Thank you Maestro ))
here’s the link, it’s sold in Ebay, Amazon, or direct. Not cheap. They have many different models. I’m currently in conversation with seller about the fact that this case, while very rigid, has pour torsional stability, gets twisted a bit when fully assembled, so one foot is off the ground. He’s thinking how to improve on that. But I do like it’s medical/lab/industrial look and ventilation.
https://www.ebay.com/itm/1250081594...Y3yTBXVSY2&var=&widget_ver=artemis&media=COPY
Hi All
I asked the seller if they are shipping the "A" version and did not receive a reply. I took a risk and ordered one and they are definitely not the A version so we all need to look elsewhere. After a painful search-- the simplest answer is to order a 1.05 version from Ralph Cooke so we don't have to worry about it.
Hi all. A minor problem (I think): when I press “start”, for the guest sending I can hear the belt slipping on pulley, until platter catches up. It’s a factory Sota pulley and belt. I remember reading somewhere in the threads, that motor should start at only 5v, preventing belt wear. I can see by the current draw that motor pulls about 800 ma at start, and after a second or two it drops to 340 ma. Is anything wrong with my build?
The SG4 does not have the same ramp up in speed that the Condor has as it is designed to be used with 115V AC synch motors as well as BLDC types. The Condor starts at ~5Hz and ramps up to 20Hz and the step up transformers used in some SG4 applications would never tolerate those frequencies. The SG4 does start at full voltage to provide more torque to get the platter moving, then drops the voltage to a user programmed level to reduce vibration which is what you are seeing. It is working as designed.
Or just apply talc to the belt O expedite slippage, as recommended by several TT manufacturers.
I don't recommend doing this as it can affect both belt slippage and belt creep and will not be consistent across the length of the belt which will adversely affect speed stability. As far as I know, VPI is the only mfr that used to recommend this; their resident expert (Brf on their forum) no longer recommends this either.
Before I obtained factory Sota pulley, I used the one a few people used here, for a round belt, I forget the brand. It was also larger in diameter. There was nearly no slippage on that one, just a tiny squick at the very start. W/f figures were not as good. But perhaps a slightly larger diameter pulley would “tame” the excessive torque at start? I remember Sota using a huge pulley in their Mk IV Cosmos. This is more of a ”nuisance” thing, table/system other wise run great.
There’s also a very slight noise from the motor. Zero vibration, but slight mechanical noise, resembling “wshshshshh”, so it located in lower table area. I have to put my ears close to motor to hear it. I wonder if my bearings are shot, or may be this is normal. Ori hi inal Papst “pancake” was dead silent.
Hi All
I'm having a lot of trouble getting my SG4--rev C + TDA7492 Class D amp 50W + Amgis L01-6362 12V toroid transformer to power a Lenco 50Hz motor.
I'm trying to troubleshoot where the problem may be.
SG4: Measured at the output pins 60Hz : .091vdc : same reading with 1.03 and 1.04 chip
SG4 Output______2.5_______1.75_________5.0
Thanks
Mark
I'm having a lot of trouble getting my SG4--rev C + TDA7492 Class D amp 50W + Amgis L01-6362 12V toroid transformer to power a Lenco 50Hz motor.
I'm trying to troubleshoot where the problem may be.
SG4: Measured at the output pins 60Hz : .091vdc : same reading with 1.03 and 1.04 chip
- is this correct for Rev C?
SG4 Output______2.5_______1.75_________5.0
- SG4 measured after the fixed voltage divider of 8.2K and 1.8K resistors: .008
- Amp output into transformer 1.4 v
- Transformer output before .22uF 400v dc capacitor: 11.4 v
- Transformer output after 22uF 400v dc capacitor: 11.5V
Thanks
Mark
Your output after the divider looks wrong, to a first approximation, if the SG4 o/p is 1.75 rms,
then you should get 10% of that, or 0.175V after the divider.
Without knowing which TDA7492 amp you're using, make sure there's a capacitor between the
SG4 and the amp, you don't want DC on the amp input, depending on the amp input impedance 0.1uF or more should be fine.
then you should get 10% of that, or 0.175V after the divider.
Without knowing which TDA7492 amp you're using, make sure there's a capacitor between the
SG4 and the amp, you don't want DC on the amp input, depending on the amp input impedance 0.1uF or more should be fine.
Hi Ralph
Thanks for the quick reply. I apologize for not being clear. The spec output for the sg4 is supposed to be 2.5 VDC or 1.75 v rms. Mine measures. .091 v dc .. far below spec.
After the divider network it measures .008 or about 9%— not too far away from the 10% you mentioned.
On the surface it appears that the sg4 isn’t putting out enough voltage to get the job done. All parts were purchased from mouser per the latest project list they have.
Does any of this make sense ?
Thanks
Mark
Thanks for the quick reply. I apologize for not being clear. The spec output for the sg4 is supposed to be 2.5 VDC or 1.75 v rms. Mine measures. .091 v dc .. far below spec.
After the divider network it measures .008 or about 9%— not too far away from the 10% you mentioned.
On the surface it appears that the sg4 isn’t putting out enough voltage to get the job done. All parts were purchased from mouser per the latest project list they have.
Does any of this make sense ?
Thanks
Mark