you can try to replace the capacitors from the LC network (C28 and C34), i made 2 versions of this boards, one with 1uF and one with 0.22uF. the advantage of the lower capacity is the higher cut-off freq. of the filter, which lead to more clear and natural sound. i assume that on your board they are 220nF, change them with 1uF capacitors, and also the capacitors from RC network (C29 and C35) with 1uF. this will decrease the amplitude of the residual noise to less than 1V but it may lower the filter cut-off frequency. you can increase the value of this capacitors up to 2.2uF, but not more, otherwise the sound quality will be altered.
i will send you the schematic by mail later.
if you don't have the capacitors, i can send you and whatever else u need for this. i didn't forgot about the input connector which i didn't sent last time, when i saw the message after i sent the parcel. i said that i will send to you at the next delivery.
i won't charge you anything for the parts, but i preffer to send them at a next order, since the shipping cost...
furthermore, as i sad before if you want to reduce even more, you can increase the order of the filter, by adding anothrer LC and RC network with same values on each channel.
let meknow the result after you change them.
i will send you the schematic by mail later.
if you don't have the capacitors, i can send you and whatever else u need for this. i didn't forgot about the input connector which i didn't sent last time, when i saw the message after i sent the parcel. i said that i will send to you at the next delivery.
i won't charge you anything for the parts, but i preffer to send them at a next order, since the shipping cost...
furthermore, as i sad before if you want to reduce even more, you can increase the order of the filter, by adding anothrer LC and RC network with same values on each channel.
let meknow the result after you change them.
New version of TA3020 amplifier released
the new version includes the rectifier bridge, bigger capacitors, supply for the fan, improved layout and routing. this version will replace the actual one, which stock is almost finished.
the size of the board is the same, and arangement is similar, but some parts which are under the heatsink were added, and rerouted.
the price will be a little higher that the previous version, considering that has the supply included, but lower price than an TA3020 amplifier board and a separate supply.
the new version includes the rectifier bridge, bigger capacitors, supply for the fan, improved layout and routing. this version will replace the actual one, which stock is almost finished.
the size of the board is the same, and arangement is similar, but some parts which are under the heatsink were added, and rerouted.
the price will be a little higher that the previous version, considering that has the supply included, but lower price than an TA3020 amplifier board and a separate supply.
I guess many DIYers will prefer to have the power supply on the board. I for one though prefer not to have it on board and to create my own. Plenty of options for purchasing caps etc.. here, don't need to pay the postage cost from China. Also, later on when a SMPS option become available if you purchase PCB without the power supply gives you the option to change.
One thing I would appreciate though, is somekind of option on the board to use balanced inputs. All these Tripath amp modules and kits from all the different suppliers don't have this option. Is a hassle if you are using Pro-audio gear or all your other stuff has balanced connections.
People in Pro-audio industry won't use anything without balanced connectivity, your product is missing an entire market.
col.
One thing I would appreciate though, is somekind of option on the board to use balanced inputs. All these Tripath amp modules and kits from all the different suppliers don't have this option. Is a hassle if you are using Pro-audio gear or all your other stuff has balanced connections.
People in Pro-audio industry won't use anything without balanced connectivity, your product is missing an entire market.
col.
cnx said:
Hi,
Good news (although current version is fine).
Power supply on board... hmm, for this kind of amplifier, I prefer not to have it on board. It permits to go for SMPS or have linear power supply adapted to your needs.
In case you are not yet 100% done with PCB, there is a couple of point I'de like to share:
- Fan connector: connector like what we have on computer motherboard (3 pins) is really more convenient as it authorizes to try different fans without having to cut cables.
- Am I the only one who would appreciate to have holes used to fix PCB on case to be isolated from amplifier ground ?
Anyway, nice amplifier. Thank you.
Cheers,
Christian
col said:
I had similar feeling some time ago but then realized that having both 5balanced + unbalanced) will make it more expensive and a bit more complex. Maybe you reach another market (although I'm not sure pro audio market is looking at this stuff) but you loose an existing one.
If balanced inputs is a must, why not going for Neutrik input transformer or additional board dealing with this stuff ?
Christian
I have already been using NTE transformers or Balanced input PCB (plus power supply), see the projects on my website.
I think the Hypex approach is the best one. Just make the default connection balanced. If any one wants unbalanced they can just use psuedo-balanced leads.
Martin-Q, the question you ask about DA-1 has already been answered. Why don't you read this entire thread.
col.
I think the Hypex approach is the best one. Just make the default connection balanced. If any one wants unbalanced they can just use psuedo-balanced leads.
Martin-Q, the question you ask about DA-1 has already been answered. Why don't you read this entire thread.
col.
thanks everybody for advices. as i said before, i will take into account the users requests and oppinions, so, i will update the next version based on this.
this new version, v2 has the mounting oles insulated from the ground, but i kept the star ground at the mounting hole between the output coils, just in case somebody want to use that for connecting to the chassis.
from this board can also remove the rectifier bridge, and use external capacitors, if somebody consider that those from the board are not big enough or want to use an SMPS.
the fan connector which i use right now has two pins, due to limited space. and can use one from mainboards, which has also 2 pins.
balanced input option i will include also in the next version, and the advantage of having it is not only the use with pro-audio, but is also more simple bridging the board using +- and -+ connection.
any other sugestions are welcome.
DA-1 amp, is based on TPA2001 chip, class D filterless audio amplifier, followed by two power stages for each channel, since they are connected in BTL mode. this amp is more suited for subwoofer applications, since the freq. response favorize the frequencies below 10 KHZ, is not linear on all audio bandwidth, but has high efficiency and requires single power supply and one control supply only.
this new version, v2 has the mounting oles insulated from the ground, but i kept the star ground at the mounting hole between the output coils, just in case somebody want to use that for connecting to the chassis.
from this board can also remove the rectifier bridge, and use external capacitors, if somebody consider that those from the board are not big enough or want to use an SMPS.
the fan connector which i use right now has two pins, due to limited space. and can use one from mainboards, which has also 2 pins.
balanced input option i will include also in the next version, and the advantage of having it is not only the use with pro-audio, but is also more simple bridging the board using +- and -+ connection.
any other sugestions are welcome.
DA-1 amp, is based on TPA2001 chip, class D filterless audio amplifier, followed by two power stages for each channel, since they are connected in BTL mode. this amp is more suited for subwoofer applications, since the freq. response favorize the frequencies below 10 KHZ, is not linear on all audio bandwidth, but has high efficiency and requires single power supply and one control supply only.
I think if you make a balanced version of the TA3020 board then you have something that will really compete with the Hypex modules. This will be very interesting!
My DA-1 is still sitting in its cardboard box. I don't have an idea for a power supply. I'm hoping that the SMPS will be available shortly, waiting paiently for that
Iv'e been testing my TA2022 board today but I am having alot of problems with noise. Sounds like static from tuning a radio and I can't get rid of it. Iv'e tried balancing up the connections using NTE transformers but no difference.
col.
My DA-1 is still sitting in its cardboard box. I don't have an idea for a power supply. I'm hoping that the SMPS will be available shortly, waiting paiently for that
Iv'e been testing my TA2022 board today but I am having alot of problems with noise. Sounds like static from tuning a radio and I can't get rid of it. Iv'e tried balancing up the connections using NTE transformers but no difference.
col.
col,
try to use diferent location for connectinng the signal gnd with power gnd. and also, try to make an stand off for the output inductors, so they will not be that close to the signal path. furthermore, can try to route signal directely to the pins of the IC so, in this way can eliminate the noise completely. i can give you instructions how to do that.
anyway the new version whicj i sell now is totaly remade and has better layout, and no signal or noise issues at all.
try to use diferent location for connectinng the signal gnd with power gnd. and also, try to make an stand off for the output inductors, so they will not be that close to the signal path. furthermore, can try to route signal directely to the pins of the IC so, in this way can eliminate the noise completely. i can give you instructions how to do that.
anyway the new version whicj i sell now is totaly remade and has better layout, and no signal or noise issues at all.
col said:
Here's what happened Col.
I saw the question about the DA-1 and had some vague memory of that module. I went to the website to find out more about it and only found a minimal amount of information (one picture, a brief description, and a PDF link). So, I came back here and asked my questions. If I cannot find the information at the source I will ask. I would not consider digging for the information unless it was necessary.
I will say that the website has improved quite a bit and I've noticed that many of the modules now have a great deal of information available and that is great to see.
Hi,
I would also be interested since I also bought a TA2022 from you, it was an older version without mounting holes and with no heatsink (but very good price), does it has the same problem.
Regarding the TDA8920BTH PCB, the amp is finished and sounds pretty good (way too much work to change these capacitors), I will bring it next Saturday to a DIY gathering in Montreal so I will get some feedback from many musicians, I will report back since they have way better ears than I do
Thanks,
Eric
I would also be interested since I also bought a TA2022 from you, it was an older version without mounting holes and with no heatsink (but very good price), does it has the same problem.
Regarding the TDA8920BTH PCB, the amp is finished and sounds pretty good (way too much work to change these capacitors), I will bring it next Saturday to a DIY gathering in Montreal so I will get some feedback from many musicians, I will report back since they have way better ears than I do
Thanks,
Eric
ttan98 said:
sorry, i missed your question.
theoretically the amplifier can work from +-28V to +- 65. but to make-it work with less than 35V need to replace few resistors from under/over voltage detection circuit. right now is set at 36-64V range. of course it has about 10% tolerance and can be working even with less than 36, as xaudiox mention before. but without changing this resistors values, it is very possible to enter in undervoltage lockout when playing loud and voltage drops.
if you will modify the range to start at 28V, it will also change the upper limit from 64 to about 56V so cannot use at higher voltages until replacing the resistors with the previous ones.
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