MichaelW
Well-known member
- Build Rating
Just buttoned this one up this afternoon.
Took a bit more fiddling with getting the bias right than the first one but it's pretty dialed now.
The one thing I did different on this build was changing the input impedance resistor.
After chatting with @Guardians of the analog I decided to go with 1m.
The BOM follows the schematic of the original DMM with 100k which is pretty low input impedance. It gets a bit finicky with hotter pickups and stacking drives into it.
Brian's build doc recommends raising this to 220k or 300k. I used 330k on the first Skoolie but decided to try higher impedance on this one.
As I'm running these two delays in series I have the higher impedance one first then the 330k one. It all works well with whatever guitar I'm using so far.
I may go back in and change out the 330k to 1m on the other one as well. (And maybe even my Total Recall and Tourbus builds. I went stock on those).
So now 4 DMM's in, I really like these 9v neg ground versions! A lot more convenient to power on a pedalboard.
Having said that, I think the full size 24v positive ground Total Recall sounds the best of the bunch, not exactly sure why but we're talking splitting hairs here.
They are all remarkably consistent in how they sound. The difference may simply be component variables.
I used the same violet Tayda enclosure just different color knobs.
I also used some lower profile WIMA 1uf film caps on the BBD board for a bit more clearance for the back cover. Otherwise it's a mix of electrolytic and tantalum caps chosen primarily for size. The Silver Mica cap next to the 4047 is something that MBP threw in with the first batch of Skoolie orders. It's a 250pf cap.
Here's how my "amp rig" is shaping up. And yes that's a retail reverb pedal (egads!!!)
Waiting for my Gravitation board to show up to round out my time based effects sitting in the tube driven effects loop of the amp.
The amp has two different preamps, a Fender style and a Marshall style with two inputs. So I built a little active ABY pedal using one of of the IC buffer boards from General Guitar Gadgets so I can switch between the channels or combine them. Still fiddling with the amp trying to get it dialed but I'll post a NAD report when I get there. I need to make some cables for the ABY box and tidy up all the cable routing. But I need to build one more buffered AB switch box to switch between my desktop rig and the amp rig without having to change a bunch of cables. Waiting for another buffer board from GGG to arrive.
(just noticed the white hair on my ABY switch from Bonnie the Wonder Dog....
)
Took a bit more fiddling with getting the bias right than the first one but it's pretty dialed now.
The one thing I did different on this build was changing the input impedance resistor.
After chatting with @Guardians of the analog I decided to go with 1m.
The BOM follows the schematic of the original DMM with 100k which is pretty low input impedance. It gets a bit finicky with hotter pickups and stacking drives into it.
Brian's build doc recommends raising this to 220k or 300k. I used 330k on the first Skoolie but decided to try higher impedance on this one.
As I'm running these two delays in series I have the higher impedance one first then the 330k one. It all works well with whatever guitar I'm using so far.
I may go back in and change out the 330k to 1m on the other one as well. (And maybe even my Total Recall and Tourbus builds. I went stock on those).
So now 4 DMM's in, I really like these 9v neg ground versions! A lot more convenient to power on a pedalboard.
Having said that, I think the full size 24v positive ground Total Recall sounds the best of the bunch, not exactly sure why but we're talking splitting hairs here.
They are all remarkably consistent in how they sound. The difference may simply be component variables.
I used the same violet Tayda enclosure just different color knobs.
I also used some lower profile WIMA 1uf film caps on the BBD board for a bit more clearance for the back cover. Otherwise it's a mix of electrolytic and tantalum caps chosen primarily for size. The Silver Mica cap next to the 4047 is something that MBP threw in with the first batch of Skoolie orders. It's a 250pf cap.
Here's how my "amp rig" is shaping up. And yes that's a retail reverb pedal (egads!!!)
Waiting for my Gravitation board to show up to round out my time based effects sitting in the tube driven effects loop of the amp.
The amp has two different preamps, a Fender style and a Marshall style with two inputs. So I built a little active ABY pedal using one of of the IC buffer boards from General Guitar Gadgets so I can switch between the channels or combine them. Still fiddling with the amp trying to get it dialed but I'll post a NAD report when I get there. I need to make some cables for the ABY box and tidy up all the cable routing. But I need to build one more buffered AB switch box to switch between my desktop rig and the amp rig without having to change a bunch of cables. Waiting for another buffer board from GGG to arrive.
(just noticed the white hair on my ABY switch from Bonnie the Wonder Dog....
)
