Electrovoice Interface. Posted June 27 Share Posted June 27 (edited) Hi all looking for technical answer please I have a valve amp on the rear you can use either 4 ohm or 8 ohm connections The bookshelf speakers are rated at 6 ohm nominal my question is what do I use 4 or 8 ohm connection Much appreciated... Speakers NOS Mirage 1994 M190 IS Amp Cayin CS 55A Edited June 28 by Electrovoice Interface. Link to comment Share on other sites More sharing options...
andyr Posted June 28 Share Posted June 28 The info I was able to find said it was "6 ohm nominal, 4 ohm minimum". That suggests to me you should use the 4 ohm taps. Link to comment Share on other sites More sharing options...
Electrovoice Interface. Posted June 28 Author Share Posted June 28 Really ok thanks Link to comment Share on other sites More sharing options...
andyr Posted June 28 Share Posted June 28 1 minute ago, Electrovoice Interface. said: Really ok thanks NP ... but I suggest you wait to get a few more answers B4 you make that connection. 1 Link to comment Share on other sites More sharing options...
andyr Posted June 28 Share Posted June 28 Someone like @xlr8or should be able to help. Link to comment Share on other sites More sharing options...
Electrovoice Interface. Posted June 28 Author Share Posted June 28 27 minutes ago, andyr said: Someone like @xlr8or should be able to help. cheers sent him a message 1 Link to comment Share on other sites More sharing options...
Gav Posted June 28 Share Posted June 28 My amps had the same option I chose 4ohm option as the speakers liked heaps of watts and it is my understanding that the 4ohm option would deliver more watts to the speakers. 1 Link to comment Share on other sites More sharing options...
andyr Posted June 28 Share Posted June 28 7 minutes ago, Gav said: My amps had the same option I chose 4ohm option as the speakers liked heaps of watts and it is my understanding that the 4ohm option would deliver more watts to the speakers. While more watts into 4 ohms, compared to 8 ohms, is true for ss amps ... I believe it's not true for tube amps. 1 1 Link to comment Share on other sites More sharing options...
Ihearmusic Posted June 28 Share Posted June 28 (edited) As the turns ratio of the output transformers reflects the impedance of the speakers back to the power tube, a different load (Speaker impedance) will change the operating point of the tube and therefore can change the sound as well. In your situation you can use either of the two taps without any problems. Your operating point of the tubes will not change to much as to cause a problem. One could give you a more exact answer if I would know the specs of the OPT and what power tubes you are using. Edited June 28 by Ihearmusic 4 Link to comment Share on other sites More sharing options...
muon* Posted June 28 Share Posted June 28 2 hours ago, andyr said: While more watts into 4 ohms, compared to 8 ohms, is true for ss amps ... I believe it's not true for tube amps. Yup, a 50 watt tube amp will be 50 watts on the 4ohm taps, and 50 watts on the 8ohm taps. 1 1 1 Link to comment Share on other sites More sharing options...
marcusD Posted June 28 Share Posted June 28 You can safely use either and won’t damage your amp, the taps will sound different to each other. the eight ohm tap will give you a slightly more airy presentation with looser bass, the 4 ohm tap will give you tighter bass and sound overall. listen to them both and decide for yourself which one you prefer, but the correct answer from a technical point of view is the 4 ohm tap 4 Link to comment Share on other sites More sharing options...
muon* Posted June 28 Share Posted June 28 Just try them on each of the taps and see what you prefer. 5 Link to comment Share on other sites More sharing options...
Recommended Posts