[john61ct]

Hi, see my Starting block for some background.

Looking for a stereo power amp, to power a pair of LS50's, so rated 100Wpc minimum, ~250Wrms peaks (into 4-8 ohms would be better, ideally one OK with 2 ohm speakers for future flexibility.)

That would allow getting the most out of the KEFs right? A lot of my listening will be outdoors far from any neighbors, and my companions do enjoy dancing! But really, I want all the watts needed for good dynamic headroom more than dB / SP / volume. . .

Aside from the deal-breaker issues in my topic title (please avoid reco's requiring AC power input!)

smaller size and energy efficiency would be a plus.

But more important is a clean sound, ideally transparent. I do plan to get into DSP, or maybe a tube preamp if I want coloration, but let's set those aside for now unless there are appropriate power amps that happen to have integral DSP.

I assume 99.99% of "car audio" is very poor quality (yes that is a question!) and I am likewise wary of "RV-class" stuff. Maybe stuff for boats (a yacht is a boat with its own boat(s)).

Also no up-front "head units" here please, no radio wanted nor DAC at this stage, and I plan to never use vinyl nor AV disc media.

Adjustable line-level gain on the input seems critical? It would be nice to do without a dedicated pre-amp, will never need phono, could just use a passive device for source-select and volume, but I hate the idea of attenuating upstream. . .

_______
Lesser issues:
Some ability to L/R balance would also be nice, don't see that much anymore. . .

Bridgeable, for flexibility, buy 2-3 of them turn them into monoblocks?

I will likely want to add a subwoofer later, so at least a "straightwire / pre out" RCA pair would be nice, an adjustable "sub out" for an active one even better.

I believe true "bass management" for a passive sub, as in high / low pass / adjustable crossover subwoofer-out type features would only be available via a pre-amp or in a power amp with integrated DSP?

I've come across amps that are designed to primarily drive a big subwoofer, and then has a "satellite out" high pass output for the full-range pair? seems promising. . .

With a non-DSP amp, then a separate standalone DSP would just go upstream of the amp inputs I guess? Not many preamps seem to have the good old tape monitor / dubbing / external processor loop feature I used to use for equalizers, but I guess that discussion is mostly irrelevant here.

But side tangents on how to rig a facsimile of that functionality with high SQ (straightwire invisibility) from passive mixer / switches would be most welcome!

Preamp bypass, "pre out / main in" is that the same?

In any case, I do not want to imply DSP is important at this stage, really just want focusing on quality power amps here. It's just that it "would be nice" to eliminate the need for a pre-amp at all, but "DC powered portable integrated" with a decent feature set seem thin on the ground.

_______
Probably unrealistic:
A remote for mute at least (worst case I'll rig a wireless controlled relay to just cut power), but a nice volume control would of course be better,

sub adjust / tone / balance also in the remote would be ideal, yes I know I'm dreaming, might need to just get an RLC-1, at least that runs on DC power

But seriously, I **really** do not want an inverter in the mix; all reco's here **must** be at least adaptable to run off DC with a bit of soldering if necessary, any voltage mix is no problem

Any and all feedback welcome, sorry if much of the above is "silly noob" level ignorance.

Thanks in advance!

[john61ct]

Sorry, forgot to mention, I find the nCore modules very interesting, but know nothing about op-amps and line buffering.

Could the power output inside a finished unit like e.g. Audiophonics' MPA-S250NC RCA  be reverse-engineered so the integrated SMPS gets bypassed?

I understand besides the 65Vdc main rails, the input buffer needs 18V, couple other lower level voltages in there too.

I've used Vicor DCDC converters for that sort of stuff.

Probably a nutty idea. . .

[john61ct]

mods, did this post ever get approved?

or is it just too long?

[GentleBender]

We can see your post, but not sure who can answer your questions.

[timind]

Have you considered auto amps? Sorry, that's all I got.

[mikeeastman]

When my main system was 12volt I use a classD amp with a Dodd tube buffer, I believe its 120 watts per channel. I powered it with an external battery but I've had 12volt gear the has internal batteries mounted in the chassis. PM me if you want more info 12 volt set up.


  Mike

[john61ct]

Yes of course if there are great quality amps designed for auto / RV / boats, I'd be very grateful. I was just under the impression that these market niches did not have a great rep.

Any specific suggestions?

Or a good audiophile sub-forum focused on these ?

I'm looking at the ICEpower and nCore modules, but I guess that's more DIY?

When my main system was 12volt I use a classD amp with a Dodd tube buffer, I believe its 120 watts per channel. I powered it with an external battery but I've had 12volt gear the has internal batteries mounted in the chassis. PM me if you want more info 12 volt set up.

Thanks Mike! Why not discuss in the open? Public back & forth might trigger some serendipity!

Is there enough interest in DC/battery power here for a circle?

I would be most grateful if anyone knows members with a particular interest, please point them here. . .

[mikeeastman]

The ICEpower and nCores are both a/c I believe.
You'll need a charger and battery, most use AGM sealed batteries, the size will be determined  by how long you want to play. Most with 12 volt system use a Ctech battery charger because it put no noise into the system while playing with it on, in your case you could us a less expensive charger as you'll not be playing it when charging.

As far as car audio ADS made some very nice car amps in the 90's that would probably meet your requirements.

[john61ct]

When my main system was 12volt I use a classD amp with a Dodd tube buffer

Wow, read up on that preamp, cool stuff!

But I don't think tubes are robust enough for being smashed around in a transportable rig?

[john61ct]

The ICEpower and nCores are both a/c I believe.

They have "add-on" lines that match the ones with integrated PSU, but feed off the extra capacity on the DC rails. e.g. ICEPower ASP has the integrated sub, 500A is the bare amp module no rectifier.

A bit of parsing datasheets, maybe reverse engineering the connections between, I think a skilled DIYer would find it straightforward.

EDIT: thread dedicated to running ICEpower modules off DC / Batteries directly https://www.audiocircle.com/index.php?topic=170617.msg1806470#msg1806470

I already have all the LI banks, chargers, lab PSUs telecom / server rectifiers DCDC converters etc up the wazoo, so let's assume from the battery upstream as given.

Its the audio side I need help with. . .

> As far as car audio ADS made some very nice car amps in the 90's that would probably meet your requirements.

Thanks I'll have a look on fleabay. Anyone have suggestions on models with enough actual power to max out the LS50's?

I've also come across JL Audio's marine line, e.g. M600/6 600 W 6channels bridged to three @ 200W into 4Ω, $410 refurb

Seem decent features, anyone know if good SQ?

[john61ct]

ADS P650.2 might be (just) enough power

but from the aughts rather than the 90's

still good quality that recently?

[john61ct]

Same question wrt  a/d/s p850.2

more power but asking almost double

bit of an odd grounding issue here
http://www.carreview.com/product/car-audio/amplifiers/ads/p850-2.html

[Phil A]

Is something like this of interest?  https://www.amazon.com/dp/B085KRMCCY/?coliid=I3Q6QB5TKL7GZ8&colid=321FECHQA1Z6W&psc=0&ref_=lv_ov_lig_dp_it

[john61ct]

Is something like this of interest?  https://www.amazon.com/dp/B085KRMCCY/?coliid=I3Q6QB5TKL7GZ8&colid=321FECHQA1Z6W&psc=0&ref_=lv_ov_lig_dp_it

Not in the least, like paying for a Hummer but getting a skateboard. But thanks anyway!

> I already have all the LI banks, chargers, lab PSUs telecom / server rectifiers DCDC converters etc up the wazoo, so let's assume, "from the battery upstream" as given.

Its the audio side I need help with. . .