Avonessence
Hiking Consistency Rapporteur
Would using a 16 ohm speaker on a valve amp with an 8 ohm output cause any problems or issues for tube life, O/T life?
16 ohm speakers on a 8 ohm valve amplifier
- Thread starter Avonessence
- Start date
Darth Vader
From the Dark Side
"When using mismatched impedances between the amp and speakers there is a greater strain on the output stage. Total output power to the speakers is reduced, the tonal balance changes, and part of the output signal is reflected back to the amp. This reflected signal can exceed the voltage ratings of your output tubes and cause them to arc or short out - even worse the output transformer can be damaged. Try to keep the output below maximum, this will prevent possible problems.
Whenever you mismatch a tube amp with a much higher load (speaker) impedance, a higher signal voltage is produced across the primary of the output transformer. This is why you cannot run a tube amp without a speaker connected to it.
Having said this, and making it very clear that I do not advise anyone to connect a higher than rated impedance to any tube amp, generally there is no problem when operating the amp at 8 ohms if your amp is well designed and in good working condition. Connecting a 16 ohm load to a 4 ohm amp is, of course, more risky.
As with all tube amps the correct impedance setting for the amp is the one that is the same as the total impedance of all the speakers that are connected to it. Set the impedance selector in the back of your amp to match the load (speaker) impedance that you are using."
Cheers,
DV
Whenever you mismatch a tube amp with a much higher load (speaker) impedance, a higher signal voltage is produced across the primary of the output transformer. This is why you cannot run a tube amp without a speaker connected to it.
Having said this, and making it very clear that I do not advise anyone to connect a higher than rated impedance to any tube amp, generally there is no problem when operating the amp at 8 ohms if your amp is well designed and in good working condition. Connecting a 16 ohm load to a 4 ohm amp is, of course, more risky.
As with all tube amps the correct impedance setting for the amp is the one that is the same as the total impedance of all the speakers that are connected to it. Set the impedance selector in the back of your amp to match the load (speaker) impedance that you are using."
Cheers,
DV
Arkless Electronics
Trade: Amp design and repairs.
It will be fine but output power will be less than if you had a 16 Ohm setting on the amp.
Avonessence
Hiking Consistency Rapporteur
Thanks Robert, DV and Arkless for your replies.
DV - I had seen a similar post to the one you quoted, so thought I would ask before cooking anything.
Arkless - I have noticed a drop in gain have to turn the volume from 7 o'clock to 8 o'clock now with the 16 ohm speakers.
DV - I had seen a similar post to the one you quoted, so thought I would ask before cooking anything.
Arkless - I have noticed a drop in gain have to turn the volume from 7 o'clock to 8 o'clock now with the 16 ohm speakers.
linnfomaniac83
I bet you can’t wheelie a unicycle!
To be expected, although the sensitivity of the speakers will make a greater difference.