i tried the last 2 pcs of nichicon UES - bipolar - 10µF/16V at the inputs of the RCA - left and right mounted directly beside the rca plugs.
i am very satisfied
sounds great - is this becuae of an effect of the opamps??
Chermann - Chris, notice you have such a strong passion for improving FX502Spro. I am out of town this moment, could you help to share if you have a front pic of FX502Spro full PCB without heatsink for doctormord? ...please...thx
Hi forestgump
yes i will, actually i am in the office...no pic stored...at home in the evneing i will do...
Hi Forestgump
Hi doctor
sorry the PCB is coverd with a thick pianting so backlight is not able to view the layout. the same is with the blue_v3 pcb board.....
i try my best to light an make a contrast as good i can...but i think its not useful to track the pcb.
btw......@ Forestgump
do you ahve troubles with on/ off pop? my amps are quiet.
no moding needed.
chip is U8- the chip for switching on/off?.....i dont know...
label
ST 78788
85003 F3P6
PHL 742 Y
chris
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I made a full XLR, only two inputs.
I hooked directly on the input TPA3255
bypassing the pre amp
Hello,
Would someone know which powersupply modules are used here in Sybic design?
Best regards,
JMF
Hi Kurt,
The Allo Boss DAC has a non-balanced single line output (one for each channel) and I hope your TPA3255 amplifier has a similar input.
The DAC is specified to deliver 2.1Vrms at the output (fine) but no mentioning of the output impedance.
I assume you connect the potentiometer at the output of the DAC and continue straight into the amplifier?
The DAC should be able to handle a 10K potentiometer which also leaves a low impedance for the amplifier input. A volume potentiometer should be logarithmic but they are more difficult to find.
My suggestion - a 2x10K stereo potentiometer.
The Allo Boss DAC has a non-balanced single line output (one for each channel) and I hope your TPA3255 amplifier has a similar input.
The DAC is specified to deliver 2.1Vrms at the output (fine) but no mentioning of the output impedance.
I assume you connect the potentiometer at the output of the DAC and continue straight into the amplifier?
The DAC should be able to handle a 10K potentiometer which also leaves a low impedance for the amplifier input. A volume potentiometer should be logarithmic but they are more difficult to find.
My suggestion - a 2x10K stereo potentiometer.
Thank you FauxFrench for your reply, it was the advice I was looking for. I was thinking one of the Vishay stepped potentiometerso or the Alps rk27 but at least I know what value to get now. The tpa3255 arrived from China yesterday, it didn't have the "genuine Elna caps" but quite honestly from what others have said I wasn't surprised.
Thank you. I'll find a cheap 10k to see how it works. My other priority is a power supply, I'm very much off grid here but have a healthy 24v dc power supply and am looking at step up power supplies to run the the tpa3255. The 220v ac inverter is noisy, modified sine wave, so want to exclude that from the supply.
Hi Kurt,
Just to understand right, you are in France but without regular grid connection such that your main energy source is 24V generated by solar-panels/wind-generators or the like?
If so, you can for a start run the TPA3255 directly from the 24V (with a car-fuse in-between). For higher voltages, you can use a "boost converter" without galvanic isolation because you do not have the safety problem.
400W DC DC Step up Boost Converter Constant Current Power Supply Module LED Driver Step Up Voltage Module DC8.5V 50V To DC10V 60-in Inverters & Converters from Home Improvement on Aliexpress.com | Alibaba Group
1800W 40A CC CV Boost Converter DC DC Step Up Power Supply Adjustable Module DC 10V 60V to 12V 90V DIY kit Electric Unit Modules-in Integrated Circuits from Electronic Components & Supplies on Aliexpress.com | Alibaba Group
High Quality Boost Converter Step up Module Power Supply 600W DC DC 10V 60V to 12V 80V NG4S-in Inverters & Converters from Home Improvement on Aliexpress.com | Alibaba Group
No electricity in France - Alpes, Pyrenees, "Massif Centrale"?
Just to understand right, you are in France but without regular grid connection such that your main energy source is 24V generated by solar-panels/wind-generators or the like?
If so, you can for a start run the TPA3255 directly from the 24V (with a car-fuse in-between). For higher voltages, you can use a "boost converter" without galvanic isolation because you do not have the safety problem.
400W DC DC Step up Boost Converter Constant Current Power Supply Module LED Driver Step Up Voltage Module DC8.5V 50V To DC10V 60-in Inverters & Converters from Home Improvement on Aliexpress.com | Alibaba Group
1800W 40A CC CV Boost Converter DC DC Step Up Power Supply Adjustable Module DC 10V 60V to 12V 90V DIY kit Electric Unit Modules-in Integrated Circuits from Electronic Components & Supplies on Aliexpress.com | Alibaba Group
High Quality Boost Converter Step up Module Power Supply 600W DC DC 10V 60V to 12V 80V NG4S-in Inverters & Converters from Home Improvement on Aliexpress.com | Alibaba Group
No electricity in France - Alpes, Pyrenees, "Massif Centrale"?
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Hi FauxFrench, yes that's correct, in the Couserans in Ariege. I will try connecting the tpa3255 to the batteries via fuse. During the day when the sun is out the voltage can increase to 29v which will be closer to the voltage I understand the amplifier preformso better at. The inverter is connected to them as well so I may experience a bit of noise but won't know until I've tried. Thank you for the links, they are what I've been looking at. I'm presently using one on the 12v system to power a tpa3116 at 19v and it works fine. I may just wire up the tpa3255 and use the software volume control to get an idea of how it compares to the tpa3116.
Interesting to see these converters now being sold as 40A modules, they where 30A a year ago and even only 20A without fan and single-core inductor. Keep in mind, current rating is primary limited, so at 10Vin the 1800W converter only does 400W input side * efficiency (like 0.85) = 340W