AC supply noise being injected into the system at one of the most vulnerable points... The low level mag phono input....

Just a thought.... Kind of a two for one, two birds with one transformer....

Johnk

 

[txturbo]

It could be that the existing power supply will actually work with 120v input.

It looks like the 24V is managed by a three trerminal regulator. Most of them can handle up to a 40V input. You would need to pull the regulator out and see what the input was to it when running under 120V comparing it to the data sheet.

You could also replace the transformer with a new one. An off the shelf 115 to 24V transformer would be easy to get.

As Jstang mentions above the easiest thing to do would be to get an external step down transformer.

 

[Trucker1964]

I know there are no additional taps on the transformer and I believe restorer-john is correct that most Japan only units do not have additional taps. There’s quite bit of really great vintage equipment being sold on eBay out of Japan that’s strictly 100 volts.

jstang: Thanks for that bit about the “isolation transformer. I was wondering if there might be a benefit to putting an additional transformer in front of the power supply; I just needed an avionics engineer to point it out

I am still considering a completely redesigned transformer but in the interim maybe I’ll just run the variac I have in the garage.

 

[restorer-john]

There’s quite bit of really great vintage equipment being sold on eBay out of Japan that’s strictly 100 volts.

The transformers themselves had to only have 100V primaries to be sold in the home market. No cheeky internal multitaps or hidden taps. It was to stop home market gear getting rewired and sent out into the world through 'grey' secondary channels. They had a huge export economy to protect.

I always prefer the gear sold with the full range of primaries. Those transformers are considerably better than the single voltage ones. Pretty much all the gear bought back in the day through the military Xs was switchable 100/110/127/220/240 50/60Hz. It had to be.