New Turntable Advice

So, you are saying you know a guy who says the SR510 is as good as the DDX 1500. Is that correct? And by the axiom "things equal to the same thing are equal to each other", you are inferring that the SR510 may also be as good as or better than the Nak; is that correct? But it all hinges on the perspicacity of the unknown "vinyl source enthusiast". Before swallowing that odiferous proposition, I would like to know more about the system in which turntables were compared and whether that was the judgement of one person or a panel of listeners. I admit that I am making a judgement based only on photos of the SR510 and the selling price of $100 and the fact that the manufacturer is unknown in the world of high end Japanese vintage DD (JVDD, in your parlance), but based on that information, I cannot agree with your "vinyl source enthusiast" that an equivalence (between the SR510 and either the DDX or the Nak) is possible, let alone the possibility that the SR510 could be superior. That’s only my opinion, of course.

Does anyone have experience with the 

Kenwood Trio KP-9010- 

Wow/flutter 0.005%, SNR 90 dB some of the best I've seen.

This is the best engineering document on the nak, very detailed with blind panel listening.

https://www.gammaelectronics.xyz/audio_04-1985_nak.html

The missing features are azimuth and VTA adjustments, can be overcome by 5 - axis head shell and shims, or the tonearm

@lewm I have supplied proper sources of where info is to be found to verity the info I passing on along with a forum Monika .

All that I have stated is able to be found that there is substantiation to what is shared.

I will not be giving guidance to lazy researchers, I done my footwork and kept bookmarks for times like this. 

During my exchanges the demographic I am looking to give something of value to is not even considering regular posters in the Analog Section of the Gon, that sound like bloody had work.

badbruno being a very infrequent forum contributor over 9 years is a great place to offer assistance, especially when attempting to assist with showing their is a good experience to be had and keeping $4.8K in their Coffer.

I would like to think my info is now in the hands of few hundred who was not with such a awareness of the SR 510.

I would really like to think that after reading the info in the Link and learning a little more about the forum member, the SR 510 is on a list of a couple of those who are recently aware of it. Mine are not for sale, no dog on this fight as already stated, but the Link and follow up investigation and private mail is the cause of my now owning 4 x SR 510's and one which will be my wife's 'already stated' is not selling her short ' already stated'.

For the record the person who put me onto the SR 510 has not at any time referenced the Nak' CT Dragon as a comparison, but Tech Das might have been briefly referred to as they own a TOTR Model.

@lewm

What is “slam”? I mean to ask what can a TT do to create slam? It might be the capacity to maintain constant rotational speed despite stylus drag. But that is a strength of dd as well. Otherwise, I’m stumped. I think slam is also an often repeated adjective associated with idler drive

Don’t direct drive turntables rely on feedback mechanisms to continually adjust the speed?  If so, there first needs to be a speed discrepancy, no matter how slight.

By contrast my Garrard 301 idler drive has no feedback mechanism at all.  A stonking big motor, which has been likened to a washing machine motor, spins at about 1,000 rpm.  Like some direct drives, it can spin the platter up in under a second, and in my estimation is unlikely to be over-bothered by stylus drag. 

It is not a synchronous motor either, so it does not rely on mains frequency, or any electronically generated frequency.  Fine speed is controlled by varying the drag created from eddy currents induced in an aluminium disk attached to the motor shaft, by a movable permanent magnet.

It takes about 10 minutes to warm up to final speed.  Not sure if the motor windings or the bearing lubricant, or both, are responsible?

The motor of the Garrard 301 is indeed physically large, but if I recall correctly, the torque is less than one might expect based on size alone.  And as you adjust V to regulate speed, torque goes down, until at some point torque disappears and the platter coasts to a stop unless braked. But I admit I don’t know how important that phenomenon might be, because torque comes into play when the platter is accelerating.  I do know there is a consensus of opinion that 301s benefit greatly from a motor controller. I was thinking earlier of the Supreme Court judge who said he could not define "pornography", but he knew it when he saw it.  The same may apply to slam. I certainly would not deny that idler drive TTs have a quality one might call slam but so also do DD TTs when you compare either type to a belt drive that is not well engineered.

By the way, DD TTs are not constantly adjusting speed based on feedback. Different designs from different companies use different circuits that have varying sensitivity to speed. For example, my Kenwood L07D has a relatively loose feedback mechanism but it uses a heavy platter with peripheral mass that tends to keep speed constant without much feedback,  Technics TTs, on the other hand, tend to have rather tight control on platter speed. I think Richard Krebs can comment, because he has looked extensively at the audibility of feedback affecting speed.