I've started doing some mono block amps for custom orders and thought I'd share a few quick pics.
Here's the Legendarium 2A3 SET amp modified for mono block configuration. When split into two separate chasses, the power supply changes to account for less current demand. This means a smaller power transformer and choke, and in this case it makes a little more room for the output transformer to be upsized. I also used a GZ34 rectifier instead of the 5U4GB that I normally use in the Legendarium, since it worked out better for the voltage drop based on the power transformer I chose. This particular customer wanted volume control still on the amp, which allows a form of balance control and attenuation relative to some other amps he was using in his setup. In some cases, you might not want volume controls on a mono block, since you would be controlling your listening volume from the preamp.
For anyone not really familiar with a mono block configuration, it's simply a way to split each channel's amplifier into a completely independent unit. This can be for a variety of reasons, such as putting the amplifiers physically closer to each speaker, to manage channel separation more strictly, or related to what I mentioned above it can be easier than fitting big transformers for both channels onto a single amplifier chassis.
Hope you like it! Let me know if you have interest in this type of amp. I may at some point put these into my standard lineup, but presently am just doing as a custom option.
Until next time, happy listening!
I am definitely considering the purchase of another 2A3 amp. I like the idea of mono blocks as well. Of the seven amps I use in rotation, 4 are mono blocks.
I too, find a volume control useful. The amps I mentioned as being in rotation are used to power the mid and high frequencies of my bi-amped K-Horns. The volume control allows for sound tuning of the system for maximum enjoyment!