New TK2050 board

[hifimediy]

Originally Posted by zog666

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!

Hi, I just can tell you that your transformer can work with AMT2050 v2 boards. And if your transformer is big(powerful)enough, it will work good.

[alkasar]

This transformer will provide 24V DC to the amp.
I don't know the max power at 24V, but 160 VA transformer might be too low to get the most power out the amp. This is not an issue if you listen in normal conditions (ie not in a night club!)
edit: let me correct myself the transformer provides 2x18V and you need only 1x18V AC with the tk2020. So you can parallel the outputs and have all the 160VA available. so no issue with power.

I would upgrade the caps to 2x10 000µF : this will definitively help with linear supply.

[franske500]

>Nick, hifimediy

Why do the coils on the V2 pictures on eBay and here NOT look like what I received?

On my received one, it seems the wire is wound over the full area, 2 or three times.
Is it still about 10uH? Because a LOT more windings than on here/eBay give more inductance.
Weird.

What's up?

[hifimediy]

Originally Posted by franske500

>Nick, hifimediy

Why do the coils on the V2 pictures on eBay and here NOT look like what I received?

On my received one, it seems the wire is wound over the full area, 2 or three times.
Is it still about 10uH? Because a LOT more windings than on here/eBay give more inductance.
Weird.

What's up?

Hi,
We used T60-2 coils on v2 before, which is smaller and looks more wound layers on, but it's 11uH too.

[whelibob]

Originally Posted by hifimediy

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

So to increase input sensitivity I should change the stock(20kOhm(?)) R3 and R5 with 47kOhm? Just like i did with V2.0? And it should work the same way? No problems should theoretically happen?

[hifimediy]

Originally Posted by whelibob

So to increase input sensitivity I should change the stock(20kOhm(?)) R3 and R5 with 47kOhm? Just like i did with V2.0? And it should work the same way? No problems should theoretically happen?

Hi, they are R2 and R3 on v1, and it will work same way as v2.

[whelibob]

Originally Posted by hifimediy

Hi, they are R2 and R3 on v1, and it will work same way as v2.

Thanks for the help, works great now!

[kc7wdg]

Originally Posted by whelibob

Thanks for the help, works great now!

Awwww surface mount.. I have a Weller EC3001 with the right tips but have yet to use it for SM.

[whelibob]

Originally Posted by kc7wdg

Awwww surface mount.. I have a Weller EC3001 with the right tips but have yet to use it for SM.

It was also my first time soldering surface mounts with the V2.0-board, but i succeeded very well.

[zog666]

Originally Posted by hifimediy

Hi, I just can tell you that your transformer can work with AMT2050 v2 boards. And if your transformer is big(powerful)enough, it will work good.

Originally Posted by alkasar

This transformer will provide 24V DC to the amp.
I don't know the max power at 24V, but 160 VA transformer might be too low to get the most power out the amp. This is not an issue if you listen in normal conditions (ie not in a night club!)
edit: let me correct myself the transformer provides 2x18V and you need only 1x18V AC with the tk2020. So you can parallel the outputs and have all the 160VA available. so no issue with power.

I would upgrade the caps to 2x10 000µF : this will definitively help with linear supply.

Thanks, yes I think it will power it well! Just I havent noted anyone else doing it, still will be fun to try.

I am getting the v2 which from the pictures has a single 50V 4700uF capacitor.. my target amp enclosure already has 2 35v volt 10,000uF caps in it.
As a possible future "easy" upgrade can put them in series to make a 70v 5,000 uF cap which I can wire in parallel with the onboard cap, doubling the capacitance.