Hi!
I just read the review and I noticed something that I had to check from Thule (I read again the Thules 'Virtual Class A' -documentation). I have looked at one Thule amp and had read their literature recently. And I started wondering...
In the review the following is stated:
"...most modern linear amps these days are of a Class A/B design where the amp operates in Class A for low power levels. Although Thule was able to achieve a higher bias into Class A while preventing excessive heat build up by rail switching at higher power levels."
As far as I understood this means Thule is just using higher bias current (100mA)? And when an A/B amp is switching from A into B with higher current the other transistor is switched off like normal A/B amps do?
But when reading Thules document:
"...a variable control voltage in tune with the musical signal, is used to set the idle current, so that the idle current is maintained through both output transistors regardless of the output current. This means that both output transistors stay active the entire time."
Doesn't this mean that the transistors are not switched off - no matter what level of current is output? So the reviewed Thule would actually differ from traditional A/B amplifiers and would not be just a high biased A/B? It would not make it a 'true' Class A-amp since those might have full current flowing through transistors instead of a low variable current.
Which one is right? Is it just anohter class A/B amp or do they actually have something more sophisticated inside?
