Gain Cards and Gain Clones, how do they different

Sorry if the question is too simple, or is gonna leave me in a "uh duh" situation.
But I've read about 47 Labs Gain Cards" and there have been "gain clones" in the auctions.
What are they? How do they differ from "standard amps" to the point that they are called something different?
Any benefits to the design over "amps" and are the "clone" type just "mid fi"?
Gain clone is a copy of the original Gaincard.
Peter Daniels of Audio Sector in Canada has gain clones reviewed at and they are rated better than the original gaincard and priced at 1/2 the cost to boot.
Well, it says there are no responses, but above this that I am writing is a brief and helpful statement "clones are copies of the original gain card".
So how do Gain Cards differ from Amps then?
Gainclones or Gaincards use a high power op amp chip to power the speakers. Unlike a conventional amplifier that uses transistors like mosfets or bi-polars..etc. There are roughly 9 parts in the signal path of a gain clone or Gaincard. The signal paths are also some of the shortest for an amplifier..only a few millimeters long.

This equates to a very pure sound. These amplifiers don't hide the source at all. If the source is sub par you'll know it.
Most aren't designed to power tough loads. They run out of steam quickly if pushed too hard.With properly matched speakers the sound is fluid, pristine and grain free. Op chip amps sound like neither SS or tubes... IMO it falls some where between.

The Gaincard was the original op chip amp. It is just the name of an op chip amp like the Patek.

Scott Nixon also makes mono block op chips amps...they sound great!

There's an agon member who builds these to order. From his feedback..he knows what he's doing and the prices are very reasonable.
thanks! Tough loads... meaning under 2 ohm at places, or is it a matter of the db rating?
Yes the ohms load is critical with the op chip amps. 6 to 8 ohms is prime for these units. Some are built to work well with 4 ohms. The key is a stable load. Don't mate this type of amplifier with a speaker known to have a peaky load. For example a speaker that goes from 8 ohms to 2 ohms depending on the frequency probably wouldn't be the best match. The more efficient and stable the better.