A Quick Kenwood Repair

I did a trip with my friend Clint out to Pure Sound today. We took in a Sansui amp, a Dynaco SCA-80Q and a Harman Kardon 630. I had had a look at the H/K and the Dynaco and they were both items that I did not want to take on trying to repair. The fellow there is a real audio technician; I'm just a hack.

Later I went back to Clint's shop and dropped off a Kenwood KD990 turntable which was one of my faster turntable repair turnarounds. Thankfully it was simple as the circuitry in this would have been tricky to work with. In fact it was not much worse than the best case scenario of a blow fuse, but it did not have fuses.



It turned out to be (probably) just dirty contacts or sticky switches. It would not power on at first, and after opening it up and checking to see if it was getting power to the circuit board at the brown/red/black wires near the top, I simply detached the 2 circuit boards that the microswitches attach to and cleaned them with contact cleaner. I also pulled the black ribbon cables out of their sockets and cleaned those contacts.



Back together it went and it worked!

It's a very nice and high quality turntable, weighing about 14 kilos. Unfortunately this one is a bit beat up which is quite the shame. The piano gloss black finish is not my favourite as it easily shows marks and this has more than a few of those. It also is missing a dustcover, and had an ugly Sansui headshell with an even uglier Stanton DJ cartridge on it.



When I took it back to Space Lab, I moved the cartridge to a better looking shell that was at least closer to the original model (not shown). I do like the tonearm with it's machined look. The antiskate is an interesting variation on the weight on a fishing line concept.



Anyway I did not get to to play with this one too much. It worked and sounded fine on the single record I played on it, but then it went back to the shop to go on display. And I am on to the next project, a NAD 7020!

Oh No! It's a new media format!

No it is not a new digital thing to take over from CD, Blu Ray MP3 or whatever. It's actually a very old format... Reel to Reel tapes. It's just new to me.

Even that is not quite true. I have used RtoR a lot but that was back in the 1970's either at home with cheezy portables or at CHSR radio at university where I used some very good gear and was pretty good recording and editing on it. I might have to relearn some of those skills.

I answered a Free ad on Craigslist and was not the first in line but the other guy could not make it in from Surrey right away and the owner called me back. The Akai 1730D-SS tape deck and the Akai AA-6100 amplifier that he gave me with it are still in the car (so no pics yet) but I got manuals, about 30 tapes, a tape head demagnetizer plus some Dual turntable parts and brochures too. Even the Puma sports bag was almost worth the trip.



I don't know where I am going to put this but it should be fun to play with! At least it came with an instant music collection so I don't have to search that out right away.



...I couldn't resist. I went down to the car and brought them up for a quick test before bed. I have Janis Joplin (backed with The Stones - Get Yer YaYa's Out) on the phones right now. It looks like the tapes were all recorded at 3 3/4ips and 2 sided. They are also about 40 years old, and the amp & tape deck have not been cleaned in any way so far so the fidelity and noise level is not the best, but they work!

I took a U-Turn the other day

Or rather I will take, or maybe get, a U-Turn sometime next year.

U-Turn Audio is a start-up venture by 3 young guys (geeks? nerds? hipsters?) with big dreams. Dreams of building a turntable they can bring to the masses at an affordable price but with great performance for the dollar.

They have been working on the project for over a year now and hope to have the turntable hit the market by the middle of 2013.  A few days ago they launched a Kickstarter campaign where essentially you pledge to support the product launch. Various dollar commitments will get you things from stickers to t-shirts to custom painted versions of their turntable.

I signed up. $150 is not a lot of money really and I am even thinking of upgrading to the next level of $250 so that I can get the acrylic platter and that green colour. I don't know about that colour but maybe I should go for it. It would be different from the other 10 or 15 turntables I have at least! It's not like I need another one, but if I eventually do get it (Kickstarter campaigns are not guaranteed) it should be worth it, from what I have read about the design so far.

The design of this turntable is very simple, and something similar to what I would like to try to build myself some day. I don't plan to mass market any ideas but would like to try my hand at it. Now where is my CNC machine?

  

Trying to get organized...

Yes I have to clean up and get some organization. My dining room has been a disaster lately and we won't even talk about the living room.

Some storage drawers will help with the various components: one for fasteners and fittings like RCA jacks and speaker binding posts, another for resisters, capacitors, coils and another for belts, lamps, LEDs and wire. That's a start...

Selling some of the extraneous turntables and receivers is part of the plan and having a better spot to display them for photos and auditioning will help. The new record cabinet helped as it gives me a good spot to highlight pieces. I turned an empty console stereo cabinet into a storage unit for 300 or more records in a few hours. It holds about 1/4 of my record collection but the rest of them are at least in some other form of shelving. These ones were just in piles until the other day.

Before:



After:



After getting this corner of my small place cleaned up I was able to quickly set up and swap in and out several pieces of gear for photos. One sold right away and others had interest. Another I just took the pictures for and did not advertise as I don't know if I can sell it...yet!

First, the Akai AP-004x turntable which is a very attractive turntable and a Sanyo DCX-1970k receiver.



The Akai deserves another picture:



This cute little Sansui R-5 receiver sold practically immediately after I Craigslisted it:



The Technics SL-D2 was up next:



And one of the receivers I am not sure I want to sell, but took the pictures anyway, is the Mitsubishi DA-R10.



I know I should get rid of it...pay some bills, reduce, unclutter...but darn! I like it...

I have to start selling some of this stuff

The last little while I have definitely been taking in more than is moving out. Today I picked up a Scott turntable, model PS-87. A few days ago I went to get a Technics SL-D2 and an SL-1700 MKII, and the guy also gave me a Sansui FR-1080.

Scott PS-87 (before)









The Scott was filthy but has already cleaned up nicely and as has the SL-D2. The Sansui and Scott will need some lid sanding and polishing that I should get to tomorrow. Once that is done and I do some tweaking on all of them they should be ready to hit the road, or at least Craigslist.

Scott PS-87 (after)





The Scott looks like a solidly built and pretty good quality piece. Not top of the line by any means but a capable direct drive with a nice heavy mdf plinth, large transformer and motor and very nice controls. I will need to repair the tonearm lock and the arm lifter platform as they are both broken but I am some plans that I think will work out.





In addition to the tables mentioned above, I am soon going to be able to finish off the the Technics 1300 and the Akai AP-004X. I have the new cables for the 1300 and the headshell for the Akai will soon be here.

I should have lots of record players ready for that Christmas rush!  

The Gear Still Flows

I've been happily listening to my Technics 1200 and have swapped back in the Yamaha CR-820 that arrived from Seattle several weeks ago, after a few weeks with a Carver MXR-130 hooked up. The Technics still has a minor issue or 2 which hopefully I can resolve and so does the Carver.

The turntable speed still has a tendency to fluctuate for a few seconds when I first turn it on. This is probably circuitry or solder joints that are suspect but it might just be the pitch slider. I am going to order one from KAB as that is a relative simple and inexpensive item to replace.

The record above, by the way, is Muddy Waters at the Checkerboard Lounge in Chicago, recorded 1981. It's a great package of a double album, 1 black vinyl and 1 white, plus a DVD of the show. Most of the Rolling Stones (Mick, Keith and Ronnie) showed up Muddy was soon joined on the tiny stage by all 3 of them. Terrific show and a nice presentation in this recent release.



I don't have any pictures of the Yamaha yet but the Carver I have snapped. I listened to it for a few weeks essentially without issue and have done nothing to it internally or externally as it is in nearly perfect shape. A couple of the controls are a touch scratchy & in need of cleaning and the lamp behind CARVER is burnt out. When I switched it to the tuner the other day I found the first indication of the issue that the previous owner pointed out and one that is well documented with the Carver receivers. The tuner tends to stop working or perform erratically and that is exactly what this did.

Being as well known as this issue is and Carver being not only well known but also not a cheap piece of crap, it has also a well documented set of repairs. There is an issue of a trim capacitor and an IC in the tuning circuit that are prone to fail. In addition the output relays and some resisters are frequently problematic. In fact there is a vendor on ebay that markets kits with instructions for just these repairs.

I am going to proceed with most if not all of the failure prone areas even if only the tuner is currently causing problems (and the bulb and pot cleaning from above). I ordered the tuner TC9147BP integrated circuit from ebay, though from a different vendor, and will get the relays and other parts as well. As usual I like to try to upgrade if I can, and I will actually install a socket for the IC instead of direct soldering to the printed circuit board. I don't want to burn the IC and I figure out of 42 pins I might mess up 1 or 2 and overheat the darn thing. 

The Carver won't be a keeper. I don't need 130 watts (!) per side, or is that over 150? It's the same receiver apparently as the MXR-150 and they both don't clip until around 157 watts. It's cool and all that, but I figure with the amount I spent on it plus the time and parts I will come out well ahead if & when I sell it. 








A few more things will go on the block soon too. I have a recently acquired Akai AP-004X turntable that will clean up nicely. A Sanyo receiver and a small Sansui R-5 receiver will complement one of my turntables just fine and along with a set of just refoamed EPI 100 speakers will be an ideal system. 

Actually though the best match for that Akai even though not quite of the same period would be the Mitsubishi DA-R10 with its rosewood finish. I will be sad to see it go but I fear it must...

The 1200 is ALIVE!

I got back into finishing the Technics 1200 in the last few days. I had been putting it off while waiting for parts, working on other projects or just procrastinating. However once I started again I finished in 2 evenings.



One of the problems with waiting as long as I did was the possibility of losing pieces and or just forgetting what went where. The good thing about this turntable is that there are so many pictures, forum threads, how-to's, documents and videos about it that as long as I had a computer near I could not get too lost.

I still wish some of the parts came with some form of instructions though. KAB has some so-so pictures on his site but nothing at all comes with the actual parts, such as the hinges or turret board. Even suggested wire routing, or a parts list or sequence of assembly. I am very mechanically inclined but even so. I also think I might not have received some of the screws with the hinges. I could be wrong about that but anyway I managed to find some appropriate bolts in one of my bins.



In the first pic above you can see the tonearm after internal wiring was updated with new Cardas 33g wire. I also added some cotton batting inside the arm as damping material to reduce resonance. The black stuff on the outside is heat shrink tubing to help play a similar role. However it looked ugly in that on the curves and ends it developed wrinkles. Pretty ugly and of probably very small sonic benefit, so I stripped it off.

The second pic shows the underside of the arm with the new terminal board attached. The tonearm wire meets the external wiring at the 5 pin strip here. This replaces a small printed circuit board that Technics originally installed.

Some instructions online make things look dead easy. Easie-Peasie in fact if you can believe the English bloke on YouTube who has lots of videos on the 1200. He describes how to thread the 2 base parts together using the 0 marking on the height adjustment scale as a guide and he gets it right first try in a few seconds. The Technics Service Manual says use the 3 (scale is from 0 to 6 for millimetres of height adjustment) as your starting point. I tried at least 5 or 6 timed before I got it right, and using the Technics method, not his.

The next photo just shows an alternate view, plus the record weight I had powder-coated at the same time. Below that is a top view of the new KAB interconnect board. This attaches on the same bolts (longer ones than stock) as the right side hinge. This external connection enables you to use your choice of RCA cables. I don't particularly like the wires being as exposed as they are, but I used a bit of tape to anchor them somewhat, but I think I will also make a small clamp or sleeve to attach to the underside of the table to protect the wire.

Another thing I supplied myself was some adhesive backed felt from a fabric store. This went under the pitch control slot and directly on top of the control itself and acts as a dust shield. Another piece goes on the underside of the knob itself.





And finally the end result!



I am practically ecstatic with how good it looks. It also works great (but see below) and sounds terrific. I still have to fine tune a few things and there are still a couple of issues.

The cartridge position has to be checked, the VTA (tonearm height) and the anti-skate verified. One of the issues is that the tonearm rest does not fit this arm well. The mount for it on the old arm was just slightly different. I had to gently ream out a bit to make this fit, and I don't have the right nut or spacer for it. It also won't quite clamp the arm properly. I think that just maybe it was not from the same model of turntable. With the damage that was done to the old tonearm I would be surprised if this was also replaced at some point.




The bigger concern is a bit of speed instability. The pitch slider is supposed to completely lock the speed at the centre setting. It adjusts speed up or down by 8% over the range. When I first turn the table on it sometimes seems spot on, but other times runs very fast in the middle of the scale. It can be zeroed at a postition just off centre but that bugs me. When I have played a side or 2 it seems to stabilize and zero means zero. I have more testing to do, and some troubleshooting.

A lot of my stuff has been coming courtesy of KABUSA, just so you know.