I picked up a Dual 505-2 turntable on craigslist. I don't need another turntable. I have a Thorens TD 316 in the den that I bought used from The Sound Well in Berkeley, CA in the 1990's, and it has served me faithfully. I also have a Technics SL-7 that someone left out on garbage night a few years ago. It needed a little work (I replaced the arm drive belt and cleaned and lubricated the rails), and it works perfectly now. I have it in the living room system.

I bought the Dual because it was advertised as working "perfectly" and it was only $40. One of my first turntables (circa 1981) was a Dual 604, which served me well. I thought I'd pick up the 505, play with it a bit, then pass it on to someone wanting to get into vinyl. I read some contemporary reviews, and they were good ("The Dual pickup arm is well-designed and generally superior to those often found on medium-priced turntable packages" - Gramophone, 1986).



I wasn't able to audition the turntable, just plug it in and confirm that it worked. I knew it had one broken hinge and a small crack on the rear of the dustcover. It came with a pre-mounted Ortofon OM 5e.

I got it home and plugged it into my Rotel RA-931. I set the tracking force and anti-skating to zero, balanced the arm, and set them both to Ortofon's recommended 1.75 gms. Then I double-checked it with my Shure stylus force gauge. Tracking force was dead on.

I inspected the stylus, and the needle and cantilever both looked very clean. I have no way of knowing how worn the needle is, so I picked an unimportant record and gave it a listen. There was no sound from one channel. After a bit of troubleshooting, I found it was one of the RCA jacks. Wiggling it didn't help, but when I pulled it back slightly out of the amp, it worked fine. I put that on the list for another day.

The turntable ran smoothly and quietly (I thought I heard a funny noise at first, but I haven't heard it since). It sounded fine (no audible wow & flutter or rumble), though the cartridge sounded a bit dull. I decided to check the alignment.

I downloaded an owner's manual and service manual from Vinyl Engine. The 505-2 was sold with the Ortofon OM cartridge pre-mounted, and the manual has an illustration of the cartridge in the headshell, so I mounted my Ortofon in exactly the position it was in the illustration. Then I checked it with my Needle Doctor paper alignment tool, and it appeared to be spot-on. I listened to it again and it still seemed a bit dull to me. I did an A/B comparison between an LP and CD of CSNY's Deja Vu, and they sounded virtually identical, so perhaps my current cartridge (Ortofon X1-MCP) is a bit bright and I've gotten used to the sound.

I checked the rotational speed. I put on my Shure test record, played the 1000 hz tone, then opened the Gibson app on my iPhone, which said the tone was 999.09 hz, off by less than .1%. The pitch belt is broken, but that's fine, as I have no use for adjusting the pitch. I just want it to be correct. The Technics SL-7 is quartz locked, so as a comparison, I played the test record on the SL-7, and the tone read 999.09 hz again. That seemed odd for it to be exactly the same to the hundredth place. But then I checked it on the Thorens, and it was the same: 999.09 hz. Just to confirm that something hinky wasn't going on, I touched my finger to the platter and slowed it down a hair, and the Gibson app immediately registered the drop. I concluded that 1. All three turntables are running at exactly 33 1/3 RPM (since the SL-7 in quartz-locked), and 2. the error is either in the Gibson app (unlikely) or the record (more likely) - either the oscilloscope they used during recording was slightly off, or a small error was introduced when the record was pressed.

Next I probed the service manual and checked some things on the turntable. The tonearm bearings were loose, and I successfully tightened the vertical bearing, but the adjustment screw for the horizontal bearing would not budge. I tried all my tricks: WD40, a little heat, but no luck. So for now, I'm stuck with loose bearings. The OM 5e is a budget cartridge, so I suspect it isn't as sensitive to this as a finer cartridge would be.

I repaired the broken hinge with epoxy, but the hinge is under spring tension when the cover is closed, so it only lasted an hour. A dual parts company I contacted wanted $14 ($10 + $4 S/H) for the new hinge, which is more than I want to spend on a $40 turntable.

The turntable as it is now would be a good basic turntable for someone wanting to get into records. It operates smoothly and quietly, and has satisfactory sound. To get this turntable to where I'd want to use it in my system, I'd want:
1. A better cartridge, or possibly an upgraded stylus for the OM 5e
2. correctly adjusted tonearm bearings
3. New RCA cables

I'd also want to determine what lubrication is needed before I put it into regular service. 

Specifications:
Drive: 16-pole synchronous motor with precision flat belt for flywheel drive
Wow and flutter: 0.05% WRMS
Rumble (weighted): 70dB
Speeds: 33.33 and 45rpm
Pitch control: 6%
Tonearm: distortion-free ultra low mass aluminium tubular tonearm in 4 point tip bearing
Years Manufactured: 1984-89

I showed off the Dual to a friend, and he wants it. He has records he wants to listen to, but no turntable. He also doesn't have an amp with a phono input. I have a 90's Denon amp in the basement on which one AUX input went bad, so I offered that to him as well. I mentioned to him that I wish I had a cordless drill, so he is trading me an old Porter Cable cordless drill for the turntable and amp. It couldn't have worked out any better. I'm glad to see the Dual go to someone who will appreciate it.

I explained the little problems with the turntable to him. I don't believe the loose tonearm bearings impact the sound much (if at all). The effect of loose bearings is supposed to be audible "chatter," but it sounds fine to my ears.

I ran it through the trackability test bands on my Shure test record, and it performed admirably, only showing some difficulty with the sibilance test (the OM 5E is a budget cartridge, after all). I see that an OM 10 replacement stylus can be had for under $40, and I think it would be a nice upgrade for the unit.

Update: the Dual is gone. It went to a good home. The Porter Cable cordless drill is quite nice - it came with a case and spare battery. I'm going to keep my eye out for other Dual tables because I think they're undervalued. I was impressed by the 505-2 and I thought $40 was an incredible bargain.

Update: I obtained a used replacement hinge on eBay for $3 with shipping, and the new owner was glad to have the cover working right again.