Good day all,
I am new to the forum but it seems that there is a wealth of information to be had here 🙂
I was looking for a good set of 2.1 desktop speakers/amp but unfortunately high end models like the corsair SP2500 is not available in my country and importing it via the likes of amazon will work out more than double the list price when taking shipping and taxes into consideration.
That's when I thought that I might take my first step into the world of DIY audio. I can get my hands on the TPA3255EVM (TPA3255 325W Stereo/ 600W mono PurePath Ultra-HD Analog Input Power Stage Evaluation Module - TPA3255EVM - TI Tool Folder) for $250 converted when it releases and figured that might be an ideal place to start if I can buy some descent bookshelf speakers for a quality 2.0 setup.
I am by no means an audio expert but I have degree of experience with electronics in general and I was hoping someone on the forum could help me with the following questions:
1) What do you think of the TPA3255DDV specifications? I reckon I will drive 2 x 100 Watt, 8 ohm bookshelf speakers so I will stay well below 1%THD+N. Do you think it's good value at that power and distortion level considering the Class D amp can get away with a much smaller PSU? Or are there commercial options that are better value(I have not seen any)?
2) What is a good PSU to use for this amplifier? Would something like the SP-750-48 (http://www.mantech.co.za/datasheets/products/SP-750-MW.pdf) work are switching mode PSUs a very bad idea for audio amps? Ripple noise is listed as 120mVp-p max which is a very small % at 48V, but information regarding the switching frequency is not available so I am not sure if anything will fall within the audio band. Where can one buy stand-alone low noise linear amps? They seem to almost non existent.
I do have some additional questions but those above are the ones that will determine if proceeding with a project like this is even worth while.
Your input on this is much appreciated 🙂
I am new to the forum but it seems that there is a wealth of information to be had here 🙂
I was looking for a good set of 2.1 desktop speakers/amp but unfortunately high end models like the corsair SP2500 is not available in my country and importing it via the likes of amazon will work out more than double the list price when taking shipping and taxes into consideration.
That's when I thought that I might take my first step into the world of DIY audio. I can get my hands on the TPA3255EVM (TPA3255 325W Stereo/ 600W mono PurePath Ultra-HD Analog Input Power Stage Evaluation Module - TPA3255EVM - TI Tool Folder) for $250 converted when it releases and figured that might be an ideal place to start if I can buy some descent bookshelf speakers for a quality 2.0 setup.
I am by no means an audio expert but I have degree of experience with electronics in general and I was hoping someone on the forum could help me with the following questions:
1) What do you think of the TPA3255DDV specifications? I reckon I will drive 2 x 100 Watt, 8 ohm bookshelf speakers so I will stay well below 1%THD+N. Do you think it's good value at that power and distortion level considering the Class D amp can get away with a much smaller PSU? Or are there commercial options that are better value(I have not seen any)?
2) What is a good PSU to use for this amplifier? Would something like the SP-750-48 (http://www.mantech.co.za/datasheets/products/SP-750-MW.pdf) work are switching mode PSUs a very bad idea for audio amps? Ripple noise is listed as 120mVp-p max which is a very small % at 48V, but information regarding the switching frequency is not available so I am not sure if anything will fall within the audio band. Where can one buy stand-alone low noise linear amps? They seem to almost non existent.
I do have some additional questions but those above are the ones that will determine if proceeding with a project like this is even worth while.
Your input on this is much appreciated 🙂
this clould be another option
https://www.aliexpress.com/store/product/TPS3251PurePath-Ultra-HD-Analog-Input-Class-D-Amplifier-integrated-with-global-AC-supply/601158_32695980769.html?spm=2114.8147860.0.0.MxuDrM
or in a box
https://www.aliexpress.com/item/G3H-300W-TPA3251PurePath-Ultra-HD-Analog-Input-Class-D-Amplifier-integrated-with-global-AC-supply/32712158006.html?spm=2114.12010108.1000013.1.132roX&scm=1007.13339.33317.0&pvid=ce55cb72-9db2-4da0-a699-768bd2d065e2&tpp=1
https://www.aliexpress.com/store/product/TPS3251PurePath-Ultra-HD-Analog-Input-Class-D-Amplifier-integrated-with-global-AC-supply/601158_32695980769.html?spm=2114.8147860.0.0.MxuDrM
or in a box
https://www.aliexpress.com/item/G3H-300W-TPA3251PurePath-Ultra-HD-Analog-Input-Class-D-Amplifier-integrated-with-global-AC-supply/32712158006.html?spm=2114.12010108.1000013.1.132roX&scm=1007.13339.33317.0&pvid=ce55cb72-9db2-4da0-a699-768bd2d065e2&tpp=1
So I just ordered the TPA3255EVM today 🙂
Not sure on PSU yet but will use a bench supply in the meantime to test.
What would you recommend for volume control? A potentiometer in line with the input will be the easiest but surely this cannot be good for audio fidelity?
I am looking at designing a custom pre-amp using the PGA2311 and a MCU with a little LCD display.
If the amp is supplied with a full volume input and my speakers are rated for 100W per channel surely the amp will blow my speakers!
Not sure on PSU yet but will use a bench supply in the meantime to test.
What would you recommend for volume control? A potentiometer in line with the input will be the easiest but surely this cannot be good for audio fidelity?
I am looking at designing a custom pre-amp using the PGA2311 and a MCU with a little LCD display.
If the amp is supplied with a full volume input and my speakers are rated for 100W per channel surely the amp will blow my speakers!
If you will keep the distortion down, then the TPA3255 in stereo mode is "just" 100 watt in 8 ohm. But even quite high music level in normal living room only requires 20-30 watt.
So this are the first comercially available boards with tpa 325x chip? Looks like the power supply is already integrated on the board...right? Enyone thinking to buy one to test?
We have had a discussion about this board/amp in the 3251 thread - there where some flaws in the first batch/revision, now fixed. To my knowledge no "real" measurements available.
tnx Doctormord ....how far is the development of your board? I would really love to get those chips run into the production. 3116 is good, but a little more power would be perfect 🙂.
I'm quite busy with study and work atm but the boards are "high-priority" in the pipeline.
The "old" boards are working fine but have some room for improvement in the analog front end section.
(in the sub 0.01% THD..)
Inductors also have a significant impact on these numbers.
Should i run another batch of those, to get you happy? (Need solder on your own)
The "old" boards are working fine but have some room for improvement in the analog front end section.
(in the sub 0.01% THD..)
Inductors also have a significant impact on these numbers.
Should i run another batch of those, to get you happy? (Need solder on your own)
No noise at all - it's completly silent (and still in transit)
I will compare it to my Panasonic SA-XR55 and Audiopower MDA-400
I will compare it to my Panasonic SA-XR55 and Audiopower MDA-400
So I have built a prototype of the volume control / preamp while I am waiting for my TPA3255EVM to arrive. It uses a MSP430 MCU to drive the display, with a rotational knob with click in push button being the user control. I use a PGA2311 which is controlled by the MSP430 to adjust the volume.
Credit to my colleague for writing the firmware.
I will now do a proper PCB layout.
Short video clip link below:
https://youtu.be/NK38RXbrUQg
Obviously I will work on the scale once I get the TPA3255EVM.
Credit to my colleague for writing the firmware.
I will now do a proper PCB layout.
Short video clip link below:
https://youtu.be/NK38RXbrUQg
Obviously I will work on the scale once I get the TPA3255EVM.
I've also ordered the TPA3255EVM. But I'm considering cancelling my order(not in stock yet, anyhow) in favor of the SineWave G3H. Should I hold out for the EVM and find a suitable PSU or just get the all-in-one finished product G3H(or wait for the 360customs board)? My application is with 93-100dB speakers. Thx.
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If you can effort, get both and do a comparison.
Keep in mind, the G3H is a 3251 based amp - (bit less power but also bit less quiescent current and "noise" - if any)
Point of the 360customs board is, you'll most likely have to solder it on your own.
Pricewise, the G3H is a great deal - if anything is "original" and from good quality. The EVMs are made in the United States if you care about that.
The EVM will (most likely) measure better. (From my own experience, these specs are hard to met.)
2c.
Keep in mind, the G3H is a 3251 based amp - (bit less power but also bit less quiescent current and "noise" - if any)
Point of the 360customs board is, you'll most likely have to solder it on your own.
Pricewise, the G3H is a great deal - if anything is "original" and from good quality. The EVMs are made in the United States if you care about that.
The EVM will (most likely) measure better. (From my own experience, these specs are hard to met.)
2c.
Thanks for your reply. I guess the G3H proves to be the best value at the moment, with the advantage of being in a nice box and ready to play.