“grand champion”
(delivery letter to the client follows):
Hi Victor!
I am super happy to deliver you this amp! I just want to say a word or two or three…
I call this build the “Grand Champion”. All the parts are the finest, smoothest sounding combination of modern and old-style parts – Copper-foil-in-oil coupling caps, solid fine silver wire signal path, carbon comp resistors, 1% wirewound power supply and bias resistors, low ESR electrolytic capacitors of minimal values, all running at a cool 25% of their rated capacity and linked together with 4% silver solder.
It sounds like it looks – familiar yet unique.
You will notice that this amp makes some serious heat. The dual 6550 / KT88’s are in a deep Class A operating point, with a relatively low voltage swing and very high current, running at their design maximum of 40w heat dissipation per tube. The transformers and tubes are running at full tilt, like a top fueler with the hammer down, even with no guitar signal applied.
The “low and hot” operating points for audio tubes are suggested by the original engineers of these tubes in the ancient tube manuals as giving a optimally pleasing and musical sonic spectrum with even-order harmonics predominating. These classic operating points are rarely exploited in the guitar amp design world as they yield lower power numbers than the typical higher voltage swing class AB operating points. Although “low and hot” operating points are rare in guitar amps they are revered in the world of underground audio as the operating points of choice for dimensional, dynamic tube sound that transitions to distortion gracefully.
This power section and driver stage work together to create a fairly high powered amplifier (approx. 25 watts) in which even-order harmonics predominate at all gain levels. You will no doubt notice that the sonic characteristics of the “Grand Champion” somewhat resemble a Fender tweed Champ, but with 10x more power and voiced brighter to more modern standards. In fact, the waveform this amp makes is almost identical to a Tweed Champ (soft, asymmetrical 2nd harmonic clipping characteristics) but with a lot more juice. Another difference is that the “Grand Champion” has a good deal more drive and can be pushed into a crazy distortion, going from a moderately loud clean tone with a sweet holographic midrange though a singing bluesy and aggressive lead tone all the way to a fragmented and psychotic fuzz, which can be tamed with the single high-end rolloff control and the master volume, both of which I recommend leaving wide open for normal use.
Speakers are a complementary set of 2 x 8″ alnico. Smaller speakers tend to be less directional so off-axis audibility is improved by using multiple small drivers.
The handle has been eliminated as an unnecessary part. Align the thumb of your right hand with the acorn stenciled on the top of the box when lifting, and the amp will balance perfectly.
Included is my favorite guitar cable, a Cardas Golden Chord with solid billet brass Switchcraft connectors soldered with 4% silver eutectic solder. Please observe the directionality – the arrow printed on the cable is the direction of signal flow, point it toward the amp (a small point but what the hell). You will find the cable is somewhat microphonic but I like the sound of ’em, lots of lively signal delivered to the amp. Sonics can be easily tailored by choice of cable and I urge you to compare different types to find your preference. Cable differences will be very audible with this amplifier.
This amp was inspired by reading the Pechanga tribal website, which challenged me to build you a personal statement that avoids genericism and imitation while showing respect and affection for the past. Also inspired by our shared friendship and spirit of support for Paul and Chuck at Go-Go Guitars.
Your friend,
-blackie
ps. Guaranteed for as long as it took to build…
…forever!!
New power tubes every 8 months if you play it every day!