That doesn't really answer the question "why?". You could feed the balanced input just fine from an unbalanced source.The previous PA5 in fact had balanced only inputs and not had the N5532 input operational amplifier.
How exactly do you feed a truly balanced (and required) input from an unbalanced source?That doesn't really answer the question "why?". You could feed the balanced input just fine from an unbalanced source.
You can try it, but two TPA235x amplifiers on a single power supply could negatively influence each other.So i couldn't run two amps off the one power supply
That makes sense. Thanks for the great information.Therefore, both op-amps are utilized by the SE and DIFF modes. Just that the SE -ve signal goes through both op-amps, whereas all the other ones go through just one op-amp.
Suggested reading:How exactly do you feed a truly balanced (and required) input from an unbalanced source?
I'd be really interested to know.
Sorry, cannot buy any power supplies in the HRP series over here in the uk.Mean Well HRP-150/N/N3
You don't need to post a reading tip for me. I wanted to know how you plan to do it without electronics, because that's not possible.
What do you mean it is not possible? Just connect the hot lead of the unbalanced output to the + (non-inverting) input, and source ground to the - (inverting) input.You don't need to post a reading tip for me. I wanted to know how you plan to do it without electronics, because that's not possible.
They have nothing to do with each other? Do you know what "balanced" means? Did you actually read and understand the Putzeys piece?In simple terms, the TPA325x is about symmetrical signal processing, and you're referring to symmetrical signal transmission, two areas that have nothing to do with each other.
Sure, you can do that if you want to. It is not needed.I've been running my PA5 (first generation) since day one with RCA cables and a converter board with two DRV134s directly in front of the PA5. This is the correct application for driving
Please re-read the reply by @NTKa truly balanced device via a SE signal. And this is exactly what the OPAmps in the other TPA325x devices are needed for, as is also intended by the IC manufacturer TI.
The Mean Well HRP series is a power supply designed for industrial applications that require high inrush power/currents or have short-term power peaks, such as CNC milling. The HRP series is now in its 3rd generation. HRP 150%, HRP N 250%, HRP N3 350%. The % number indicates the power that can be delivered for 5 seconds, based on the nominal power.Sorry, cannot buy any power supplies in the HRP series over here in the uk.
You said that this is the best power supply for amplifiers, what do you think makes it so, and can any of these mods be applied to the stock pA5 II power supply
Maybe we're just talking past each other.What do you mean it is not possible? Just connect the hot lead of the unbalanced output to the + (non-inverting) input, and source ground to the - (inverting) input.
They have nothing to do with each other? Do you know what "balanced" means? Did you actually read and understand the Putzeys piece?
Sure, you can do that if you want to. It is not needed.
Please re-read the reply by @NTK
Maybe, yes.Maybe we're just talking past each other.
For an input to be truly balanced, it needs to be differential. That is why I always talk about "balanced/differential", because while electrical engineers know what "differential" means (and why it is essential in this context), laypeople seem only to (vaguely) understand "balanced".We're talking about TPA325x-based amplifiers that only have one balanced input, like the original PA5. That's not a pro audio device and doesn't have a balanced input suitable for pro audio.
Yes. A differential input stage.You're referring to this circuit diagram, which is completely correct and clear. (I hope I'm allowed to post the excerpt?)
View attachment 448410
But that refers to the receiver duly subtracting the potentials of the two wires.
Then it isn't differential. How can it then be balanced?That doesn't exist in the original PA5.
A balanced input has two terminals, neither connected to earth. That means than they have to also be differential - one of them has to be inverting - otherwise you would not get any output signal.Gamerpaddy was kind enough to publish the circuit of the PA5 before the TPA325x; see also the circuit diagram of the PA5 input in the Topping PA5 fix - D01 Module Replacement for everyone thread.
How do I get the required inverted signal with a cable whose circuit diagram, in the case of the original PA5, looks like this?
View attachment 448417
Zwischen dem Kabel und dem TPA325x ist dann nur noch das 4 kanal Lautstärkepoti und die verlinkte Schaltung.
Thanks ! Did you notice any improvements in sound quality with the meanwell HRP versus the stock PA5 II power supplyThe Mean Well HRP series is a power supply designed for industrial applications that require high inrush power/currents or have short-term power peaks, such as CNC milling. The HRP series is now in its 3rd generation. HRP 150%, HRP N 250%, HRP N3 350%. The % number indicates the power that can be delivered for 5 seconds, based on the nominal power.
Related to 4 amps/150 watts, for example, this means for 5 seconds: HRP 6A/225W, HRP N 10A/375W, HRP N3 14A/525W.
This is ideal for audio applications, as these power supplies are particularly well-suited to meeting the high pulse/power requirements, especially in the low-frequency range.
Therefore, these power supplies should never be oversized in audio applications, as this would only reduce efficiency and increase power consumption. The big advantages are also their stability, reliability, and durability. I've been using several HRP power supplies for my amplifiers (including PA5/II) for over two years, which had previously been in 24/7 industrial use for several years.
You can order such power supplies from Mouser or Digi Key. In the UK, you just have to google it; you could, for example, ask at ecopacpower.co.uk.
eBay is also a good source, for example, for used power supplies.
You can of course also use other power supply series, such as Mean Well UHP, LRS, MSP, some of which are available on Amazon.
You can't modify the original Topping switching power supply; such power supplies are complex designs that can't be easily modified.
Audiophonics offers the original power supply at a very reasonable price, but I don't know if they ship it to the UK. Perhaps someone can bring it to you.
TOPPING Switching Power Adapter 38V 4A GX12
MEAN WELL UHP-500-36 also a very good option (active PFC function,slim and fanless design, 95% efficiency), it is possible to increase the output voltage to 38 volts with a built-in variable resistor, as a result you will receive 38V 13A . Or MEAN WELL UHP-350-36 with which you can get 38V 9A.I am looking at the Mean Well HRP-450-36
But with the HRP N3 300 Watt, you get over 31 amps, or over 1000 watts, for up to 5 seconds.MEAN WELL UHP-500-36 also a very good option (active PFC function,slim and fanless design, 95% efficiency), it is possible to increase the output voltage to 38 volts with a built-in variable resistor, as a result you will receive 38V 13A . Or MEAN WELL UHP-350-36 with which you can get 38V 9A.
View attachment 448622
But with the HRP N3 300 Watt, you get over 31 amps, or over 1000 watts, for up to 5 seconds.
This is a huge advantage in the audio sector, where high pulse power has its advantages.
The 36-volt HRPs can all be set to 38 volts.
TI recommends that the oscillator clocks be synchronized when a single power supply is used to power multiple amplifiers.And is it possible to power three PA5 II amps from the HRP as it has three outputs, or is this a bad idea