Dual 1019 Idler Deck

[pre65]

Hi-i have now collected the Dual 1019 and have started to play.
i have stripped all the linkage etc from underneath and then found i had to put some back to make the idler wheel stay in contact (good job i took a photo of underneath before starting).also i had to modify the automatic switch for the motor-wired in a separate switch.
initially i found it playing slightly slow,even with the pitch control fully + but an adjustment of the motor pulley and lubing all the bearings seems to have cured that.
the plinth that came with it was **** but i have glued two layers of 25mm mdf inside as a temp measure.
the dual sits on the plinth via 3 springs sitting in steel cups (with rubber),the cups sitting in holes drilled in the plinth top.

thats all so far,i've left it running for a couple of hours to let the lube get through and it seems quiet.if you put your ear right above the platter you can just hear a faint whirring.

next step is to mount my rega and see how it sounds.

if anyone wants any of the bits ive removed,feel free to ask,better than binning them.


Philip

[pre65]

Hi-i have now made up a small 3/4" ply armboard which is screwed to the plinth.
i have cut the corner off the dual and have left the base sitting on the original spring mountings.i had to put a weight on the arm end of the base to balance things up.
so how does it sound ? NICE !
to be honest i wasn't expecting it to sound better than my home made belt drive-but it does.much improved in the lower regions.
now it shows up more the mismatch between 300b s/e and KLS3 on anything other than simple music.
the dual platter is smaller in diameter than usual,and as the arm was a bit high i put an old LP (lena zavaroni) under the silicon rubber mat to even things out.
now i know it works i will make a proper plinth,should have some 1" ply left after making the Adire HE10's.

Philip

[James D]

Using it in the original plinth you are only scratching the surface of it's performance too I had a 1218 a few years ago and it was very nice when re-mounted.

James

[pre65]

Hi James-i only used the original plinth (modified) as an experiment.
i would like to have a semi skelatal plinth,not lightweight but not super heavy.
dont want to depress the mid/high range at the expense of bass.any ideas ?

would i be better dispensing with the 3 springs and solid mounting the baseplate to the plinth ?

Philip

[James D]

Hello Philip,

Definitely dispense with the springs and solid mount the baseplate for new plinth.

There are two main catagories of solid plinth. Heavy plinths that may be CLD as well, these aim to 'sink' the energy coming from the arm and deck by absorbing and dissapating it within the mass of the plinth. The ball bearing mount aims to prevent external energy corrupting the plinth by decoupling it from its mounting.

The second type is the skelatal plinth that aims to transmit the energy coming from the platter and arm into the support structure and away from the record playing interface.

Of course there are designs that mix both properties as well...

Then there are designs that, by design or otherwise, only sink or transmit part of the energy spectrum away from the record so that some influences the pickup and produces more apparent 'life' or bounce in the music - these are much the same as the LP12 in effect and can be pleasent to listen to but can never be considered accurate...

Then there are some that just plain don't work! I've built all these types and can say that the heavy plinth, with or wIthout CLD, is the easiest to get right and the others are always difficult to get right... which doesn't mean they shouldn't be attempted - just be prepared to play with it to optimise the sound.

ciao

JAmes

[pre65]

hi-i'm not understanding CLD.

we need a page on this site with all the common abbreviations IMHO !

Philip

[James D]

CLD - constrained layer damping.

Basically alternating hard and soft layers of different materials with different resonant frequencies. The layers are bonded via lossy flexible glue that also helps break upvibration paths through the plinth.

So one might use a 2 cm maple top layer, a 1cm rubber layer, a 5cm mahogany layer, a 5mm lead layer and a 3cm oak bottom layer bonded with a mastic glue as a plinth.

James

[pre65]

Hi-ive finished the plinth/base for this !

see the gallery for a picture.

playing now and sounds good,well worth the effort.

Philip

[Gerry]

Philip

Looks excllent.
What are the pillars that the arm is mounted on, MDR then pillars then MDF again?
Are the feet solid aluminium with no spikes?
i like the look of your record weight...I need to make one for my JVC as the one I have is magnetic and the magnets in the DL304 are so strong they pull the arm across to it at the end of a record!!

Regards

[pre65]

Hi Gerry-the armboard is a piece of delrin sheet.the supporting columns are also delrin with a small rubber mount at the top.
all the wood is 26mm maple MDF which was left over from the speaker cabinets (job still in progress).
the plinth is separated from the base with delrin (again) columns and alluminium collars held together with 10mm setscrews.
i wanted to make sure the motor got some airflow as it runs a little warm (not hot).
also i wanted it to look "nice" and not offend the other half.
the puck is a piece of brass i had in the garage which had been machined as an ashtray years ago.

regards Philip