Experience Restoring Dual 1226

[Tim D]

I recently decided to get back into vinyl and was reminiscing about a Dual 506-1 belt drive that I had about 20+ years ago. I spent a few weeks shopping around for a basket case and found a Dual 1226 on flea bay. It was one of those parts/as-is deals. I paid about $80 incl shipping. Knowing that I was into a project, I still decided to jump in.

It was largely complete with M91ED cartridge and a cover. The stylus was trashed. The cover had some strange markings on it. It came with the changer spindle only.

In doing my research on this forum and on VE, I found that there was a manual available on servicing and restoring vintage dual's. It comes with the tiny part called a steuerpimpel and some recommended grease to do a portion of the lubrication. The guy sells on ebay. I decided to give it a try.

When the turntable arrived, I plugged it in and gave it a try. The turntable spun momentarily when I pressed start, but stopped again. Pressing it again got it to start spinning again, but as soon as I let go it stopped again. The manual start when moving it off the tone arm rest didn’t seem to be working either. Hmmm. There’s more than one thing wrong here.

In looking it over the “United Audio” badge on the base/plinth was missing. The plinth was scratched, but not horribly so. The single play spindle was nowhere to be found. It had the original black and white RCA cables w/ground, and the power cord. The dust cover had some strange pattern on it like it was set down on a hot waffle iron, but no cracks. It still had the original hinges. The tone arm rest was missing the hold-down.

I took the turntable out of the plinth and found that the masonite board supporting the turntable had broken in places. The holes that support the suspension were punching through. That board would need replacing.

I downloaded the available user manual and services manuals. (Thanks VE!). After reading those and the restoration manual it was time to get started.

First I built a cardboard ring to fit around the platter. It was about 4-5 inches high. I taped down the tone arm so that it wasn’t swinging around. I removed the RCA cables. I put down some heavy paper I got from the local HD on the dining room table and flipped it over making sure that the tone arm wasn’t in the way or taking any stress. Looking it over, the interior was a bewildering array of clockworks. For the next week I spent a couple of hours here and there each night cleaning it with 91% isopropyl and cotton swabs. Interesting enough this thing had sand in one corner of the underside. I have no idea on how that got there. The old grease was thick and a bit of a chore to remove. In places it was the consistency of dried out toothpaste. With patience I was able to clean up the underside. From time to time I would temporarily re-install it in the base and try it to see what part of the mechanism was functioning. A simple cleaning wasn’t fixing it – yet.

 

[Tim D]

With most of the old visible lube gone it was time to look further. I tried to locate where the original steuerpimpel was. I couldn’t initially find it. Upon doing some research I eventually found the location and of course the original was gone. Eureka! I have a new one on hand. Let’s install it and see what that fixes…. I had to remove the main lever which has a paddle on the end which slides over the steuerpimpel. I did some more cleaning with the lever out of the way and installed the steuerpimpel. Time to try it out. After re-assembling the main lever and putting it back into the plinth I tested it and no real change… Well, it didn’t fix much, but it felt like progress.

Next I tried to tilt it on its’ edge and force the main cog to rotate with the tone arm off its’ rest. This seemed to produce a result. The main cog cycled through a full 360 degrees under its own power– moving levers and making some mechanical sounds along the way. Now that was progress, but of what type of progress I didn’t know yet.

I found a video of a guy working on a similar turntable on youtube. He was investigating the movement of the arm. His videos had some incorrect statements on them, but the learning was terrific as he had micro-cameras that illustrated what the various levers and gears were doing. That helped to understand the various motions of portions of the mechanism. It also took away some of the mystery and dare I say it? “Fear of the unknown.”

With a little more cleaning (no new lube yet) and some working of the arm mechanism, I found that the manual start was beginning to work. I continued to clean and to move the arm and it started working more and more reliably. Eventually, I could declare that the manual start was working. The automatic start still was not.

I investigated what the start lever was doing and followed the movements of the various levers when it was pressed. It led under the main cog and from there visibility was limited, but I could see that it was moving something under the main cog. I figured it was time to dig further. I noticed that when rotating the main cog that it was very stiff to the point where I believed that something wasn’t right. I looked for a way to remove it and found that the axle for the main cog was held by a nut under the platter on the other side of the turntable. I removed that nut and a couple of small bolts that held the main axle for the platter from underneath the turntable. The cog and main axle assembly became loose, but I couldn’t extract it because of the other mechanisms in the way. I ended up removing the muting switch next to the cog (2 screws) and the cog came right out. I was able to take the cog off its’ axle and discovered more coagulated grease. I spent a few minutes cleaning the new areas of the cog that were exposed and the axle. Fitting them back together I could tell that the cog was definitely freer. I could now inspect that autostart mechanism under the cog and it didn’t look damaged and had no apparent visual issues. I reassembled the cog, re-installed it, put the muting switch back and replaced the main lever which fits over the main cog. I tried the mechanism again and there was no change in behavior.

 

[Tim D]

At this point it was time to focus on what was happening under that main cog with the autostart mechanism. I read through the service manual and it had a section on the “Shut-off and Change Cycle” which didn’t sound like the autostart, but it was the same mechanism, so I read through it. It seems that the mechanism needed to catch a drive gear on the platter to give it a kick so that the gear teeth on the main cog would rotate and engage that drive gear. For some odd reason that mechanism wasn’t giving it a kick. I worked the mechanism many times with the turntable tilted on edge and I could see that the mechanism wasn’t extending far enough. Hmmm, was it bent? Didn’t seem so. Why wasn’t the mechanism extending far enough to give it a kick? In using a cotton swab I was able to reach the edge of the mechanism and give it a push and suddenly the cog engaged by itself and the autostart sequence took off and completed on its’ own for the first time. Apparently, there is a lever (somewhere) that is pushing that mechanism, but the lever wasn’t extending far enough. In looking around I couldn’t immediately see with all of the motions under the turntable which lever might be involved. Time to move on to something else. In the service manual the mechanism above is listed as part 158 for reference.

I spent some time checking on the manual start and along the way decided to try the autostop. It worked! It was the same lever as the autostart, but it was pressed in the other way. Why did it work going to stop, but not to start? It took a bit of investigation, but I eventually found a not so obvious slide on one of the lever arms driven by the start/stop control lever. This slide had a slot in it that actually moved to extend one of the levers if stop was fully selected and engaged. By investigation of the stop selection, I figured out that once stop was selected and the slot was engaged, that the whole mechanism was locked into the stop operation until it was completed and the slot was disengaged. Wow, I found something interesting! I wondered how this might be related to the start operation. The same sliding levers actually had two slots in an “H” pattern. The stop selection used one leg, I was guessing that the start selection used the other leg. I worked the mechanism several times and could get the sliding lever to engage on the stop selection on one leg, but the start selection would never engage on the other leg.

I found that I could partially disassemble the sliding lever and access its’ two sliding parts. They were connected by a small spring. I could see that with manual manipulation that for whatever reason the geometry just wasn’t quite right for the slot to engage. I looked like the levers needed some adjustment. At that point I determined to try a little minor surgery. I took some very small needle nose pliers and bent the lever with the tooth that engages the slot ever so slightly to see if I could move the geometry to allow the other leg of the “H” to engage. Disassembled, a small test showed that it would now engage on that other leg. In fact it could engage on both legs now. I hastily re-assembled the entire mechanism and put the turntable back in its plinth and plugged it in. I held my breath and gave the start control lever a push. It worked!!!! After dancing a bit I took the turntable out again and flipped it over. It was time to start lubing the system. The two parts of the sliding lever are listed as parts (189) and (185) in the service manual. It was the lever 185 which I adjusted so that the tooth on the end of 185 would fit into the “H” slot on 189. These are joined by a spring, but the 185 is on the upper side of the turntable under the platter and the 189 is on the underside.

I found that the new start sequence was not entirely reliable. I performed a little more adjustment of the part 185 and then decided it was time to move on to lubrication and then to see if all mechanisms would work reliably. So I moved on to the lubrication instructions in the restoration manual I purchased off flea bay.

In moving on to the lubrication, the inclusion of the grease with the restoration manual was very helpful. I did find that the various oils mentioned in the restoration manual and the service manual were bewildering and a bit confusing. I guessed my way through which ones were appropriate. I had purchased two kinds of “3-in-one” oil, some Singer sewing machine oil, and some Norwich oil which I had heard about in my investigations. I wasn’t entirely sure which oil in the documents applied to the ones I had purchased. In the end I followed the lubrication points in the two documents and worked my way through the grease and oils and exercised the mechanisms thus lubed to ensure that they were free and functioning. This included the bearing at the bottom of the platter axle and the various joints in levers and the main cam/cog. When finished, I tried out the turntable again and it worked perfectly! Start worked! Stop worked! Manual start worked! I took out the turntable and cleaned the underside and the area under the platter to remove fingerprints, smudges, and excess oil/grease.

I replaced a few items such as the tone arm rest with one I had found on flea bay (it was missing the hold-down), and the stylus. I had found a new stylus from EV which had decent ratings for the M91 cart. After re-installing the turntable I felt it was time to adjust the turntable and try it out.

Adjustment was a bit of a research project. I found that the tone arm wouldn’t balance. I couldn’t move the counterweight out far enough without it falling off the end of the arm. I did some research and found a secondary adjustment with a screw that allows the tone arm shaft to extend out the back that took care of this. I balanced the arm, set it to 1.25g and then set the anti-skate to the suggested setting in the manuals I had downloaded. I plugged the whole thing into my Marantz 2220b that I had just picked up from a local electronics store and hit “start”. Sure enough, it played. And it sounded terrific!

 

[Tim D]

My next step is to restore the plinth and the dust cover. I also have more to get to complete this turntable, such as a strobe disk, protractor, and record cleaner. I have purchased a single play spindle for it. Not sure I’ll ever purchase the 45 changer spindle unless I want to collect it. I was never a 45 person. (Sorry, no offense to those that like 45’s.)

Well, I enjoyed writing this. My intent is to help others that have problems with the start/stop engaging. I was starting out with no prior experience with this mechanism or this kind of work. While it was a challenge and took me a week or two to get the whole mechanism running, I found it quite enjoyable to work on this complex machine. Thanks to the various sources for the information. Most of what I needed was out there, but the interaction of the two levers I mentioned above wasn’t mentioned in the sources I looked at. (Not saying that it wasn’t out there, but I ended up figuring this out myself once I got to the two levers at issue.)

I’ll post some pics soon.

 

[EchoWars]

Good write up. And kudo's for your tenacity.