I make o lot of modifications on guitars,pedals and amps.Here are some of them!
treble bleed and Philips Orange drop capacitor for the tone control! The lower pot has been modified so that at the zero point it makes a switching so tha no conection betwen the two conecting points in use!This is becaouse this pot is no longer a tone control but a Neck pickup blender that an mix the sound of the Neck pickup directly to the output of the guitar anytime!!!! A very versatille strato!
And this is some hours later with 3 new switches feeted to control the new mods!! 4 mods in it 3 through switching and 1 permanent!
1st. change the C2 cap with a higher capacitance(47nf instead of 18nf) so as to allow low frequencies pass to the next stage of the schematics. This is permanent and adds some more bass harmonics.
2. cut or let as was the C6 a famus mod.Alot of owners just put out this capacitor!My opinion is to keep always the physical character of any devise!!
3. Change between symmetrical and asymetrical clpping by taking out and short circuit the ends of D6.By default it is assymetrical and i like it more!maybe later I will try to change the D4 with a Led Diode!
4, the most effective mod!Changing the R6 (4k7) to a 1k resistor in the same time with changing C3 from stock (47nF) to 470nf!!!This adds a LOT og gain and bass sounds that gives a thick and tight sound transfoming the sd1 into another stronger pedal!!Try it!!
This old Aria pro II 30w BassGuitar amp was given to me as a gift as it was problematic and the owner didn't want to repair it! So I decided to make the biggest mod! Only the wooden case the chassis and the speaker were left and all the parts went away to give housing to a fulltube handwired clone(modificated also) of the Cornford Harlequin 6w boutique amp.
but the modding madness never ends!!So it's time to get one more output tube(in parallel) and double the power! Also adding ,through a switch, capacitors inparallel to the cathode resistors in two different preamp stages(this amp has four preamp stages 2xdouble triode tubes means 4 triode tubes!) can make a switch for 3 different kinds of overdrive!
And here it is! The switch to the left has 3 options!A-0-B A & B are 2 different kinds of "marshall like" overdrive and the 0 position is the normal aw the schematics!The switch in the Middle place is a voicing switch from the original schematics ,smthg like a brightness control, and I like it! Now I am planning in building a very good new wooden box that can accept a bigger speaker,this is 8" and it sucks!
then i had to install a Line out,a triode\pentode switch ta play 15\7,5w,a stand by switch and a "Marshal Mode" switch that can give an extra boost (smthg bit stronger than FAT) that can be controled by a footswitch and can play alone or together with fat and gives a variety of sounds to this amp!! Very usefull mode!!