I eventually got round to building my self a gain clone, just to check, is it is any good....?

front.

not very pretty but it works.

Very short feedback path, loops etc!

I have used a 50VA 18-0V 18-0v transformer with Schottky diode bridges, coupled to 1000uf caps for each chip. Gain set by 20k and 1k, DC coupled. Seems to look well behaved, but so it should with that substantial zobel network of 1R and 220n! (aren't they normally 8R and 100n?) certainly gets hot as you crank the frequency up past 100kHz, with smoking zobel resistors... hmmm. Not very happy about that so I added a lowpass filter at about 50kHz to try and keep any stray RF nasties our.

So how does it sound?
So far not that impressed really. The T-amp has better top and cleaner sound, the clone is competent but nothing special IMO. It is a bit grey and lacking in resolution. It will be quite useful for testing speakers however, with its good measured behaviour and unbalanced output!