built mini booster...is that all there is?

[Dragonfly]

Ok, tried it on my amp. Much better with the NTE. I no longer need more mids ! However the low end is too much and kinda fuzzy. i think it may be that the fuzziness is part and parcel of the excessive lows and that attenuating them may do the trick.

So i'll try Eric's suggestion and replace the .022 with an .001. Other than that i'm hearing some good stuff.....maybe a touch of that "magic" after all. We shall see...

glad youre liking it better....the NTE is a REALLY nice fet....and like you mentioned, its quite a bit better (imo) than the mpf102 in this circuit.

changing the .022 shouldnt make a difference in the tone, unfortunately...at least according to people more knowledgable than "i" ...

however...DEFINITELY let me know how the cap change goes, and whether it does change the low end...

[oczad]

Hmm....one of my favorite builds that i've been using for years is the rat. Not sure what the fet does  in this circuit, but i used a mpf102. Anyone know if in the context of a rat circuit changing to the NTE would make any difference? I love the rat, but theres always room for improvment.

[oczad]

Oh, and to reduce low end on the SB, what about a cap in series with the output to the volume control? Maybe something in the PF range?

[Dragonfly]

Hmm....one of my favorite builds that i've been using for years is the rat. Not sure what the fet does  in this circuit, but i used a mpf102. Anyone know if in the context of a rat circuit changing to the NTE would make any difference? I love the rat, but theres always room for improvment.

im not real familiar with the rat circuit...what does the fet "do" in that particular circuit ?  the NTE puts out TONS more signal than the mpf102, so depending on the fet's purpose in the rat, that could be a very good, or a very bad, thing....   :twisted:

MUSCLE RAT !!![/size][/b]

[javacody]

For less bass, tweak the 10uF cap on the source of the FET. This effects which frequencies get amplified. Try a 0.1uF cap here and see if you like it.

Also, the FETs on the rat probably act as buffers or are for switching, but I'd wait until someone more knowledgable in this area pops in.

Last but not least, I wonder how much signal that tone control will eat up? Maybe two of these boosters in series with the tone control between them?  

[petemoore]

http://www.diystompboxes.com/pedals/PCRAT1.GIF
 In this case the signal passes from Gate to source, no gain stage here, changing that Q may or may not change the sound [not as much as if you were looking for alot of gain and A/Bing 102's and 458's], or change it to where yould like it better.

[Alpha579]

damn, i gotta get me some nte's, sounds like there working some kinda magic here...and yeh, decreasing the source bypass cap would cut lows sufficiently...

[Dragonfly]

For less bass, tweak the 10uF cap on the source of the FET. This effects which frequencies get amplified. Try a 0.1uF cap here and see if you like it.

that makes a ton of sense...realize, however, that as you decrease the cap size on the gain control, the less "grind" you will perceive, due to limiting the frequencies that are distorting...

Last but not least, I wonder how much signal that tone control will eat up? Maybe two of these boosters in series with the tone control between them?  

in its stock form, this booster has a TON of gain, so it "should" be able to handle a simple tone circuit tacked on the end....

[Dragonfly]

damn, i gotta get me some nte's, sounds like there working some kinda magic here...and yeh, decreasing the source bypass cap would cut lows sufficiently...

theyre definitely "hotter" than the J201's...i prefer the tone of them as well, though the 201's are nice...

[oczad]

http://www.diystompboxes.com/pedals/PCRAT1.GIF]
 In this case the signal passes from Gate to source, no gain stage here, changing that Q may or may not change the sound [not as much as if you were looking for alot of gain and A/Bing 102's and 458's], or change it to where yould like it better.

That link is bad, tho you can get to it by cutting everything after "gif". Anyway, that schematic isn't the right one. there are a ton of them floating around that have 2 fets, but the original rats only have one. The one at the input in that schematic isn't there on a early rat.It may be a turbo rat or one of the incorrect schematics.In any case, mine just has the one at the output side.

[oczad]

Oh, and even the rest of the schematic is different including the circuit where the output fet is. Theres a diode there in mine.(Not talking about the clipping diodes upstream)  Mine is much different. I copied it from an old rat someone let me borrow.

[Alpha579]

...and yeh, decreasing the source bypass cap would cut lows sufficiently...

hmmm, quoting myself...

rethinking that, if you lower the bypass cap you will boost more highs than lows, but as you decrease gain the eq differences will flatten out, which could sound great, a mid boost for a bit of overdrive for a ts flavour and nice flat eq for transparent boosts....

[Dragonfly]

...and yeh, decreasing the source bypass cap would cut lows sufficiently...

hmmm, quoting myself...

rethinking that, if you lower the bypass cap you will boost more highs than lows, but as you decrease gain the eq differences will flatten out, which could sound great, a mid boost for a bit of overdrive for a ts flavour and nice flat eq for transparent boosts....

might be worth trying something between a 1uf and a 2.2uf cap instead of the "full range" 10uf ....

[oczad]

well i tried a 2.2 with no real difference. So i'm not gonna bother with trying smaller.

[javacody]

The difference would be subtle. I would go for a much smaller value.

[WGTP]

Don't forget there are J202's that are hotter than the J201's.

[oczad]

Tried the smallest i had on hand, and .33 and still no cigar. I'm starting to realize this circuit is just not for me. Don't get me wrong...it's nice. In fact i'll go as far as to say it's the best clean boost i ever tried in a certain way. That being the grindy attack that i love. I tried it in different ways such as a boost to go over the edge gainwise when my amp is set for medium gain. Then i tried turning the gain down lower than i'd ever want it and using the pedal not as a solo boost, but as an always on boost to bring the gain back up to my normal level. It really does add a bit of that magic i was after. I'll keep messing with it.

But the overall inherent character of this pedal is just not what i need for my purpose. It has a certain midrange quality that doesn't work right for me as a gain boost for solos, which was what i was after. It's great, but sounds sorta specialized instead of being versitile. Sounds to my ear like a great boost for gritty blues, but not tight enough for me in other contexts. Also the low end isn't tight enough for me. The overall tone is it's own thing, and for some things it's really happening. just not for my main purpose. But i do like it for certain things and i'll contine to use it.......but just at home, not for gigs.

I think you said it best dragonfly....it has a lot of potential. If you're serious about marketing it, i'd start messing with it to try and get the sound a bit tighter. Then find a way to give it a bit of those tube screamer mids and make that switchable. I think it's a very good pedal, but do those 2 things and i think you'd have one hell of a good pedal.

[RDV]

No offense intended, but I hate all that TubeScreamer mid stuff. I could see it being very useful with a Fender style amp cause they lack mids in the first place, but with a Marshall it's just too much. I've got a terrific sounding Boss Super Overdrive that's been converted to TS-808 specs(save for the clipping which I left the way it was), but unless I ever get a Fender style amp, that sucker will stay in a drawer and off my pedalboard.

RDV

[RedHouse]

I threw that sparkle boost together on my proto-board a couple days ago, couldn't get it to work. Tried J201, 2N5457, MPF102 got nada but a big thump when switching on the power.
(yes I biased to 4.5v and had the pinouts correct)

Maybe the proto-board has some substancial effect on the circuit, I may try it on perf-board.

[mat]

Hi  Andy, Torchy

Still havent solved the problem  

the pins of the j201 are ok.

the two drilled cuts are ok.

the soldering should be ok.

the wiring should be ok.

the j201 (tried several) should be ok. (anyone else bullt this with j201?)

hmm.. my skills ends here    maybe i'll start to swap one component after another to see if i can find the faulty one  :?

Three images of the patient. Any further recommendations doctors(s) ?  :shock:  :lol:  


 

 

 

thanks,
mat