Ambrosi Amps' K-Power Amps - Retrofit poweramp solutions for the Lunchbox - With pictures & videos

Quote from Ingolf

My question is: What does 'less musical' actually mean? Is it perceivably less good sounding or what?
Generally I'm seconding @mbenigni for sure: quality over quantity IMO.

I'll ask Andrea and report back in detail. I don't want to put words in his mouth
The K-Power amp will certainly not sound worse than a class D amp anyway.

Quote from Tilman

I am holding myself back from commenting about musical power supplies and class D ; class A/B statements in this thread very hard already

This is not really holding back, is it?
We have a way to say for this in Italy: throwing the stone and hiding the arm

Quote from Ingolf

Please Tilman, go ahead and open the new thread now.

Wholeheartedly seconded

I have just heard from Andrea.

There's the possibility to keep the current layout and technology and have more wattage, specially for those who use 8- or 16-ohm cabs.
This solution would also easily address the need for a 115 or 230 V mains compatibility.

For around 20 € more we can have

32W / 16ohm, 58W / 8ohm, 70W / 4ohm

against the "old"

22W / 16ohm, 38W / 8ohm, 68W / 4ohm.

Other specs remain the same, as well as the original concept and the design.

Also, note that the 70W / 4ohm datum is quite conservative, there could be around 10-15 W more at that impedance.

What do you think?

So guys, my last posts have probably generated some confusion, about which I apologize

Here's what's going on:

After some briefing, Andrea decided to produce a first batch of all-analog amps like the prototype.
In the prototype, the excellent amp section (by National) was oversized respect to the transformer (i.e., it can be driven by a much higher voltage than the prototype's transformer can supply in its linear window). Now he's found a different transformer (still of the traditional, non-switching type) able to supply higher voltages, so he can squeeze a higher wattage out of the power section.

As for the "less musical" aspect, that was related to one of the options taken into consideration: to mount a switching transformer. He thinks that you need an above-the-average quality in order for the high freqs generated by a switching transformer (several tens of kHz in this application) and their subharmonics to not bleed through the power section if not properly filtered by design. Or, as I got it, you'd need a more robust filtering section in the amp, which would lead to other issues.

In the end, we agreed that the new more performing traditional transformer (same weight as the prototype) he's found is more philological to the original design and goal, which was to supply a robust, well-made, good-sounding, not expensive "small" amp to retrofit the Profiler.

So basically nothing has changed, except for a couple of bucks more and more watts to drive our cabs.
Furthermore, with this new transformer the K-Power Amp will be available @ 115 V at no extra cost.

PS: Andrea just told me that the laser-made labels have been printed by the service. Now he is looking for the best aluminium plates, and seeing if they can supply them in different colours. DADA's, Waraba's and Pick's Ferrari red is still a chased option

Quote from Robman

This question has probably been asked but are these units available now to order?

Hey, I'd not be surprised if the first units left the house around 2Nd-3Rd quarter of January

Quote from mbenigni

I can't speak to the technical or quantitative angles here, but avoiding noise is always better than introducing noise and then filtering downstream. Less is more.

Oh, do not take me wrong, switching transformers all work in high frequency. The generation of ultrasonic signals is intrinsic to the technology if I got it right. A good transformer is well filtered to prevent to output unwanted noise, or you have to use good filters downstream the transformer. It's not really an issue, but just a characteristic, such as the need for an anti-aliasing filter in a converter.

Quote from mbenigni

Fantastic. I hope these are actually affordable by the time exchange rates, shipping costs, etc. are all accounted for.

I'm guessing around 280 US$ plus delivery. But I'm not the one who sails the boat

Quote from rdwilson

PLease let me know when it is available , & keep adding videos, thank you , roger

Well, TBH the remaining footage was just me noodling, but the sound quality we got was, as I said, not even near to what we were hearing in the room (as Lance pointed out, we know how the Profiler sounds, and the published videos did not certainly make it justice).
Considering that this material would go onto YT and have a global visibility, I prefer to avoid the usual "my POD sounds better" or "the Axe blows this crap out of the water" comments

But we might consider using real mics and shoot some more.

Quote from DADA

Nice to see this moving forward
Next year the 1U stereo version?

Uh, really don't know. The K-PA makes sense in itself because it responds to a need, but as Tillman pointed out there are so many other amps here around.
I guess it would depend on how sales go.
Let's see what happens

Quote from Ingolf

Awesome news.
As for the colour of the plate, green on red (or vice versa) is always a bit disturbing to me, as green doesn't mingle well with other colours.
It's like Ferrari-Red over British Racing Green, urrgh!
Isn't something greenish for the plate also an option?

There will certainly be the basic model available first. Since the production is completely hand-made, a coloured plate might be an extra-option for some special request, but nothing more IMO

... The initials for the new power amp are AA's K-PA... which seems to join the two most interesting music-related devices of the last few years... The CLR and the KPA.