Ethan O'Toole's Blog

Sony ES Cassette Deck

No great pics of the deck during this post, maybe I will update.

So I swung by a Goodwill to donate some things, and did a quick check. I never find vintage computers, and most of the video games are picked over. I never find that copy of Space Quest III. But on this trip I did find a Sony TC RC70ES. I debated with myself over it for a little while. It didn’t have the wood ends, so it doesn’t really seem like a ES home component. But it is an ES deck. Less than a year ago I picked up the Nak 680 and have been enjoying it, so why not a little competition? And I tried to fix my childhood Sony dual tape deck and failed — so that still stung a bit. Should I? Yeeeaaa why not.

Brought it home right as I went on vacation. Diving in Jupiter with Eric, Chris and Mary! Chilling in Key West. South Beach Miami! Silverball Museum in Del Ray! Hanging with family. And pre-ordering some belts for this thing from eBay.

So when I got home from vacation the parts were there and ready to swap.

First, the old belt was nasty AF. It was goo, and the goo got on everything. Rubbing alcohol cleaned it off well, but I have no idea if that will hurt the new belts.

Removing the first layer to get to the flywheels was no problem. But the next layer of disassembly resulted in parts popping out all over. So service manual was found, so that is good. People care enough about this model for it to be out there.

Got it back together, annnnnd BAM. Sounded bad. I had to play with the speed adjustment on the motor, but I don’t have a real reference tape. I recorded 400hz from youtube on the Nak (which is not speed calibrated) and threw it in the Sony. It seemed to be moving all over the place.

But the Nakamichi didn’t just work. It seemed to come to life after playing a tape or two and loosening up. So I ran a tape on the ES.

After one side it started squealing. LOUDLY. I ran. I ran so far away. Hit power button. Did some quick google research, and as I remembered the pointer is to the drive motor that moves the capstans. So I put a drop or two of oil on it via a syringe type device used for purging air from printer lines. It cleared up pretty quickly. But not sure if mineral oil is ideal.

The speed still seems to be unreliable, and I don’t know that I really like the sound quality. The CrO2 tape that I recorded Capital Cities – A Tidal Wave of Mystery on the Nak when played back on the Sony just isn’t the same. First the deck detects the CrO2 and you loose high end I think. And there is more hiss. So far I don’t have much of a love relationship with the deck, but I still like the Nak 680 a lot.

Also, after working on the Sony ES deck I now know that I could have probably fixed that childhood Sony deck with motor lubrication. The mechanisms are still crazy complex, kudos to the Sony engineers that came up with auto reverse system and rotating head and all of that.

Time will tell on this deck. Next will be to get a real calibration tape. But I fear I might have to rebuild the motor as well, and I’m not sure of my motivation on it.

Digital Music Corp MX-8 repair

Years ago I picked up a handy unit called the MX-8. I think I found it for $20 on craigslist. The unit has 8 or so inputs and 8 or so outputs. You can software connect any input to any output. It can do data inspection and changes and other stuff, but all I use it for is basically a multi thru box.

I tend to leave my cheapest synthesizer on all the time, it’s a Roland JV-30. I bought that dead, swapped a diode on the power input and it was good to go. By leaving the keyboard, MX-8 and one MIDI module on all the time I am more tempted to stop and bang around on the keyboard a little.

All this uptime on the little MX-8 eventually resulted in it dying. Hit keyboard key, nothing happened. Figured power loss wiped out the current settings but nope, no power.

First I checked the fuse, but the fuse broke off in the fuse holder and wouldn’t come out. Fuses blow for a reason anyways.

De-racked unit and popped lid off. Was always curious what was inside.

CR-2032 (I think that is the size) lithium battery holds the memory. If your MX-8 forgets everything, this battery is easy to replace and this should fix your issue.

The power issue was a standard ?7805? voltage regulator. It died from heat. The heat is from being left on 24×7 for 10 years. When I replaced it, I re-spooged it with some fake artic silver heatsink compound. For sport, I added a 2nd heatsink behind the factory one so there is a bit more surface area ti dissipate heat.

Unit looks well made inside.

I think the hardest part of this entire ordeal was replacing the fuse holder I broke.

I did consider moving to a switch mode power supply, like from a phone charger. I didn’t have anything handy so I just kept it on the original linear regulator. I could save some heat and power by converting it. Perhaps next time.

One of my… Let me re-phrase this. My favorite TV design of all time is the Sony PVM “cube” monitor. It’s an early 80s television set where the back of the TV is framed in with a plastic and perhaps metal frame that makes the TV perfectly square. On the left and right of the screen there are touch buttons. The text of the buttons is invisible until you press one button that turns on illumination behind these. It’s just so damn cool, and it’s from the early 80s.

I owned one before, a 25″ or 27″ model. But the picture wouldn’t always come on and I didn’t know why. At that point in my life I was still under the idea that I would never, ever, repair televisions. High voltage risk and all that. My attitude changed when I got my 2nd arcade cabinet and it had a failing Wells Gardner open frame monitor in it. But my early 25″ or 27″ PVM monitor would snap and the picture would go away. Or it wouldn’t come up at all. I now know the issue is probably the take off feed on the anode line from the flyback. But I sold that old monitor many years ago.

So it has been kind of a thing to want to pick up one of the smaller 20″ versions of my favorite TV. I’m not a super CRT enthusiast, I keep a few around for old computers. I keep my arcades on CRTs. But I don’t consider myself a die hard.

Opportunity hit and my good friend Matt had a PVM-2030 that was said to not work. And I could have it. Thanks Matt! So he brought it to me on one of his trips up to my area. I finally got around to checking it out. It just seemed to work. No repairs needed! It has some rash, some rough scrapes on one side. But who looks at the side.

I hooked it up to what I had laying around. I was too lazy to hook it up to the sencore signal generator that I usually use to poke at arcade monitors. But I found an old Video Essentials DVD and threw it in an XBox Classic. Things were looking okay! Until I noticed that the picture was kind of crooked. And maybe some convergence issues.

Off came the cover!

First thing I did was to hunt for the schematics. I couldn’t find them. I did find the PVM-2530 schematics, and low and behold there is an adjustment that will rotate the screen. Except the PCB it is on in the PVM-2530 model doesn’t exist in the PVM-2030. Most likely old caps have caused it to drift. So my fix, with a ton of sweat was to rotate the yoke on the neck of the CRT. Rubber mallet and stick, true sweat.

There are some adjustments found through holes on the sides. I used plastic CRT adjustment tools that can be found from electronics parts places. Blue plastic thing with rainbow of tools. The tools are poor quality, and I was disappointed when I tried to use them to adjust arcade monitors (mainly the hex width coil on G07.) But they came in handy with the Sony.

I don’t have the speakers for the TV, they were an option and mount to the sides. They come up on feeBay from time to time for around $50. I might pick a set up some day. I will only go for the “APM” flat and square speakers since those were the ones I remember.

I haven’t built any fun cables for the RGB input. IIRC I could probably feed the output from an arcade PCB to this TV, or maybe an Amiga.

I sharpened the picture up a bit and tried my best with the convergence playing with the rings on the back of the neck. That too took a good amount of time. There is still convergence drift on a test pattern in some of the corners as I recall.

Overall though, mission accomplished! Still an awesome physical design. I think PVMs became way more advanced and my choice of one from that point lead to a TV that does not have as good of a picture that later (and especially the Broadcast series BVM) but whatever. Also, those sexy pushbuttons for adjustments? Without onscreen displays and without some indication that you are in the middle it is impossible to tell what the settings are. If you touch the balance adjustment on the set for the audio there is no way to “center” it again without hitting the reset button, and that reset button will reset all picture tweaks. So that aspect of the TV really falls short.

I do hope the schematics for the set become public at some point. That would be helpful.

Sony PVM-2030 tune up