(TQ) Atom - By Colin Wonfor Jun 20, 2016 16:08:15 GMT
Post by Deleted on Jun 20, 2016 16:08:15 GMT
The 'Atom' is the little amp that can, it is a special thing. As originally sold, it was a class A/B transistor amplifier with a special sliding bias system to eliminate crossover distortion. While it is a modest 20W per channel it's other specifications are very much more interesting:
Out put maximum voltage swing; 30V peak-peak nominal
Maximum Gain: 19dB
Frequency bandwidth: 5Hz - 300Khz flat response
Frequency bandwidth: 2Hz - 300Khz -3dB
Phase angle change 0 degrees +/- 1 degree 85Hz to 300KHz
As with everything designed from scratch at TQ, Colin Wonfor is the brains and designed the Atom from the ground up. I understand the Atom is not dissimilar to the well loved Inca Tech Claymore in many ways. Although TQ have parted company with their designer (Colin) and no longer produce the Atom, there may yet be opportunity to purchase something very similar to the Atom in the future. Not sure if a ready built product or a kit - Colin or Alan E will confirm, I'm sure.
Relatively few Atom amplifiers were sold early on and none escaped the crusher at thieving morons when they booted Colin (they crushed Atoms, Iridiums, Claymores - everything). The Atom is loved by those who have them, I adore mine.
The next few photos show internals of the amp, and a mod suggested by Colin that anyone could follow:
Inside we find a cool little circuit in both senses, made to a very high standard:
Notice those two turquoise wirewound resistors nestled against the rear panel by the fuses? We're going to bypass them with little coils made of enameled copper wire, formed by wrapping around a pencil. The resistors appear to be there in order to limit the Atom and degrade the sound quality and output. If we replace them with coils and the Atom will be more powerful, and sound nicer. This is how Colin originally designed the Atom but he was vetoed.
Here is a coil, shown with a 2p and a dinosaur for scale:
Being lazy I snipped the resistors out leaving the tin legs standing proud. I soldered the coils to the legs:
This is a most robust amplifier circuit. I am told that during testing at thieving morons, an Atom was run short circuited on the output for two days! Eventually one channel failed, not the output device but one of the transistors in the circuit. This was replaced and the amp worked 100% perfectly once again. It now sounds most agreeable, more bass, better 'slam' at low volume, and more of the class A 'warmth'. The imaging is spectacular - I'm very happy indeed.
A few months later Colin rebiased it more into class A, I think around 47 Watts now. Really! It is an amazing little thing for sure. Nearly SECA good.