SET output impedance vs speaker impedance

[Arno Pf]

Besides and effect on damping factor and output power I would like to know what the experiences are regarding (mis)matching SET output impedance w.r.t speaker impedance.

For example 8Ohm out driving 16Ohm loudspeaker increases damping factor and reduces output power bit what are the experienced differences in sonics (I am asking since my amp requires soldering to change the impedance so quick comparison is no option)

Thanks in advance

Arno

 

[dsavitsk]

The 8 Ohm tap on your OPTs does not imply an 8 Ohm output impedance. If your transformers are 3.5K:8, since the rp of a 300B is ~800 Ohms, the Zout is ~1.8 Ohms + the impedance added by the transformer (usually a few Ohms.) The 8 Ohm tap indicates where a to connect an 8 Ohm speaker in order that it reflect the load you are expecting.

As for mismatching, it depends largely on whether the transformer is up to the task.

 

[Arno Pf]

The 8 Ohm tap on your OPTs does not imply an 8 Ohm output impedance. If your transformers are 3.5K:8, since the rp of a 300B is ~800 Ohms, the Zout is ~1.8 Ohms + the impedance added by the transformer (usually a few Ohms.) The 8 Ohm tap indicates where a to connect an 8 Ohm speaker in order that it reflect the load you are expecting.

As for mismatching, it depends largely on whether the transformer is up to the task.

This was understood..still the question is remaining what the experiences are regarding difference in sound....any experience on this?

 

[dsavitsk]

It depends on several factors, such as whether your transformers have enough inductance, how damping factor impacts your speakers, etc. I've had it work well, and badly, and how it will work in your case is dependent on your amps and speakers.