Larry, the British Purist SH rough channel is working with the tube booster too like the bigger brother?
Yes, both have exactly the same preamp circuit.
I just have moved the Pregain of the big BP from the rear panel as Drive to the front panel of the SH BP
What is the funktion of four mini switches on the front panel?
Basically the Classic channel is the brighter channel of a '68 (not '69 !) Plexi Marshall.
- The 1st mini switch up accentuates the high mids, not like a 'Bright' switch, rather like an 'Edge' switch
- The 2nd mini switch up adds a well dosed amount of low mids to the sound and makes it meatier, similar like a 'body' switch
Basically the Rough channel (Booster off) is a refined Marshall 2203 MV channel.
The original is designed to be a bit wiry and slim. Good for rhythm and riffing, but rather unwilling for soloing.
- The 3th mini switch up adds a wide range of mids and makes this channel a vintage lead channel even without a booster
This mini switch is only active in the not boosted mode of the Rough channel.
- The 4th mini switch up boosts (independent of the integrated tube booster) all frequencies from the low mids, but not the bass, so that this channel - regardless of whether in basic or drive mode - always remains tight despite the significantly increased gain.
This mini switch is active in the basic mode and also in the drive mode of the Rough channel.
And then there's still the integrated tube booster, what activates an additional tube and the Drive control on the front panel as well as the Bite & Punch controls on the rear panel.
If in this mode you now push up the 4th mini switch, you'll have gain almost as much as with a Dino, just with more vintage flair
