Switching between two Output Transformers ( low watt SE amp )

[walkman]

Hi

I'm Building a little single ended amp out of junk parts. I have two suitable OT's for the project. Each has only one secondary tap. The first has a 16 ohm tap and the second has 8 ohm tap.

It will be a combo amp and one speaker will be wired directly to the small 16 ohm internal speaker. Id like the option to run a 12'' 8 ohm external speaker.

Id like to find a way to switch between the OT's using only one switching jack.

So that when the speaker cable is connected, the signal from the output pentode will switch from the OT with the 16 ohm tap to the OT with the 8 ohm tap ( with the amp turned off )

As the amp will only output 1-2 watts i don't want to to lower the level at which the amp will breakup by having the incorrect load.

Yes, i could either run it with a mismatch or could just buy a multi tapped OT or different speakers but i have these ones that here and were free and are suitable.

thanks in advance

Walkman

[d95err]

Pick one OT and ignore the impedance mismatch. Look at the mismatch as something that adds some "color" to the sound...

[alien_audio]

Or you could keep things really simple and use a 16 Ohm extension speaker instead of an 8 Ohm.

A

[mooreamps]

I have a stereo tube keyboard amp that I have been using for the last 6 years. The 8 ohm woofers connected to the 8 ohm jacks, and the 4 ohm ribbon tweeters connected to the 4 ohm jacks. Yes, I've read "many" a thread saying this arrangement tanks the reflected impedance back to the power tubes. But I'll only hearing everyone else complain about it, except the power tubes ; and the amp still works just fine.

-g

[walkman]

Could be better to run both transformers, and have a load resistor when the external speaker is not plugged in.