The Cool, a Tripath TA2020 CLASS-T based Amplifier

When the heat of continental summer still lingers heavy until late evening, the threshold for switching on a tube amp that dissipates 50 Watts of heat or more, rises high. What to do? Let the tubes glow and let their frustrated efforts to cool down by covection taint the listening pleasure?
As I write this, an unexpected mild, humid and windy weather haunts south Germany. The above question seems far away, the winter lays still before us and glowing triodes are a welcomed sight in the dark winter evenings. Nevertheless those thoughts drove me -earlier this year- to checkout what is all the fuss about the Tripath amplifiers.
Picture of the CoolAmp
Sadly Tripath as a company no longer exists. Fortunately their integrated circuits are still available. From China a number of ready assembled boards are offered on the internet and I went for one with the TA2020. I set it up and was delighted.
For me it is a good alternative for enjoying music on long hot summer evenings.
Once -while under the spell of music coming from a single Tripath running off a 12V battery- it came to me, that this amplifier is the perfect choice for bi-amping. I ordered the same board a second time and the result is what you see in the pictures. The two amplifier modules are mounted on a wooden frame anchored on a one-sided copper clad PCB board. The back and front are made of L-shaped aluminum profile pieces.
CoolAmp side view
The amps are sourced from the same input signal that is split after the ALPS 50K input pot. On one of the two amps (it was my first) I changed the red WIMA 1.8uF MKP input caps. for 3.3uF ERO MKT (green). The difference is subtle. I prefer the EROs in this case. Both amps share one power supply. A 22000uF/16V cap. soldered close to the amplifier intended for the bass drivers, buffers transient high current demands. On board, much closer to the output transistors, a couple of 1800uF caps do the same. The power supply can be a battery (I use a lead/acid 12V 14Ah) or a good 12V linear power supply giving a continuos/peak 2A/3A or more. Each amplifier board has a trimm pot. per channel to null out the output offset voltage.
CoolAmp case front view
The sound -closer to tube than to transistor amplifiers- has a distictive pleasant character. Musical, smooth, involving with excellent depth and detail. Anything but cold.
CoolAmp case front view
Dec. 17. 2011, Carlos Durandal
inserted by FC2 system