MBP Skoolie (Deluxe Memory Man)

MichaelW

Well-known member
Build Rating
5.00 star(s)
This is the first of two Skoolie builds I'm building for my amp rig.

As some you may know I'm running dual DMM delays on my desktop rig and most of the "reverb" that you hear in my demo's are really how these two wonderful analog delays work together.

I just got a new amp and I had a buffered effects loop installed and I'm basically replicating the same time based effects set up on that rig so I don't have to swap back and forth or plug and unplug a bunch of cables as inspiration hits me.

This pedal is essentially the former MadBean "Tourbus". It's a real feat of engineering to squeeze a classic Deluxe Memory Man into a 125B.
The difference with this version is that 1) it runs off standard 9vdc (instead of 18) and 2) it's standard negative ground (instead of positive ground on the Tourbus and Total Recall).

Super nice to be able to run these pedals off my pedalboard power supply and not have to worry about non-standard voltages.

It's not an inexpensive build and it's rather complicated but it's also not super hard either. Just a lot of components and you need to be careful with your soldering. Not a lot of margin for error with sloppy soldering. It needs to be precise.

I did one mod on this, which is bumping up the input impedance slightly as the original DMM's had relatively low input impedance which makes it a bit finicky where in the pedal chain it is.

Soundwise, it sounds like my Tourbus. I did the @Betty Wont standard procedure for biasing, namely setting everything at noon and firing it up!
(Yah, I know it's not recommended for this type of pedal..... :ROFLMAO: )

It needed some fine tuning but honestly, not a whole lot. It "seems" like the noise floor is a little higher on this version but I'm not 100% positive. I'd need to take my Tourbus out of the loop it's in and isolate both pedals to compare. Also, one is running with an amp the other direct into my digital interface.

I may try replacing the 4558's with TL072's (which is a recommendation in the build docs to lower the noise floor)

It's wired True Bypass and I opted to go with the toggle for the modulation instead of the "extended modulation" mod I did on my Tourbus. (I never use it).

But I'll probably wait until I get the second one finished in a couple of days (hopefully:)

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Oh and one note, if you're building either this or the Tourbus, the two 1uf film caps on the BBD board may not clear the back of the enclosure depending on the enclosure and the type of film cap. This was a Tayda enclosure and I had to slightly angle the board down towards the footswitch in order give myself the extra mm I needed to clear. (Which is why my status led looks like a big nipple :ROFLMAO: )

I may or may not go back and fix the LED but just a word of warning. On my second one I'm going to use my pricey lo profile WIMA 1uf film caps instead of the KEMETs.
 
Oh and one note, if you're building either this or the Tourbus, the two 1uf film caps on the BBD board may not clear the back of the enclosure depending on the enclosure and the type of film cap. This was a Tayda enclosure and I had to slightly angle the board down towards the footswitch in order give myself the extra mm I needed to clear. (Which is why my status led looks like a big nipple :ROFLMAO: )

I may or may not go back and fix the LED but just a word of warning. On my second one I'm going to use my pricey lo profile WIMA 1uf film caps instead of the KEMETs.

Why not CyberCow's SMD solution?

Superb build. Will you post a separate build report for the next one or post it here?



Hope I can replicate your success, and maybe even tidiness.
 
Oh and one note, if you're building either this or the Tourbus, the two 1uf film caps on the BBD board may not clear the back of the enclosure depending on the enclosure and the type of film cap. This was a Tayda enclosure and I had to slightly angle the board down towards the footswitch in order give myself the extra mm I needed to clear. (Which is why my status led looks like a big nipple :ROFLMAO: )

I may or may not go back and fix the LED but just a word of warning. On my second one I'm going to use my pricey lo profile WIMA 1uf film caps instead of the KEMETs.
I used some ceramics(had to bulk buy for some pedalpcb boards had NO room for film anyways...)

Marvelous work Mike.
 
A TL072 @ IC1 might reduce the noise floor slightly, since that is where the main amplification comes from. Honestly, I've never really bothered. But, if you are experiencing very high noise amounts then it is worth investigating. Audio probing the outputs of IC1 and the Compander are the starting points for that.
 
A TL072 @ IC1 might reduce the noise floor slightly, since that is where the main amplification comes from. Honestly, I've never really bothered. But, if you are experiencing very high noise amounts then it is worth investigating. Audio probing the outputs of IC1 and the Compander are the starting points for that.
Right on. It’s not a lot, but I’d like to get it as clean as I can. Thanks!
 
A TL072 @ IC1 might reduce the noise floor slightly, since that is where the main amplification comes from. Honestly, I've never really bothered. But, if you are experiencing very high noise amounts then it is worth investigating. Audio probing the outputs of IC1 and the Compander are the starting points for that.
That seemed to do the trick. Sorry to hijack your thread @MichaelW
 
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