Dan Armstrong - Man & Guitars

As seen upper left, there is yet another set of wires that employ the use of vacuum tube type plugs. Seen here, the plug and receptacle are much smaller in size - like a 12AX7A size tube. Notice how the larger plug can be seen in the background plugged into the amp. At upper right, the two male plugs, as well as the pre-amp section of the Dan Armstrong amplifier can be seen.

However, this second plug was a weakness of the amp. As seen upper left, although placed far enough away from most everything, the plastic plug tends to wear down, and even show signs of heat stress after awhile. As can be seen at right, the plastic plug often gets changed out by a serviceman to a metal type plug. Sometimes, even the female receptacle gets changed out as well to accommodate what the technician can supply for a male plug. Seen here, it appears that a plug looking somewhat similar to a low impedance plug is used. Even the grey colored cable extending from the pre-amp section has been replaced.

Also notice the addition of a metal plate bolted to the grounded portion of the pre-amp and lying between the two far left transformers. It would appear that this plate may offer some hum cancellation from the large power transformer as it comes up and bends over - shielding the electronics in and around the last couple of sliders. At first thought to be an alteration - other amps also reveal this plate, suggesting that it was most likely added onto later models. Internally, the amplifiers utilize EL34 output tubes which give it that 'British' sound, reminiscent of Marshall, Hiwatt, and Vox amplifiers of that period. The circuitry utilizes a transistor pre-amp, (which was not to Dan's liking), but to warm things up, an ECC83 driver tube was also used.

Above left, and seen better in enlarged view, off to the right hand corner of the chassis the female receptacle for the smaller cabling from the pre-amp section can be seen changed out on this amp with the newly replaced metal male plug residing within the amp head cabinetry.

Above right, the metal shielding can be seen in its entirety. Earlier amplifiers seem to be lacking this metal plate. Off to the left of the shield the other, larger cable assembly from the pre-amp section can be seen. Off to the right, and seen better in enlarged view - the black wire for the smaller pre-amp cable can be seen tied into the pre-amp circuitry.