The original had a funky power arangement which demanded an own power supply. This layout has a power supply mod with a voltage regulator so you can daisy chain it. I also added a gain pot, replacing the internal gain trimpot.
Any chance of a link to a picture of the pinout of the 3P4T Rotary switch you have laid this out for? Looking online there are so many variations on the pinout.
Tried both a plastic one with numbers and a metal style one without. Still getting the same problems with the effect just downtuning the guitar. Must be a faulty HT8950.
I'm going to have to admit defeat on this one. Tried 2 HT8950's and 2 rotary's in a variety of positions and still no joy.
Maddeningly I have 3 of the functions working - 8 bit fuzz, upper octave & arpeggiator. However, these only work with the Switch A output connected to Switch C and the Switch C output connected to Switch B.
The Switch B output is disconnected, if I try connecting it it detunes the sound by a semitone!
I'm in a filter frenzy with a Lovetone Meatball done (Sabrotone/Johnk's layout). Seeing how you've done a ton DBA layouts over the years, you don't happen to have an Evil Filter layout lying around (with a solution for the expression input)? Or a Maestro FSH-1 (with the ticking issue fixed)? Sorry to request all the stuff (I'm still working on the Maestro Ring Mod - complex thing!)
Evil Filter is very cool! I did a layout a few years ago for the filter section only since I diddn't care for the fuzz. No expression output though since I couldn't find a solution for the wiring.
One thing that bugs me about the trace is that I have seen guts with four transistors in the fuzz section, not Three. Which could explain the anemic weak fuzz...
DBA released the fuzz section as a standalone pedal a few years ago called Evil Fuzz. I did some guess work and did a layout with 4 transistors, the last one being switchable.
But as I said....guesswork, I don't know whats inside Evil Fuzz for sure.
Hi Anders, any recommendations on where to get the HT8950 IC. There are some on eBay but I dont fancy taking my chances with potential fake parts. Cheers
I checked it everything seems to fine. According to the schematic, the 27k on the left should connect to pin 1 of the dual op amp but on this layout it's connected to pin 2. And the fuzz pot wiring doesn't match the schematic too. I made the corrections on my board but the volume still doesn't work. Volume seems to always be at max no matter where I turn.
I checked it against the layout at tagboards and you are right about the fuzz and pin connection. It does work as expected tho, I've built 2 or 3 of these without issue
Finally got back to this one today. What i ended up doing was bypassing the volume pot here by connecting the holes that say volume 1 and volume 2 together, and the. Connecting the output to lug 3 of a 100k pot, lug 1 to ground and used lug 2 as the output. Works fine now.
Hi there
ReplyDeleteAny chance of a link to a picture of the pinout of the 3P4T Rotary switch you have laid this out for? Looking online there are so many variations on the pinout.
Cheers
I'll try to draw up a rotary pinout picture. If you have a plastic rotary its ususally has labels at each pin already.
ReplyDeleteTried both a plastic one with numbers and a metal style one without. Still getting the same problems with the effect just downtuning the guitar. Must be a faulty HT8950.
DeleteI'm going to have to admit defeat on this one. Tried 2 HT8950's and 2 rotary's in a variety of positions and still no joy.
ReplyDeleteMaddeningly I have 3 of the functions working - 8 bit fuzz, upper octave & arpeggiator. However, these only work with the Switch A output connected to Switch C and the Switch C output connected to Switch B.
The Switch B output is disconnected, if I try connecting it it detunes the sound by a semitone!
Working nicely for me. Thanks for the layout.
ReplyDeleteI'm in a filter frenzy with a Lovetone Meatball done (Sabrotone/Johnk's layout). Seeing how you've done a ton DBA layouts over the years, you don't happen to have an Evil Filter layout lying around (with a solution for the expression input)? Or a Maestro FSH-1 (with the ticking issue fixed)?
Sorry to request all the stuff (I'm still working on the Maestro Ring Mod - complex thing!)
Evil Filter is very cool!
DeleteI did a layout a few years ago for the filter section only since I diddn't care for the fuzz. No expression output though since I couldn't find a solution for the wiring.
One thing that bugs me about the trace is that I have seen guts with four transistors in the fuzz section, not Three. Which could explain the anemic weak fuzz...
DBA released the fuzz section as a standalone pedal a few years ago called Evil Fuzz. I did some guess work and did a layout with 4 transistors, the last one being switchable.
But as I said....guesswork, I don't know whats inside Evil Fuzz for sure.
Hi Anders, any recommendations on where to get the HT8950 IC. There are some on eBay but I dont fancy taking my chances with potential fake parts. Cheers
ReplyDeleteTry this shop.
Deletehttps://www.uk-electronic.de/onlineshop/product_info.php?products_id=1688
Been shopping there several times and they are very reliable.
Great, thanks mate!!
ReplyDeleteCan a clean blend circuit be added to this circuit?
ReplyDeleteThe volume pot on mine doesn't work. It's always at full volume I guess. Tried 5k and replaced it with a 100k like in the schematic but no change.
ReplyDeleteMake sure to check the link between Volume 1 and ground is good (H13-M13)
DeleteCheck your build for the usual; solder joints, etc... I've made a couple of these with no volume issues - in fact its pretty loud
ReplyDeleteI checked it everything seems to fine. According to the schematic, the 27k on the left should connect to pin 1 of the dual op amp but on this layout it's connected to pin 2. And the fuzz pot wiring doesn't match the schematic too. I made the corrections on my board but the volume still doesn't work. Volume seems to always be at max no matter where I turn.
DeleteI checked it against the layout at tagboards and you are right about the fuzz and pin connection. It does work as expected tho, I've built 2 or 3 of these without issue
DeleteFinally got back to this one today. What i ended up doing was bypassing the volume pot here by connecting the holes that say volume 1 and volume 2 together, and the. Connecting the output to lug 3 of a 100k pot, lug 1 to ground and used lug 2 as the output. Works fine now.
ReplyDelete