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Help in restoring a 1970's Kenwood PC-400U

E

electrofelt

New Member
Hi everyone!

I stumbled across here searching for info on a Kenwood PC-400U. I'm a novice in this world but I'm hoping for some suggestions on repairing/caring for my record player. A few years ago the needle was damaged resulting in scratchy sounds, since then it's been wrapped up in the attic.

I took it out to sell it, but instead I think it's worth resurrecting. I've read a few comments that say it's a good table but it's been neglected. Any suggestions on general beginner how-to's would be appreciated, the manual doesn't seem to be available for this guy...

It looks like it has a Grado G cartridge, but I can't see any other identifying numbers. It's a medium tan, not green like the dining room lights suggest. Do you think it's possible to find a replacement needle or should I just go with a newer set-up? Any suggestions on types that would fit? Or maybe another reason I might be getting the scratchy sounds...

The insides probably need some cleaning/greasing too. Molybdenum grease seems generally suggested but what type of oil should I use?

And I apologize for the ignorance! Thanks in advance if you take the time to reply.

Jess


Click the pic for high-res.










 
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Cool table and well worth putting back in service. Without any documentation, you need to do a bit of learning as you go. This seems to be a heavy belt and idler drive turntable that would have been a very nice machine in its day. The well known belt and idler drive table from Thorens, the TD-124 sells for a grand give a lot take a little depending on condition. I don't think this one is in that class of value because it is not a Thorens but it probably can perform close to that table because of the very heavy (for the time) platter and the nice drive system.

It does not appear to have a diamond at the end of the aluminum cantilever on the cartridge. No worries with that at all. We can get the table up and running right and then put just about any cartridge on it you want. Price is the determining factor there. Good better and best and from reasonable to way out of our price range. Your table has the standard ½" mounting style cartridge and this is the most common type, priced from $25 to about $15,000, That table can use one up to the early 4 figure range and get the most from it. The table is that good. But you don't have to go there. You can get a new stylus or a new cartridge for a couple hundred and have something.

So first the table. Search the web find some info on what to do to refresh the table and see if you understand the info. If not, post back with pics and we'll help you through it. Won't be hard. Everything is repairable. A new belt, keep the old one until you know the new one works. New idler since the rubber it old, dry and hard, no problem, the idler can be rebuilt. This table is well worth the work and expense.

What do we need to do to get you going?
 
Sorry for the delay! Both my husband and I's cars broke down, so it's been a hectic week. Finally just sitting back down to this project.

Thanks for the info. I've been doing some reading and I've finally gotten the wheel off the top to take a peek inside. I understand it uses both an idler wheel and a belt drive which is a bit more uncommon? Haven't found much info on those either. The parts inside seem fairly clean and the belt doesn't show any signs of dry rot or wearing from what I can see. I even found a 50 year old bag of desiccant :)




I guess my first question is about oiling the motor... Is this something I can do without disassembling too much? If not, then are there certain things I should watch out for when taking it apart, such as the *exact* location of certain parts? The only example I can think of is marking the cylinders-wire match ups on a distributor cap before unplugging... things like that. It's rotates just fine now so I don't want to do more damage

Also, for cartridges, it seems that everyone has a different type installed and a different opinion of what's best. So are there certain types of cartridges or do they have a universal fit? Is it likely that I'll have to upgrade the head to accommodate a modern cartridge?

Edit: No idea how to remove the hyperlink, sorry about that...
 
Cartridge is standard ½" mount and you can use any of them out there except the P-mount.

I would carefully pull the belt and clean the motor pulley, see all the built up belt material on it? Also clean the big pulley that the belt turns. Some like alcohol. I use all sorts of chemicals because I have them and am not scared of them. Don't know what would be best for that. A q-tip would be some work but wouldn't damage the pulleys.
I would put a drop of machine oil (3 in 1, 0W-30 synthetic) at the base of the shaft where it enters the motor.
I would think about pulling the three screws that hold the spindle and look that over to see if it is something that can get lubricated.
I would see if the big screw on the idler comes out to be able to put a drop of machine oil on whatever is turning against something that doesn't turn under the idler.
If the idler tire is hard or has a flat spot on it, I would get it rebuilt. Maybe http://www.terrysrubberrollers.com/ can make it new again. I'd check, he does great work but I have only had tape deck parts done there. There may be some TT specialists that do the same thing, I just don't know them.
It looks like it would be difficult to remove the big pulley to lubricate it so maybe this will be fine for now. As a matter of fact after cleaning the pulley if everything is moving smoothly, limit the work until you get the table up and running and think about what it might need. This might give you time to find service and owners manuals.

What is the switch at the top of the picture?

Now that we have the table done, we can look over the tonearm. If it moves smoothly, all is good and you just need to mount a cartridge, align it and set the tracking force and antiskate. I mentioned all that so you would know all the work that needs to be done. It is not hard and even without manuals we can help you through that. With a couple pictures of the back of the tonearm, the pivot, weight on the back end and such, we'll know what is there.

How about plugs on the table to plug into the wall and to the stereo? What do you have for stereo to plug into.
 
All that sounds pretty doable. I'll grab some oil today. The idler tire seems to be in good shape, not dry or has any hard spots, so I'll give it a try first and see if it has any issues.

The switch at the top of the picture is just to change the output voltage from 120V to 220V. Also, what is the 60Hz/50Hz switch for?

Do you think a cheaper cartridge to get me by for now while I get it up and running would be ok? I saw a recommendation for a Shure M92E budget cartridge but I don't know if getting a cheap one would just be opening up a new can of worms... https://www.shure.com/americas/products/phono/m92e-value-phono-cartridge

For the plugs in the back I have a wall outlet (no ground) and the RCA audio plugs with a small ground coming off of that. Where does this ground go to on a newer stereo? I also have an old Sony receiver (STR DE-185) (no phono input), two Boston Acoustic speakers, and then a cheap pre-amplifier (TCC TC-400G). The last time I ran it all together it played sound but was very noisy. I tried two different records to confirm it wasn't the record itself.

I'll upload pictures of the tonearm, pivot, and weight assembly tomorrow or Monday.
 
NICE turntable!
I just bought a similar one, a KP-5021.
Will be very interested in how the rebuild goes.
Please keep us posted!
 
I would probably replace the stylus on the Grado. Similar price, but I don't know Grados enough to say which stylus and whether it would work. I know they like the more expensive stylus but we are not going there.

People talk a lot about the Audio Technica AT95 being a good inexpensive cartridge. It will work with the table, half inch mounting. The Shure shows it as being a P-mount (plug in) and without the half inch adapter it will not work. I don't know if Shure supplies that adapter or not, didn't look to far into it.

The ground goes to the TC-400G, that goes to an line/aux/high level input. Newer stereo? don't know what inputs that would have. but on the Sony any of the inputs would work. Just select the correct one. I'd use MD.

Worldwide electricity is 100, 120 and 220 volts and 50 or 60 Hz. Your switches should be 120 and 60 for US power. There will be ranges on the voltage numbers but not the frequency (Hz) numbers.
 
2020 said:
NICE turntable!
I just bought a similar one, a KP-5021.
Will be very interested in how the rebuild goes.
Please keep us posted!
Click to expand...

Yeah I am pretty happy with it so far! It seems really sturdy. And I'm planning to take as many pictures as I can to document all the steps and post it somewhere. There isn't much info on these guys, but I guess the KP-5021 is very similar the the PC-400U.


I missed that the Shure was a P-mount, but I'll do a bit of digging on the Grado and see if I can just replace the stylus. There are no model numbers on the cartridge that I can see, so I'm assuming they are on top underneath the Kenwood cover?
 
Hi, You need one of the Grado folks to chime in. I would not remove the cartridge from the headshell at this point ( you will loose the alignment if you do this ). @marcmorin I believe can tell you by the color the Grado styli replacement.
Good luck, Nice looking table,
 
electrofelt said:
Oh I'm glad I didn't start it yet, that's what I was worried about. I'll wait to hear back. Thanks for the tip!
Click to expand...

Hi, is that a light tan cartridge body?

edit: re-read the original post. There is no model number on that, most likely a 'world market" cart that wasn't named as the American market carts are. if there are silver dots on the stylus, it's a GTE+1, if there are no color dots, it is a GF3. any of the current production styli Grado offers will plug right in. Quite a few favorable reviews on the new "2" line.
 
Haven't forgotten about you guys! I've been stonewalled by a lack of a working receiver to test everything (tried two... still need a different one).

I confirmed that the cartridge is the GF3. Thank you so much for the info! I was planning to get the green Grado cartridge, it seems most people recommend that one over the black one. I also realized while cleaning it that the whole head wasn't screwed in all the way. I fixed it but haven't been able to test it yet to see if that's the source of the scratchy sounds. So to be continued...

In the meantime I've been cleaning things up. Took the cover off, oiled and realigned the hinges. I used some automotive buffing compound on the plastic dust cover and it made such a huge difference! Looks (almost) brand new.

One of the hinges had fallen off the track and caused small stress cracks around the hinge points. They aren't hugely noticeable, but I don't want them to get bigger. I could drill a small hole at the crack tip if I'm really worried about it, but it might look a little funny. I was thinking of using a small piece of clear automotive paint protector to reinforce the crack. Have you guys used a different method for cracks?

Also uploaded a pic of the weight assembly at the end of the tonearm.

IMG_0310 by Jessica, on Flickr

IMG_0325_2 by Jessica, on Flickr

SF103787 by Jessica, on Flickr

SF033695 by Jessica, on Flickr
 
In my experience, plastic weld is the best way to repair broken acrylic. It’s usually available in model shops. Unlike glue, it really “welds” plastic together and restores original strength
 
I was thinking of that but worried I might not have steady enough hands. Might try on some spare acrylic first. Does it need a weld groove like metal?
 
Have you seen the refresh of one of these on pinkfishmedia? http://pinkfishmedia.net/forum/thre...d-pu-400-idler-turntable-which-grease.121288/

Different ways to work on that crack. maybe gluing a reinforcing U on the cover around each hinge, but I don't know for sure. You do want to keep that cover in good shape, gonna be hard to find another one.

Did you find the pictures of the PU-350 service manual on vinylengine:
https://vinylengine.com/turntable_forum/viewtopic.php?f=18&t=55909&start=30#p454253

Might need some photoshop to make them into a nice readable document.
 
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Oh awesome find on the 350 manual! That's really helpful. I'm surprised how short they were

I had seen the few pictures from the pinkfishmedia site but I guess I missed half the thread with all the different steps he took. The only part I'm still unsure of is where to oil the motor. The 350 mentions oiling it but seems to be in a different spot than mine. I'll grab some pictures, maybe you'll recognize it
 
As we get further along on this and need to set up the tonearm, may need to look carefully at the antiskate contraption hanging on the outside of the arm. I think the pin coming out of the arm should be behind the contraption arm that does not have a weight. The weight should set up so that it causes an outward pull on the arm.

Points to lube a big motor like that would be the top and bottom bearing areas. The area were the shaft of the motor is supported so it does not wobble. Maybe you can use that info to hunt for a place that looks like it should be an oiling location.
 
Blue Shadow said:
As we get further along on this and need to set up the tonearm, may need to look carefully at the antiskate contraption hanging on the outside of the arm. I think the pin coming out of the arm should be behind the contraption arm that does not have a weight. The weight should set up so that it causes an outward pull on the arm.
Click to expand...

Indeed. As it appears to be a unipivot design ( if so ,as the name implies , it pivots in all direction) a bit of special care is needed. Aside from the VTA the azimuth ( cart being perpendicular to the record) needs to be taken into consideration as well. Went through this with my Mayware arm. Of course if its not this is moot. Good looking TT. Bob
 
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