New TK2050 board

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Notice that with SMPS you don't need large tank caps, instead they could create some problem to the SMPS for some reasons related to its feedback circuit.
Bye
theorethically agree, but I read on diyaudio the feedback of someone who tried smps + very large cap. He says the classT sound much better overall and particularly significantly improvement in bass. I will try out by myself with T3 when its ready :p
 
theorethically agree, but I read on diyaudio the feedback of someone who tried smps + very large cap. He says the classT sound much better overall and particularly significantly improvement in bass. I will try out by myself with T3 when its ready :p

I am really interested in your results. I also read here where someone tried one of these big Farad !! powercaps usually taken for caraudio ... 10 x bigger and heavier than the amp board:D
 
now i am confused :confused:
This is a linear PS board, with rectifier and filtering+tank caps. Only needs a transformer and done. In this use case, caps need to be bigger.

If SMPS is used, there is no need for an additional PS board, correct ?
The only reason I can see to use this PS board with SMPS, is to benefit from the tank caps. But then, why bother with a board : simply wire one large cap or more in parallel up to the desired tank size.

Sorry, i just don't get the use case you have in mind for this PS board.

Can you share the schematic of the PS board ?

I use upc1237 on this board and you can find that rectifier can be used for instant turn off function, duiring both a transformer or an SMPS is using.
If an SMPS is used with T3, we don't suggest too big caps.
If a transformer is used, the VA value should be big enough, or you have to improve the tank caps then.
So, may be we can say 4700uF caps are built in for common usage?
 
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Cables for T3. Made by hands:D
 

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I use upc1237 on this board and you can find that rectifier can be used for instant turn off function, during both a transformer or an SMPS is using.
If an SMPS is used with T3, we don't suggest too big caps.
If a transformer is used, the VA value should be big enough, or you have to improve the tank caps then.
So, may be we can say 4700uF caps are built in for common usage?
Thanks hifimediy. I now remember you said you will also put a loudspeaker protection on the PS board. This is a reason to use the PS with T3 even with SMPS.

If an SMPS is used with T3, we don't suggest too big caps.
you mean T3 board may suffer from large caps or you mean that large caps are useless as they will not improve performance ?
 
yes, this is the comment I also read but can't find the link anymore :(
1F :eek: these caraudio guys are crazy :D
In the car audio the voltage is fixed to 12V (13.7V when the engine is working), so if you wanna increase the watt you've to rise up the current available (W = V*A).
In the home audio you can easily increase the voltage, for example 30V for the TK2050, so the current issues are less significative.

Also consider that if you connect a 1F cap to an smps, it will never power on!
An smps is not capable of working in short circuit, and during the power on (transient) a capacitor is equal to a short circuit.
In such case the smps would go into the protection mode for overcurrent.
Assuming that it works, then there will be the risk of smps oscillating, because is "difficult" for the feedback circuit understand what's happen to the load if there is too much capacity into the line.

In my opinion if the smps is a bit overpowered for the application, you don't need any "extra" capacitors (just a good cap on the board as near as possible to the power stage).
In my case I'm using 18A max smps (ATX modified...) for the TK2050, is like a cannon to shoot a fly :)
When I shut down the power supply, the board still work for a couple of seconds... that's the demonstration that extra caps are not needed.
Bye!
 
Thanks hifimediy. I now remember you said you will also put a loudspeaker protection on the PS board. This is a reason to use the PS with T3 even with SMPS.


you mean T3 board may suffer from large caps or you mean that large caps are useless as they will not improve performance ?

I think neither of them.
Too large caps will lead to SMPS error as Don just said. And caps we use now is not "Too big" in my opinion. But refer to different type of SMPS used, the caps may have to change to reach the best. If you find that overcurrent is happened to your SMPS, you may have to remove some of the 4700uF caps on the PSU.
 
Trying the T3

I have received a pair of T3. Don't have the PSU board yet. Currently hooked them up to two meanwell SMPS's, one 27V and on 36V meeting at around 30V.
They do make a sound when power on/off. First when I tried them, they made almost no sound. But I discovered that when I connected a source, a quite unpleasant, but not too loud pop/click sound emerged on turn on/off. Most when using my ipod, less with DAC, but still a bit. On the 87db/w speakers it is ok, not really a problem. on the 99db/w speakers it is more unwelcome..
Just listened a little bit to them so far.

First I connected them without any vol pot, as I didn't have any. It was of course very loud, but I also got a quite loud shhhh sound in the tweeter. Now with the pot, the shhhh is very quiet, but if I open the pot completely it is back. but as soon as I close the pot 1 mm only, it dissapears. Can anyone explain this? Not a problem of course, most out of curiousity.

I have also tried connecting them to only 1 SMPS, and could't hear any noise on my 99db/w speakers.
 
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First I connected them without any vol pot, as I didn't have any. It was of course very loud, but I also got a quite loud shhhh sound in the tweeter. Now with the pot, the shhhh is very quiet, but if I open the pot completely it is back. but as soon as I close the pot 1 mm only, it dissapears. Can anyone explain this? Not a problem of course, most out of curiousity.

...

EMI? You can try to connect the metal part of pot to GND on board.:)
 
I modded my V2.0 - 2*100W@4ohm-amps input sensitivity from 22kOhm to 47kOhm and im now happy with the loudness. Now i recieved the newer V1.1B - 2*80W@8ohm-amp and the stock input sensitivity is 50Kohm, but it doesn't sound even close to the V2.0-version of the amp. Should I double V1.1 input sensitivity aswell?
 
anyone using AC to power the v2 unit (or any others?)

I just fried my slightly tweaked YuanJing TDA8920 amp .. bit of an annoyance, but it was a cheapy so no stress.. (fried it due to slipping with a screwdriver adjusting a trimpot on a preamp I'm making.. BZZT dead amp..)...

Anyway I'd already ordered my HIFIMEDIY AMT2050 V2 from ebay.. which looks to be a far better amp anyway.

I was powering the now dead TDA8920 with a 18-0-18 160VA transformer, strikes me that I can repurpose this nice toroidal transformer with the windings in parallel and it will drive the AMT2050, and the enclosure with RCAs and banaplugs etc is already made. Measuring with my voltmeter the output is closer to 20VAC on this unit anyway.

Is anyone else using this with an AC power supply? I read through a lot of postings in this thread, I can see a lot of people discussing the theoretical requirements but didn't notice someone saying they are actually using AC power and what kind of results they are getting.

As a potential upgrade would upping the PSU capacitor from 4700uF help much?

thanks!
 
I modded my V2.0 - 2*100W@4ohm-amps input sensitivity from 22kOhm to 47kOhm and im now happy with the loudness. Now i recieved the newer V1.1B - 2*80W@8ohm-amp and the stock input sensitivity is 50Kohm, but it doesn't sound even close to the V2.0-version of the amp. Should I double V1.1 input sensitivity aswell?

Hi, why not? if you like the modification on v2.:)
 
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