Roger Modjeski is an outside-the-box designer, his RM-200 an example of his originality. He bristles a little at the amp being called a hybrid, but yes, it does not have a tube input stage (the driver and output stages are pure tube, however). But it isn’t a normal solid state input stage, either. It’s comprised of a pair of transistors and some resistors, in a zero-gain circuit. In the RM-200 he manages to get a hundred watts out of a pair of KT-88’s (or 6550's) by employing low screen voltages and higher-than-normal plate voltages on the tubes. A clever fella who knows as much about tubes and tube amp design as anyone living.
Output Impedance and Speaker Impedance
I'm a bit of a novice so please excuse this if it is a stupid question. I have a Mac MA 7900 (200 watts) that I use to power Aerial Acoustics 5T's and a MC275 (75 watts) powering Triton 2+'s . The preamp in the 7900 controls both amps.
In an attempt to find ultimate sonic balance, I switched the amps - 7900 powering the Tritons and the 275 powering the Aerials. Not as good of a set up and would guess it has to do with the sensitivity/ efficiency of the speakers and the corresponding power provided by the amps. Tritons are 91dB / 8 ohm and the Aerials 87dB / 4 ohm (nominal, 3 ohm minimum) . In this configuration the Triton's drowned out the Aerial's. When balanced, these speakers compliment each very well IMHO..... Plus the sonic benefits of tubes and SS.
While switching the speakers around with the amps, I connected the 5T's back to the 7900, but connected them to the 8 ohm outputs. It really opened up the lower frequencies and I didn't notice any loss in the mid or high frequencies. Finally, my question... Is there any inherent danger powering 4 ohm speakers through the 8 ohm outputs on the amplifier. Recommended power for the Aerials is 25- 200 watts.
To me, it sounds better and volume output is nicely balanced. However, I do not want to damage the amp or the speakers. Thank you in advance for any guidance you can provide.
In an attempt to find ultimate sonic balance, I switched the amps - 7900 powering the Tritons and the 275 powering the Aerials. Not as good of a set up and would guess it has to do with the sensitivity/ efficiency of the speakers and the corresponding power provided by the amps. Tritons are 91dB / 8 ohm and the Aerials 87dB / 4 ohm (nominal, 3 ohm minimum) . In this configuration the Triton's drowned out the Aerial's. When balanced, these speakers compliment each very well IMHO..... Plus the sonic benefits of tubes and SS.
While switching the speakers around with the amps, I connected the 5T's back to the 7900, but connected them to the 8 ohm outputs. It really opened up the lower frequencies and I didn't notice any loss in the mid or high frequencies. Finally, my question... Is there any inherent danger powering 4 ohm speakers through the 8 ohm outputs on the amplifier. Recommended power for the Aerials is 25- 200 watts.
To me, it sounds better and volume output is nicely balanced. However, I do not want to damage the amp or the speakers. Thank you in advance for any guidance you can provide.