Dryad - My Rega Planar Project

[AJSki2fly]

I'm surprised how much more detail it's pulling out compared latest P3 or even my other modified offerings.

It looks very well done Malcom, great that you are finding it to be so good. I think often good results can be achieved that are as good as a Hifi manufacturer with a bit of effort and care, and usually for much less expense.

[willbewill]

A small alteration and some motor musing:

I removed the platter damping ring, it spoiled the aesthetic and, due to the increased platter diameter, made it difficult to remove records - especially with the deck running. Can't say I noticed much, if any, difference in sound.

Motor Musing

I've been wondering about the benefits of the Rega power supplies/controllers. The currently available options are 100mA wall wart, 350mA wall wart (I believe these are both transformer based?), and Neo Mk2. I currently own: 100mA, 350mA, Neo Mk1 and the earlier TTPSU (these are both powered by a 350mA psu).

TTPSU

"TTPSU uses exactly the same high stability crystal locked low distortion sine wave generator as is used in the heart of the P9 power supply. This, along with an efficient drive amplifier fed from a stabilised DC power supply, generates a 24V AC balanced signal of less than 0.1% distortion, which is completely un-affected by any changes in the mains/line voltage and conditions. This then drives the turntables antivibration circuit, which is situated beneath the turntable." (from Rega instruction manual)

"TT-PSU is a dual frequency supply that uses 2 fixed frequency crystals to generate the 33/45 RPM sinewave signal. The clock source for 33 RPM is a 3.93216 MHz crystal (60 Hz) or a 3.2768 MHz Crystal (50 Hz). The clock source for 45 RPM is a 5.32021 MHz crystal (60 Hz) or a 4.433618 MHz crystal (50 Hz). All crystals have a frequency stability of .01% (100 PPM). There are 2 buttons on the front panel, an on/off switch and another for switching between 33 and 45 RPM; the Rega Logo is back lit with a red LED for 33 and green for 45 RPM." (https://www.turntablepsu.com/rega.html)

NEO

"The new Neo MK2 is housed in a redesigned case to bring it in line with other products in the range creating an improved family feel. The Neo MK2 PSU is an advanced turntable power supply providing user controllable fine speed adjustment, an advanced anti-vibration motor circuit and the convenience of electronic speed change. The Neo MK2 will make a welcome addition to any compatible Rega turntable by reducing motor noise, improving speed stability and rotational speed accuracy. Using the same DSP (digital signal processing) generator found in the Planar 10 power supply the Neo MK2 is built upon a high stability crystal.

The DSP generator will divide the accurate signal from the crystal to the exact frequency required to turn the platter at the selected speed whilst producing a near perfect sinusoidal waveform to drive the 24v motor. Fine speed adjustment is made via the rear panel using the supplied custom Neo trim tool (supplied)." (https://www.rega.co.uk/accessories/neo-psu-mk2)

"Neo TTPSU is a dual frequency supply that uses DDS to generate the 33/45 RPM sinewave signal. Despite the claim that the PSU uses DSP, it uses a conventional PIC processor and a dedicated Analog Devices AD9837 28 bit DDS. The PIC 16F1827 processor uses a 4.00 MHz ceramic resonator separate from the DDS cystal controlled clock. There are 2 buttons on the front panel, an on/off switch and another for switching between 33 and 45 RPM; the Rega Logo is back lit with a red LED for 33 and green for 45 RPM. The back panel has the 2.5mm barrel connector for power input, a 4 pin DIN connector for the motor, a momentary switch to put the unit into frequency program mode, an LED to indicate program mode and a rotary encoder to change frequency; the encoder switch uses a 1/16" hex drive (allen wrench) to make the adjustments (not included)." (https://www.turntablepsu.com/rega.html)

I believe the only major different between Neo mk1 & 2 is a redesigned case.

So, according to Rega, the benefits of the TTPSU & NEO are reduced motor noise (vibration), improved speed stability and rotational speed accuracy. Let's take these in turn:

Motor Noise

I do not have any equipment, other than my ears, to test this. But due to the design of my Dryad the motor is now well isolated from the rest of the deck - if one taps the top layer whilst playing it can be heard through the speakers but if the bottom layer (the one with the motor) is tapped it cannot be heard at all through the speakers. As ALL Rega turntables rely on just one layer to mount all components is the TTPSU & NEO main raison d'etre to reduce motor noise? Whereas Dryad removes/isolates it.

Speed Accuracy

How to check? A number of different strobe discs were used in conjunction with a 50hz LED strobe light and all PSUs displayed a 'steady' reading. Then RPM Speed & Wow Android app was used to compare each psu - I do not find the app accurate for speed checking but it is useful to give comparative judgements. Neo (factory reset) 33.69, TTSU 33.71, 350mA 33.80, 100mA 33.76 - not much variation and not enough for me to hear.

Speed Stability

Again using the RPM Speed & Wow Android app, w&f readings were taken (but I think the app really only measures variations in speed) Neo +-0.12%, TTPSU +-0.12%, 350mA +-0.14%, 100mA +-0.11% - again very little variation.

Conclusions

When I used Neo with a 'standard' RP3 there was a noticeable difference but with Dryad the evidence is not so compelling, indeed even the 100mA supply might suffice on its own. For now though I will continue to use the TTPSU with Dryad, which doesn't have an on/off switch, for convenience.

I would welcome other thoughts/opinions/comments.



Yes the Neo can be adjusted for speed

[willbewill]

Did some more to the Dryad:

Bought a double 33rpm pulley, as fitted to Planar 8 & 10, which allows use of double belts. It wasn't easy and definitely not for the faint hearted! Was difficult getting the old pulley off, I used acetone dripped into center hole to loosen any adhesive and then this puller.



The new pulley was also difficult as it needed to be set to the correct height and also super glued in place - the glue has a tendency to set before it hits correct position. But I finally got it in place with both belts running on lower section of sub platter - couldn't go any higher as top of pulley would rub on platter, or any lower otherwise bottom belt would come of sub platter and also the pully would be too low on motor shaft.

Motor was then refixed in place with double sided sticky pads.





The next problem, and one that took me ages to sort out, was the fact that two belt exert a greater pulling force on the sub platter. So with just 3 sorbothane hemispheres supporting the top plinth layer it tended to move and so correct belt tension was difficult to achieve! I eventually found a solution in using 4 more hemispheres to support the top - this works but I'm not sure it is a permanent solution, so I'm open to suggestions.

[mayebaza]

A wonderful looking turntable, from experience, I can imagine the sound matches it's looks😍😍😍

[willbewill]

As this build worked out well, I did a whole new build with a modified design using different materials, I've named it "The Dagger" hope you like it...











Full details of build can be found on Lenco Heaven