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Marantz Model 9 Prototype

Cages are back and on. Still need to find some hardware that attach the cage to the transformers. Have been in touch with VAC and they may have what I need.

Looks so much neater with the cage on!
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I also made my own faceplate bolts to appease myself until I find the originals. Found bolts that were the proper size but they were stamped with the strength etc. Put them on the drill press over some 220 grit and gave them a spin. I'd say they look damn good!

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Wondering if any of you guys are still following this thread, I could use some of your advice.

I have some free time this weekend and Im thinking about trying to fire this beast up. I know I mentioned that I was thinking about doing the time capsule thing but Id really like to know if this unit works. Id also really love to hear it compared to one of my Dynakit Mkiii's.

My tube experience is very limited. I recently built a pair of new MkIII's but that was like painting by numbers and on something replaceable, that's it. No other tube experience. Also, they are tube rectified which allowed me to check filament AC on the drivers without having the output tubes installed. This unit looks SS rectified and Ive never tried to bring something like this up slowly.

Whats the safest way to attempt a fire up here? I have a variac, ammeter, dummy loads, scope, half a dozen DVM's and lots of lead clips. I also have the production schematic and voltage chart so I know what I should be looking for voltage wise but getting to this point is where Id like some advice.

How slowly should I bring up the line voltage?

Can I pull the output tubes to test the drivers first?

Should I have a load on it?

Any advice would be greatly appreciated..
 
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Definitely still following.....but I have zero experience with tubes.....good luck. If it was mine I'd surely want to know if it worked and what it sounded like !
 
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Definitely have a load on it. Install a fast acting 2A fuse. Use a shorting plug in the input.
Bring it up slowly on your VARIAC, watch current draw.
My VARIAC doesn't have a built in ammeter so I use a modified Kill-A-Watt device plugged into it for that purpose. There is a thread here on AK describing the Kill-A-Watt method.
A properly working production Model 9 draws around 1.3 amps at 110-113V AC. Good luck!
 
crooner said:
View attachment 811908
Definitely have a load on it. Install a fast acting 2A fuse. Use a shorting plug in the input.
Bring it up slowly on your VARIAC, watch current draw.
My VARIAC doesn't have a built in ammeter so I use a modified Kill-A-Watt device plugged into it for that purpose. There is a thread here on AK describing the Kill-A-Watt method.
A properly working production Model 9 draws around 1.3 amps at 110-113V AC. Good luck!
Click to expand...

Thank you so much! Will update on the progress this weekend
 
How would you guys recommend determining the output Impedance of these terminals? I know production models had 1,4,8,16 connections but this weirdo only has 3 connections aside from com.

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Maybe the one missing is the 1ohm tap for the phantom center channel and that I may just have 4,8,16? I think im going to gice red a try. It appears to be the only screw to have been used by the wear on the screw and back plate. Im finally getting around to comparing this witing to all other 9's and there are ALOT of differences. Yikes. This is what sucks about oddball stuff, I have no reference material. I've looked across the Web at the wiring on other but none are the same color.

I also found a fingerprint!
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IT'S ALIVE!!!

Drawing about 1.1amps and all the output tubes biased properly as well as the ACDC balance. I'm going to it it warm up for about 60 mins or so and run through the tests again. Meanwhile I'm going to some voltage checks.

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:D:D:D
 
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Congrats on electron movement! You are doing a great job!
Love the picture of The Fingerprint! That picture should hang above the unit! It will hereby be known as "The Fingerprint"!
Any chance that you will allow visitors to come over and meditate Marantzfully in genuflection to this sacred piece?:bowdown:
I understand if you charge admission...
 
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biscuithead said:
Congrats on electron movement! You are doing a great job!
Love the picture of The Fingerprint! That picture should hang above the unit! It will hereby be know as "The Fingerprint"!
Any chance that you will allow visitors to come over and meditate Marantzfully in genuflection to this sacred piece?:bowdown:
I understand if you charge admission...
Click to expand...

Anytime! My gear is always open to fellow AK's to come over and enjoy.
 
Oh wow. That's a sight to behold!
As for the speaker connections, I am sure it is the same as a Model 8/8B (COM, 4. 8. 16)
The 1 ohm tap intended for a center channel speaker was probably added later.

Perhaps that's Sid Smiths fingerprint on that turret board? Way Cool!
 
You have an absolute gem there. A fully working Marantz 9 prototype!
Triode mode is indeed fantastic. Sounds powerful, authoritative, yet with beautiful subtle details. The human voice has great body as well

I would build an all mono setup around it and play the old Rudy Van Gelder engineered Jazz recordings, for instance. The resolution is so high, that you don't miss stereo with those.
Ditto with the old Sinatra Capitol stuff...

Alternatively, keep looking for the matching amp.... I wouldn't be surprised if Sid had two of these built and listened to them in pairs. After the Marantz company was sold, perhaps they got separated...
 
Just a thought. See if Marantz would be interested. Maybe they're just a bean counting money grabbing corporation now (i don't know). They may have some desire for archival or possibly advertising purposes. It might be worth an email
 
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