New TK2050 board

[alkasar]

Originally Posted by Opher

Could a V2 board be powered by a toroidal instead of SMPS?

I would like to use a smaller case with a toroidal transformer. Is this possible? If so, would quality suffer?

sure it can. AC 16-22V
see website Hifimediy T2 amp

[Opher]

Any remmendations on which Toroidal to use for this?

Could I use something like this:
150W 22-0-22V+12V Ultra-Thin Toroid Power Transformer - eBay (item 300483038394 end time Nov-18-10 08:03:50 PST)

Are there any disadvantages or risks to going this route?

[alkasar]

Originally Posted by Opher

Any recommendations on which Toroidal to use for this?

Could I use something like this:
150W 22-0-22V+12V Ultra-Thin Toroid Power Transformer - eBay (item 300483038394 end time Nov-18-10 08:03:50 PST)

Are there any disadvantages or risks to going this route?

the one you link has two secondaries and an additional 12V voltage. You only need one secondary, and unless you need the 12V additional voltage for something else, you can avoid. A single 21 or 22V toroidal is ok.
I would take more than 150VA. At least 250VA.

My personal belief is that a regulated SMPS is even better for these amps.
The meanwell offers 350W for same or less money.
If size matters, you can look at this.

[SoldierAnt76]

You might want to check with the seller about the maximum amperage of each secondary before you buy. "150 watts" could refer to the combined output of both secondaries together instead of just one secondary, so you might not be getting as much power as you think (i.e., only 75 watts).

As Alkasar points out, the new Connex power supply might be a better choice if size is a concern. It's only slightly more expensive than the transformer you linked to, but it provides a lot more power and is smaller.

[Opher]

Thanks for your replies. I think I'll go with the Connex PSU recommended, as size is indeed my main consideration.

[jtjy]

guys i got my stuff today. do i need to adjust the voltage of my SMPS or is it alr adjusted?

[jtjy]

guys also, my tk2050 seems warm when i touch it, is it normal?

[benoar]

Hi hifimediy,

I just saw that the website was updated, with a schematic for T1, great !
But then I see that Rfbb/Rfbc is 1k/9.1k, why ? This is optimum around 20Vcc, and I thought this board was rather optimized for a 30V supply…
Again on the feedback circuit : you use 390pF for one channel and 150pF for the other one ?! Isn't the second one a bit too low ? What idle frequency do you get with that value ?
And about the output filter : you use the smaller (than on the datasheet) 11uH coil, that's OK, but you don't compensate with a bigger capacitor like on T2 : you keep it 0.22uF on T1, while you put 0.47uF on T2. Do you think it will be enough to avoid beginning picking low-end switching noise ?

In the end, I find that T1 has strange component choices compared to T2.

[datawolf]

I want to change the resistors R3 + R5 on my T2 board to increase sensitivity but I find there are several types of surface mounts.. wire wound foil etc and various other parameters like power and tolerance.
Can anyone tell me the exact spec of the resistors I should get?

[Nick122147]

Originally Posted by jtjy

guys i got my stuff today. do i need to adjust the voltage of my SMPS or is it alr adjusted?

I think it's normally in the mid possition around 27V. Anyway, it should work in any position, as the voltage range of the meanwell is around 24V - 31V. But you might wanna measure it to get it exactly where you want it.

It is normal that it is a bit warm.