- Jan 17, 2011
- Reaction score
I really like guitar amps with 15-inch speakers and I especially like the Ampeg M-15 (non-reverb) and Ampeg R-15R (reverb). I thought it would be fun to compare a 1961 Ampeg M-15 to its contemporary -- a 1962 Guild 100-J. Both amps were aimed at jazz players. They pump out about 25 watts of power and have 15-inch Jensen C15N speakers, tremolo, and are powered by a pair of cathode-biased 6L6GC tubes with a 5U4GB rectifier. Each amp has two channels – one with 2 inputs, one with a single input, and stereo jack for using both channels simultaneously. Even the width, height and weight of the amps are nearly the same. That’s where the similarities end.
The Ampeg’s cabinet is 3 inches deeper and uses 6SL7 tubes for the preamp, tremolo oscillator, and phase inverter. Each channel has a tone and volume control and there are controls for tremolo speed and intensity. The Guild uses 12AX7 tubes for the preamp, tremolo oscillator and, oddly, a pair of 12AX7s in parallel for the phase inverter. Each channel has a volume control, and there is a single set of treble and bass controls that is shared by both channels. Finally, the Guild has controls for tremolo speed and intensity. Both amps have footswitch capability to activate the tremolo. Only the Guild is fitted with a standby switch.
So with slightly different circuits and preamp tubes, I’d expect these two amps to sound quite a bit different as well. Amazingly, that is not the case! Being voiced toward the jazzbo crowd, both amps have a pronounced midrange and warm sound. But that doesn’t limit them to only jazz. The Guild is a bit more versatile thanks to the bass and treble controls versus the master tone on the Ampeg. The Guild has a clearer voice while the Ampeg has a more aggressive overdriven sound. They both take pedals well. The tremolo, being of the bias varying type, pretty much sounds the same on both amps. The Ampeg is louder than Guild when dimed, but that could be a function of speaker condition. I do appreciate that the Guild has a standby switch.
In my opinion the Ampeg is better suited to single coil pickups while the Guild does fine with both humbuckers and single coils. However, that observation is based on my musical preference. The Ampeg does the smokey jazz sound really well. This was sort of like comparing a Fender 5D3 to a Fender 5E3 Deluxe. They are on the same tonal stage, but they have different qualities.
Here are a couple of quick (read: unsophisticated, not rehearsed) sound clips recorded on an iPhone 3 feet away from the amps using a ’97 Starfire II (bridge pu). The Ampeg settings were: Volume = 3, Tone = 8. The Guild settings were: Volume = 3, Treble = 8, Bass = 3.