Hello.
I've been digging around and trying to know more about making an amplifier. I have decided to make something, that is hopefully not too big of a mouthful for me. We all have to start somewhere, and for me, that somewhere is here.
I hope i can get some feedback of the parts list and possible some recommendations for changes to the parts list. As soon as I, hopefully, have received some feedback, and corrected the parts list, I will try to make the PCB layout and post it in here.
The end goal is to have a couple of boards for my own use.
What do i want out of this project:
I want a PBTL mono amp (switchable to BTL Stereo if possible), that also has a build in 5v 1a output for an Arylic Bluetooth Receiver.
Be somewhat on a budget.
Has to play clean, but I do not need something over the top.
Possible a change of OPamps if it is worth it, to spend some extra
A reliable amplifier, that can be used for a party speaker and/or some nice mono speaker for the living room.
... I considered adding PFFP to the board, but i honestly do not think it is worth it for this project. Correct me if I am wrong.
I also dreamt about having 3 chips on the board, and DSP, making it real easy for crossovers for my projects, but unless I have a schematic I can follow, this will be too complicated.
Parts list:
I listed my parts list below. That is including the schematic and parts list for the voltage converter for the 5V 1A.
All the green markings are items, that have been changed from the reference design schematic. If you have any tips of changes in values, parts etc., please let met know.
I've been digging around and trying to know more about making an amplifier. I have decided to make something, that is hopefully not too big of a mouthful for me. We all have to start somewhere, and for me, that somewhere is here.
I hope i can get some feedback of the parts list and possible some recommendations for changes to the parts list. As soon as I, hopefully, have received some feedback, and corrected the parts list, I will try to make the PCB layout and post it in here.
The end goal is to have a couple of boards for my own use.
What do i want out of this project:
I want a PBTL mono amp (switchable to BTL Stereo if possible), that also has a build in 5v 1a output for an Arylic Bluetooth Receiver.
Be somewhat on a budget.
Has to play clean, but I do not need something over the top.
Possible a change of OPamps if it is worth it, to spend some extra
A reliable amplifier, that can be used for a party speaker and/or some nice mono speaker for the living room.
... I considered adding PFFP to the board, but i honestly do not think it is worth it for this project. Correct me if I am wrong.
I also dreamt about having 3 chips on the board, and DSP, making it real easy for crossovers for my projects, but unless I have a schematic I can follow, this will be too complicated.
Parts list:
I listed my parts list below. That is including the schematic and parts list for the voltage converter for the 5V 1A.
All the green markings are items, that have been changed from the reference design schematic. If you have any tips of changes in values, parts etc., please let met know.
You can't switch the mode pbtl to btl on the same chip as the outputs are soldered together in parallel.
Alright. That is good to know. I thought that the evaluation board had switchable channels, but i guess I'm wrong. Well I'll just go for a PBTL board only, as I wont be making stereo projects very often.
You can (like on the eval board) connect paths when needed in stead of soldering or designing them permanently together. But if you just need the PBTL, designing it this way can reduce the parts count.
Tommy
Tommy
Yeah, that is what i thought aswell. I Think i’ll just be sticking to the PBTL build then.
Any thoughts on the parts list?
Any thoughts on the parts list?
At least you wont need C21, C34, C42 and C56 as these are only needed if using SE outputs. I'm not the most qualified to make qualitative judgment on your choices. You might want to take a lock at XRK's reference TPA3255
Going Pure PBTL you could save some parts on the output filter, also on the input side there would be some redundancies.
In the end you'll find that the cheapest route would be one of the higher quality Chinese boards.
Tommy
Going Pure PBTL you could save some parts on the output filter, also on the input side there would be some redundancies.
In the end you'll find that the cheapest route would be one of the higher quality Chinese boards.
Tommy
I see.
Know when i have decided to only use the PBTL, I can remove certain parts.
Probably a good idea to compare parts with others.
I am not making the project to save money. I want to be able to make amplifiers in the future. As a young novice, this is hopefully a first step. What i meant was, that I would save money, where it makes sense.
Thanks for all the feedback. It is really helpful
Know when i have decided to only use the PBTL, I can remove certain parts.
Probably a good idea to compare parts with others.
I am not making the project to save money. I want to be able to make amplifiers in the future. As a young novice, this is hopefully a first step. What i meant was, that I would save money, where it makes sense.
Thanks for all the feedback. It is really helpful
If you go for PBTL as I did, the better option is paralleling the output pins of the chip, before the output filter.
Which is in contrary to the PBTL available on the evalution board.
This improves performance and simplifies output filters.,
Which is in contrary to the PBTL available on the evalution board.
This improves performance and simplifies output filters.,
I see. That would be great for me. Do you have any schematic of this etc.? Just so i don't make any mistakes.
Will you be using balanced or SE inputs?
And I'll take it you are working from the EVAL board schematic.
And I'll take it you are working from the EVAL board schematic.
I was thinking balanced, but I haven't decided yet. Yes, unless someone recommend something else, I'll be using the EVAL board schematic.
OK, if you look at the pdf for TPA3255 input C and D get routed to ground so the lower opamp in the EVAL schematic can be omitted. R43 C71 and the connection made at J4 is the difference between SE and Diff.
For the output if you look at page 28 of the TPA3255 pdf and replace the two 470nF with one 1uF cap you have basics of the board minus the power supply section.
For the output if you look at page 28 of the TPA3255 pdf and replace the two 470nF with one 1uF cap you have basics of the board minus the power supply section.
Alright. So i just need one opamp?
Also, do you think it would be worthwile to upgrade the standard opamp?
A thing i was wondering was that if there was a labeled schematic. In the parts list, there is labels for all the parts, but not in the manual. Would be nice to see a schematic with opamp etc. just so I dont miss anything.
Any advantages of switching to a 1uF cap instead?
Also, do you think it would be worthwile to upgrade the standard opamp?
A thing i was wondering was that if there was a labeled schematic. In the parts list, there is labels for all the parts, but not in the manual. Would be nice to see a schematic with opamp etc. just so I dont miss anything.
Any advantages of switching to a 1uF cap instead?
Just one, personally I'd use the OPA1642, but that is just personal preference, and in the end might be all in my head.
Every thing should be available by corelating the EVAL and TPA3255 pdf's
1 less cap, apart from that not much.
Tommy
Every thing should be available by corelating the EVAL and TPA3255 pdf's
1 less cap, apart from that not much.
Tommy
Alright, sounds good. I'll draw up the schematic and try to understand it better.
Do you have any experience with Bucks Bunny's suggestion, that was to parallel the output pins of the chip, before the output filter?
Do you have any experience with Bucks Bunny's suggestion, that was to parallel the output pins of the chip, before the output filter?
If you look at the picture you posted the pins are paralleled (A+C B+D) before the filter, and it uses only 2 not 4 filters.
It might be possible to use only one filter, but this would place the filter on opposite sides of the speaker for the outputs and I'm not sure about the effect of this.
It might be possible to use only one filter, but this would place the filter on opposite sides of the speaker for the outputs and I'm not sure about the effect of this.
I now tried to draw the schematic in EasyEDA, to get a better understanding of the schematic. It will probably be obvious to most, that this is my first schematic drawing.
Warning:
It may or may not trigger you and hurt your head. It is very messy.
I still don't know where the OPamp etc. is on this drawing? What am I not understanding.
Warning:
It may or may not trigger you and hurt your head. It is very messy.
I still don't know where the OPamp etc. is on this drawing? What am I not understanding.
If you look at the EVAL schematic you'll find it there between the 10uF and the chip. They have simplified the schematic in then TPA3255 schematic.
Thanks for all the help Gulo_Gulo. Sorry for being such a newbie!
I wanted to update my progress for today.
I guess i just need to figure out what to do with the TLV1117, LM2940IMP and LM5010A. I guess some of it has to do with the 12v that my schematic needs. The thing i have the hardest understanding, is clearly when the schematics aren't combined. Makes it harder for me to comprehend, but I hope I can figure the rest out.
I wanted to update my progress for today.
I guess i just need to figure out what to do with the TLV1117, LM2940IMP and LM5010A. I guess some of it has to do with the 12v that my schematic needs. The thing i have the hardest understanding, is clearly when the schematics aren't combined. Makes it harder for me to comprehend, but I hope I can figure the rest out.