Vintage Denon Direct Drive Turntable

Lew, I was asking about routing, for the armboard recess, inside the main plinth, rather than making a second plinth for an armboard (which should be possible with a waterjet as it could simply be two pieces of the same single slab (a large rectangular with a square cut out at one corner), though small adjustments could be difficult to make using a large block of slate...

FWIW, the 75 (which came with plinth), and the 80 (which was sold plinthless, but with at least three choices of plinth) are not that far off in terms of specs. The DP-75M was JPY 180,000 (with plinth and arm), and the DP-80 was JPY 95,000 by itself, the DK-2300 plinth retailed for JPY 70,000, and arm was separate. The S/N ratio and self-reported WOW/Flutter numbers are better on the 75, but the Japan Institute of Standards put the WOW of both at the same level (and both slightly higher than the self-reported numbers). The spin-up of the 80 is supposed to be slightly faster, and the DP-80+DK-2300 is about 10% heavier than the DP-75M (including arm). Either one should be serious contenders as those were the prices of most firms' 'one-down-from-the-top' offerings around 1980 (the top-priced offerings were things like the DP-100M, Technics SL-1000, Yamaha PX-1, Sony PS-X9, Exclusive P-3a, etc).

I would love to try one a Denon but I have too many 'projects' lying in wait...

S/N Ratio: DP-80 S is 77; DP-75M is 80dB
Wow/Flutter: DP-80 is <0.015%; DP-75M is < 0.008%w.rms
The JIS measure shows both below 0.02%.
I don't know how rumble is measured.

Wow and flutter (originally separate measurements, now put together) measure the level of frequency instability below and above 4Hz of wobble. I read once a long time ago that the weighting system of measurement tends to be inaccurate at high wobble frequencies, making it effectively meaningless. I have thought that this is one reason why high mass platters are supposed to sound better on almost every kind of drive system - they effectively reduce the possibility of high levels of high frequency flutter.

As for levels vs the competition, it was quite good (there weren't many tables made which spec-ed better) but several tables were similarly below 0.015% or 0.1%.

Dunno. Can't account for the difference. I was quoting from notes I made last year (I looked it up last year when I was doing research on Japanese DD TTs from the 70s and 80s) but just now checked over at the Vinyl Engine website and found an English-language brochure for the DP-80 giving the same numbers I previously noted. Perhaps things were improved in the latter years of production and that is where your ad comes from. FWIW, the brochure provides a great deal of info on how the thing was designed and built - very instructive in its own way.

The 75 improved on the 80 in some ways, and was made afterwards, I bet to a slightly lower price point when sold separately to assuage fans of the DP-80 (Denon themselves were trying to bring the DP-80 to the masses based on the DP-80's critical success and Japan's economic development in the meantime). The Vinyl Engine is a fantastic resource for fans of non-current analog equipment. The library for Denon is here.

I am far from an expert on these, but i have done some reading on them. My speculation on the 75, and this comes from comparing original pricing, brochures, sales method, specs, embedded technology, etc, is that after 5+ years of making the DP-80 and seeing it become something of a hit, they had come up with some slight technological improvements in platter and chassis to reduce rumble a bit more, and as Japan was entering a disposable income boom and doodadegadgetry was king, it was a great thing to add to the line-up. Voila! The younger brother to the DP-80 coming of age. Unit costs were much lower mostly because fixed costs had been amortized already, but based on a suspicious lack of info about the DP-75 motor, and the few specs I see, I suspect the DP-75 motor had a fair bit less torque than the DP-80, and while I do not know for sure, I think the DP-75 had fewer manual override possibilities than the DP-80. This table appealed both to the crowd who had not already replaced their DP-3000 and DP-6000 with the DP-80 over the previous 6yrs (it was too expensive, etc) and to the people who wanted to hit a certain price point vs income. With the DP-75, one got almost the same thing, and better specs to boot, for about 30% less (table only), so just like the top top end of digital cameras these days when technological obsolescence happens much faster, manufacturers keep just a bit back on model numbers offered with a lower price point, just to stay sane. Only after the deceased has been respectably buried do they offer better-in-all-ways technology for less money.

I own neither, and offhand, if I really wanted to choose one of those two only, I would buy both and try them in the same plinth, keep one and sell the other. I have no further basis to go on than that for deciding which one I would prefer. I can say that the DP-80 is iconic, because it was the first of the 3-phase motor split-platter construction Denons made to dramatically reduce acoustic feedback-induced resonances, and while icons are not always better performers than their descendants, they are icons, and that has some value to some people.

Thanks Raul, for chiming in and filling in the blanks. The lack of manual pitch control was the one I thought was the case (does it have screws underneath to control that way like some of its contemporaries which had pitch control underneath as well?)

damn fine lookin' table ya got there treehugga.

Question for the people who fill the ring... What does that do to the ability to fix your electronics/wiring should it go...?

It turned out that in my stack of un-plinthed TTs, I had a DP-80 that I had picked up a while ago. This morning, on a whim, I put it in a solid wood DIY plinth that someone had built a number of years ago with a couple of SAEC armboards, and sold on the net for $50, and I installed my SAEC 407/23. Using the old "eyeball-it-and-guess" set-up technique, I got a wonderful TT in about 10mins. It has great stability, and I was reminded yet again how good the SAEC arm is. Upon returning home this afternoon, I spent a bit more time on set-up, and it turns out I was really lucky the first time. After several records, I continue to be surprised at how good it is. I think I need to look into a better plinth, but I am going to keep this TT in rotation for a little while.

Treehugga, what are you going to do for tonearm? Get one hole drilled for the tonearm of your choice? Put in a slate insert so you can put multiple slate tonearm boards in?

Thanks Treehugga. If you wanted to have slate cut out at half height partway into the block, does that work? Or does it have to be the same vertical cut through the piece? In a simple example, I am thinking of a cylindrical cut out with diameter of 6 inches going halfway through the block, stopping there with a horizontal plane, and then having a further cutout of 4 inches' diameter going the rest of the way through. If so, that makes for some interesting possibilities, but I do not know how these things are cut. Perhaps the only way to do that is to cut two pieces with super flat surfaces (with cutouts beforehand) and bond them.

Treehugga, so how do you like it (from the last picture, it looks like it is already spinning tunes)?

I would love to do the same but unfortunately, while the tables come from Japan (where I am), the slate does not, and I fear the slate plinth is going to be expensive to get shipped to Japan...

Treehugga,
Marble and granite are available in Japan. I've always been afraid that either one would ring like a bell...

Lewm, I anxiously await pics. If you have any comparisons against other tables, I for one would love to hear them. Mine remain in wood plinths (both my -80 and my -75) so I can only expect what I would hear (though an air-bearing or magnetic-float isolation platform works wonders on both).