A new TT from Steve Dobbins,"The Beat." ???

Ken, I keep forgetting that we are near neighbors. We should get together for a dd fest one of these days. Lets make email contact. Howard serviced my L07D and it is now in use. SP10 Mk3 will soon follow.

Interesting thing about the L07D is that Kenwood planned for increasing platter mass by providing a switch on the PS that alters the servo when one is using the optional peripheral ring and center weight. In addition, there was an optional ceramic mat that added yet another 1.4 lbs. Someone else calculated that the servo and motor will take up to 21 lbs of platter mass.

Lewm,

If I'd had my wits about myself I would've called you a week or so ago. I'll be driving to ATR Services on Thursday to attend my THIRD seminar and pick up my last machine. I've attended two seminars so far and feel as though I'm the dunce in the class, which I am. Everyone else is from the studios that record the music we all listen to. The techs and studio owners leave me in the dust but I'll keep on keeping on.
Ken

Ken,
Thanks for the color. I might do the same thing on the platter for my 308. It would be great to get a better one. I would love to build a better platform as well - rather than the MDF box. As to numbers, in Japan at least, there are probably a fair bit more DN-308s than 100 because it seems like every NHK broadcast center and recording location, and a huge number of schools/universities/libraries/museums/etc were convinced to buy them (by government bureaucracy-funded NHK). I expect this was because of pressure to monetize the time spent by the engineers, and commit everyone to the NHK standard. I have heard that NHK effectively designed much of this table for Denon using their own engineers. FWIW, I have probably seen a couple dozen 308s over the years, and fewer 307s, and still fewer 306s (which I think were belt-drive). I have probably seen 20% of that number of console tables like this made by Victor and Matsushita (the original pro-use in the early 70s were Matsushita-labelled, not Technics it appears).

As to usage... it does have that funky headphone jack for headphones of a particular impedance (one can still buy them for about $350), and the mini speaker, but it is clear they were also meant to play for broadcast as well because the thing has a built-in phono stage AND preamp with 600ohm balanced output for direct-to-amp playback. When I talked to Denon today, the two people I know there separately said that Denon would refuse to service a table owned by an individual in Japan and it was explicitly up to the user to figure it out for himself. Not a terribly satisfactory response, but it is what it is. Thankfully, there are a number of people out there in the private sector who can service them.

The same people, speaking about the DP-100, said that the DP-100 was sold to a few radio stations but the vast majority were sold to consumers. Most commercial users took the DN- series because they came with a service/maintenance contract (like most companies do with copiers these days), whereas the DP-100 did not come with the same service package.

As to total numbers made, on the DN-308 (and earlier DN-307 and DN-306) they said they WOULD not answer. As to the DP-100, they said they COULD not answer because the data was lost (but noted that it was only an order-built machine, and production lasted 4 years). That is four times I have asked in the last year to four different people involved with Denon servicing and four times I have been told they have no idea. Not encouraging, but it is what it is. Based on serial numbers, I know it approaches 50.

As to the motors in the DP-100 and the DN-308. They are, I was told today by a guy who serviced the DN-308 in the past and now does old tables in the consumer section, completely different beasts. This makes some sense when I think about it because the DN-308 came out before the AU-169 cutting head motor (which is in the DP-100) which was first presented in a technology show in 1979. I think my Denon DN-308 comes from 1979 (you can check your date by looking on the bottom row of the serial number plaque on the front underneath the console portion; an "S" (or a 昭和 or a 昭) and a two-digit number; "45" is 1970 and "55" is 1980 - If you have an "H" or 平成 then a number, it will likely be a single-digit number and H1 was 1989).

Separately, you've got mail...

Any news about KODO turntable ??

A few notes on the Denon DN 308 and other Denon DD Turntables.

As some of you know I restore many of the magnificent old Denon DD tables mainly the DP3000, 2000, 6000 and 80 - I turn them into these 

http://pbnaudio.com/audio-components/audio-turntables/groovemaster/groovemaster-vintage-direct

There is a few mentions above about the platers on these. Please note that the rubber mat that they were originally supplied with is an integral part of the platter system , with the mat on,  the platter is virtually "dead"  The design of these mats vary some,  the earlier DP3000, 6000 and 7000 have a circular ribbed design, the newer DP2000 have a softer but also circular ribbed design, the 75 and 80 have a almost flat but much harder rubber mat.

 On the older ones 3000, 6000 and 7000 the platter it self have a raised center portion which makes it hard to use any other mat than the originally supplied mat, the 2000, 75 and 80 have a flat platter making it possible to use almost any aftermarket mat desired.

We are in the process of making copper mats with a large center holes that will make the platters on the 3000, 6000 and 7000 flat facilitating the possibility of using any desired aftermarket mat. The weight of these will be apx 4.5 lbs adding substantially to the weight of the platter.  lewm above mentions that the weight of the platter should not be increased substantially because the servo control is "tuned" to the weight of the platters they are controlling, I find absolutely no evidence of this - checking the already astonishingly accurate drive systems with a phoenix engineering tachometer which displays RPM with a 5 digit read out i.e. 33,333 the added weight only makes any slight variation in speed better - the 6000 and up, after restoration,  typically runs with only a one number variation on the very last digit i.e 33.333 to 33.334. For an example a DP2000 with a Micro Seiki CU500 mat and a SS record clamp increasing the weight of the platter with over 100% makes the drive system even more consistent. 

The platters on the 75 and 80 are a laminated design with a light sub platter carrying a much heavier platter on three leaf springs, there is rubber dampening material applied into every other one of cavities at the circumference of the sub platter with the alternating ones having  foam rubber pads that couple the platter to the sub platter. on restoring them the foam rubber obviously is replaced,

On the DN308, the drive system is quite substantial the motor is gigantic the outside rotor is apx 3/4" thick and laminated with what appear to be brass for added weight.    I have procured 3 of these and will restore them into new table top machines with plinths made from Slate and Hardwood also they will be fitted with 4" custom made by Steve Blinn Isoped's.  I envision them having the possibility of using two arms, I'll probably supply them with either a SME V12 or a 312S. Also since these don't have a strobe light the Phoenix Engineering Tachometers will be built in to the control interface.  The platters will be damped, possibly by spraying a polymer on the bottom on them then laminating them with a copper mat.  Really looking forward to this project, if any of the above DN308 owners are interested in this please let me know, as I'm already building 3  -  5, 6  or 10 for that matte is not an issue.  

As far as how many of the DN308 is out there Im guessing at less than  2000 of them. Of the three I have here the oldest one is from May 1978 and it is number 472 the two other are quite  newer one is from Jan 1992 # 1558 and from Jan 1993 # 1608. They are very close to identical.

On a side note restoring / "GrooveMastering"  3each DP7000 machines to be fitted with the SAT tone arm  for a major cartridge manufacture, this project too will be lots of fun.

Good Listening

Peter