I am thinking about building a functional equivalent of XTZ A2-300 Edge:
- integrated power supply
- small form factor
- auto on/off based on input sensing
- adjustable gain
I will use a TPA3255 board (by 3e audio) coupled with a Connex SMPS (but will leave place to replace them with an icepower board.
I will try to build the input sensing on-off switch based on the Project 38 schematic by Rod Elliott.
I have question on the "adjustable gain" thing: what do you think it is in the original product? Is this simply a voltage divider potentiometer on the input path, or something else? XTZ A2-300 is based on Icepower 300 AS. As far as I know, it does not have any built in gain regulation.
Thanks
- integrated power supply
- small form factor
- auto on/off based on input sensing
- adjustable gain
I will use a TPA3255 board (by 3e audio) coupled with a Connex SMPS (but will leave place to replace them with an icepower board.
I will try to build the input sensing on-off switch based on the Project 38 schematic by Rod Elliott.
I have question on the "adjustable gain" thing: what do you think it is in the original product? Is this simply a voltage divider potentiometer on the input path, or something else? XTZ A2-300 is based on Icepower 300 AS. As far as I know, it does not have any built in gain regulation.
Thanks
Inside pics of the XTZ shows some sort of active circuitry, but no idea what it is more specifically. XTZ EDGE A2-300 - Pictures from Inside | Audio Science Review (ASR) Forum
Also, apart from the signal sensing, a "functional equivalent" of the XTZ is really just a 2-channel power amp 😀
Ha, well that's true - but these small additions actually make it extremely flexible and fit for my use.
I already have a DIY triggered source switch: when TV is turned on, the device switches to to TV input, when TV is off, it goes back to default input (streamer input). It already allows me to hide the amplifier, and never touch it - TV sound is controlled by TV remote, streamer's - by music app.
If additionally I can get the amp to go to an off state when not in use, and turn on, when a signal hits it, it will make it even neater.
Now, regarding the gain control - is this basically a preamp then? I am bit puzzled that they recommend, to keep it at max gain if possible. I would understand this recommendation if this was just a potentiometer. But if it amplifies signal before it enters the power amp section, I am surprised it's the recommended default - I would think of it as necessary evil in some cases.
I already have a DIY triggered source switch: when TV is turned on, the device switches to to TV input, when TV is off, it goes back to default input (streamer input). It already allows me to hide the amplifier, and never touch it - TV sound is controlled by TV remote, streamer's - by music app.
If additionally I can get the amp to go to an off state when not in use, and turn on, when a signal hits it, it will make it even neater.
Now, regarding the gain control - is this basically a preamp then? I am bit puzzled that they recommend, to keep it at max gain if possible. I would understand this recommendation if this was just a potentiometer. But if it amplifies signal before it enters the power amp section, I am surprised it's the recommended default - I would think of it as necessary evil in some cases.
I am thinking why the xtz's engineer put one channel together with the power supply, while another channel is standalone.
I doubt that they might wanted to go for dual mono for better performance in beginning but end up the chassis are too small to fit?
I doubt that they might wanted to go for dual mono for better performance in beginning but end up the chassis are too small to fit?
This is how the ICEpower modules are designed so you can do modular 2/3-channel designs using just one PSU. The only XTZ decision here is if they wanted to pay a fair bit extra for a full dual-mono design and that answer was obviously "no" 😀
I see... i wouldn't do that because it might end up using much more time to solve the ground loop issues later on. 😱
If you were starting from scratch then yes. However, when you buy a pre-made amplifier as a subassembly from a manufacturer that is able to provide you with design-in support and good documentation on what to do, then that concern is mostly out the window.
And if you can get (say) 90% of the performance for a (say) 80% cost-reduction on the BoM for second channel, then that decision becomes extremely easy 😀
Remember that if you build one unit then the math looks different, but if you can amortise your R&D efforts over thousands of units sold, then even a small cost saving on the final product becomes well worth fighting for.
This mechanism drives a lot of decision-making for manufacturers and it also informs things like how IC datasheets are written, because those small cost savings are part of what design engineers have to look for 🙂
And if you can get (say) 90% of the performance for a (say) 80% cost-reduction on the BoM for second channel, then that decision becomes extremely easy 😀
Remember that if you build one unit then the math looks different, but if you can amortise your R&D efforts over thousands of units sold, then even a small cost saving on the final product becomes well worth fighting for.
This mechanism drives a lot of decision-making for manufacturers and it also informs things like how IC datasheets are written, because those small cost savings are part of what design engineers have to look for 🙂
now I get you... I just browsed to the icepower webpage and saw that they even have their own vlsi engineers for their class D drivers, very very cool!