Which basic amps can drive 1 ohm loads ?


Which amps will drive 1 ohm loads like Apogee Speakers?
seadogs1
There was a guy here on Audiogon that was running Perreaux PMF-2150's in bridged mode to drive Apogee's. I can't remember who it was, but that is one helluva testimony to the ruggedness / reliability of the Perreaux. In bridged mode, the amps were seeing somewhere around half an ohm (.5 ohms) !!!

As a side note, my Perreaux 3150's have no problem driving very low impedances. Much of this has to do with the heavy gauge output inductor that Perreaux uses. Not only does the amp maintain a low output impedance as power is increased*, it can pass more current on demand as needed without any type of restriction. That's why these amps, when running properly, have great bass impact. Most amps have relatively scrawny output inductors, so they lack the capacity to pass enough current as needed. The end result is a lack of control as impedances are reduced and a reduction in "slam" at any impedance.

Other than that, the two channel Sunfire Signature will drive Apogee's with no problem. Sunfire even has a specific set of "factory mods" that they do for Apogee's. I've had this done to my Signature and it noticeably increased the bass impact. One of the reasons for better bass response ? They install larger output inductors to pass more current : ) Sean
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* damping factor varies with the dynamic load and output levels that the amps sees and responds to. Many "techs" & "engineers" will say i'm off my rocker, so believe whom you want.
Wow, Sean, I have been an Apogee nut for nearly twenty years, and I have never heard of Apogee mods... home remedy tweaks, yes.

My last speakers were Sigs. Awesome.
Just to clarify things, the "Apogee mod" is the slang term that Sunfire uses for the mods that they do to their amps to better deal with very tough to drive, low impedance, low sensitivity speakers. Since Apogee's are the "ultimate" in terms of "low impedance, low output, high reactance" speakers, they chose to name the mods for the amps after those speakers. As such, Sunfire does not perform modifications to Apogee speakers.

Other than that, i'm sure that there are mods and tweaks that one can do to the various Apogee models. Sean
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You may find that the Zero Autoformer useful with low impedence speakers. The "Zero's" multiply the speakers' impedence allowing an easier load for your amp. I use them very successfully with Audio Research tube amps and Soundlabs. The designer recommends caution when using the Zero's with certain SS amps with excess offset voltage (details are in the literature) Check out the website for more information: www.ZEROimpedence.com.
Muralman1
Have you ever tried a 1 ohm load with the palladiums..
The head sinks are "v" grooved in the center and rather effective. As differential monoblocks, you have only one channel per chassis to cool... Granted the Krell ksa's have alot more Visible heat sinks, I have run most every kind of speaker load with the palladiums with no failure in the short term and no signs of fatigue.
All due respect,
Joe
Custom Audio LLC