Topping TP21 - 15v PSU too much?

[Kaizen22]

I know a lot of people recommend adding extra capacitors to beef up the low end on this amp and I now see that it is often sold with a 14v (4A) PSU instead of the 12v (5A) that mine came with. In general people

I happen to have a spare 15v laptop PSU but does anybody know if 15v would be too high, or would it reduce the life of any of the components?


Cheers,
Will

[theAnonymous1]

The absolute maximum voltage for the TA2021 is 16V, but the maximum operating voltage is 14.6V.

15V is pushing the limits of the chip. I'd say there is significant chance that it will blow at 15V, but it might not. Is it really worth the risk?

[Kaizen22]

OK thanks. In that case, probably not - I've just been giving it its first proper test on some large 3-way Alesis monitor speakers, rated at 75W RMS (4 Ohm), and with bass heavy music it looked close to achieving the X-Max of the 9" woofer.

This was just with the 12V (4A) PSU, I also A/B tested it connected to a computer PSU with a 15A 12V rail and it made a surprisingly small difference to the low end output, if any really. I would need to do more precise A/B tests but perhaps what I've read about the benefit of adding additional capacitors etc is largely a placebo effect?

[kristleifur]

I'd think that if the supply can put out reasonable amounts of current, as your 4 Ampere supply probably can, then the capacitors aren't adding that much.

You do get about 1dB of headroom going to the higher voltage, so bumping the voltage to 14.5V is worth it if there's next to no extra cost - but it's not worth buying a new supply for IMO.

[Tripath07]

Hi Kaizen22,

I was wondering how you liked the Topping tp21 amp? How does it sound compared to the TA2020 chip? I was looking at that amp along with several other TK2050 based boards.

Thanks!

[Kaizen22]

I think it's really impressive, especially for the money. I bought it just as an experiment to try out a Tripath amp really, as it's not powerful enough to do most of the speakers I have justice.

I don't have many other HiFi amps to compare to but the clarity right across the frequency range is excellent, obviously very little distortion and still sounds great when pushed hard. One thing that particularly impressed me was its control over the speaker cone, even with lots of low end EQ and the amp nearly at full the bass still sounded very tight, controlled and deep, all at the same time. I didn't expect it to be able to handle such large inefficient speakers so well without running out of headroom, so its got all the detail/resolution for high end work and delivers enough current to handle heavier loads.

I measured the voltage across the reserve capacitors while it was running hard and it never really dropped below ~12.5v, so obviously that supply has enough juice.

Sorry I'm just rambling on - this is the first Tripath amp I've heard so I don't know how it compares to the TA2020. I think some of the kits you can buy have better components and a more refined circuit design but for something cheap in a well made and good looking case with a decent PSU you can't go wrong.

[Tripath07]

Thanks for the info on the Topping TP21 sound. It sounds like it's a pretty good amp! You may have heard this before, but since it's your first Tripath amp, I'll mention it, the more you play it the better the sound will get. It takes up to 300 hours of listening to break in the chip fully, but after around 50 hours you should start to notice even better sound.

[Kaizen22]

I've heard lots of people talk about an amp sounding better after it has been 'broken in' but I have to say I've always been sceptical about whether it happens or not. With speakers this effect is sometimes very noticeable, especially with some of the larger 18" PA subs, and it's clear for all to see that it's caused by the cone surround reaching its specified elasticity/rigidity.

I'm not sure what changes occur in an amp that would cause it to sound better though, hence the scepticism. I'm by no means an expert though so I'm not ruling it out, is there a commonly accepted mechanism by which this change could occur?