Pro junior r1 value question

[ballynally]

As far as i can tell most Fender amps have a 68kOhm resistor on the first (R1) input before the 1st gain stage. Any idea why the Pro junior uses a 10K? In addition, does it boost the signal too much before the first preamp tube?

[Enzo]

The old school amps used 68k, largely so they could make the 2/1 voltage divider between the two input jacks - those high and low sensitivity jacks. SOme reissues, like the Twin AMp used a single 33k to emulate the typical 68kx2 in parallel.

A quick tour through my Fender disc shows most of them using a 10k grid stopper, rather than 68k. When there is only one jack, there is no longer a need for the 68k resistors.

And I don;t know what you mean does it boost signal too much? Resistors are passive and do no boosting. But in the larger sense, are you suggesting that Fender just stuck a random value resistor in ther? Or that they designed this without knowing what they were doing?

[ballynally]

i actually meant ' let more signal through' when i wrote 'boost'. I know it filters out unwanted noise RF etc.before it can reach the first gain stage . I just thought a cap would do any filtering and no, i don't mean to suggest anything..