New TK2050 board

[Nick122147]

Originally Posted by panda360

I have visited your shop in Taobao, but I can't find this board.

Think I got the last one of the 50 he had made. He said he'll have more ready next month.

[panda360]

Originally Posted by Nick122147

Think I got the last one of the 50 he had made. He said he'll have more ready next month.

You are so lucky.

[Nick122147]

Originally Posted by sendler

I like the Wurth WE-PD, XXL coils in smaller values of 6.8 or even 4.7uH for an 8 amp rating vs about 3 amps for those. The type 2 cores are the most common since they are the ones that Tripath originally recommended but even with 18guage wire on my 106mm cores they are not as transparent as the Wurths which come preasembled and ready to install for $4.

Another questions about the coils. The values you mention are much lower than the stock (11uH). It looks to me as the output filter on this board is slightly different from the sure board. It doesn't have the last 0.22uf cap after the coil. Will this affect what value of coil needed? Or could i still try with the 4.7uH coil?

[sendler]

Originally Posted by Nick122147

Another questions about the coils. The values you mention are much lower than the stock (11uH). It looks to me as the output filter on this board is slightly different from the sure board. It doesn't have the last 0.22uf cap after the coil. Will this affect what value of coil needed? Or could i still try with the 4.7uH coil?

You can try the lower value Wurth coils with the stock caps no problem. Then if you want, it will be easy to add the differential cap across the speaker outs as a mod. I use this filter with 3.5uH coils but 4.7uH has less out of band peaking and sounds really good.

[hifimediy]

Hi all, thanks for your discussion, so helpful for me to do improvement for next production.

[hifimediy]

Originally Posted by panda360

I have visited your shop in Taobao, but I can't find this board.

I'm sorry, please give me message in Taobao if you still need it. i will reply as soon as i have.

[Nick122147]

Thinking of changing to a stepped attenuator. The onboard one is 20K. Should I go for 20K, or can I try 50K? What difference does it make? What's best when connected to DAC Tube preamp?

[Nick122147]

I ment to say dac, or tube preamp. (It wont let me edit my post)

[sendler]

Originally Posted by Nick122147

I ment to say dac, or tube preamp. (It wont let me edit my post)

I have done a lot of work with passive volume control. Having the pot right on the board as you do is the best way. It minimizes all of the interactions caused by it's high output impedance. I would still try 10k. 50k will sound better only with a buffer following it. A tube pre might as well bypass the pot. Switched resistors might sound a little better and offer matched steps for active cross users with multiple channels of amplification but would have to be wired on.

[Nick122147]

Thanks sendler! So you're saying that the present solution is prefarable to adding an (higher quality) stepped pot which is wired on?