I've not built it yet, but the Trimodal is at the top of my 'next project' list. I have studied the circuit in some depth and have carried out a number of simulations on it to determine its suitability for my needs. If you can be more specific as to the feedback you are looking for, I may be able to help.
Just in case you are not aware, pcbs for this design can be obtained from the Signal Transfer Company:
It would be interesting to find out how they sound as I looked into building a TRImodal and/or Load Invariant when the article first came out but couldn't get the pcbs at the time .
A mate of mine also modified one of his amps at the time with Self's modifications and wasn't impressed in the least.
From notes I've seen around Self designed an Amp with the object in mind of having lowest possible distortion and that the amps 'sound' took second place. Of course this is subjective and could start a mini war.
All this aside I then found Marshall Leach's 'Leach Amp' and
have built one .Best sounding amp I have heard in a while and a 'Proven' design originally published in the late 70's and improved over time till now. I personally liked the idea that ''ALL the BUGS'' have been weeded out and if you read the stories of what UNI students who have built the amp have put the amp through you may be impressed .Like the idea that you can bung a 2uf cap directly across the speaker terminals and the amp won't go nova .
Thanks for posting a reply. You can see from the number of replies that there does not seem to be many of these amps built. I decided to can the idea and try my hand at the JLH class A. I'm just starting the power supplies having built the amps. Geoff Moss has been most helpful and very patient with my questions. I have not built an amp for many years and if my JLH turns out ok I will move on to other projects maybe the Leach amp. I'm also looking for a preamp circuit to build using AD797's mainly because I have a couple of these chips on hand and their specs look good.
I have read similar comments about Doug Self's designs.
I did build one of his preamps in the late 70's and was very pleased with it.