I know Sony and JVC made turntables with an active feedback loop to suppress the arm/cart resonance. Did anyone else?
If the crowd has any personal experience I'd love to hear it. Did these actually do what they claimed out here in the real world? Thanks.
If the crowd has any personal experience I'd love to hear it. Did these actually do what they claimed out here in the real world? Thanks.
Well, Denon had their Dynamic Servo Tracer which works as intended, looking at measurements. Audibly I haven't tried comparing directly yet, so I don't know. This tt sound great without DST, so there's nothing obvious jumping at you when turning it on. I will study it further, for sure. Here's a measurement 🙂. As you can see, it knocks down the ca 9hz peak considerably.
Signal source is 250hz-30khz pink noise, Denon Dp-57L S-wand with Signet TK7E and AT20SLa shibata stylus, via heavily modified Simaudio Moon 110LP mk2 phono stage.
Signal source is 250hz-30khz pink noise, Denon Dp-57L S-wand with Signet TK7E and AT20SLa shibata stylus, via heavily modified Simaudio Moon 110LP mk2 phono stage.
All those electronically controlled tonearms were nothing moe than a gimmick to lure people into buying them.
And those same turntables today, aged, and those servo systems are giving people major headaches.
It's well documented online in plenty of websites.
They may have worked when new.... who knows.
Someone GAVE me (free) a cosmetically perfect Denon DP-59L about 7 years back, with a Grace F9 cartridge having a $400 Soundsmith Ruby cantilever stylus.
Yes, the turntable worked as it should, obviously was never used.
But I shoved that thing on Craigs List for $800 to get rid of it.
I want no parts of those things.. 2 weeks listed, some sucker bought it.
Good riddence to bad rubbish IMO.
Do yourself a favor, stick to traditional ways to play records.
Because gravity is much more stable than a bunch of coils, capacitors and sensors.
And those same turntables today, aged, and those servo systems are giving people major headaches.
It's well documented online in plenty of websites.
They may have worked when new.... who knows.
Someone GAVE me (free) a cosmetically perfect Denon DP-59L about 7 years back, with a Grace F9 cartridge having a $400 Soundsmith Ruby cantilever stylus.
Yes, the turntable worked as it should, obviously was never used.
But I shoved that thing on Craigs List for $800 to get rid of it.
I want no parts of those things.. 2 weeks listed, some sucker bought it.
Good riddence to bad rubbish IMO.
Do yourself a favor, stick to traditional ways to play records.
Because gravity is much more stable than a bunch of coils, capacitors and sensors.
Good results with a Sony PS-X500 Biotracer, great at reducing low frequency feedback and external noises from a less than perfect playback environment. Edit: and handling a few warped records admirably.
Definitely not snake oil, lol and I do not regret the purchase.
Definitely not snake oil, lol and I do not regret the purchase.
Sorry, I'm too lazy Photoshopping. FFTs were made using RightMark Audio Analyzer @0,73Hz resolution.
I have a few other turntables from the era; Technics, Kenwood, Thorens, Dual, Heybrook and the Denon is maybe the best 🙂. The DP-57L (same as 62L) is my current "SME-headshell connection" tt, and replaced a very nice Technics SL-150 with SME 3009 S2I/FD200 tonearm.
Thanks - a tonearm that does exactly what it says on the tin, complementing a powerful motor with excellent speed control. I agree with rockies914 - the tonearm is very good at playing warped LPs, taking a couple of revolutions to settle into excellent tracking, providing the warp is not so big as to bottom the body of the cart on the vinyl!!
Undoubtedly!! However, having owned a few turntables (Oh the struggles with the Linn! Ah the issues with the Dual!! Deary me, what to do with the Garrard!!) with various tonearms (lovely Grace, serious SME, damped Jelco etc) it's the DP67L with the straight 9" Dynamic Servo Tracer tonearm (designed for the Stevenson alignment) that has been in constant use since I passed my DP35F to my son. The current cartridge is a Grace F8c - preceded by an AT-ML150/OCC, a VDH-MM2 , a Garrot Optim FGS, a Denon DL60, an AT-440MLa .... the Denon DL107B waits in the wings ....
And I have a damaged DP59L to repair ... 🙂
I'll likely be buying another similar/identical Biotracer model, and sourcing the typical parts that go out (electrolytics, mechanical stuff like bearings) plus anything that will be hard to source. This way I'll have a pretty good chance of always having a working servo tt available. When one goes out, the other goes in place, and the first one gets lined up to be fixed. Gravity is (effectively) a constant, but it does not account for other forces.
One of my turntables, obviously shunned upon by the "purist audiophiles", is installed into a stereo console, whuch I've completely overhauled and modified to my liking.
Oversized 12 inch woofers, a relatively powerful PP 7189A tube amp chassis, internal bracing of the cabinet panels, etc..
Initially, whenever turned up to a loud volume, I got nasty feedback from playing records.
Even isolating the turntable's underside from speaker vibrations, and modifying the turntable's suspension, I got that "howl" if cranked up.
The turntable, is a shunned by many model 3000 Garrard - record changer, with its Pickering magnetic cartridge, completely overhauled.
My final resolution to ceasing and ending the howling feedback problem? - using a relatively simple design of a Sallen-Key filter, offered by Rob Elliott on his website (project #99).
The turntable now performs as if it's seperate from the console - absolutely no issues, not even any detracting sonic effects. - and no rumble, either!
And that same filter system can be used in any amplifier/preamp to quell issues the same way.
I've implimented in several systems with no ill effects, just the absolute absence of feedback/tracking issues.
And.... no loss of that all-important deep bass sound that attracts people like a drug.
In fact, if I turn the bass control fully up and crank the volume, I get perfect playback.
Only the glass doors of the nearby china cabinet start to rattle, and those will be tended to in the future.
Oversized 12 inch woofers, a relatively powerful PP 7189A tube amp chassis, internal bracing of the cabinet panels, etc..
Initially, whenever turned up to a loud volume, I got nasty feedback from playing records.
Even isolating the turntable's underside from speaker vibrations, and modifying the turntable's suspension, I got that "howl" if cranked up.
The turntable, is a shunned by many model 3000 Garrard - record changer, with its Pickering magnetic cartridge, completely overhauled.
My final resolution to ceasing and ending the howling feedback problem? - using a relatively simple design of a Sallen-Key filter, offered by Rob Elliott on his website (project #99).
The turntable now performs as if it's seperate from the console - absolutely no issues, not even any detracting sonic effects. - and no rumble, either!
And that same filter system can be used in any amplifier/preamp to quell issues the same way.
I've implimented in several systems with no ill effects, just the absolute absence of feedback/tracking issues.
And.... no loss of that all-important deep bass sound that attracts people like a drug.
In fact, if I turn the bass control fully up and crank the volume, I get perfect playback.
Only the glass doors of the nearby china cabinet start to rattle, and those will be tended to in the future.
Good for you! Anyways back on topic, I'm also interested like the OP about any other implementations of servo tonearms.
We have Sony, JVC and Denon, and it's established that they work well in general. I know mine works nicely and sounds wonderful with fantastic bass, tracking, no feedback (even with footsteps in a less than perfect environment) and handles warped records.
I'm in the process of deciding whether to stay with Sony (since I have one already) or go elsewhere. Any others?
We have Sony, JVC and Denon, and it's established that they work well in general. I know mine works nicely and sounds wonderful with fantastic bass, tracking, no feedback (even with footsteps in a less than perfect environment) and handles warped records.
I'm in the process of deciding whether to stay with Sony (since I have one already) or go elsewhere. Any others?
External influences, including rumble, feedback, and warped records, are easily handled with the Sallen-Key filter, and can be used with any turntable.
While you may be hooked on the servo tonearm idea, I like to stick with simplicity - less to adjust, less to fuss with, and less to potentially go wrong.
I've seen too many turntables, like the Denons, etc, come into the repair shop for arm issues due to aging.
And the Denon's in particular require a high-experience tech with plenty of test equipment to do the repairs.
That's why I sold off that DP-59L quick while it still worked.
While you may be hooked on the servo tonearm idea, I like to stick with simplicity - less to adjust, less to fuss with, and less to potentially go wrong.
I've seen too many turntables, like the Denons, etc, come into the repair shop for arm issues due to aging.
And the Denon's in particular require a high-experience tech with plenty of test equipment to do the repairs.
That's why I sold off that DP-59L quick while it still worked.
I'm so glad you are having success with your system! Just fyi, I'm not "hooked" on anything and if a better solution comes along, I'll adapt to it (as any reasonable person would) given costs and practicality.
I'm sure everyone is well aware of the complexity of doing a servo implementation and the inherent drawbacks. As a decent tech myself, I'm personally not scared of complexity, especially when it provides a superior technical solution, regardless of the costs of repair, which are of course a factor!
Anyways, good for you for being a tech! I am too and I'm very happy with my well-performing and reliable Sony PS-X500. I'm learning how it works, and will be able to service mine as a result. I would love to know about other implementations and how reliable they are, which is why I am part of this thread.
Could we limit the discussion to the effectiveness of servo tonearm systems and the various implementations of them? Thanks in advance.
I'm sure everyone is well aware of the complexity of doing a servo implementation and the inherent drawbacks. As a decent tech myself, I'm personally not scared of complexity, especially when it provides a superior technical solution, regardless of the costs of repair, which are of course a factor!
Anyways, good for you for being a tech! I am too and I'm very happy with my well-performing and reliable Sony PS-X500. I'm learning how it works, and will be able to service mine as a result. I would love to know about other implementations and how reliable they are, which is why I am part of this thread.
Could we limit the discussion to the effectiveness of servo tonearm systems and the various implementations of them? Thanks in advance.
I'm all about learning new stuff. Please do as I previously asked, and if you have a problem with this discussion, you can unwatch this thread. Time for you to move on.
Anyways, I'm learning about these systems! It's complicated, naturally, but I'm now inspired to collect info about debugging the Sony PS-X series of servo dampened tonearm turntables. Some good discussion here:
https://forum.audiogon.com/discussions/servo-controlled-arm
Anyways, I'm learning about these systems! It's complicated, naturally, but I'm now inspired to collect info about debugging the Sony PS-X series of servo dampened tonearm turntables. Some good discussion here:
https://forum.audiogon.com/discussions/servo-controlled-arm
Now, I don' think this is a "purist" table, I call it a very well made, vintage semi-auto turntable, with pretty rosewood veneer and comfortable operation. A nice representative for the era and style of tt . Of course, after 40 years of duty, faults may occur - I like to start with a working specimen with low milage/wear. And it certainly has has a different complexity level compared to a Thorens TD-160, for instance.
To add something about the Denon DP-57L since the tonearm is stuck on a plinth and drive. It has a very high torque motor, spinning up very fast and even maintaining speed while cleaning! The spindle bearing is extremely good, a spindown from 45rpm while sampling pink noise took more than 2 minutes, exceptional. Two different armwands and multiple counterweight sizes makes it very flexible regarding compliance and cartridge weights. It allows for some height adjustment of the tonearm, also a nice feature for flexibility.
The UFO drive and buttons is maybe an aquired taste, but I like it 😀. Here with Audio Technica AT25 from 1978, just arrived from Japan via USA.
@bondini : Nice collection of carts, even a 107B! Rare bird 🙂!
Dagfinn
To add something about the Denon DP-57L since the tonearm is stuck on a plinth and drive. It has a very high torque motor, spinning up very fast and even maintaining speed while cleaning! The spindle bearing is extremely good, a spindown from 45rpm while sampling pink noise took more than 2 minutes, exceptional. Two different armwands and multiple counterweight sizes makes it very flexible regarding compliance and cartridge weights. It allows for some height adjustment of the tonearm, also a nice feature for flexibility.
The UFO drive and buttons is maybe an aquired taste, but I like it 😀. Here with Audio Technica AT25 from 1978, just arrived from Japan via USA.
@bondini : Nice collection of carts, even a 107B! Rare bird 🙂!
Dagfinn
Some more discussion here, including a tentative listing of tables with electronically damped tonearms at post #6: https://audiokarma.org/forums/index.php?threads/does-q-damp-really-work.629031/
@dagfinn : What's the ECM on the platter? 🙂
@dagfinn : What's the ECM on the platter? 🙂
@bondini thanks for that. Lots of great info.
Great to (pretty much) just slap a different cart on & not have to worry about spending a lot of time doing setup. In my case, I'm running a Ortofon OM20; it's not super high end, but the sound is significantly better than on the medium range Denon it was on previously.
Great to (pretty much) just slap a different cart on & not have to worry about spending a lot of time doing setup. In my case, I'm running a Ortofon OM20; it's not super high end, but the sound is significantly better than on the medium range Denon it was on previously.
I didn't figure out how to edit my post above (edit: looks like there's a short window of time for editing), just wanted to point out that the Denon mentioned above was a turntable (not a cartridge). There was a significant SQ increase with everything else the same 🙂
Another Audiokarma link. Post #17 (near the bottom of the page) is particularly useful and it's not just Sony content. It looks like it's good to know how to use an oscilloscope 🙂 If I obtain the service manual (no luck so far with finding a scanned copy) I'll look at it in detail and post some observations here.
https://www.audiokarma.org/forums/index.php?threads/sony-ps-x500.123593/
edit: woohoo! service manuals are at:
https://www.audioservicemanuals.com/s/sony/sony-ps/sony-ps-x/
https://www.audiokarma.org/forums/index.php?threads/sony-ps-x500.123593/
edit: woohoo! service manuals are at:
https://www.audioservicemanuals.com/s/sony/sony-ps/sony-ps-x/
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