Dating a marshall amp bsd updating ports collection
However, tubes are still used in several specialized applications such as guitar amplifiers (also called a valve amp outside the U.
S.) and high power RF transmitters, as a display device in television sets and in microwave ovens.
The large black choke was replaced with a regular size RS, The RS Deluxe out-put transformer was still used, a voltage selector mains transformer was also introduced (like the previous model it did not drop to USA Voltages) the larger oval ring RS indicator light was also introduced at this period.
THE ABOVE TRANSITIONAL JTM45 Has original caps dating 1st and 2nd quarter of 64, it has an RS deluxe output transformer with early pitched Bulgin knobs, as you can see it has an alley front panel and a polarity switch ,also a short leather handle..SN 20** is STAMPED on to the alley chassis BUT with No JTM45 OR MK11 front markings and 4 very close inputs (just like the above 63 model)...."Perhaps Jim had an old panel etc to use up" However it differs from the 1st 63 model by having slightly different (64 STYLE) cab/panel contours, outer lip chassis anchors and sandwich front ie "cloth and vynal" and the later RS mains transformer,choke and indicator light. This Rare Early Maroon Block logo JTM45 has Smooth black Tolex,short leather handle, Bulgin pitched knobs,alley front pannel"with MKII and JTM45" and 4x wider input jacks.
The rear wooden panel had a cut out "so you could store your Bulgin mains cable in the rear of the amp" you can just see in the photo above the divider that stopped the cable damaging the valves, The cut out was adding time and expense and was discontinued after the first 40 units which were NOT made out of the birch ply we all know and love.
Its interesting that the indicator light on these early models are very small (the oval ring RS will not fit) the amps also have regular gold string that's stapled into the top and bottom route line where as speaker cabs from this period often have mini gold T piece not stringing.
Looking at serial numbers next to the ’60 5G5 brown Pro Amp for example, we see numbers ranging from 00001 to 02000, suggesting that there are 2000 of these amplifiers made in ’60.It would be more accurate to say that approx 650 of each of these models were produced in ’60. Oddlings – Yet another printing error has surfaced, this time from the FEI (pre-CBS) days. Besides, no article in the Dating Fender Amps by Serial Number series would be complete without some interesting information, n’est ce pas? I promise the tables will still be there after you finish reading.