Princeton Reverb Clone Lacks Treble

[blewgrass]

Hello fellow amp geeks!

I have a nice Princeton Reverb Clone that I am generally satisfied with. I have a Weber California (non aluminum dust cap) that has nice meaty low end and good balance overall...

The one thing I would like to tweak on this amp is increase treble response. This build lacks the shimmering high end I get from my SF vibro champ, my DRRI, and others. It is quite posible that the builder intentionally did this. I have to max out the treble at 10 to come close to the typical silver face jingle jangle. As a disclosure, I usually roll off the treble close to what this amp will do at maximum as well.



what should I look for? Values of caps and resistors near the treble pot? Is there something in the tone stack I would look for that might not be stock? I also noticed on this build that there are more than the normal amount of resistors clustered at the two inputs. The builder also reversed the gain arrangement on the inputs. (Input 1 is attenuated while input 2 is not) I mention these things as possible cues that something is amiss, and I know sometimes just a simple solder joint or little deviation can solve the mystery.

Another problem with the amp is the intensity of the vibrato. you need to turn the intensity up full blast where on other fender amps it would only be half way... Tubes?



I do have a schematic and I will look for anything that is not "original" to the layout.

Thanks for any ideas.

[tubeswell]

Its difficult to tell what the values of the caps are in those pics.

Just as an aside, have you got the geetar plugged into the Hi impedance input (or the lo-impedance input)? (Whoever built it may have wired the #2 input to be the Hi impedance input.)

[blewgrass]

Thanks for the repsonse tubeswell.

I have tested the amp with both inputs, with little difference in overall tone except the gain. I have tried several speakers and any speaker I put in there gives the same overall characteristics of rolled off highs. I will study the components on the layout and see what the standard values are, and if my amp deviates in any way. I just posted here to see if there was any special area to start looking.

I could take some close ups of that area and list values and parts. Would that give a better idea of what to test for?

thanks

Steve

[tubeswell]

The cap values should be the easiest things to check. I see they are all orangedrops, check the numbers on the side