Edit Dec 5. 2020: the GB is now taking preorders in my shop. I am including a free BTSB PCB with each order.
XRK RTR TPA3255 Reference class D Amp GB2
RTR TPA3255 Reference Class D amplifier | Etsy
This is the GB number 2 thread for the ready to run (RTR) TPA3255 reference Class D amp from this thread:
TPA3255 Reference Design Class D Amp GB
The thread has a lot of details on the development process and build question and answers. A GB interest list will just get buried and lost in it so I decided to make a new thread as there seems to be some renewed interest now that Redjr has just released his masterpiece build using this amp. I have already received several requests for more RTR amps.
To make this viable for a manufactured amp from a California based assembly house, I will need a commitment for at least 20 amps from folks here. I will pledge to buy another dozen amps and we then get these professionally made using a pick and place machine with a genuine Mouser BOM.
As before, the default amp will be balanced input stereo BTL output. We now have the BTSB Buffer board to go with it which will provide the necessary conversion from SE inputs and gain to drive this amp effectively.
BTSB Buffer - SE/Bal to SE/Bal Buffer GB
The amp will be manufactured using 2mm thick pcb’s and 2oz copper and ENIG finish. Amp modules will be fully tested and come with a set of Molex connectors for audio in, speaker out, and PSU in. Pricing of the amp will be $277 each. The lead time may be up to 3 months, although I think it will go much faster this time since it is a second run and we have the kinks all worked out.
Edit Aug. 21, 2020: Special Promotion - Free BTSB Buffer PCB (TH or SMT) with your order of the RTR amp. A $23 value that allows this amp to be used with any source.
Please put your name, number of boards, and country down on the list below. Once we have 20, I will put a preorder listing on my shop for you to purchase.
Thanks,
X
Interest List:
Name / number of amps / country
____________________________
JohnDoe / 2 amps / USA
XRK RTR TPA3255 Reference class D Amp GB2
RTR TPA3255 Reference Class D amplifier | Etsy
This is the GB number 2 thread for the ready to run (RTR) TPA3255 reference Class D amp from this thread:
TPA3255 Reference Design Class D Amp GB
The thread has a lot of details on the development process and build question and answers. A GB interest list will just get buried and lost in it so I decided to make a new thread as there seems to be some renewed interest now that Redjr has just released his masterpiece build using this amp. I have already received several requests for more RTR amps.
To make this viable for a manufactured amp from a California based assembly house, I will need a commitment for at least 20 amps from folks here. I will pledge to buy another dozen amps and we then get these professionally made using a pick and place machine with a genuine Mouser BOM.
As before, the default amp will be balanced input stereo BTL output. We now have the BTSB Buffer board to go with it which will provide the necessary conversion from SE inputs and gain to drive this amp effectively.
BTSB Buffer - SE/Bal to SE/Bal Buffer GB
The amp will be manufactured using 2mm thick pcb’s and 2oz copper and ENIG finish. Amp modules will be fully tested and come with a set of Molex connectors for audio in, speaker out, and PSU in. Pricing of the amp will be $277 each. The lead time may be up to 3 months, although I think it will go much faster this time since it is a second run and we have the kinks all worked out.
Edit Aug. 21, 2020: Special Promotion - Free BTSB Buffer PCB (TH or SMT) with your order of the RTR amp. A $23 value that allows this amp to be used with any source.
Please put your name, number of boards, and country down on the list below. Once we have 20, I will put a preorder listing on my shop for you to purchase.
Thanks,
X
Interest List:
Name / number of amps / country
____________________________
JohnDoe / 2 amps / USA
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It’s self protected via smart startup and shutdown built in to the chip. See features on data sheet.
Also detects pop induced by hot plug of input connector and will self protect / auto error shutdown. Requires manual reset push button or power cycle to restart.
https://www.ti.com/lit/ds/symlink/tpa3255.pdf
Also detects pop induced by hot plug of input connector and will self protect / auto error shutdown. Requires manual reset push button or power cycle to restart.
https://www.ti.com/lit/ds/symlink/tpa3255.pdf
The way to prevent pop sound on power-up is a delayed release ob TPAreset-pin=low. For power-down an early TPAresetpin=low mutes the output before pops come in. This requires some extra circuitry like an power-on-reset-chip with delay or a microcontroller. Which is the way I do it.
Furthermore it is helpful to study TIs datasheet completely which tells you that increasing input coupling caps beyond sane values is another source of introducing pop noise.
Furthermore it is helpful to study TIs datasheet completely which tells you that increasing input coupling caps beyond sane values is another source of introducing pop noise.
Yes, my TPA3255 has a microcontrolled reset using this part (N211 on schematic):
https://www.mouser.com/datasheet/2/268/mic8114-778430.pdf
There is no issue with turn-on turn-off pop at all with my impementation.
See 4-pin critter on lower portion of photo (N211):
https://www.mouser.com/datasheet/2/268/mic8114-778430.pdf
There is no issue with turn-on turn-off pop at all with my impementation.
See 4-pin critter on lower portion of photo (N211):
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If anyone has doubts about the sound quality or performance of this amp, you might want to look at Redjr's review of his build here:
https://www.diyaudio.com/forums/class-d/87913-class-amp-photo-gallery-162.html#post6305030
Redjr has kindly provided the CAD files for making the same custom front and rear panels from Frontpanelexpress here:
TPA3255 Reference Design Class D Amp GB
https://www.diyaudio.com/forums/class-d/87913-class-amp-photo-gallery-162.html#post6305030
Redjr has kindly provided the CAD files for making the same custom front and rear panels from Frontpanelexpress here:
TPA3255 Reference Design Class D Amp GB
Absolutely no doubts ) The amp seems as good as the DrMordor one using his selfmade PSU )
This is the first version. Looking forward to test the last version !
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New measurements using the BTSB Buffer for SE to Balanced conversion with 20dB gain turned on. Beautiful result - the BTSB doesn’t add any noise or distortion. Basically at the limit of the Focusrite.
Here is the reference condition of 10Vrms into 10ohms (10w). At 0.0012% THD is similar to earlier measurement with THAT1646 but we now have up to 20dB of gain. Plus the HF hash is reduced.
The noise floor is so low (-130dB) you could use it as a headphone amp.
More info on the measurements here:
BTSB Buffer - SE/Bal to SE/Bal Buffer GB
Here is the reference condition of 10Vrms into 10ohms (10w). At 0.0012% THD is similar to earlier measurement with THAT1646 but we now have up to 20dB of gain. Plus the HF hash is reduced.
The noise floor is so low (-130dB) you could use it as a headphone amp.
More info on the measurements here:
BTSB Buffer - SE/Bal to SE/Bal Buffer GB
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Hi everyone, I'm Italian and I don't speak English, I use a translator, if I understand correctly you assemble TPA3255 homemade and then sell them? explain me better please I am very interested, for the moment I have a simple TPA3255 AIYIMA A07 that does not make pop noise and with a DC 48V 7.3A power supply and sounds great with Speakers (Focal Chorus 726).