At last, I may have found the right product to implement for my SG-4 controller project.
I've changed SG-4 LED display to 0.56" size and found a same sized AC Voltmeter display that will be connected to the output to the motor. Now I can have both on the front panel in the near future. I found this while shopping for electronic parts locally. Glad I saw it for real and don't have to guess from online vendors. I seem to like what I see. Now I've to think how best to locate it on the aluminum front panel. I will have the panel machined out to fit for a professional finish as done on my Arduino tachometer.
I've changed SG-4 LED display to 0.56" size and found a same sized AC Voltmeter display that will be connected to the output to the motor. Now I can have both on the front panel in the near future. I found this while shopping for electronic parts locally. Glad I saw it for real and don't have to guess from online vendors. I seem to like what I see. Now I've to think how best to locate it on the aluminum front panel. I will have the panel machined out to fit for a professional finish as done on my Arduino tachometer.
Attachments
Last edited:
The DS1833-5 or DS1833-15 will also work; any active high reset controller with a threshold >4V in a TO92 package will work (with the correct pin out, or you could rotate the package in the PCB if needed).
Digikey has ~2300 pcs of the DS1833-5.
It is not easy, but with some BLDC motors it is possible to separate the three wires at their 'common point' and bring out an additional 3 wires, allowing each phase to be driven independently. I don't have access to the recommended motors, so have no idea if it is feasible in this case. It might be worth a look?
I just wanted to give a quick thank you to Pyramid and everyone else who has contributed to this thread, my turntable is up and running and appears to be speed stable. I am waiting on the roadrunner sensor boards to build the tachometer from another thread to test but, when I get my results I will post them back here. I am using a 3d printed pulley and from what my eyes can see and two phone apps it looks to be rock solid.
The RPM iPhone app is useful for showing small speed fluctuations that wouldn't be obvious from the tachometer (the app is garbage for actual RPM measurements, though, as it reports about 0.3RPM faster than actual with my phone). This could help you determine if there's any imperfections in your pulley, assuming you haven't smoothed it out with a lathe or something to that effect.
Hi gents!
What do I need to use SG4 on a 24V Rega RP8 motor?
Would I see any improvement over original REGA TTPSU besides the capability to fine tune the speed, which is already a huge improvement per se.
While I´m in the process of waiting for the SG4 parts to arrive, I ended up upgrading my TD, the previous had a 115V and the new one is 24V, both AC.
HAppy New Year to You All!
Thanks a lot!!
Billy
What do I need to use SG4 on a 24V Rega RP8 motor?
Would I see any improvement over original REGA TTPSU besides the capability to fine tune the speed, which is already a huge improvement per se.
While I´m in the process of waiting for the SG4 parts to arrive, I ended up upgrading my TD, the previous had a 115V and the new one is 24V, both AC.
HAppy New Year to You All!
Thanks a lot!!
Billy
Hi Billy,
Not too long ago, I connected a Nigel Speed Controller (configured for 230V/50hz output in my area) and plug a recent Rega P3 with 24V motor, it works fine and you can finetune the speed. I didn't have to do anything to it. Just plug its transformer wall wart to the controller. The SG4 is objectively the same. I only tested to see if it works, I've no idea as to sound improvement. I believe the motor is merely 24VAC model and frequency dependent on rotational speed, therefore the SG4 controller should work fine.
Thanks for your replay!
If I plug the wall wart to the SG4 with it´s outlet ready for, let´s say, 230V I will be modulating frequency and phase that feeds the wall wart tranformer, which is a 230V60Hzx24V AC already, if I´m not wrong. It will work, as it worked in your example, but I´ll need a bigger xformer for the SG4. Not sure how the adjustment capabilities og the SG4 will perform doing so.
The whole idea is to get rid of the original Rega wall wart, as here in Brazil it´s 115V 60Hz and, apart from that, original TTPSU, as it doesn´t have speed adjustment capabilities.
Hello,
I don't see any reason for a bigger transformer for the Rega. The motor is only 3-5Watt@24VAC. If you rid the wall wart, then feed 24VAC from the SG4 and vary the frequency to adjust your platter speed accordingly. The PCB to the motor under the plinth is a motor phase shift circuitry. Alternatively, you can rid the circuitry and feed 2 phase directly to the motor from SG4 built to output 24VAC. If I'm not wrong, you may now need a custom 12V to 24V output transformer within the SG4. I think this this whole topic here is focussed mainly for 110V or 230VAC mains output speed controller, which this kind of transformer is easily available on the open market.
Last edited:
Thanks for your replay!
That´s the whole point for me to swap the Rega TTPSU for the SG4.. Both speed adjustment, keeping the phase fine tunning.
My mistake!
I thought you´re suggesting to hook the Rega wall wart 230x24 AC xformer that feeds the Rega TTPSU to the SG4. That´s why I mentioned the need for big xformer.The P3 has not TTPSU, the 24V motor is feed by the wall wart xformer, what makes all sense, as you have a controller with 230V output already.
So if I install 2 12x24V xformer to the SG4 and make the proper wiring to the connector I´ll be able to hook the RP8 motor to the SG4 and beneffit from this beatyfull project?
Maybe I better make myself clearer. I had an Avid Ingenium, which has a 115V AC motor, no controller, which was a perfect contender for the SG4, but I sold It and bought a Rega RP8, which comes with a 24V AC motor feeded by a dedicated PSU, that lacks adjustment capabilities. That's why I want to use the SG4 for. Besides that, I have already bought everything só, why not? : )
Its a case of building SG-4 to output 24VAC feed to your Rega RP8 that would make it work nicely. I'm almost sure Rega does not offer any external controller with variable frequency control, its a regenerated fixed output.
You can generate 24VAC directly using the MK-154 amp as shown in this thread: 60 WPC Amplifier for DIY Turntable Motor Drive
24VAC is ~68VPP. You will need to power the amp with 2x25VAC or a 50VAC secondary with a center tap. That will provide ~±35VDC which will allow 70VPP without clipping.
Instead of adding 2K2 in parallel with the 22K resistors, put 10K in parallel with the two 22K resistors as shown in the thread. This will give you a gain of ~13.75 and with 5VPP from the SG4 will provide 68.75VPP or 24.3VAC at the output.
You will not need a transformer between the motor and the MK-154. The output is centered a zero VDC and can drive the 24VAC Rega motor directly.
24VAC is ~68VPP. You will need to power the amp with 2x25VAC or a 50VAC secondary with a center tap. That will provide ~±35VDC which will allow 70VPP without clipping.
Instead of adding 2K2 in parallel with the 22K resistors, put 10K in parallel with the two 22K resistors as shown in the thread. This will give you a gain of ~13.75 and with 5VPP from the SG4 will provide 68.75VPP or 24.3VAC at the output.
You will not need a transformer between the motor and the MK-154. The output is centered a zero VDC and can drive the 24VAC Rega motor directly.