TDA2050 (single & dual PS, mono & bridge)
Hallo everyone,
I started my amp builder career with ROG Ruby, then Noisy Cricket, then Tube Cricket, then I moved to higher voltage amp IC: TDA 20x0.
I've built a bridge dual supply TDA2050 AMP. Until I supplied with 36V and voltage divider (low current, ±18V) it worked as expected and louder.
Then I moved to transformer ±18V and 6 elna 10mF filter caps and... probably I cooked my ICs.
A bit disappointed, I bought 2 modules from aliexpress, TDA2050 single supply single IC.
Then I tried to modify one from single supply to dual supply. Here the schematic.
The problem is that I find 1.8V on signal line and my + is 18 and my - is -1.8V.
Seems i forgot a resistor from - to GND.
Here pics.
Thanks
I started my amp builder career with ROG Ruby, then Noisy Cricket, then Tube Cricket, then I moved to higher voltage amp IC: TDA 20x0.
I've built a bridge dual supply TDA2050 AMP. Until I supplied with 36V and voltage divider (low current, ±18V) it worked as expected and louder.
Then I moved to transformer ±18V and 6 elna 10mF filter caps and... probably I cooked my ICs.
A bit disappointed, I bought 2 modules from aliexpress, TDA2050 single supply single IC.
Then I tried to modify one from single supply to dual supply. Here the schematic.
The problem is that I find 1.8V on signal line and my + is 18 and my - is -1.8V.
Seems i forgot a resistor from - to GND.
Here pics.
Thanks
In other words.. can someone check last shematics to help me to troubleshoot why I cant achieve ±...V equal in both rails?
Im not using Transformer, Im using 36v and voltage divider (as I did initially with bridge amp) so it should work fine (if I modufied right the module).
Im not using Transformer, Im using 36v and voltage divider (as I did initially with bridge amp) so it should work fine (if I modufied right the module).
- FiveseveN
- Cap Cooler
Information
Please draw a clear schematic that includes everything you're using: PSU, volume pot and all.
Leaving the center tap open, i.e. using it as a unipolar/single supply seems much simpler than what you're trying to do.I tried to modify one from single supply to dual supply.
Ignorance more frequently begets confidence than does knowledge. (Charles Darwin)
- Frank_NH
- Solder Soldier
I have several of these cheap power amp modules that I bought to play around with. I find it's much easier just buying a single +voltage power supply to use with these amps versus a bipolar supply (stand-alone off-the-shelf bipolar power supplies seem to be few and far between). The disadvantage is that you need the huge capacitor at the output to the speaker, but for low power guitar use it probably isn't a big deal.
The module is single supply so your advice is no mod. Thanks for nothing.Frank_NH wrote: ↑26 May 2023, 13:47 I have several of these cheap power amp modules that I bought to play around with. I find it's much easier just buying a single +voltage power supply to use with these amps versus a bipolar supply (stand-alone off-the-shelf bipolar power supplies seem to be few and far between). The disadvantage is that you need the huge capacitor at the output to the speaker, but for low power guitar use it probably isn't a big deal.
I'm an expert in electronic DIY. Ive made very complicated layout like Kongpressor.
So my skill is not in doubt.
Probably Ive missed a PCB PATH that cause this.
When I connect 18V to the voltage divider (made by 3 parallel 470K resistors betweeen 3 poles) I measure
+ 9V
0 0V
- -9V
Then they start to change increasing + and decreasing - potential
After some minutes
+ 17V
0 0V
- -1.18V
The schematic are these.
Upper scheme is DUAL SUPPLY
Lower scheme is SINGLE SUPPLY module schematic.
PSU 18V or DRILL BATTERY 18V
Original module scheme Lower
Actual modded scheme Upper (see above)
- FiveseveN
- Cap Cooler
Information
My brother in Christ, you're the one who came asking for help.
No they fucking aren't! The volume pot's connection is important for your issue, and so is the PSU.The schematic are these.
And it's still not clear why you're trying to adapt it for bipolar supply when you can easily use it as intended.
Ignorance more frequently begets confidence than does knowledge. (Charles Darwin)
Can you please stop helping? And maybe be more clean at talking since we are in a public community?FiveseveN wrote: ↑29 May 2023, 19:26My brother in Christ, you're the one who came asking for help.
No they fucking aren't! The volume pot's connection is important for your issue, and so is the PSU.The schematic are these.
And it's still not clear why you're trying to adapt it for bipolar supply when you can easily use it as intended.
My achieve is convert it to bipolar.
Since I really checked 10 times everything the only explaination is fried IC.
These modules are very conservative and the effective power output is subpar. I would like to use bipolar since I have 2 batteries 18V and I want to achieve highest power changing the "parallel to speaker" resistor and cap to lower ohm.Frank_NH wrote: ↑26 May 2023, 13:47 I have several of these cheap power amp modules that I bought to play around with. I find it's much easier just buying a single +voltage power supply to use with these amps versus a bipolar supply (stand-alone off-the-shelf bipolar power supplies seem to be few and far between). The disadvantage is that you need the huge capacitor at the output to the speaker, but for low power guitar use it probably isn't a big deal.
I think my IC is dead.