Ok, digging around my amp I can't see a op amp near the input (I can't see one at all, actually), and now I bring up the escort lead 30 schematic I'm wondering if the preamp is closer to what's in that... My input resistors are certainly not 470k though, they are 100k on both high and low inputs.. however they DO both go from tip to ground of their respective jack sockets as per the Escort Lead 30 schematic. It looks like I have a 10n cap on the Low and 470n cap on the High rather than both 100n like on the escort lead 30 schem.
Still, its 'High and low' on mine, not 'normal and bright', so I'm guessing the Lead 30 design gets the sonic difference in channels later with those two inputs going to the base of 2 different transistors with their own respective 'normal and bright' pots. Mine just has a 'master volume' and 'volume' (which works like 'gain') which effect both channels equally, so I'm guessing those two different caps on mine are what gives the difference in sound between the high and low channels. Both those caps are chicklets, so TMU not likely to be bad but I certainly could change them...
Worth trying 470k resistors on the inputs? Or would 100k with this design be fine and so I should look further into the signal path?
Dammit I wish I could find a schematic for this amp!
Still, its 'High and low' on mine, not 'normal and bright', so I'm guessing the Lead 30 design gets the sonic difference in channels later with those two inputs going to the base of 2 different transistors with their own respective 'normal and bright' pots. Mine just has a 'master volume' and 'volume' (which works like 'gain') which effect both channels equally, so I'm guessing those two different caps on mine are what gives the difference in sound between the high and low channels. Both those caps are chicklets, so TMU not likely to be bad but I certainly could change them...
Worth trying 470k resistors on the inputs? Or would 100k with this design be fine and so I should look further into the signal path?
Dammit I wish I could find a schematic for this amp!
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