B
bluesboogieman
New member
Hello.....can i plug a 4 ohm or 8 ohm speaker cabinet into a 2 ohm (super reverb) head without damaging the head or speakers? Thank you.
Doug
Doug
miroslav
Cosmic Cowboy
Yup....not a problem, just a slight level drop.
Dogbreath
Im an ex-spurt
It's the other way around ya don't wanna do. 
Lt. Bob
Spread the Daf!
yes ..... and you actually don't run speakers into amps. You run amps into speakers so the real question is can you run an amp rated at 2 ohms into a 4 or 8 ohm cab.It's the other way around ya don't wanna do.
As miro said ..... no problem.
S
soundchaser59
Reluctant Commander
Depends partly on how good your amp is. There is a very real threat from flyback voltage if the impedance mismatch is too great. Cheap amps can get zapped by it, good amps can mostly handle it.....but it's not worth the risk. I would never mismatch more than 1 level. I would mismatch a 4 ohm amp out to an 8 ohm speaker, but not to a 16 ohm speaker.
I have never seen an amp with a 2 ohm output. I don't understand why they would design it that way, other than to maximize power and current and minimize tube life. For one thing, you could never get a proper match with just one speaker, as nobody that I know of makes a 2 ohm speaker.
I have never seen an amp with a 2 ohm output. I don't understand why they would design it that way, other than to maximize power and current and minimize tube life. For one thing, you could never get a proper match with just one speaker, as nobody that I know of makes a 2 ohm speaker.
mjbphotos
Moderator
4 - 8 ohm speakers wired in parallel would give you a 2 ohm load.
cavedog101
Well-known member
All of the original Super Reverbs were 2 ohms. I'm sure there are others. They had 4-10" 8ohm speakers in parallel. One of the features about this particular amp was its obvious ability to get into power tube distortion at an early stage. One of the reasons so many Blues guys love these.
Lt. Bob
Spread the Daf!
lots of amps have a 2 ohm out.
All my 70's Ampegs have 2 ohm outs .... the old Fender super Reverb was specifically set up for 2 ohms.
My Mackie 808 PA head is rated to 2 ohms and several power amps I have are rated to 2 ohms and that's all stuff that's just sitting in MY house.
I wouldn't personally worry at all about running an amp into a higher load than it's set up for.
There may be SOME possibility of a problem but it's very remote. In 40+ years I've never seen it.
M
mixsit
Well-known member
Interesting stuff about the power tube effect there. When I had one I wasn't paying much attention to how low that's running- and there's still that extension speaker jack. Presumably then that could lead to trouble easier than their other amps?
cavedog101
Well-known member
If by "trouble" you mean adding another load to the output and creating more heat then yeah....maybe. The old 40 watt circuit they were designed around could actually work at 1 ohm (ie: 2-2ohm loads) . They got hot as the road to hell but they'd work. recommended? I doubt that you get it serviced on warranty but they did put an extension speaker jack back there for a reason.....
Understand this about speaker loads. and I'll use the Super as an example. It has a 2 ohm load in its stock speaker form and an extension jack also. If you add something like another speaker load of another value, say a four ohm cabinet, you do create an odd impedance that the output stage "sees" and because its a simple tube amp, it will compensate for. However, the majority of the sound is going to go to the original 2 ohm load. Its not going to 'divide' the output evenly between the two different loads but will, like all electricity, (which it IS), seek the path of least resistance and go there first and strongest.
That old circuit design had a monster of a supply transformer as well as a way overbuilt output tranny. Its why they sound so good. Probably the best amp Fender ever made in terms of tonality and the ability to drive them with a lot of voltage at the input.( humbuckers sound great through em) These amps clean up so nicely with a simple twist of the volume knob on your guitar and scream like Mamas' head in a vise when you crank em. Its my favorite anyway as well as the Pro Reverb. Same circuit, 2-12's.
Understand this about speaker loads. and I'll use the Super as an example. It has a 2 ohm load in its stock speaker form and an extension jack also. If you add something like another speaker load of another value, say a four ohm cabinet, you do create an odd impedance that the output stage "sees" and because its a simple tube amp, it will compensate for. However, the majority of the sound is going to go to the original 2 ohm load. Its not going to 'divide' the output evenly between the two different loads but will, like all electricity, (which it IS), seek the path of least resistance and go there first and strongest.
That old circuit design had a monster of a supply transformer as well as a way overbuilt output tranny. Its why they sound so good. Probably the best amp Fender ever made in terms of tonality and the ability to drive them with a lot of voltage at the input.( humbuckers sound great through em) These amps clean up so nicely with a simple twist of the volume knob on your guitar and scream like Mamas' head in a vise when you crank em. Its my favorite anyway as well as the Pro Reverb. Same circuit, 2-12's.