Thank you! That's surprising : isn't the original supposed to work with an unobtainium vactrol? By using OTAs, the reissue makes it closer to the FX25...?
Yes, the "classic" 440 had an optocoupler and a completely different circuit. This one one the other hand has more in common with FX25 just as you said. Some parts of the circuit is almost identical but there is also lots of extra stuff happening.
Hey, got it working. There are two corrections to be made: -10k misplaced between Vref and grnd: move 10k from C14 to N14 -move 22k from Q7 to R7 Cheers!
I’m having trouble to get this to sound correct. I see the 22k at R7 but did the C14 to N14 change happen? I’m not seeing which 10k is being referred to?
Would the LM1458 replace the TL062 and LM358? Does it sound better? Thanks for the heads up, I wasn’t sure if anyone had successfully done this one other than crissip I’m either getting really tinny or really bassy sounds. The bottom right 10k trimmer seems to adjust across the frequency range and the other one doesn’t do too much. It’s really squirrelly sounding.
I accidentally put the 062 and 13700 upside down due to getting all of the pins in — it burned out that 062 but the 13700 seems to be fine. I popped it in my Shallow Water/Low Tide build and it functioned fine. Tried a different 358 to be safe. No difference. Usually I’m missing a link or cut but so far no dice.
Click on the link to the schematic, it will open the PedalPCB docs. The correct voltage for the trimmers are listed there. When you get these in the right spot it sounds good.
Thanks, I just adjusted the trimmers to the correct voltages -- I do get effect but the overall sound is still super shrill. I don't have a 100kC on hand and am using a 500kC, so I'm not expecting the pot rotation to be correct (effect is mostly bunched up one end of the pot).
I think the Level control is working. The switch in the up position is even more shrill, kind of have an airy high freq whine in the background. The down position is better but still shrill. Here is an example of what I'm hearing:
I had something similar before changing out the IC's. Try changing two ICs to LM1458s and change that C500K pot to a B100K if you have one. It defo works and it seems you are close
I replaced IC1 and IC2 with LM1458 (and replaced with the better type of IC socket) and put in a different LM13700 I know for sure works, re-checked the trimmers and I'm still having the same issues. Very shrill and when I turn pots it can cause wild oscillation that would make a Fuzz Factory proud!
I've verified placements, links and cuts, the only other thing I'm wondering is if when I put the TL062 in upside down initially and fried it, if it took any other components out with it?
I think I’m going to pop a leg on each and measure. I measure as I solder things in but maybe I missed something. However did you wire your DPDT like this
Checked every component on the board by lifting a leg or removing. All of the components are okay. Tried some TL072s in IC1 and IC2 but no difference. One of the switch positions doesn’t really quack. The other one does but the Level pot (100kB for now) only introduces the effect at whatever end of the pot I’m sending the Level 3 wire to. As soon as I turn away the signal goes mostly clean but also introduces some brief oscillations/drop outs. I’m pretty sure the Range pot isn’t doing anything. I also tuned the trimmers by ear along with the suggested voltages but while the build partially works it’s still acting weird…
Thank you!
ReplyDeleteThat's surprising : isn't the original supposed to work with an unobtainium vactrol?
By using OTAs, the reissue makes it closer to the FX25...?
Yes, the "classic" 440 had an optocoupler and a completely different circuit.
DeleteThis one one the other hand has more in common with FX25 just as you said. Some parts of the circuit is almost identical but there is also lots of extra stuff happening.
gave this one a try - no luck. I get a very quiet fuzzy signal
ReplyDeleteI'll take a look at the schematic again...
DeleteDid you get chance to check out the schem again mate? I built up the guyatone one, really interested in this too
ReplyDeleteHey mate. No never got around to check the schematic, sorry about that. Will try to find some time the nexrt coming days.
ReplyDeleteHey, got it working. There are two corrections to be made:
ReplyDelete-10k misplaced between Vref and grnd: move 10k from C14 to N14
-move 22k from Q7 to R7
Cheers!
Thats awesome!
DeleteLayout is tagged and updated.
I’m having trouble to get this to sound correct. I see the 22k at R7 but did the C14 to N14 change happen? I’m not seeing which 10k is being referred to?
DeleteI've built this recently and it does work, try LM1458's for both IC''s too.
DeleteWould the LM1458 replace the TL062 and LM358? Does it sound better? Thanks for the heads up, I wasn’t sure if anyone had successfully done this one other than crissip I’m either getting really tinny or really bassy sounds. The bottom right 10k trimmer seems to adjust across the frequency range and the other one doesn’t do too much. It’s really squirrelly sounding.
DeleteI accidentally put the 062 and 13700 upside down due to getting all of the pins in — it burned out that 062 but the 13700 seems to be fine. I popped it in my Shallow Water/Low Tide build and it functioned fine. Tried a different 358 to be safe. No difference. Usually I’m missing a link or cut but so far no dice.
Yes, the LM358 & LM1458 are both dual opamps & have the same pinout.
DeleteClick on the link to the schematic, it will open the PedalPCB docs. The correct voltage for the trimmers are listed there. When you get these in the right spot it sounds good.
DeleteThanks, I just adjusted the trimmers to the correct voltages -- I do get effect but the overall sound is still super shrill. I don't have a 100kC on hand and am using a 500kC, so I'm not expecting the pot rotation to be correct (effect is mostly bunched up one end of the pot).
DeleteI think the Level control is working. The switch in the up position is even more shrill, kind of have an airy high freq whine in the background. The down position is better but still shrill. Here is an example of what I'm hearing:
https://jmp.sh/s/HXpXzAuUQhE8YARAY0Vv
My voltages are...
IC1 - TL062
4.49V 9V
4.49V 4.45V
4.29V 4.45V
000.2mV 4.49V
IC2 - LM358
3.81V 9V
3.81V 1.462V
3.76V 1.467V
000.3mV 1.467V
LC3 - LM13700
1.198V 1.194V
2.90V (?) 1.5V (?)
4.49V 4.49V
4.99V 4.49V
5.66V 5.65V
001.7mV 9V
5.66V 5.64V
4.50V 4.48V
Two of the pins (with question marks) on the LM13700 seem to change value a lot so it was hard to lock down anything concrete there.
DeleteI had something similar before changing out the IC's. Try changing two ICs to LM1458s and change that C500K pot to a B100K if you have one. It defo works and it seems you are close
DeleteI replaced IC1 and IC2 with LM1458 (and replaced with the better type of IC socket) and put in a different LM13700 I know for sure works, re-checked the trimmers and I'm still having the same issues. Very shrill and when I turn pots it can cause wild oscillation that would make a Fuzz Factory proud!
DeleteI've verified placements, links and cuts, the only other thing I'm wondering is if when I put the TL062 in upside down initially and fried it, if it took any other components out with it?
The main issue I had before changing IC's was clipping, it was almost like an overdrive. You may have a wrong resistor or capacitor value somewhere
DeleteI think I’m going to pop a leg on each and measure. I measure as I solder things in but maybe I missed something. However did you wire your DPDT like this
Delete1 - 4
2 - 5
3 - 6
Or
1 - 2
3 - 4
5 - 6
DPDT pinout is
Delete1 - 4
2 - 5
3 - 6
Checked every component on the board by lifting a leg or removing. All of the components are okay. Tried some TL072s in IC1 and IC2 but no difference. One of the switch positions doesn’t really quack. The other one does but the Level pot (100kB for now) only introduces the effect at whatever end of the pot I’m sending the Level 3 wire to. As soon as I turn away the signal goes mostly clean but also introduces some brief oscillations/drop outs. I’m pretty sure the Range pot isn’t doing anything. I also tuned the trimmers by ear along with the suggested voltages but while the build partially works it’s still acting weird…
DeleteAs I know, FX25 uses LM13600 and 440 uses led/ldr combo. Is it different on the reissue?
ReplyDelete