[KevinW]

I just got the LC Audio Zappulse 2.1 SE modules wired up in prototype form.  Kevin Haskins at DIY Cable is distributing them.  I've got a thread about it here.

The sound is VERY good.  If you're interested in a fun and relatively easy amp project, with outstanding sonics for under $1k... this is it.  I know Kevin is working on a kit, and I'll eventually have a finished version.  But if you want to DIY, feel free to contact me with questions.  I'm quite happy to help out any DIY'ers who want to tackle it.

[sica]

Looking forward to the final product!   Will this be kept under $1000?

[KevinW]

There may be a version under $1000.  There will definitely be a version over $1000.  More info to come soon.

[JohnR]

$1k on a DIY project is not exactly what I'd class as a "fun project" -- you want to be pretty sure of a damn good result for that much.

Do you remember the various discussions on line filtering? Do you have any observations in that area? Inquiring minds want to know..

[KevinW]

When I'm talking about prices... it's my prices for a finished product.  I don't know what DIY Cable is planning to charge for a kit.  I also don't have a firm price yet either, as I am waiting on some price quotes from vendors.

The sonics of the amp are VERY good, and would be worth $1k of kit time, IMO.

What do you mean, "ideas on line filtering"?  How does this relate to Class D amps?

[JohnR]

What do you mean, "ideas on line filtering"?  How does this relate to Class D amps?

You don't want switching noise getting back out of the amp on the power line.

[DVV]

What do you mean, "ideas on line filtering"?  How does this relate to Class D amps?

You don't want switching noise getting back out of the amp on the power line.

Also, what do you think those trannies use when they switch on? Air?

Point is, digital amps need line filters just as much as analog amps. ANYTHING using power from the grid needs a line filter (if it's electronics, of course, no sense in filtering power for an air con, or a fridge).

Cheers,
DVV

[JohnR]

I disagree. Besides, we're talking about something completely different here.

[DVV]

I disagree. Besides, we're talking about something completely different here.

By all means do, JohnR, but i tried it with a Sharp and a TaCT amp. Each in turn sounded audiably better with a line filter, and those are no garage projects, those are serious devices.

In other words, I'm not theorizing here, I'm relating my own experience and the consensus of those present at the time, during the last Belgrade audio show.

Cheers,
DVV

[JohnR]

Well, my experience is that line filters can have detrimental effects with some components. Hence, my disagreement with your blanket statement.

[DVV]

Well, my experience is that line filters can have detrimental effects with some components. Hence, my disagreement with your blanket statement.

I agree line filters can have unfavorable effects on some equipment - hence my usual suggestion to try before buy if at all possible.

However, some audio designers actually use the line hash to mask some deficiencies - they do it on purpose. Remove the hash and their highly priced audio turns up as no more than garden variety audio, only all sexed up. France's Jadis comes to mind here.

The other side of the coin is the filter itself - of course. Not all were made the same, several general principles are used, and ultimately, they cost from a little to a lot, therefore differences caused by them are inevitable. No different to any other strictly audio component, really.

Because of all this, my comment was one of general principle only; please note I didn't name any names, which, by whom and at what price is the buyer's business.

But it should be obvious that if an amp is to deliver an amplified signal at its output, it must work off some power supply line or lines, analog or digital, class A...Z. A loudspeaker will recognize a signal to be reproduced only if it has a voltage and a current, right? To deliver that, any amp must have a power supply of some kind, which draws power from the mains. If it draws power from the mains, with that power it also sucks in a lot of junk, like it or not. Hence, in principle, any such device will benefit if that power is cleaned up before it reaches it, by a line filter.

My experience is limited to the aforementioned TaCT and Sharp power amps. Both profited by my DeZorel line filter when inserted. Without the filter, the TaCT (second generation) was the better of the two, with the filter this difference shrunk to almost nothing, so small I couldn't swear to it. In terms of effects, both reacted more or less the same as their analog counterparts - soundstage opened up in all direction, they became smoother in general, and in the treble range especially (this being the main problem with digital amps).

I honestly couldn't swear to it that this was a greater benefit than with say Krell gear, or C-J gear, but I do know, and the people present agreed, that the improvement was easy to hear and very much in the right direction. Then, by the same token, practically all tube audio at the show (locally made) also reacted, in my view even more.

If it has a power supply, it can and should be given a line filter. No matter what "it" is.

Cheers,
DVV

[JohnR]

You just flat-out contradicted yourself.

Anyway, this has veered well off from what I was asking. I think I've had about enough preaching about line filters to last a lifetime now, thanks.

[_scotty_]

I used Jensen 4pole caps in my Tripath based amp. They have an ultralow
impedance at up to 1Mhz.I haven't noticed any real problems with noise coming out of the amp and into the power grid.Other builders have reported radiated RF interference through the air as a problem.The power line contamination issue seems to be solved by the prescence of the ultralow impedance caps in the supply.I used 10,000mfd.63volt x 2 per supply
rail.The amp has 108watts/8ohms and 220watts/4ohms at .03THD+N.The
radiated RF noise comes from switching up to 100amps at 1.5Mhz and is emitted from the DC wiring between the main power supply capacitor bank
and the entry point on the circut board.Shorter power supply wiring can reduce emission levels by reducing the size of the antenna doing the emitting.The inductance in the power supply traces or wiring can form a resonant circuit which can cause ringing or oscillation.This is another reason to keep the wiring short.Power line filtering  when I have tried it on power amps has always reduced dynamics and constricted the the space reproduced.Simple filtering approaches almost always raise the impedance the amplifier sees looking at the power line. The ability
of current to reach the amplifier instantaneously is also compromised. A higher power supply impedance seldom sounds better. However YMMV
                                                    Scotty