Amp Camp Amp people -- is the ACA OK with a lower impedance load (6 ohm)?

mhardy6647
mhardy6647 Posts: 32,927
edited February 2018 in 2 Channel Audio
Easy question: I want to try some nominal 6 ohm impedance loudspeakers with the Bottlehead-esque ACA variant built by our friend @All212.

EDIT: Thanks to a benefactor who will remain anonymous (unless, of course, he wants to share his story), that amp is currently (still!) cooling its metaphorical heels here in Northern NH. :) (for which I am deeply grateful, BTW)

32407212255_49ad86ff9d_h.jpgDSC_6919 (2) by Mark Hardy, on Flickr

Is using the ACA with nominal 6 ohm speakers an OK idea or -- a not-so-OK idea?

I googled but didn't see any clear guidance how it would feel about a lower-than-8-ohm (nominal) impedance load.

Don't want to immolate anything, you know?

Thanks!!!

PS In terms of what I am up to -- further details as events warrant. ;)

Comments

  • Clipdat
    Clipdat Posts: 12,560
    Cool CPU heatsink fans.
  • tonyb
    tonyb Posts: 32,903
    I would say not so ok idea Doc. 6 ohm nominal means it can dip to 4 on occasion. Maybe at low volumes, you should be ok, but I wouldn't go all out Hardy on the thing.
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  • mhardy6647
    mhardy6647 Posts: 32,927
    edited February 2018
    Indeed.
    That is my fear (the low impedance, not gettin' all analytical about the topic) ;)

    OK, regular ol' sandy (soiled state) amp to start with, then.
    Thanks!

    (I am nothing if not -- umm -- conservative -- when it comes to electronics)
  • ALL212
    ALL212 Posts: 1,553
    That is a sweet looking device! Obviously designed and built by someone of a very high intelligence, good looks and inoffensive body odor. B)

    There are two threads over in DIY land that might give away some possibilities.

    This one is fairly short
    http://www.diyaudio.com/forums/diyaudio-com-articles/214808-amp-camp-amp-1-a.html

    This one is approaching 400 pages.
    http://www.diyaudio.com/forums/pass-labs/215392-amp-camp-amp-aca.html


    Still hard to believe that something ALL212 put together is still functioning. :*
    Aaron
    Enabler Extraordinaire
  • heiney9
    heiney9 Posts: 25,053
    It's an NP design, probably rugged enough to do 6 ohm nominal as long as you don't get too crazy. Never know him to present a "wimpy" design.
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
  • mhardy6647
    mhardy6647 Posts: 32,927
    Given that it is a class A amplifier, it should be dissipating full power all of the time -- but I don't spend most of my time using devices that aren't transformer coupled, so I don't know what if any impact the impedance of the load has on the amp... maybe none, I dunno. :)
  • mhardy6647
    mhardy6647 Posts: 32,927
    edited February 2018
    OK, went with tubes to start. Push-pull 11BM8 amplification (S-5 Electronics amp kit) for a blistering 8 wpc :)

    Class AB :/


    Initial results -- surprisingly positive.

    40366570962_eb171d1b9e_h.jpgDSC_0619 (3) by Mark Hardy, on Flickr
    Post edited by mhardy6647 on