Is 6 Ohms from an amps 8 Ohm tap ok?

[Bloc Riff Nut]

Thats it really.  My valve amps lowest speaker input is 8 ohms. Im using a 12ohm 2x10 and an 8 ohm 2x10 and the amp is at half volume.

Will this bugger the amp? Its an old Marshall. 

 

Cheers 

 

Phil

[goingdownslow]

The 12Ω and 8Ω cabs in parallel will give you 4.8 Ω.

[paul_5]

Short answer is yes, a load of less than 8ohms will knacker your amp. Running the 2 cabs in series will give your amp a load of 20ohms, so it’ll be safe, can’t guarantee it being loud though.

[Bloc Riff Nut]

Of course it is. Ouch!

[Bill Fitzmaurice]

Again? Really? Wasn't this addressed less than 48 hours ago, as well as in the sticky? OK, one more time, with feeling:

SS amps have a minimum load, valve amps have a maximum load. Run an SS amp with a load equal to or higher than its minimum load rating, run a valve amp with a load equal to or less than the tap rating.

[Bloc Riff Nut]

Oh, so the Marshalls Super Bass can take the 4.8 ohm load:  I just have to be aware that its working hard and use my ears. 

[fretmeister]

Bookmark this calculator!

 

http://www.speakerimpedance.co.uk/?act=two_parallel&page=calculator

 

 

[barkin]

52 minutes ago, paul_5 said:

Running the 2 cabs in series will give your amp a load of 20ohms, so it’ll be safe, can’t guarantee it being loud though.

Trouble with this though, is that the cabs will almost certainly be in parallel - not series. 

Edited July 19, 2019 by barkin
.

[Bill Fitzmaurice]

He has a valve amp. He does not want his cabs series wired. He does not want a 20 ohm load.

Edited July 19, 2019 by Bill Fitzmaurice

[Phil Starr]

Listen to Bill. That is correct.

Are you sure it is a 12 ohm cab? Most drivers are 8 ohm with 4 and 16 being the main alternatives. I'd expect a 2x10 to be  4 or 8 ohms, maybe 16.

In any case using cabs of differing impedances  means the power will be shared unevenly between them. You won't be getting the best out of them.

[Bloc Riff Nut]

Its a barefaced Retro210 which is switchable between 4 and 12 ohms.  I just added the 4 ohm SWR 210 because I wanted more volume. I know the power isn't being shared equally.