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dave2010
24-10-2016, 17:25
Are there any amps which are good to work with low impedance speakers, such as the nominal 4 ohm speakers of yesteryear?

Are any new ones being made which will do, or is it best to look for older models, when such speakers were more common?
I read recently of someone having 3 ohm speakers, though I suspect that 4 ohms is close enough, as loudspeaker impedance is a pretty approximate measure anyway for many designs.

Audio Al
24-10-2016, 17:40
My John Wood amp can do 4 ohm speakers

Arkless Electronics
24-10-2016, 17:49
The vast majority of amplifiers will work just fine into a 4R load and are usually designed to do just that perfectly happily. Notice that nearly all amp specs will give power into both 8R and 4R loads and that most reviews will state measured power into 4R loads. It is normally cheaper, less well engineered amps that fair worse into 4R but most will probably work well enough. There are also some rather more "left field" units about which due to the topology chosen only just manage an 8R load but we are talking things like OTL valve amps here... Most conventional valve amps have taps for 4R speakers.

In general, modern amps are more tolerant of low impedance loads due to higher current output devices with larger safe operating areas being available.

Look for more than one pair of output devices per channel, a decent sized mains transformer, plenty of heatsinking and big smoothing capacitors if worried about it though.

daytona600
24-10-2016, 19:41
Use 0.5ohm speakers myself & 7,000wpc power amps stable into a 1/3th of a Ohm

Arkless Electronics
24-10-2016, 19:48
Use 0.5ohm speakers myself & 7,000wpc power amps stable into a 1/3th of a Ohm

Do you have a 3 phase supply?:D

daytona600
24-10-2016, 21:59
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