1964 Fender Champ-Amp
The Black-Panel 1960’s Champ-Amp was Fender’s smallest and most simple amp/circuit and was intended for students and amateurs of the time. It was immediately cherished however by a different crowd, that of professional studio owners and pro guitar players looking to get that cranked-amp, everything-on-ten sound for their albums. Eric Clapton was probably the most famous player associated with this amp. It has an incredible overdrive/fuzz when used with humbuckers with all the controls set at ten - which is my preferred way to play these amps.
This one came in having already been “restored”, however the quality of the work was terrible with shortcuts used everywhere, non-original parts values, and necessary preventative maintenance left undone. The one good choice made was the speaker having been changed out to a Kendrick Black Label 8” 10 Watt type unit. Which is a good choice for this amp - honestly it’s an improvement over what were installed in these originally. It also had a leaking filter cap can, and needed new power resistors. A standard restoration was in order.
The amp was completely restored. The electrolytic cap can was replaced with a new USA made CE brand exact replica (20uf x 4 @ 475v) for the filter section. The bypass caps were replaced with MOD/Vishay brand electrolytics with upgraded voltage and temperature ratings. New 2 Watt Metal Oxide/5 Watt cement power dropping resistors were installed for better reliability and lower noise floor. All plate resistors were replaced with 2 Watt Reduced Mass Metal Film type units for preventative maintenance and reliability. A new 5 Watt 750 ohm Wire-Wound cathode bias resistor was installed for better reliability and for stability of the 6V6GT bias. All coupling caps were replaced with high quality CDE Orange Drop's to replace the mix of original and replacement parts that were put in by other tech's. A new 3 prong AC cord was installed to replace the old AC cord and the death cap was removed.
All of the original tubes tested good and were kept in place. The final lineup was: V1 = Fender/GE 12AX7A, V2 = Harmon Kardan/GE 7408/6V6GT, V3 = RCA 5Y3GT. A 7408 is just a high quality 6V6GT - the difference was that the 7408 was intended for industrial or military use and had better ratings for vibration and other more obscure parameters not relevant to audio. The 7408's Cathode Bias was set to 106% Class A Plate Dissipation with a B+ of 410VDC. The tube sockets were all re-tensioned to stop the tubes from jiggling or falling out while they hang upside down - they also were cleaned with a De-Oxit treatment to prevent noise from corrosion. The pots were sprayed out and the amp was cleaned inside and out.
