Debugging the Sparkle Boost

Dragonfly · February 07, 2005, 01:50:02 AM

Quote from: analog kidOH YEAH , Loud LOUD LOOUUUDDDD
still tell me though if anytyhing looks funny And if you could give me some ideas and sample settings for what you have used and heard this pedal used for. I have never used or heard a booster til now. IF it ONLY boosts volume and that's ALL , I can't think of too many uses and benefits besides just setting it for a tad more gain and kicking it down for solos but most people use their overdrive boxes for that I think. I guess that would free up the overdrive for just your Gain and you could still get an extra boost on top of that.
But anyway I don't know about them , Some ideas are appreciated.

congrats on the successful "debug"

...im guessing you learned more from debugging your build than you would have if it worked right away...its a pain, but learning is always a good thing.

uses for a booster....

*add versatility to an amp by pushing it "over the top"
*solos
*makeup gain after your fx chain
*use before your fuzz pedals to really make em nasty (a good nasty )

*use after your fuzz pedals to help give em some balls
*get more harmonically rich tone, by making the amps tubes work harder
*the right booster can add definition to a muddy sounding amp

thats a few uses off the top of my head...as you get more and more into fx, you'll start to appreciate how great...and useful...a good boost pedal really is !

so far ive had great results by using the sparkle boost to push a JMP and my Egnater, and have had "reports" of it really matching up nicely with Fender HR deluxe's and Deluxe reissues...it really brings out the best of what these amps are capable of.

enjoy !

andy

Dragonfly · February 07, 2005, 01:53:20 AM

Quote from: analog kidI have never used or heard a booster til now.

btw...play with the booster "on" for a while, then turn it off and let your ears "hear" all the things a good boost pedal can add ! many people keep their boost pedals "on" all the time, because of the richness they add....

RAWK !

andy
dragonfly fx

lethargytartare · February 07, 2005, 02:07:31 AM

Wow. That's all I can say! The thing has some serious power, and it just adds a sharpness to the tone...blew my guitarists away. I've gotta box this one up and make another one for the other guitarist...he's also using a ZVex Super Hardon, and I think this is gonna go right alongside it -- no small compliment there!!

Great work -- THANKS for the plan!!

ltt

Quote from: Dragonfly...

how'd you like the Sparkle Boost once you debugged it?

analog kid · February 07, 2005, 02:20:04 AM

anothe question , i am using a 10k audio ithink for my gain. I may try to change it to around 4.7 with a 10k resistor ,but should the Gain pot cut the volume OFF totally when down all the way OR should it just add and take away SOME of the volume?? what "does" it give the circuit?
Oh, and a Blues Deluxe TWEED is what I play through with the old bassman type circuitry NOT the HR and others with the 3 channels.it's a killer vintage sounding amp so I think this may really make it even brighter and richer. But what about BRINGING ON EXTRA NOISE??

Dragonfly · February 07, 2005, 08:14:41 AM

Quote from: lethargytartareWow. That's all I can say! The thing has some serious power, and it just adds a sharpness to the tone...blew my guitarists away. I've gotta box this one up and make another one for the other guitarist...he's also using a ZVex Super Hardon, and I think this is gonna go right alongside it -- no small compliment there!!

Great work -- THANKS for the plan!!

ltt

Quote from: Dragonfly...

how'd you like the Sparkle Boost once you debugged it?

cool...glad its workin' out for ya...im really happy with the circuit !

Dragonfly · February 07, 2005, 08:18:14 AM

Quote from: analog kidanothe question , i am using a 10k audio ithink for my gain. I may try to change it to around 4.7 with a 10k resistor ,but should the Gain pot cut the volume OFF totally when down all the way OR should it just add and take away SOME of the volume?? what "does" it give the circuit?
Oh, and a Blues Deluxe TWEED is what I play through with the old bassman type circuitry NOT the HR and others with the 3 channels.it's a killer vintage sounding amp so I think this may really make it even brighter and richer. But what about BRINGING ON EXTRA NOISE??

the gain pot "shouldn't" cut the volume off...you should be able to turn the gain 100% down, and still have TONS of clean boost available using the volume pot. if the gain pot is cutting the volume completely, then theres still some debugging to do....

as far as "bringing" extra noise...this cicuit is EXTREMELY quiet...BUT...like ALL boosters, it WILL amplofy the noise thats already there....

andy

GreenEye · February 07, 2005, 11:26:01 AM

Quote from: analog kidOH YEAH , Loud LOUD LOOUUUDDDD
still tell me though if anytyhing looks funny And if you could give me some ideas and sample settings for what you have used and heard this pedal used for. I have never used or heard a booster til now. IF it ONLY boosts volume and that's ALL , I can't think of too many uses and benefits besides just setting it for a tad more gain and kicking it down for solos but most people use their overdrive boxes for that I think. I guess that would free up the overdrive for just your Gain and you could still get an extra boost on top of that.
But anyway I don't know about them , Some ideas are appreciated.

As I've been preaching, clipping diodes at the end of this circuit work great for adding more distortion for bluesy solos, and even some riffage (say, with 2 silicon diodes). However, the boost by itself does add some overdrive when played through my favorite tube amp. I'm going to post some sound clips of my amp alone, with the booster as it was designed, and with 2 different clipping diodes. Make sure you run a a ground line from your gain pot - I forgot at first, and the volume still works, but not the gain, making it seem the gain may be there, but very subtle.

analog kid · February 07, 2005, 03:06:02 PM

again, I do have this thing going pretty good but I'm still not sure abou the Gain pot. ??
Is it supposed to only boost the Volume/Gain at the last 20% of rotation. ?? it stays at the volume set by the volume pot for the first 80% of the turn then at the very end it will boost it up a good bit.
Is that right? I have a 10k pot on there( audio I think) and I've tried it with a resistor to bring it down to 5k and it is the same. I've also tried two different pots in case one was bad.

RjM · February 07, 2005, 08:05:42 PM

Alright. I went around the Sparkleboost circuit and measured the resistors. It's strange... where the 1M is, I didn't have a 1M, so I subbed a 2.4M for it, but its resistance reads at 1M! I found a problem I think, I have two 47K resistors in series for the 100K resistor. I measured resistance, and each one measured about 37K. When I measured both of them at the same time, the total resistance measured at 47K. Should I put 4 of these resistors in series, or should I put them in parallel?

Dragonfly · February 07, 2005, 08:26:55 PM

Quote from: analog kidagain, I do have this thing going pretty good but I'm still not sure abou the Gain pot. ??
Is it supposed to only boost the Volume/Gain at the last 20% of rotation. ?? it stays at the volume set by the volume pot for the first 80% of the turn then at the very end it will boost it up a good bit.
Is that right? I have a 10k pot on there( audio I think) and I've tried it with a resistor to bring it down to 5k and it is the same. I've also tried two different pots in case one was bad.

earlier in this thread, or maybe another sparkle boost thread, i suggested using a 2-3k resistor from lug 2/1 of the gain pot to ground....as it sits, the 5k pot stays clean for quite a bit of its rotation, and this small mod should help "even out" the gain pot....

andy

Dragonfly · February 07, 2005, 08:27:39 PM

Quote from: GreenEye
Quote from: analog kidOH YEAH , Loud LOUD LOOUUUDDDD
still tell me though if anytyhing looks funny And if you could give me some ideas and sample settings for what you have used and heard this pedal used for. I have never used or heard a booster til now. IF it ONLY boosts volume and that's ALL , I can't think of too many uses and benefits besides just setting it for a tad more gain and kicking it down for solos but most people use their overdrive boxes for that I think. I guess that would free up the overdrive for just your Gain and you could still get an extra boost on top of that.
But anyway I don't know about them , Some ideas are appreciated.

As I've been preaching, clipping diodes at the end of this circuit work great for adding more distortion for bluesy solos, and even some riffage (say, with 2 silicon diodes). However, the boost by itself does add some overdrive when played through my favorite tube amp. I'm going to post some sound clips of my amp alone, with the booster as it was designed, and with 2 different clipping diodes. Make sure you run a a ground line from your gain pot - I forgot at first, and the volume still works, but not the gain, making it seem the gain may be there, but very subtle.

im looking forward to your clips !

Dragonfly · February 07, 2005, 08:31:04 PM

Quote from: RjMAlright. I went around the Sparkleboost circuit and measured the resistors. It's strange... where the 1M is, I didn't have a 1M, so I subbed a 2.4M for it, but its resistance reads at 1M!

thats very odd...

Quote from: RjM
I found a problem I think, I have two 47K resistors in series for the 100K resistor. I measured resistance, and each one measured about 37K. When I measured both of them at the same time, the total resistance measured at 47K. Should I put 4 of these resistors in series, or should I put them in parallel?

your only getting a 47k resistance from two 47k's in series

? very strange...something is VERY weird about that....

me, personally...id go to the Rat Shack and get a couple 100k resistors for $1 and call it done....

im not sure why youre getting the strange readings...

andy

RjM · February 07, 2005, 08:55:09 PM

The local radio shack didn't have any 100k resistors. Anyways, I put three 47K resistors in series, and my transistor voltages are at least normal again!

Q1
D-4.78
G-0.08
S-2.10

Now I'm going to fire it up and see how it sounds. Hopefully, there aren't any more problems....

analog kid · February 07, 2005, 09:09:13 PM

to RjM: just a dumb question maybe but are you by chance taking those resistor measurements WITH power to the circuit?? I just noticed the 2.4M reading you said you were taking and I remember that when I tried to check my 2.2M resistor with power on I got something just under 1M instead . Probably because of the .022 cap >>

If so that might be why you're getting a strange reading from you in series resistor too.

dragonfly: youre throwing me a little bit again. But just to clear it up You are saying to put a 2k resistor between lugs 1 and 2 (bridging the two signal wires coming off the pot) And then are you saying to run a ground off of lug 1 as well?? I have my pot ground coming off of lug 3 on the volume pot , since the output is going to 1.
am I getting all this right?

analog kid · February 07, 2005, 09:21:14 PM

sorry , another questoin;
WHERE would those diodes (1 or 2) ? Go??
I have some germaniums 1 N34A's And some (silcon I guess) 1N4001's 1A 50V T+R Fairchild rectifiers which one of these would work best ?

petemoore · February 07, 2005, 09:36:20 PM

Quote from: RjMAlright. I went around the Sparkleboost circuit and measured the resistors. It's strange... where the 1M is, I didn't have a 1M, so I subbed a 2.4M for it, but its resistance reads at 1M! I found a problem I think, I have two 47K resistors in series for the 100K resistor. I measured resistance, and each one measured about 37K. When I measured both of them at the same time, the total resistance measured at 47K. Should I put 4 of these resistors in series, or should I put them in parallel?

.
>>>That's not really a 'problem'. that 100k parallels the 100k output pot, will change the amount of output and impedance a little, a 100k pot I think would work there, 50k 'l get a little less output, and less resistance from SP to ground. Basically a wide target area there, anything between 40k and 100k 'll 'work'...probly has enough boost you don't need a 100k there, it'd just get turned down and might produce a noticable slight rolloff highs as it does so more than a 50k would.

Dragonfly · February 07, 2005, 09:44:54 PM

Quote from: analog kid

dragonfly: youre throwing me a little bit again. But just to clear it up You are saying to put a 2k resistor between lugs 1 and 2 (bridging the two signal wires coming off the pot) And then are you saying to run a ground off of lug 1 as well?? I have my pot ground coming off of lug 3 on the volume pot , since the output is going to 1.
am I getting all this right?

normally....

gain pot: lug 3 goes to the 10uf cap
lug 2 and 1 go to ground

modded.....

gain pot: lug 3 goes to 10uf cap
lug 2 and 1 connect together, and to a 2-3k resistor to ground.

so.....

lug 3---------------------------------------------->10uf cap

lug 2-------------\
--------------------- I------ [2-3k resistor]------->ground
lug 1-------------/

hope this explains it ok...
andy

analog kid · February 07, 2005, 11:18:04 PM

Ok just to be sure lugs one and two have the wire from crkt ground coming to them. Then only ONE end of the 2k resistor is connected to EITHER lug 1 or lug 2 . And the other end of the resistor has a wire from it running to ground Again? It sounds like those two lugs are getting double grounded only that one way it's with a resistor in series. ?/ /? Anway this is theway I have it wired now and far as I can tell when the gain pot is turned the volume and signal remains unchanged for about the first 7/8ths of rotation and then in the last 8th turn there is a few db boost to the volume. IS THIS RIGHT??? I just keep thinking it can't be cause if that's all the gain pot's for than what purpose is there for it when you could just turn the volume another notch or so instead.
confused about that....
STILL want to know about those diodes too..

Dragonfly · February 08, 2005, 12:13:48 AM

Quote from: analog kidOk just to be sure lugs one and two have the wire from crkt ground coming to them. Then only ONE end of the 2k resistor is connected to EITHER lug 1 or lug 2 . And the other end of the resistor has a wire from it running to ground Again? It sounds like those two lugs are getting double grounded only that one way it's with a resistor in series. ?/ /? Anway this is theway I have it wired now and far as I can tell when the gain pot is turned the volume and signal remains unchanged for about the first 7/8ths of rotation and then in the last 8th turn there is a few db boost to the volume. IS THIS RIGHT??? I just keep thinking it can't be cause if that's all the gain pot's for than what purpose is there for it when you could just turn the volume another notch or so instead.
confused about that....
STILL want to know about those diodes too..

you should be getting more from the gain knob...it should be able to take the boost into a "light overdrive" mode....like i said earlier, it still seems like your circuit is not 100% correct...

anyway, heres a diagram of the gain pot/resistor mod....

analog kid · February 08, 2005, 12:38:47 AM

Maybe it is giving it a tad more drive but It's not that noticeable if so , and I'm sorry to have you go to so much bother for this problem.
Well that's the way I have it(referring to the diagram) and the only thing I haven't had totally verified by myself and you all is the transistor readings so here goes again D 4.82 G 000.1 (low as it gets) S 0.467
it's a 2N5457 tranny

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Debugging the Sparkle Boost