OK, understood.
I noticed you don't have the .22uFd 400VAC film cap across the outputs. It is there mainly to filter out the switching noise from the amp, but it will also improve the high frequency stability.
I noticed you don't have the .22uFd 400VAC film cap across the outputs. It is there mainly to filter out the switching noise from the amp, but it will also improve the high frequency stability.
Yeah, I did not purchase those capacitors. I think I got confused, because on post #47 they are present, but in single phase array. On post #136, they´re not on the dual phase array, and either on post #1 wich also dual phase array. I assumed then that I would not need them, cause I was going for the dual phase.
I´ll see if I can get them.
I´ll see if I can get them.
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Hi Bill..Thank you for heads up on the film cap. I entirely forgot about this. I happened to have it and fitted immediately. Meanwhile I've rigged up everything in the open and its working reliably so far.
About those caps... I´m having a hard time finding on aliexpress 0.22uf 400 VAC caps.
I did find Polypropylene film capacitor CBB022 400VDC 220nf and CBB022 630VDC 200n ( F022 03 220nF 224 630V 10pcs CBB Polypropylene film capacitor pitch 15mm 224 220nF 630V-in Capacitors from Electronic Components & Supplies on Aliexpress.com | Alibaba Group )
Could I use those?
Also, could the SG4 be used temporarily without those caps? Because it will take up to 90 days for them to arrive in Brazil.
I did find Polypropylene film capacitor CBB022 400VDC 220nf and CBB022 630VDC 200n ( F022 03 220nF 224 630V 10pcs CBB Polypropylene film capacitor pitch 15mm 224 220nF 630V-in Capacitors from Electronic Components & Supplies on Aliexpress.com | Alibaba Group )
Could I use those?
Also, could the SG4 be used temporarily without those caps? Because it will take up to 90 days for them to arrive in Brazil.
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i would connect to motor to the amp directly and test. if it turns at the correct speed there is no need to use the step up transformer as there will be enough torque. A turntable requires less then a watt to maintain speed.
A small 3 volt DC VCO motor from a tape player would maintain a turntable at 45 rpm with proper belt ratios
A small 3 volt DC VCO motor from a tape player would maintain a turntable at 45 rpm with proper belt ratios
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Hi,
You don't have to buy or insist more than 250VAC rating. As long as its 0.22uf X1/ X2 rated, its safe to use at the output. I'm not sure if you could find some of these in junk or non functional equipment and can be used meanwhile. Yes, you can test your rig without that capacitor. Fit it later when you find one. I used 250V rating without any fear of harm.
Have you looked in this place to buy parts? http://www.newark.com/brazil-direct-ship. For American continent its known as Newark or Farnell , for my country its Element14. I buy most parts from E14, and its all genuine parts,no fakes or questionable quality only to know exactly what you're buying. Be very careful of buying parts from Aliexpress vendors located in China. They may look good but not last.
Lee
Thanks! I´ll see what I can find!
Yeah, I know the problem with aliexpress but it´s the only place I can get this kind of product delivered to Brazil with a reasonable cost.
Farnell would charge me 25 USD in shipping for 2 USD worth of products, and with import duties, that would cost me a total of 43 USD.
=/
Yeah, I know the problem with aliexpress but it´s the only place I can get this kind of product delivered to Brazil with a reasonable cost.
Farnell would charge me 25 USD in shipping for 2 USD worth of products, and with import duties, that would cost me a total of 43 USD.
=/
Ah!...Check out any or spoiled PC power supply units, these caps (may vary slightly in capacitance value), you maybe able to pull out some from these stuff. Its often I find usable high quality parts from junked gear or equipment that I can recycle or use them in future projects.
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I will, thanks for the tip!
I'm running a long test and this is what I'm getting:
1) power both SG4 and TDA at the same time - SG4 starts in Stand by
2) While in stby, set 33 RPM on the toggle switch and exit stby
3) 119.1 VAC and 118.9 VAC (two multimeters connected at the same time)
4) Press Stand By and then switch to 45 RPM and exit stby
5) 119.8 VAC and 118.5 VAC
If I change the speed without pressing stby before, the TDA crashes. If I unplug both SG4 and TDA from the outlet and replug, the TDA does not work. I have to let the SG4 in stby and unplug/replug just the TDA in order to get them working together again. Is this normal?
BTW Lee, I've sent you a PM about your tachometer, have you seen it?
I'm running a long test and this is what I'm getting:
1) power both SG4 and TDA at the same time - SG4 starts in Stand by
2) While in stby, set 33 RPM on the toggle switch and exit stby
3) 119.1 VAC and 118.9 VAC (two multimeters connected at the same time)
4) Press Stand By and then switch to 45 RPM and exit stby
5) 119.8 VAC and 118.5 VAC
If I change the speed without pressing stby before, the TDA crashes. If I unplug both SG4 and TDA from the outlet and replug, the TDA does not work. I have to let the SG4 in stby and unplug/replug just the TDA in order to get them working together again. Is this normal?
BTW Lee, I've sent you a PM about your tachometer, have you seen it?
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Question for Pyramid,
Is any reason to use Carbon comp 5% 400 ppm/c resistors on GC4? I have 1% 100 ppm/c Vishay RN55 in my stock. Should be fine. Right?
Is any reason to use Carbon comp 5% 400 ppm/c resistors on GC4? I have 1% 100 ppm/c Vishay RN55 in my stock. Should be fine. Right?
Sweet. Thanks. Can you please also detect me to info about encoder BOM and it’s integration? I have it’s PCB ordered.
Have a look at post #5 in this thread.
The IC is a CD4013 dual D flip-flop. The 2 caps are 0.47uFd 10V tantalum.
If you did the surface mount PCB, the IC pkg is SO14 and the caps are 1206.
If you did thru-hole, the IC pkg is DIP14, the caps are 2.5 or 5mm lead spacing.
The IC is a CD4013 dual D flip-flop. The 2 caps are 0.47uFd 10V tantalum.
If you did the surface mount PCB, the IC pkg is SO14 and the caps are 1206.
If you did thru-hole, the IC pkg is DIP14, the caps are 2.5 or 5mm lead spacing.
Thanks s lot for such prompt response. I ordered TH. Do not have good eyes for SMD anymore...🙁.
Last one about tranys. I see guys here used 12VA for outputs and 24VA for AMP with CG4. Is it minimum or optimal rating for power transformers? I care with regards to transient conditions particularly for outputs with inductive load.
Last one about tranys. I see guys here used 12VA for outputs and 24VA for AMP with CG4. Is it minimum or optimal rating for power transformers? I care with regards to transient conditions particularly for outputs with inductive load.
For output xfmrs, a good rule of thumb is 1.5-1.75X rated load. For supply xfmr, 2X rated load for class D amps or 4X rated load for class AB.
I have to say the optional Rotary encoder for the SG-4 is a very cool and beneficial feature. I don't think I can do without it.
Pics show my build of the Rotary encoder. The encoder is a commonly for Arduino which already have a couple of pull up resistors, some compatibles may have one resistor missing. Don't think that one matter much.
If the encoder have 3 smd 10k resistors installed, then no need to install any (R1 to R3) at the encoder pcb.
Pics show my build of the Rotary encoder. The encoder is a commonly for Arduino which already have a couple of pull up resistors, some compatibles may have one resistor missing. Don't think that one matter much.
If the encoder have 3 smd 10k resistors installed, then no need to install any (R1 to R3) at the encoder pcb.
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Thanks. Does such enforcer is fully replacing buttons actions, or any way buttons are needed be installed on front panel?