Adventures with the JHS Zonk II

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
Post Reply
User avatar
Manicstrat2112
Information
Posts: 15
Joined: 23 Nov 2019, 05:49
my favorite amplifier: Egnater Rebel 30 MK I
Completed builds: Partial list: Creepy Fingers EQ Exciter Fuzz, Tonebender MK II, Silicon Tonebender MK II, Fuzzrocious Ram the Manparts, Thunderdrive, Fuzz Face. Silicon Fuzz Face, EHX Muff Fuzz, Brian May Treble Booster, DAM Grease Box, DAM Meathead, Lovepedal Woodrow, Lovepedal Eternity, Silicon Fuzz Master, Fuzz Factory, Mastotron, Super Hard On, 73 Rams Head BM, Katzenkonig, Phase 45, Black Dust, RAH, Tentacle, MXR Distortion +, DOD 250 Preamp, Distortron, Naga Viper, JHS Andy Timmons, Pro co Rat, Celine Mark 4, EQD Dunes, EHX OD Glove,, Lemon Drop, 59 Sound, Formula No 5, Formula No. 55, Black Ash, Plexi Drive, 65 Deluxe, Hummingbird, Fuzzolo, Univibe, EQD The Depths, Guzzling, Maestro FZ-1 and FZ-1A, Tonebender MKI, Harmonic Percolator, Zonk Machine, Hybrid Si/Ge Zonk Machine, MBP Harbinger 1.5, MBP Pork Barrel (to original CE-2 specs) and it all started with the Bazz Fuss =)
Location: Portland, Oregon
Has thanked: 13 times
Been thanked: 1 time

Post by Manicstrat2112 »

Sorry to :beatdeadhorse: , but I love Zonk machines! No one likes the sound of the Zonk II (including myself, until now). To me it sounded dark and had a weird abrupt cutoff about the notes...especially lower power chords and the higher single note runs. I attributed this to just being a crap circuit, but after adjusting the bias I changed my mind. I replaced the q2 collector resistor (10k) with a pot (as close to 10k as you have.) I used an audio pot, but a linear would probably work better. I biased it at -6.3 to -6.8 volts with the fuzz maxed and now it has way better sustain! I measured the resistance of the pot (which was 7.5k). Then I replaced the pot with a 7.5k resistor, checked the q2 collector voltage again to make sure it had not changed and......rock and roll!!! It still sounded a bit dark and woofy so I changed the stock 10uf input cap to a .1uf cap (anything from .01uf to 5uf depending on your taste). In the end I used a 6 position rotary switch with a .01uf, .1uf, .22uf, 1uf, 5uf, and 10uf and it now sounds awesome!
Has anyone else experimented with the Zonk II and made any improvements?
".....and when I'm sad......I slide!"

Post Reply