The Sugden A21se single ended pure class A will give your pass lab a run for its money. It is based on the original circuitry developed by Sugden well over 50 years ago. They pioneered SS class A, they were first....and this model is only the lower tier model....the Masterclass series is even better...go and read all the countless wonderful reviews for the A21se.
"The A21 was the worlds’ first production pure class A transistor amplifier and a great success.
The partnership with Richard Allan was short lived and within a year the amplifier was renamed the SUGDEN A21."
https://www.sugdenaudio.com/a21-history
https://www.sugdenaudio.com/james-sugden