Haven't built this yet, but the PedalPCB forum suggests replacing the 33k resistor (L-14 to L-17 on this layout) for 150k for more output volume. As is, the schematic is said to barely hit unity with everything maxed out. Just a tip I saw to potentially save a headache.
i just build this according to the layout. everything seems to work, i get a weaker signal when engaging the switch in one position, the other seems loud enough ( its pretty late so i cant test the volume), but al the rest of the controls seem to work . i dont like the sweep on the pre volume, will have to see if i can get it better. but yeah this thing works. will see tomorrow about the output volume ( thanks for the tip convergentsound )
just made the correction , the sweep is perfect now, volume issue remains. for me this is verified, the volume thing is also present in the pcb and has not been resolved (https://forum.pedalpcb.com/threads/decadence-preamp-volume-issue.19286/ ( quote "However large the signal comes in, the diodes clip to 0.6V peak (1.2V p-p). Then: R20 plus potentiometer - it's a voltage divider. Signal drops below 0.2V peak (0.4 p-p). And it's with potentiometer maxed. With potentiometer @ noon it's around 90mV peak. " and here https://forum.pedalpcb.com/threads/decadence-preamp-unity-gain.14063/ ( where they say to change the 33k for 150k and someone says it does not solve the problem. also the build guide/schematic has no mention of this volume issue, so nog good advertising for pedalpcb )
What about possibly moving the diodes, along with the 22k resistor, before last Opamp. The increased gain from upping the value of the 33k resistor would no longer get squashed.
Simply adding a boost like an LPB-1 to the output and hard setting the Post function with a fixed resistor is always an option. I find that it works very well in most cases.
ok. some time a go i bought 5 mini boost boards @ moonnelectronics (https://moonnelectronics.bigcartel.com/product/boostt) and used one of those to boost the volume. used a 100k dual gang pot, added a resistor to change the value (10k for the post pot) and connected both middle lugs. the volume is much better but is still not as loud. but it is much better.
Incidentally, would someone be willing to share a link to a trusted layout creator software? The last time I tried to download the software I think I got a virus. I'd love to enter the 20th century and stop drawing things up on paper with a pencil. hehe
I believe Chris and I both use DIY Layout Creator, and that has been sans problème for me - with the caveat that I use it on a Mac, so I can't attest to how buggy or dodgy it is on PCs.
Hey Tom - I'm chiming in a little late here, but just about all the drawings on this blog were done with some version of DIYLC - the differences in appearance really come down to when you download the software - as it is constantly being updated. It takes a little while to learn your way around the shortcuts and sometimes, there is no shortcut. Example: when I draw the second board layout that just has the cuts and jumpers, I duplicate the finished one and then delete the components one at a time... every time. It's tedious, but so is stripboard, right? Good luck with it - if I got it figured out, anyone should be able to!
Word. I have wanted to tinker with layouts for some time. However, I do feel that Anders has a talent that I will never posses. I would love to contribute and throw together the odd simple one to help out. I'm currently working on an idea. Maybe I can offer it up if I can draw it up coherently.
Haven't built this yet, but the PedalPCB forum suggests replacing the 33k resistor (L-14 to L-17 on this layout) for 150k for more output volume. As is, the schematic is said to barely hit unity with everything maxed out. Just a tip I saw to potentially save a headache.
ReplyDeletei just build this according to the layout. everything seems to work, i get a weaker signal when engaging the switch in one position, the other seems loud enough ( its pretty late so i cant test the volume), but al the rest of the controls seem to work . i dont like the sweep on the pre volume, will have to see if i can get it better. but yeah this thing works. will see tomorrow about the output volume ( thanks for the tip convergentsound )
ReplyDeleteoh yeah and thanks for the layout!
ReplyDeleteok i tested a bit and the volume thing seems to be a thing , will report back
ReplyDeletechanged the 33k to 150k it does something but not enough
DeletePre 2 and Pre 3 need to be swapped. The layout above is updated.
Deletejust made the correction , the sweep is perfect now, volume issue remains. for me this is verified, the volume thing is also present in the pcb and has not been resolved (https://forum.pedalpcb.com/threads/decadence-preamp-volume-issue.19286/ ( quote "However large the signal comes in, the diodes clip to 0.6V peak (1.2V p-p). Then: R20 plus potentiometer - it's a voltage divider. Signal drops below 0.2V peak (0.4 p-p). And it's with potentiometer maxed. With potentiometer @ noon it's around 90mV peak. " and here https://forum.pedalpcb.com/threads/decadence-preamp-unity-gain.14063/ ( where they say to change the 33k for 150k and someone says it does not solve the problem. also the build guide/schematic has no mention of this volume issue, so nog good advertising for pedalpcb )
ReplyDeleteWhat about possibly moving the diodes, along with the 22k resistor, before last Opamp. The increased gain from upping the value of the 33k resistor would no longer get squashed.
DeleteAlright, just tagged. It seems to work as it should with its design flaw. I booster seem to be a good solution.
Deleteyeah but the board is very populated going to have to move around a lot to make room
ReplyDeleteSimply adding a boost like an LPB-1 to the output and hard setting the Post function with a fixed resistor is always an option. I find that it works very well in most cases.
Deleteadding a small boost like that is going to be the quickest way to fix the volume thing i think
DeleteIf you establish that there isn't anything wrong with the actual circuit, which you have done, that's generally the best option.
Deletei will add a boost and report back. the sound itself is pretty good indeed!
Deleteok. some time a go i bought 5 mini boost boards @ moonnelectronics (https://moonnelectronics.bigcartel.com/product/boostt) and used one of those to boost the volume. used a 100k dual gang pot, added a resistor to change the value (10k for the post pot) and connected both middle lugs. the volume is much better but is still not as loud. but it is much better.
DeleteIncidentally, would someone be willing to share a link to a trusted layout creator software? The last time I tried to download the software I think I got a virus. I'd love to enter the 20th century and stop drawing things up on paper with a pencil. hehe
ReplyDeleteI believe Chris and I both use DIY Layout Creator, and that has been sans problème for me - with the caveat that I use it on a Mac, so I can't attest to how buggy or dodgy it is on PCs.
DeleteI've never had any problems with DIYLC on PC either. Great software by the way.
DeleteI trust you guys. I'll give it a shot. Thanks.
DeleteHey Tom - I'm chiming in a little late here, but just about all the drawings on this blog were done with some version of DIYLC - the differences in appearance really come down to when you download the software - as it is constantly being updated. It takes a little while to learn your way around the shortcuts and sometimes, there is no shortcut. Example: when I draw the second board layout that just has the cuts and jumpers, I duplicate the finished one and then delete the components one at a time... every time. It's tedious, but so is stripboard, right? Good luck with it - if I got it figured out, anyone should be able to!
DeleteWord. I have wanted to tinker with layouts for some time. However, I do feel that Anders has a talent that I will never posses. I would love to contribute and throw together the odd simple one to help out. I'm currently working on an idea. Maybe I can offer it up if I can draw it up coherently.
Delete