Boss SD-1 questions

[Duke of Metal]

hey guys,
I noticed some people were using the Boss SD-1 to sorta thicken and tighten up their amp's sound by using it as mainly as a booster.

so I wanted to know.. does the sd-1 get its characteristics/tone from its distortion sound? or just the way the circut is built?

Also, is it possible to mod an sd-1 to work as a clean booster only without distortion/overdrive part? and how would it sound if any idea?

Any info would help!


Thanks

[Brian Marshall]

yes no and maybe.

hey duke how's it going... BTW i sold my mp1 a few months ago.

anyways...

The SD 1 is similar to a tubesreamer, with a little more gain, and not as much bass cut out of the signal.  

The way you are wording your questions makes them kind of hard to answer...

so I wanted to know.. does the sd-1 get its characteristics/tone from its distortion sound? or just the way the circut is built?

The SD1 uses what some of us here call 'soft clipping'  most opamp diode based distorters clip the output of the opamp thru the diodes to ground.  in the SD 1 the diodes are in the feedback loop.... This sounds a little different because it never allows the opamp to reach the power rails, whereas a box like the mxr distortion plus clips at the opamp and the diodes with the gain up all the way.  So yes some of its semi-unique characteristics are due to the distortion (which is also part of the circuit)

There is however more to it though... very rarely will you find a disortion box that just clips... there is usually some filtering built in to the circuit as well.  The SD1 is no exception.  Filtering is done through the input.... cuts bass a little, and probably the highs a bit too (dont have the schematic in front of me) or at least enough roll off to get rid of radio frequencies.  then there is a capacitor in the feedback loop with the diodes... this cuts some highs, or at least it cuts noise.  after the clipping stage is the tone control, and then the ouput probably has some more filtering, but its probably redudntant at that point.

----------------------------------------------------------------------------------

Anyways, my experience is that if you try to use an SD1 to overdrive your amp you have to keep the gain down.  it is too bassy if you turn it up, and bass takes over an already overdriven circuit pretty easilly.  That said, it probably would not be my first choice as a booster.

[Duke of Metal]

hey Brian,
Long time no see ..  thanks for the reply!  Too bad you sold your MP-1.. the 3TM Mod from adadepot.com makes the MP-1 one hell of a preamp.

What are you using amp wise now?

Yeah.. thats what i sorta thought about the SD-1.  I was looking for somthing to use as a clean booster to help tighten up a bit more and maybe give the sound a bit more kick.. but I would want somthing along the lines of a clean booster.  i dont want to get an OD pedal like the SD-1 and have to switch it on and off everytime i switch patches.


Thanks,
Duke

[MartyMart]

Brian is correct, the SD-1 is almost the same as a TS-9, just the symetrical/asymetrical clipping, ( overdrive ) is different.
There are much better candidates for a "boost" pedal available here, AMZ's Mosfet boost for one, though you could try reducing the input cap and using LED's instead of diodes which will give you more volume and a bit less "crunch" ?

The BD-2 makes a much better "clean boost" circuit, i've sold quite a few and thats just one nice feature, after a good "mod"  ! :wink:

Marty.

[Duke of Metal]

hey Marty,
Thanks for the reply.  see, I am sorta looking for a clean booster that I can plug infront of my rig and leave it on all the time when I am playing, even through my clean settings.  I have a reissue MXR MicroAmp, but somthing seems to be wrong about it.

When playing through my Microamp:
- it adds hum and noise to my signal, even if the dial on it is at 0
- there is a pop from the switch when I switch it on and off (not to concerned about it, but would like to get rid of it)
- no matter what setting I put it on, it seems to add a "digital" feel to the sound for some reason.  you can hear it mainly on my highgain sounds.

Maybe if I can fix those things in it, then i can put it back to use in my rig.


Thanks

[MartyMart]

No problem Duke, if you do a 'search' in the top of the page, i'm sure you can find a few simple "clean boost" projects.
otherwise fixing the micro might do it ! seymore duncan pickup booster ??

Marty.

[Duke of Metal]

No problem Duke, if you do a 'search' in the top of the page, i'm sure you can find a few simple "clean boost" projects.
otherwise fixing the micro might do it ! seymore duncan pickup booster ??

Marty.

Thanks Marty..   Problem is, I dont know what to fix in the MicroAmp. I'd like to try to fix it before moving on to somthing else.

Any ideas?


Duke

[MartyMart]

OK, well 1M ohm resistors from signal to ground on input and output should stop the "popping`", thats in the archives too and perhaps the "Digital" sound is from a "cheap" op-amp,  er I presume that its op-amp based, could be wrong  !!
You could try upgrading some parts,( replace electro caps with polyester/metal film, ceramics to silver mica )  check the pots/wiring, not sure what the "hum" is from . . . . .

Marty.

[Duke of Metal]

OK, well 1M ohm resistors from signal to ground on input and output should stop the "popping`", thats in the archives too and perhaps the "Digital" sound is from a "cheap" op-amp,  er I presume that its op-amp based, could be wrong  !!
You could try upgrading some parts,( replace electro caps with polyester/metal film, ceramics to silver mica )  check the pots/wiring, not sure what the "hum" is from . . . . .

Marty.

Hi Marty,
Thanks!  I am not concerned about the poping sound as I would turn it on, leave it on until I am finished playing/rehearsing.

Regarding the Opamp..  Can "cheap" opamps really make the sound bad and possibly add a "digital" tone/feel to the sound?

I'll look into the caps and parts replacement!


Thanks again,
Duke

[MartyMart]

The answer is yes, if you use high quality op-amps such as Texas instruments 4559p(dual) or panasonic NE5534(single)/5532 (dual) you can improve simple circuits very easily.
Its worth upgrading some caps also, give it a try !

Marty

[Brian Marshall]

hey duke, im using a peavey ranger 212 mainly... it is certainly obscure, but is more or less a fender twin with a distortion channel... I play clean, and almost clean quite a bit.

Anyways, with a high gain set up if you try to make a mosfet booster, you may want to decrease the input cap to roll off some lows, otherwise youll get mushy really fast.

[Duke of Metal]

The answer is yes, if you use high quality op-amps such as Texas instruments 4559p(dual) or panasonic NE5534(single)/5532 (dual) you can improve simple circuits very easily.
Its worth upgrading some caps also, give it a try !

Marty  

Hey Marty,
Thanks.. I'll definitly try that in my MXR and see if it helps.

hey duke, im using a peavey ranger 212 mainly... it is certainly obscure, but is more or less a fender twin with a distortion channel... I play clean, and almost clean quite a bit.

Anyways, with a high gain set up if you try to make a mosfet booster, you may want to decrease the input cap to roll off some lows, otherwise youll get mushy really fast.

Brian,
simple setups are always nice.. if it does the job and it makes you Rock and/or roll, then use it  :lol:   :wink:


take care guys,
Duke