Phoenix Engineering Eagle PSU and RoadRunner Tachometer

PeterA

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Andre Jennings just wrote a fascinating review of these two devices in the July/August issue of TAS. Has anyone read the review or have experience with these turntable accessories?

Andre's review: http://www.phoenix-engr.com/images/TAS_Review.pdf

Here is a review in Positive Feedback:
http://positive-feedback.com/review...nix-engineering-llc-roadrunner-and-eagle-psu/

Another review in Analogplanet:
http://www.analogplanet.com/content...and-roadrunner-tachometer#343RL86mO8GE2GGE.97

EDIT: Just inserted a link to Andre's review.
 
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Barry

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I've owned the Eagle and Roadrunner for about 9 months now. I'm very happy with the units. Speed stability is within about +/- .005 rpm with Roadrunner correction. These units replaced a Walker Audio Precision MC. Regrettably, I can't provide a side by side sonic or speed comparison or info on speed stability without correction (modified VPI HW MKIII TT with Applied Fidelity sapphire / ceramic bearing assembly).

There are a couple of other sources for info from Phoenix Engineering, the manufacturer, including You Tube videos and comments on DIY Audio that are worth looking at including here:

http://www.diyaudio.com/forums/vend...al-turntable-tachometer-dds-based-psu-19.html

Also, when I visited VPI in June I saw Mike Bettinger is working on a new MC to replace the SDS.
 
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PeterA

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Thank you Barry. I found the link to diyaudio very interesting and came across this link for a video installation and demo of the units: https://www.youtube.com/watch?v=4IGzgvRSNXk

I only wish the guy in the video had dropped his cartridge on an LP to see the effect of stylus drag, if any, on the digital speed readout.

One concern I would have is whether or not the real time detection of the speed with the magnet sensor on the platter and subsequent constant correction by the controller is audible. I've read some speed correction on DD tables is audible. The reports from users of these Phoenix products make no mention of audible speed correction.
 

kleinbje

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Thanks for the review link. I have been using the combo with a classic 3 for about 1.5 years ,replaced a SDS. I love the combo, I use high end power cables and have noted a tremendous improvement in background noise. I find with the the HRX pulley and 3 belts I'm +-.003 at the most, almost always 33.332-33.334. I also love not having to keep checking my speed every few months as belts deteriorate. I think it has improved the sound over the SDS for 2/3 the price with a good used power cable, I use cardas golden reference.

Jeff
 

daytona600

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+1 for the phoenix + tacho
have the newer 25w version on a 301 & make a big difference
also tried one on the kids rega & works very well
 

Barry

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I only wish the guy in the video had dropped his cartridge on an LP to see the effect of stylus drag, if any, on the digital speed readout. One concern I would have is whether or not the real time detection of the speed with the magnet sensor on the platter and subsequent constant correction by the controller is audible.

I can't hear the most extreme correction of .005, but that doesn't mean a better system with .001 variation wouldn't sound even better to me. With the tachometer in place, you can clearly see the varying digital RPM screen readout resulting from changing house line voltage. In my set-up, the amount of absolute variation changes throughout the day depending on the stability of the house line voltage. It seems to me that this variation would be even greater without DDS and any correction and hence be even more audible. With the SME 30/12's superior motor, platter, belt, and pulley machining, one would think less correction would be needed IF your house line voltage is stable. Like everything else in audio, you won't know till you try one. These units are relatively inexpensive and there's a ready market if you don't like the results. You'd probably want to keep the tach anyway unless you go crazy watching that 5th digit constantly changing. Horrors, you might even find that you actually like the warmth imparted by speed instability even though it's less accurate....
 

kleinbje

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Barry,
Nice to know it works well with the SME 30, that's my upgrade I think from my Classic 3, though the avenger looks nice, sort of an 80's micro seiki look.
 

ack

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From a cursory read of the review, the tachometer seems to offer but another somewhat-useful measurement - using a single magnet can only show you average platter speed over long periods of time, and tells nothing about short-term speed variations. Or did I misread the review. For it to be a useful Hall Effect Sensor https://en.wikipedia.org/wiki/Hall_effect_sensor I was hoping to see a belt of evenly-spaced equal-mass magnets that you attach to your platter; but that's easier said than done, because a) platters vary in diameter; b) the magnets would have to be laser-trimmed to be of equal mass and precision-placed at equidistant points. However, given the price, one cannot ask for too much.

I believe there was a laser device touted in these pages years ago, that you pointed at the platter from a fixed location - that seemed like the more appropriate tachometer, but can't recall details.
 

PeterA

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From a cursory read of the review, the tachometer seems to offer but another somewhat-useful measurement - using a single magnet can only show you average platter speed over long periods of time, and tells nothing about short-term speed variations. Or did I misread the review. For it to be a useful Hall Effect Sensor https://en.wikipedia.org/wiki/Hall_effect_sensor I was hoping to see a belt of evenly-spaced equal-mass magnets that you attach to your platter; but that's easier said than done, because a) platters vary in diameter; b) the magnets would have to be laser-trimmed to be of equal mass and precision-placed at equidistant points. However, given the price, one cannot ask for too much.

I believe there was a laser device touted in these pages years ago, that you pointed at the platter from a fixed location - that seemed like the more appropriate tachometer, but can't recall details.

Ack, I have a laser tachometer that I can point at a reflective strip on the platter. I could never get it to give me consistent readings, so I abandoned the device. Others have had success with those.

I agree with you about the once per revolution reading or once every 1.8 seconds being a long interval so we don't know about short-term speed variations.
 

PeterA

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The device you are referring to sounds like the Sutherland Timeline.

The Sutherland Timeline is placed on the spindle in the center of the platter. It is a strobe which flashes a dash on the surface of a wall in the room. One can then make note of whether or not the dash moves along the wall.

It is not a device that is pointed at the platter from a fixed location.
 

ack

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I wasn't talking about the Timeline... More like the one Peter has, but I haven't seen that either
 

PeterA

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I wasn't talking about the Timeline... More like the one Peter has, but I haven't seen that either

Correct. I have a Fieldpiece SRPM2 Laser Digital Tachometer. I never got satisfactory results from it. Perhaps it is not functioning properly. I have found that my Sutherland TimeLine is much more accurate, though some people criticize it because it does not weigh the same as one's record clamp/weight and could therefore represent a different load that what is used normally thus altering the speed of the turntable.

I have modified my Timeline to weigh the same as my SME record clamp.
 

daytona600

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kleinbje

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Did Barry write that he tested these devices with an SME Model 30 turntable? I did not see that.
That was my read on this.

With the SME 30/12's superior motor, platter, belt, and pulley machining, one would think less correction would be needed IF your house line voltage is stable. Like everything else in audio, you won't know till you try one. These units are relatively inexpensive and there's a ready market if you don't like the results. You'd probably want to keep the tach anyway unless you go crazy watching that 5th digit constantly changing.
 

TBone

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Phoenix PSU & Tacho essential closed loop speed control used in industry for speed control & positioning
Tacho speaks to the PSU and adjusts to suit & now your belt drive deck has direct drive speed accuracy

Wishful thinking; because unlike a direct drive closed loop system, the added compliance of the belt (and/or suspension) remains.
 

PeterA

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Wishful thinking; because unlike a direct drive closed loop system, the added compliance of the belt (and/or suspension) remains.

Yes, and I would think that confirming speed only once per revolution would not account for tiny variations in speed due to stylus drag during transients. However, the belt compliance might go a long way to smoothing over the constant hunting/correcting that some DD turntables exhibit and which are audible to some. And the belt and suspension on some tables does isolate the platter somewhat from the motor which is not the case with DD.

Of course belt compliance and length varies considerably on belt drive turntables.

Andre mentioned in his review that he did try these devices on an SME turntable but did not specify which model. Can anyone share his experiences of these with an SME?
 

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