Photos of CTA builds
Prototypes
Prototype #1
This is the prototype of the CTA12, built using the transformer, power supply and heatsink of a faulty Kenwood KR-A4040 amplifier.
Prototype #2
The prototype of CTA14 was made on the PCB of an LDA17 amplifier, which I did not photograph until after I soldered the output transistors out of it.
Builds by other persons
Andreas from Freiburg, Germany (July 2023)
Andreas has purchased the CTA MID kit, which includes 2 CTA14 amplifiers and solid state relays with full independent protection for the two channels. As you can see in the pictures, he used a separate transformer to generate the positive and negative supply voltages for the amplifier, which of course can be done with a single transformer. The 2 DPB protection circuits are located under the power supply panel, not visible in the picture. The external heatsink, painted black, helps to ensure efficient cooling.
Andreas listens to B&W CM4 floorstanding speakers, and this is what I got from him:
"The sound is great. The heatsink gets only a few degrees warmer when I celebrate a party. The amp is directly connected with my computer and I bought a USB remote control to adjust the volume from my sofa."
László from Oroszlány, Hungary (February 2025)
László purchased the CTA MIN kit, which includes two mono CTA12 amplifiers, the PS1S power supply, and the SMRS2 switch-on mute circuit for loudspeaker protection.
László uses a Loxjie D30 DAC as source and drives HECO Victa Elite 302 speakers with the amplifier. This is the review I received from him:
"The sound impressed me from the first minutes. Compared to my previous amplifier (which was a Pioneer A-209R), the bass is fuller and I can pick out sounds in music that I hadn't noticed before. I would describe its sound as neutral, maybe soft, if that's an appropriate way to describe sound. I listen to it up to 4-6 hours a day and the music does not become tiring or annoying. I almost forgot what surprised me the most! If there is no input, there is no output... no hum, no hiss, no nothing! I might as well sleep on the loudspeaker."
