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Newbie. Balanced 2A3 SE amplifier information

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Hello All
I don't necessarily want to start a new thread. I am sure there is information on what I'm looking for. I just need to be pointed in the right direction.

I presently own an Atma-Sphere balanced amplifier, and a Tenor balanced amplifier.

I have a 'balanced' series crossover in my speakers.

If I understand 'balanced' properly, this means the input signal to the amplifier starts with a phase splitter tube. The positive portion of the waveform is amplified, and the negative portion is amplified. It is then output at the speaker binding posts.

My basic understanding of the 2A3 tube is that push pull would be the way to go. Unfortunately I don't want PP.

Have I given enough information?
I don't want to get bogged into terminology, but PP and balanced are pretty much the same thing.

I use the term balanced to describe my circuits that are CCS tailed forced class A. Each stage has complete waveform, in antiphase.

Not much 2A3 balanced circuits around. Why not design and build your own?
From the marketing copy for The DPA-300B "an advanced,
theoretically ideal form of push–pull."

There is still only single ended or push pull even if it is "an advanced,
theoretically ideal form of push–pull" that uses a CCS in the cathodes of the output tubes.

"I have a 'balanced' series crossover in my speakers."

I am curious what speakers have balanced inputs?
OK, lets get some terminology straight. An amplifier channel can have a balanced input, a balanced output or both. Unbalanced inputs are commonly known as "RCA" inputs, balanced inputs are commonly called "XLR" or "differential" inputs. Unbalanced outputs are commonly called "single ended" because one wire changes voltage and the other stays at a common potential. Balanced outputs are commonly known as "push-pull" because both wires have changing voltages. As one wire is going positive, the other is going negative. So a balanced (signal or speaker) output is inherently "push-pull", "differential", or "balanced" in nature.

Looking at the websites of the two amps cited, it is obvious that these amps are no-holds-barred versions of antique design origin. The Atma-sphere site blatantly warps their version of a push-pull output stage into what they call "Balanced differential design". The common acronyms for this output topology are OTL (output transformerless) and BTL (bridged transformerless). It is not a mysterious, new circuit at all. The Tenor amp is about 50 years more modern a design than the Atma-sphere, mainly because it is a hybrid. Not really because of the topology, but because it uses transistor output devices instead of tubes. It also uses transistor regulated circuits in its power supply.

The term "balanced" comes into play in these two amplifiers because of the complexity of multiple parallel devices operating in as close to perfect sync with each other as is possible. Same basic concept as a tug-of-war. With equally sized opponents on both sides of the rope, the tug-of-war can go on for a long, long time. If just one of the team members is weaker, the game ends fairly quickly. With both of these amplifiers, perfect balance between members is the ultimate goal, so that the game of tug-of-war goes on forever, with no winning team, period. All components are matched to each other with microscopic tolerances, then the assembled circuitry is matched and balanced to as near as zero difference as humanly possible. The units are tortured for awhile, then rebalanced to eliminate any drift that may have occurred.

Both of these designs are pretty much the polar opposite of what 2A3 tubes do best. The OTL design is like running an 8-horse team to pull a stagecoach, where the 2A3 is like using an elephant (or two) to do the same job. To run a 2A3 in an OTL amp is not impossible, but the speakers need to have something like 500 ohm impedance. In theory you could wire up 100 2A3 tubes in parallel to drive a 5 ohm load, but in reality it would need its own power station to operate, as well as a pretty stout amp to drive the 2A3 tubes. There are many other output tubes better suited for practical OTL circuits, as well as a virtual smorgasbord of sand-based devices to pick from.
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