• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Digital Turntable Tachometer and DDS based PSU

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
A suggestion I would make : could you offer a version of the Falcon PSU designed to be close to the motor (as mine and yours are) have a female IEC plug, and plug it directly into the motor, skipping the 6 foot power cord that I have bundled up behind my turntable now.

I was going to originally offer 2 options for the cable: NEMA 5-15F (what you received) or IEC C13 which would plug directly into the motor (will limit what you can plug into it). Almost everyone I asked when they bought preferred the NEMA plug, so I stopped asking. I will send you a new cable/rear panel with a 30" cable/C13 socket. They are easy to replace.
 
Member
Joined 2006
Paid Member
Well, I live in switzerland where I have 220v at 50Hz

My TT uses a premotec 24 pole without any fancy electronics... just a cap and some résistors.

I know by experience that reducing voltage to around 70 volts practicaly éliminâtes motor noise but torque is also reduced. Gains in micro detail retrieval are significative but the low torque makes the TT loose some "snap".

I would really like to try one of those PSU's but I Wonder if only one magnet in the subplatter is enough to keep revs going where we need them.
 
Well, I live in switzerland where I have 220v at 50Hz

My TT uses a premotec 24 pole without any fancy electronics... just a cap and some résistors.

I know by experience that reducing voltage to around 70 volts practicaly éliminâtes motor noise but torque is also reduced. Gains in micro detail retrieval are significative but the low torque makes the TT loose some "snap".

I would really like to try one of those PSU's but I Wonder if only one magnet in the subplatter is enough to keep revs going where we need them.

The Falcon is only capable of 120VAC output. You will need a low power step up xfmr to bring it to 220VAC. The wall adapter that powers the Falcon is universal input (100-260VAC) and provides 15VDC @ 1.6A. The wall adapter for the RoadRunner tach is 120VAC input only; the tach will run from any adapter that can supply 8VDC-15VDC, 300mA. One of my customers in Greece substituted his own adapter for the tach.

Regarding reduced voltage, the Falcon always asserts the max voltage at start up (when torque is needed) or when changing speeds. After ~3 secs, it will reduce the voltage to a front panel selectable level (~85-115VAC) for lower noise.

Not sure I understand your question regarding the magnet?
 
Member
Joined 2006
Paid Member
regarding the voltage, it seems perfect because I estimeta 70 volts to be the optimal minimum voltage for ultra low noise operation.

If it starts up at full power, it provides more torque at startup... ok

I do not know if it is a magnet that you use as sensor on the platter to cope with rev speed....
 
regarding the voltage, it seems perfect because I estimeta 70 volts to be the optimal minimum voltage for ultra low noise operation.

If it starts up at full power, it provides more torque at startup... ok

I do not know if it is a magnet that you use as sensor on the platter to cope with rev speed....

Yes, we use a small magnet on the platter and a hall effect IC on the sensor PCB. We only need one magnet, because we are counting the time it takes to make one rev. It will work on the platter edge or the sub-platter.
 
The Falcon will work with the Linn LP12, provided there is no Valhalla (or other internal power supply) installed, or it is not set up to work with the Lingo PS. If the motor is 220V, you will need a step up xfmr between the Falcon and the LP12.

The RoadRunner tach requires ~6mm clearance for the sensor, which I believe you have at the platter edge or the subplatter.
 
I use Lingo, so I couldn't I use the Falcon?

The Lingo has 2 outputs, one for each winding in the motor and the table will have a connector to accept the signals from the Lingo (plugging the Lingo into the Falcon output would not be possible, nor would it give you any benefit). In order to use the Falcon with that table, you would have to restore the cabling and utilize a phase shifting capacitor for the second motor winding.

The Falcon PSU is supplied with a NEMA 5-15 socket (3 prong North American) on the end of a 30" cable. It can be ordered with a IEC C13 socket instead.
 
Member
Joined 2006
Paid Member
I just got around to installing the IEC cord for the back of the Roadrunner. Got rid of a lot of coiled 110vac cable under my table.

Also took a look in the inside, nice stuff on a clean board assembly. Nice work. I love this little box.

Thanks again Pyramid.
 
Digital PSU and Tachometer

Glad it's working out well for you. I get that reaction a lot from people who look "under the hood". The design is almost all surface mount and is professionally produced on automated pick-and-place machines here in the USA (Anaheim CA).

Some additional photos showing the inner workings:
 

Attachments

  • Falcon PCB1.jpg
    Falcon PCB1.jpg
    254.8 KB · Views: 540
  • Falcon PCB2.jpg
    Falcon PCB2.jpg
    252.5 KB · Views: 518
Digital Turntable Tachometer on Michell Gyro SE

RoadRunner Tach installed on a Michell Gyro SE table.
 

Attachments

  • RR1.jpg
    RR1.jpg
    54.1 KB · Views: 482
  • RR2.jpg
    RR2.jpg
    74 KB · Views: 468
  • RR3.jpg
    RR3.jpg
    62.7 KB · Views: 468
  • RR4.jpg
    RR4.jpg
    53.5 KB · Views: 213
  • RR5.jpg
    RR5.jpg
    77.7 KB · Views: 209
  • RR6.jpg
    RR6.jpg
    73.2 KB · Views: 189
The Falcon PSU only works with AC synchronous motors.

The RoadRunner tach can be used with any turntable as long is there is enough clearance for the sensor PCB/magnet (~0.25" or 6cm).

Because of the unusual design of the Michell Gyro, the user mounted the sensor on the aft support leg (4th pic). When originally installed, the platter speed was 31.76 RPM; the user was able to adjust the speed to 33.336 via the Gyro DC power supply.

Both the Falcon and the RoadRunner can be used stand alone or together.
 
The Falcon PSU only works with AC synchronous motors.

The RoadRunner tach can be used with any turntable as long is there is enough clearance for the sensor PCB/magnet (~0.25" or 6cm).

Because of the unusual design of the Michell Gyro, the user mounted the sensor on the aft support leg (4th pic). When originally installed, the platter speed was 31.76 RPM; the user was able to adjust the speed to 33.336 via the Gyro DC power supply.

Both the Falcon and the RoadRunner can be used stand alone or together.

Ok thank you. My turntable has only 5mm clearance.
Quan
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.