User manual MARSHALL AMPLIFIER 1959HW

[. . . ] Introduction ENGLISH ENGLISH Overview: Historical, Tone and Tech Talk The 1959HW is a Class-A/B, all-valve, 100 Watt, two-channel head. When building this handwired re-issue of an amazing sounding, original Plexi head made in 1969, our goal was both obvious and simple: to make it as close to the original as possible in terms of components, circuitry, constructional methods, materials, specifications, aesthetics, signal path, performance, tonal characteristics and feel. We went to incredible lengths to achieve maximum authenticity and are delighted to report that our suppliers were equally as exacting in their tasks - none-more-so than our long-time partner, Dagnall Transformers. As is now rock folklore, the 1959 came to be when The Who's guitarist, Pete Townshend, approached Marshall in the mid '60s and asked Jim to build him a `weapon' that would allow him to play so loud that he wouldn't be able to hear what the members of the audience were saying, should they have the sheer audacity to talk whilst he was performing! [. . . ] This device divides the signal into two halves that are 180 degree out-of-phase with each other, and then feed the 1959's push-pull output stage. Mains (Power) Transformer: While the original transformer is large, the custom-made Dagnall reissue has been made even larger in order to satisfy strict, current-day safety legislation. Just like the original, the re-issue transformer is what is called a `drop through, half-shroud', which sits horizontally as opposed to vertically. As with the output transformer, we went to great lengths to ensure that its performance mirrors that of the original, paying particular attention to exactly replicating an effect called `regulation' - which is the way that the voltage from the transformer that feeds the valve circuitry varies according to load. In terms of the concentric design and performance, this transformer embodies the performance of the 1203-80 original specification first drawn up for us by Drake in February 1967. The original was a 2. 5" transformer. Due to the aforementioned modern legislations, the reissue is 3". Tonal Note 4: This circuit has the same filtering on the H. T. the B+ voltage) line as later versions, a factor that contributes to the 1959HW having a tighter sound than earlier versions. Note: The 1959HW incorporates 47nF/630V capacitors fitted in parallel with each of the four diodes in the bridge rectifier circuit. These are present for today's approval requirements that necessitate a reduction in electrical interference that may be generated and put back on the mains electricity supply. The addition of these capacitors has no sonic impact. 2 3 Chassis: We are using a box-section chassis made from 16 gauge mild steel with butt-welded corner joints. The steel is also passivated giving lifelong resistance to corrosion. Our original chassis has a lot of extra holes drilled in it that weren't used. No doubt these existed because the same exact chassis was also used for other products made at the time. The most noticeable `extra hole' is one on top for a fourth ECC83 and on our reference unit, this particular hole has been covered up with a disc of steel that's been riveted into the two screw holes that would have been used to secure the valve holder, were it there. After approximately two minutes the valves will have reached the correct operating temperature and the Standby Switch can be engaged. In order to prolong valve life, the Standby Switch alone should also be used to turn the amplifier on and off during breaks in a performance. Also, when switching off, always disengage the Standby Switch prior to the main Power Switch. 8. VOLUME I This controls the overall output level of Channel I, turning it clockwise increases the volume. This channel is voiced for a higher treble response than Channel II. Tonal Note 5: The value of the capacitor across Volume I is 0. 005µF. This rather large value makes this channel aggressive and bright at relatively low settings. Many players bridge (see page 6 for details) Channels I and II (which has a darker, less aggressive tone) in order to have more control over their overall tone. [. . . ] MAINS SELECTOR Matches the amplifier's mains transformer to the incoming mains voltage. Your 1959HW should always be completely powered down before the mains selector is turned. ALWAYS ensure that this rotary selector is set to the correct mains voltage applicable for the country where the 1959HW is being used. If you do not know, consult your authorized Marshall dealer. [. . . ]