BOSS SD1 DENIZZ mod

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
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Manfred
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Post by Manfred »

I bought a long time ago this BOSS-SD1 pedal with the so-called DENIZZ mod.
About this mod I could not find any information.
There are foil capacitors exchanged for WIMA types and some component values changed and also components omitted and replaced by jumpers.
Carbon film resistors in the signal path are replaced by metal film resistors.
Some diodes and BJTs other types.
D3 omitted and jumpered.
R31 omitted and jumpered.
D1 Zener 11V exchanged for a diode 1N4001.
The operation with AC via the voltage socket is thus changed to DC.
D6 has been replaced by a jumper thus symmetrical clipping.
C3 a capacitor with the value 47n can be connected in parallel via the so-called FAT switch.
R3: 470k -> 499k.
R6: 4k7 -> 2k2.
C5: 27n -> 10n.
C6: 10n -> 27n.
R10: 4k7 -> 3k9.
C8: 47n -> 100n
R16: 1k -> 100R.
C10: 1u -> 10u
R17: 100k -> 2k
IC1: ? ->JRC4558DD
I first made an approximate PCB clone layout and then made the changes for the mod in the copy of this.
BOSS DS-1 PCB Shot1.jpg
BOSS SD-1 Denizz Mod Schematic.bmp
BOSS SD-1 Denizz Mod Schematic.bmp (2.23 MiB) Viewed 800 times
BOSS SD-1 PCB-Layout.JPG
Ready-to-print files:
BOSS SD-1 Component Side.pdf
(42.13 KiB) Downloaded 86 times
BOSS SD-1 Solder Side.pdf
(30.25 KiB) Downloaded 70 times
Sprint Layout6.0 Layout:
BOSS-SD1 layout.zip
(58.2 KiB) Downloaded 56 times
BOSS SD-1 Mod PCB-Layout.JPG
Ready-to-print files:
BOSS SD-1 Mod Component Side.pdf
(40.67 KiB) Downloaded 78 times
BOSS SD-1 Mod Solder Side.pdf
(30.24 KiB) Downloaded 72 times
Sprint Layout6.0 Layout:
BOSS-SD1 Denizz Mod Layout.zip
(56.33 KiB) Downloaded 42 times

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CheapPedalCollector
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Post by CheapPedalCollector »

Some interesting choices there, some are puzzling like the diode in the power supply. Would love to hear some comparisons, as it will have more compression than a stock one and maybe some more bass with the gain section mod. Does it oscillate at all with the gain increase, I tend not to use the pedal for it's dirt but more as a boost.

Are the WIMA's polystyrene or polypropylene?

Love your board replacements as always, they are tops.

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Manfred
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Post by Manfred »

CheapPedalCollector wrote: 15 Sep 2022, 02:15 Some interesting choices there, some are puzzling like the diode in the power supply. Would love to hear some comparisons, as it will have more compression than a stock one and maybe some more bass with the gain section mod. Does it oscillate at all with the gain increase, I tend not to use the pedal for it's dirt but more as a boost.

Are the WIMA's polystyrene or polypropylene?
I do not own an original BOSS SD-1, so I can not make a comparison.
Regarding the oscillation I can also not say anything yet, I had bought it defective, now repaired, but it is still disassembled and am just making changes.
I rebuilt D6 and bridge them with a second switch to switch between symmetric and asymertic clipping.
Now I just install the three component bypass mod.
The WIMAs are MKS4 types.
SD-1 Bypass Mod.bmp
SD-1 Bypass Mod.bmp (609.43 KiB) Viewed 735 times

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Manfred
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Post by Manfred »

I added to the existing mod a switch for symmetric / unsymmetric clipping and the bypass problem fix mod.
Also I changed the condesator values and their circuit for the FAT switching.
To the input I added a resistor of 1.2 Megohms and a capacitorof 220 Picofarads in parallel.
Without this componets, an open cable connected to the input without a guitar acted as an antenna, all interfering signals from the environment were captured.
All modified components and circuit details are marked in yellow in the schematic.
To my ear, the modded pedal sounds pretty good.
BOSS SD-1 MOD colored Schematic.bmp
BOSS SD-1 MOD colored Schematic.bmp (2.23 MiB) Viewed 571 times
BOSS SD-1 MOD Layout.JPG
BOSS DS-1 PCB MOD Shot.jpg
BOSS DS-1 Mod Fat Switch.jpg
BOSS DS-1 Mod PCB Bypass Fix.jpg

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