Hoffman Amplifiers Tube Amplifier Forum

Other Stuff => Cabinets-Speakers => Topic started by: Brendan on March 01, 2016, 02:40:49 am

Title: 3ohm speaker question
Post by: Brendan on March 01, 2016, 02:40:49 am

I have a 1955 Supro "Special" one-knob wonder that originally came with a 4 ohm 6x10 Rola oval speaker. Those Rolas were said to be quite nice, but amp was received with an RCA 6x9 that I believe is 8 ohms. I've come across a 6x10 speaker that was originally from the UK, but the schematic indicates it is a 3 ohm speaker.  I have heard that a 3.2 ohm speaker if fine to use with a 4 ohm OT and 3.0 is pretty darn close to that. However, it's I really don't want to have to do anything to shorten the life of the original components on my amp. Would using  a 3 ohm speaker be harder on my OT and tubes?

Title: Re: 3ohm speaker question
Post by: Platefire on March 01, 2016, 04:16:08 pm

Hi Brendan

I think it will be fine just one Ohm off. Reason I say this is I measure most of my speakers with a Multi Meter and it's not unusual for a speaker marked 8 Ohms to measure 7 Ohms or 6.8 or 8.2. Very seldom have I ever got a speaker that measures exactly what it's rated at. My 2 cents :icon_biggrin: Platefire

Title: Re: 3ohm speaker question
Post by: Brendan on March 01, 2016, 08:52:40 pm

Thanks, Platefire.   Speakers that size rarely come up and I've already bought it. I figured it was okay, but wanted to confirm because I don't want to be replacing an OT if I was wrong.