More thoughts on our Dual 505-2 with Denon DL-160

A few months ago I think I wrote here that I was struggling with vinyl sibilance and inner-groove distortion with our Dual 505-2, then fitted with its original MM Ortofon cartridge and DN-165E stylus. A partial solution was found with the upgrade to the significantly better Denon DL-160 MC cartridge.

We’ve moved house and played a lot of the black stuff since then, and some of it has been found to sound rather tired after a heavy life with previous owners. The result was that for some of our older discs, the inner-groove distortion and vocal sibilance caused by previous wear was getting me down.

Last night and this morning before work I spent some time with the deck in its new home, with the aim to get things set up as well as is possible.

Step 1: Align the cartridge

The first step in this journey was to find a suitable downloadable protractor to check that the cartridge was properly aligned – it’s so easy to get this wrong and somewhere in the move I’d lost my previous unit. So, off I went to Google and found this printable example, which printed exactly to the right scale on our printer the very first time.

I followed the instructions on the template, only after cutting the bottom strip (with the alignment markings) off so as to prevent the paper scuffing the arm and stylus.

The result was immediately obvious – much more detail, a little less distortion in the inner groove of older records like our copy of Marillion’s “Misplaced Childhood”. The soundstage is a little wider and set further around the speakers, both in front and behind. Centred vocals and instruments are really marked as dead-centre now.

Step 2: Check tracking weight and antiskate

Rather dangerously, this was done by ear, on the basis that I’m listening for increases or decreases in distortion in known tricky passages.  Queen’s “You Take My Breath Away” from their “Day At the Races” album was chosen for this – our first-run copy has significant problems on the left channel with sibilants blatantly distorting.

It turned out that I had to track much heavier than the Denon’s recommended 1.5g – actually I had to double that to 3g in order to take some control of the distortion. With other discs this rewards me with more detail and deeper soundstage, with better perceived stability.  My best guess at this point is that the cartridge is either a little stiff for this rig, or that the weight calibration of the tonearm has crept out of tolerance.

As for the anti-skate, the best overall sound (least background noise and lowest distortion on tricky discs) was found to be with 2.5g set in the Spherical range according to the dial on the deck – this gives a much more consistent sound across all discs tried so far.

Step 3 – Experiment with running with or without the sub-chassis suspension

Our new abode has victorian wooden floorboards on flexible joists, which happen to excite a resonance in the spring-suspended sub-chassis of this deck, particularly noticeable when someone walks across the room, or puts the washing machine on.

It turns out that turning the transport screws fully-anticlockwise to bolt the sub-chassis down cures this problem, and I’ve yet to hear any adverse affects of doing so except perhaps a very slight increase in the perception of motor rumble when listening at high volume levels on headphones. I don’t listen like that very often, so I think we can live with that.

Results

I’ve listened this evening to Jean-Michel Jarre’s “Oxygene” and Enya’s “Watermark” LP’s and am enjoying new levels of soundstaging and detail retrieval. Maybe once I’ve done some study this evening I’ll let loose with some more challenging material to see what happens. The signs are good, with hopefully little further damaging to our aging collection.

 

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