Notice that also "TheDealer" @ pag.28 wrote that the board seems weak powered.
I will compare the board to my TA2020 board as soon as I received.
However what about the Rf and Ri resistors?
How to adjust the input stage gain, if necessary?
Thanks, bye!!
Hi. thanks for your feedback. Please add a pre-amplifier to increase the gain, or you can change the output gain from audio player. Our AMT2050 boards' gain is setted at 12x(about 21dB). You can consider change the gain by changing the resistors on board, they are placed near the pot. So we can calculate the gain by:
G=12*R5/R4(Right channel) or =12*R3/R1(Left channel)
they are 1% 0805 resistors and all 20.0kohm now. Hope that will help.
What resistor values do you recommend if I want to get the gain close to sureboards gain? On the sure-datasheet it says:Hi. thanks for your feedback. Please add a pre-amplifier to increase the gain, or you can change the output gain from audio player. Our AMT2050 boards' gain is setted at 12x(about 21dB). You can consider change the gain by changing the resistors on board, they are placed near the pot. So we can calculate the gain by:
G=12*R5/R4(Right channel) or =12*R3/R1(Left channel)
they are 1% 0805 resistors and all 20.0kohm now. Hope that will help.
Imput Sensitivity: 0.771V
Input Impedance: 22k Ohm
Thanks, your info are always welcome!!Hi. thanks for your feedback. Please add a pre-amplifier to increase the gain, or you can change the output gain from audio player. Our AMT2050 boards' gain is setted at 12x(about 21dB). You can consider change the gain by changing the resistors on board, they are placed near the pot. So we can calculate the gain by:
G=12*R5/R4(Right channel) or =12*R3/R1(Left channel)
they are 1% 0805 resistors and all 20.0kohm now. Hope that will help.
The added value for the TK2050 board is that we (we = customers) can ask and discuss directly to the board designer! Very good
Thanks, bye!
hi, please try R3=R5=40k for twice gain as before. I'm not sure what you prefer, so keep changing when get what you need.
But I still suggest adding a pre-amp for better behave.
Thanks, your info are always welcome!!
The added value for the TK2050 board is that we (we = customers) can ask and discuss directly to the board designer! Very good
Thanks, bye!
Thanks, nice talking to you.
You should identify where the problem comes from.
Then you should re-do the weldings in the identified area.
Bye!
Rfbc 14K?
If your Rfbc is 14K and Rfbb is 1K as in your schematic, the gain of the amp is 15X and optimum max supply voltage is 30v with the input resistor set 1/1. Almost the same as the Sure which is 16X and 32V.
Hi. thanks for your feedback. Please add a pre-amplifier to increase the gain, or you can change the output gain from audio player. Our AMT2050 boards' gain is setted at 12x(about 21dB). You can consider change the gain by changing the resistors on board, they are placed near the pot. So we can calculate the gain by:
G=12*R5/R4(Right channel) or =12*R3/R1(Left channel)
they are 1% 0805 resistors and all 20.0kohm now. Hope that will help.
If your Rfbc is 14K and Rfbb is 1K as in your schematic, the gain of the amp is 15X and optimum max supply voltage is 30v with the input resistor set 1/1. Almost the same as the Sure which is 16X and 32V.
hi, I check that again and find that you're right. It's 15x , not 12x. Thanks.
Hi, the bad solder may not be found some times, so you can do as Don Jerry said. And a multi-meter is helpful too if you have one. Another possible reason for abnormal gain is the broken of pot, please check that too.
Wowww ! Good news ....
but let me add some critics and opinions again regarding your TK2050 board:
I think we are here to talk open about it and you can develope yourself with this feedbacks:
Contra:
- speaker terminals (right/left) don´t match with the view when the vol. pot regular shows to you
- Input DC gain is closed to the speaker outs. I have never seen this setting on other boards. You have up to 30 volts in this area. I am not technician but I dont think that this is positive. I would sever these ones in different places on the board.
- the red LED makes unsure. Steinar wrote that this is not a fault or problem but usually the color red is a sign of caution/danger and is choosed for boards to draw your attention in case of technical faults. What about blue lights ?
Pro:
- after some hours the scratching sound turned over to more smooth and I like the sound more and more. Not compared to the sure board directly yet.
- dynamics increased also. My Fostex were not connected a while to a system and had to warmed up again. So my first impression of a bit weak sound could be depended also on this.
- there must be a speaker relay. I did´nt notice any loud bump out from the speakers when powered the amp. This is fine.
- and again compared to the sure board you integrated at least a potentiometer. For the price also fine.
- heat contol without cooling fan is good. But I would suggest the folks here not to go over 27 volts DC input because at 25 volts in my case the heat sink is quite warm. If you don´t need the extra power stay at solid 24 volts.
-------------------------
Why this new amp so quickly presented ? Don´t hurry up the things because you just started your experiences with the TK2050. Is this board based on the TA3020 which usually can handle more power ?
Hi. Your feedback are all valuable for me.
- speaker terminals (right/left) don´t match with the view when the vol. pot regular shows to you
I have notice that and we will correct it later.
-- Input DC gain is closed to the speaker outs. I have never seen this setting on other boards. You have up to 30 volts in this area. I am not technician but I dont think that this is positive. I would sever these ones in different places on the board.
I don't quite get it for the input now is far awey from the outs.
-- the red LED makes unsure. Steinar wrote that this is not a fault or problem but usually the color red is a sign of caution/danger and is choosed for boards to draw your attention in case of technical faults. What about blue lights ?
Nice suggestion, I will consider that.
And about the new 300W version, it is TC2000+STA517B actually. So we have 50~300W boards now.
Would it be a good idea to increase the default input gain? As the board has a vol pot it wouldn't be a problem to lower the output. For use with ipod or similar maybe the default gain is a bit low. But with a normal cd player or DAC the current gain should be ok, but it wouldn't hurt to have more, would it?
Any more users with experience on gain on this board?
About the red LED. I myself dont agree that the red light makes it seem like it's some problem. I have many gears which uses red lights. What I like about this light is that is very soft, unlike many other chinese LEDs which lights up the whole room. What if we made a drawing that points out all the things on the board, it would say that this is a power light. I think the blue light would not looks as good together with the other green light, the two colors doesnt fit that well.. not really very important with color estethics... but that just my opinion.
Any more opinions on this?
Any more users with experience on gain on this board?
About the red LED. I myself dont agree that the red light makes it seem like it's some problem. I have many gears which uses red lights. What I like about this light is that is very soft, unlike many other chinese LEDs which lights up the whole room. What if we made a drawing that points out all the things on the board, it would say that this is a power light. I think the blue light would not looks as good together with the other green light, the two colors doesnt fit that well.. not really very important with color estethics...
but that just my opinion.Any more opinions on this?
I have my board running at 30.7v in from the Meanwell supply with no problem. The Heatsink does get quite warm but not overly so. i have it powered on 24/7 and it has not shut off.
the heatsink does not get as hot as my 4ch Sure 2050 boards heatsink does allthough that has also never shut off
The Hifimediy 2050 board just sounds Fabulous.
I dont worry about the colour of the leds on it , the gain is fine for me too but i do use a pre- amp,its an Autocostruire Tube Pre One ,a superb single triode preamp that brings out the best in any T amp i have tried it with so far.
just my 2 cents worth
have fun !
the heatsink does not get as hot as my 4ch Sure 2050 boards heatsink does allthough that has also never shut off
The Hifimediy 2050 board just sounds Fabulous.
I dont worry about the colour of the leds on it , the gain is fine for me too but i do use a pre- amp,its an Autocostruire Tube Pre One ,a superb single triode preamp that brings out the best in any T amp i have tried it with so far.
just my 2 cents worth
have fun !
Allright. Ill try 39kohm and 47kohm. Theoretically does it effect the sound in a bad manner?
Yes. Maybe a bit off topic meanwhile. If I interpret right there is no transparent LED reserved on this board for any technical faults which could happen during operation, O.K. ?
For example the sure board and the boards from Arjen own a reserved LED in case of operation problems. (Temp./Distortion etc.). These are transparent LEDs - and in case of caution they shine red. These was the main reason why I missinterpreted the continiously shining red light on this board. I thought green would be power and the red means "problem". A short manual would have cleared up the things for us all.
I am thinking about this "protection" feature if hifimedy should decide to integrate also something like this on his next TK2050 or other boards. In this case you cannot choose blue or yellow for warning. I would suggest blue for power, green for working relays and red for caution.
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