REVIEW: Keces DA-151 DAC 800+ hours burn-in

[skeptic]

Originally Posted by anadin

I have had the KECES DA-151 USB DAC for about 3 days now.

I have it connected up to a Little Dot Mk V, headphones are a pair of Senn Hd650's.

Unless there is a dramatic change in the bass area then I am going to have to let the KECES DA-151 go and get myself a CD player.

The bass is all over the place, really boomy not my thing at all.

It could also be that the Little Dot Mk V doesn't quite have enough power to push the Hd650's to where I want them to go, anyone else found this to be the case.

This is not at all reflective of my experience with my Keces.

My 131 was very pleasing right out of the box, fast and musical, with good separation and nice tight, controlled bass.

If I had to pick a weakness, I would say that the trebles were a bit muted prior to burn in - however, this is relative to the X-fi dac, which is known for harsh and somewhat fatiguing highs. The more I listen to and burn-in the Keces, the more I like what I hear.

I'm probably nearing 100 hours now, and the trebles have really blossomed, the sound stage has improved, and the bass remains solid and controlled. This DAC gives a hi-fi presentation while preserving the musicality of the source material. I'm really enjoying it

[GuyMe]

Can the Keces take bipolar input op-amps?

[Maniac]

Originally Posted by GuyMe

Can the Keces take bipolar input op-amps?

It is not recommended, we recommend FET input unity gain stable op amps.


Thanks

[GuyMe]

Why is it not recommended?

Thanks for the prompt response.

[Maniac]

Originally Posted by GuyMe

Why is it not recommended?

Thanks for the prompt response.

Most bipolar input op amp will need a bit of change to the circuit when it is used in circuit designed for FET input op amps. Thus we don't recommend using bipolar op amps.


Thanks

[GuyMe]

So they won't work at all? Is it dangerous to the circuit?

[Maniac]

Originally Posted by GuyMe

So they won't work at all? Is it dangerous to the circuit?

Most of the time, it won't be dangerous or anything, but the op amp may heat up abnormally, or the output may oscillate or a bit unstable.

Which op amp do you have in mind?

[GuyMe]

I'm considering AD797, LT1028, and AD843.

I suppose I could put heatsinks on them, but oscillation sounds nasty.

[Maniac]

I have personally tried 797 and it appears to be working, but at the time I have not tried to measure it with a scope or other equipments that can detect oscillation.

I'll inquire this part with the designer of this DAC and see what's his take on this.

[GuyMe]

Excellent, thank you!