sd-1 to zw-44?

[LoKi6922]

anyone do this? and what does it involve?

i've been wanting to make a new pedal out of my sd-1 for a long time, but cant' decide where to go with it...

i'm thinking i'd try to mod it to be closer to the zw-44 in bass response, but a little bit like an 808 as far as clarity.

i've seen tons of sd-1 to 808 mods, but how does the sd-1 to zw-44 work?

[Melanhead]

hmmmm ... I was going to do it a while back but never got around to it ... ended up buying the one that CD modded instead ...

The easiest way to do it is to look at the schematic for both and change what needs to be changed ... There's a few topics about it here as well if you do a search ...

I've since bought 2 SD-1's and modded one to be close to an 808 and the other just better, fatter sound SD-1 ... ( these pedals are so cheap to buy! )

I can post the mods if you like ... I have 'em written down at home ...

[cd]

Change the tone caps to .047u (47nF).  The tone caps are the two caps connected to the tone control.  That's all you have to do unless you want to rip the pedal apart and install a relay and a new transistor buffer.

[Melanhead]

sounds like you've does this before ... I mean the ripping the thing apart and putting in a relay etc ...

I still haven't tried it next to a ZW44, actually I only tried it when I first got it ... sounded cool! ... haven't used it since ... I have 10 o.d/dist pedals, mostly all bought for experimental modding ... maybe it's time to get rid of a few

[LoKi6922]

so basically you get a little more bass response? i thought the zw44 had more gain as well...

maybe i'll go through and do the mods from fuzz central instead... or do the 808 thing... that looks even easier than the rest.

[cd]

so basically you get a little more bass response? i thought the zw44 had more gain as well...

maybe i'll go through and do the mods from fuzz central instead... or do the 808 thing... that looks even easier than the rest.

Nope.  It has the same 1M pot as an SD-1 (same gain), same bass response in the clipper (4k7/.047u on - input).  Mind you I'm just going by the ZW-44 schematic that's going around (and no, I won't give it to you, use the search function, it's been posted 10x before) which I have no reason to believe is fake.  What you get with the tone cap changes is less highs and a slightly altered tone control range, that's all.  Really if you want that sound, you don't have to do any mods at all - just take your stock SD-1 setting, then turn the tone control down a 1/4 turn or so.  That thumping low end you hear is courtesy of a cranked up Marshall, not a modded pedal

[LoKi6922]

thats how i use my sd-1 anyway... the tone is down at around 10o'clock.

i have schematics for the zw-44 and a stock sd-1 and a modified one that i got from fuzz central. it has new opamp, and tone caps, and a couple different resistors... maybe 1 or 2 different diodes.

i also found this while surfing the net..




dunno how valid it is.

i recently bought a barber direct drive... and will probably use it more often than my sd-1 unless i can get some kickin' sounds out of the old yellow box... :lol:

[Melanhead]

that'll get you in the ball park of an 808 anyways ... There's some other differences it just depends on how much you want to change ...

I made mine fairly close to my 808, but my 808 has been modded as well ...

also you may wanna replace R9 with a 1K if you remove C6 ... It'll have less gain and be less harsh sounding ....

[cd]

Technically, there's 20+ part changes to make an SD-1 into an 808, not just three.  The symmetrical clipping is the most glaring omission.

[Melanhead]

Technically, there's 20+ part changes to make an SD-1 into an 808, not just three.  The symmetrical clipping is the most glaring omission.

Doesn't it say "remove d6 and jumper" ... in step 5.

Yup! there are a lot of changes! ... I did about 12 ( can't remember! )and got "close enough" for me anyways!

[cd]

Technically, there's 20+ part changes to make an SD-1 into an 808, not just three.  The symmetrical clipping is the most glaring omission.

Doesn't it say "remove d6 and jumper" ... in step 5.

Yup! there are a lot of changes! ... I did about 12 and got "close enough" for me anyways!

Whoops you're right  Saw the parts and didn't read the instructions.  Anyway, of the 20+ maybe 7 or 8 really need to be done.  Most don't have an affect on the frequency response.

[Melanhead]

Yup ... that's what I found ... It's a matter of figuring out which parts actually make a difference ... I've probably changed more still than I needed to but hey that's part of the fun

Even changed the op-amp to a JRC4558D instead of the DD but from what I've read, there's not much difference tonally.

[LoKi6922]

i do'nt want the overwhelming mids of the 808 or even the sd-1... but i wanted more of a bass response like the zw-44 and the clarity of the 808....

hmm..

looks like i'm going to have to spend a few bucks and play around.

keeley's 5star GE mod sounds great on his site.. but it looks to be similar to the mods schem i got from fuzz central... from the F.C. schem. it says to replace D6 with a 1N34A.... the rest of the cap changes look to be the same.. and the brown burr opamp...

i wish i had all these parts on hand to do a side by side comparison.

[cd]

Sounds to me like you don't want a Tubescreamer/SD-1 type sound at all.  The common "increase bass" mod is to increase the value of the cap at the - input of the clipping section (WITHOUT changing the resistor).  This just applies the gain of the clipping section to more bass frequencies - which means the bass gets clipped, it doesn't stay clean.  Which to my ears sound like mud and fuzz, not a good or even typical TS sound.  

Personally when I had my SD-1 modded to ZW-44 (went all the way, changed input buffer and everything) because there were less highs, I turned up the volume to compensate, which meant I was hearing the bass more.

[LoKi6922]

normally i use my sd-1 to push my dirty 800 a little more. i keep the gain down and the level cranked... just a boost pretty much.

when i use the low input channel, i use a ds-1 or hm-2 for the dirty stuff and the sd-1 for the bluesy crunchy stuff...

i'd like it to be better at doing both, essentially. so more level, tighter bass response, and slightly more gain.

the pedal sounds great when used with active pickups, like emg 81's.. but with my 70's les paul custom, its too middy.. also has to do with the maple cap on that thing i guess..

maybe i'll just build a clean boost to push my preamp a little harder. i just know there is vast potential in that little yellow monster... i'd hate to see it get thrown on the shelf with my other unused pedals.

[LoKi6922]

i must say the barber sounds GREAT. a little middy... high endy... but as a boost, with little to no gain, it sounds awesome. VERY powerful compared to the sd-1. expensive compared to the sd-1 as well...

[rama claproth]

If you have an SD1 boss pedal, you can convert it into MXR ZW44 specs!

1. Remove one leg of the resistor 33K (R5) that goes with 4K7 (R6) and connect to the diode's leg (D1) that goes to pin 7 at the opamp chip. Remove yellow wire # 4 at the PCB and also remove red wire # 2. Connect yellow wire at # 2, # 4 stays EMPTY. Connect red wire to where the 33K resistor's leg USED to stay that connects with the resistor 4K7 at R6, now this automatically goes to the opamp at pin 6.

2. Replace C4 with a 0.047uF capacitor.

3. Replace C5 with a 0.047uF capacitor.

4. Replace R3 with a 22K resistor.

5. Replace C7 with a 3.3uF capacitor.

6. Remove Q6, R15, R16, R17, and C10. These NO NEED jumpers. The white wire # 12 at the PCB must be removed and has to be connected into the hole where the base pin of Q6 used to stay.

7. Remove brown wire # 1 at the PCB and connect into ground.

8. Change Q5 with MPSA14 transistor. This is OPTIONAL.

DONE!