Musicians Roadhouse

The AFD-100 is fitted with 6550 power valves. i suppose the 5 watter is a different beast, and perhaps there an EL34 worked better. but as Santiago says, there's nothing to stop an owner trying a 6550 to see how it sounds

santiall wrote: that's because the available 3 way switches are ON-OFF-ON so there is no other chance.

On the other hand, the amp is cathode biased, can take any octal power tubes from 6V6 to 6550, EL90, etc

Can I use one of the THD adapters that do a pin match to an EL84