Loud then quiet...Bazz Fuss help

[Jango]

I'm revisiting my first build(got frustrated and put it away for a while) and I'm glad to say I've made progress.  I get sound now, finally.  However, I only get a distorted sound when I strum harder than normal, and even then the sound decays away really quickly.  I've stuck to the correct perfboard layout, but I don't know what's wrong now.  On the schematic site it mentions using a darlington transistor, and I have an extra transistor of the same type laying around.  Would this help my sustain?

[teethofthelions]

Sounds like the circuit is starving. As if your instrument is strummed hard its able to apply enough voltage to activate the base/gate but then starves out. Is the pinout correct? What type of transistor are you using? Part#?

[Jango]

I'm using a 2N5088 from Small Bear: http://www.smallbearelec.com/Detail.bok?no=292
I would like to mention that I'm using a 1Spot 9v power adaptor, but it's never given me problems in powering multiple pedals at one, and I'm using this directly.

Would reducing the 100k resistor's value do anything?

[Mugshot]

I'm using a 2N5088 from Small Bear: http://www.smallbearelec.com/Detail.bok?no=292
I would like to mention that I'm using a 1Spot 9v power adaptor, but it's never given me problems in powering multiple pedals at one, and I'm using this directly.

Would reducing the 100k resistor's value do anything?

i built one using a 2n5088 and the collector resistor needs to be increased, like a 100K or 150K to make it work, but it still decays quick.

to make the notes sustain,i suggest build one using high gain darlingtons and a 10K collector resistor instead. 

[Jango]

Can I wire up a homemade darlington like the diagram on the Bazz Fuss page shows?  And (complete noob question) is the 100k resistor the collector resistor?  Or are you talking about adding another resistor somewhere else?  THanks for the help.

[Jango]

Bump?

[.Mike]

Can I wire up a homemade darlington like the diagram on the Bazz Fuss page shows?

Yes.

And (complete noob question) is the 100k resistor the collector resistor?  Or are you talking about adding another resistor somewhere else?  THanks for the help.

Yes again. If you are looking at the top schematic (labeled v1) on this page, the 100k resistor connected to the collector of the transistor is the collector resistor. If you look at the second schematic (labeled v2), the 10k resistor is the collector resistor.

I hope that helps.

Mike

[jessej]

do you have the diode in reverse?

[Jango]

What kind of markings would the 10k resistor have?  Brown Black Black? 

Also, Mugshot mentioned both raising and lowering the collector resistor.  Now, I've already wired up the darlington, so should I lower it to 10k?  or should I still raise it to 150k?

[Scruffie]

Can't help with the other question but this may be of future use http://www.dannyg.com/examples/res2/resistor.htm

You want Brown Black Orange

[bobp1339]

If you are using a darlington,  use the 10k resistor. That's what I used and it sounds pretty good.

[Jango]

Thanks Scruffie!  That site'll help a lot.  I'll have to try out the different resistors tomorrow, though.  I'll update when I get the chance.

I'd also like to give a HUGE gracias to all the guy's who've helped me so far.  Really, it's helped me a lot.

[Jango]

What transistor should I use for the Darlington?  Im going to radioshack today and wanna know what to get.

[SirBlend12]

This thing, if built by Hemmo's schem, naturally has a very short decay, as it is not self biased (or otherwise), other than the diode. Nonetheless, that hardly could count as biasing. I've found 2 good ways to get long sustain (I love this pedal like nobody's business... excellent fuzz):

1. Use 10K from V+ to Collector, and then 100K to 1M (low, I know, but I like the "crazy" sound) from Collector to base. Another good way is to use a pot instead of a fixed resistor (off of the 10K Collector) so you can mess with your bias settings.

2. Build a switchable boost circuit in front of the fuzz circuit. Different boosters do TONS of really cool and really different things to this fuzz!

As for your Darlington question, 2 2N3904s or 5088s would work well. Also, if you are going to RadioShack, I'm pretty sure they have MPSA13s that you can get. If not, check the little semicon drawer for some Darlingtons. I'm pretty sure they have at least something.

[jessej]

I've liked results with a BC517 Darligton and using either a AA119 germ diode, a 1N4148 diode or just a plain old red LED, but it's really a lot depending on the sound you like and the kind of guitar or bass you are using.

SirBlend12, I'm looking forward trying out what you suggested in 1...

Boosters sound interesting with the bass fuzz , very true! 

It's a fun pedal to try things with and a great learning experience!

[Jango]

Blend, could you elaborate on the boosters?  What type of booster does what, etc. etc.

Also, the 10k helps the sustain a lot, although i'm going to mess around with the transistors to see what I get.

[Jango]

This is a kinda side question:  What would happen if I raised/lowered the value of the input cap?  the output cap?  Could I get away without a pot if I wire a 100k resistor into the circuit where the volume would be?

Also, sorta unrelated to the Bazz Fuss; I got my perfboard off of Small Bear, and on one side it seems like the outer and some inner ones are all connected by some solder.  However, i'm not sure.  I tried to put the ground on the line but it didn't seem to work.  Are they connected?  And is that the side all the components should be soldered to, or the other side?  Again, thanks for all the help everybody.

[mac]

guys,
i posted this long ago, but since yahoo-geocities is dead now schem is gone.
the BF collector resistor depends on transistor gain a lot. note the difference between a single and a darlington.
this is because the diode has to bias and distort at the same time.
when i was messing with arsenio novo old design i realized that there are similarities and i added a resistor in the order of mega ohms between base and vcc.
when you add this resistor you get a nice synthetic fuzz ONLY when the voltage between vcc and base is almost equal to the voltage between vcc and collector, ie voltage across the diode is almost zero.
in this case you can estimate the collector resistor if you know gain and the vcc to base resistor.

vcc-vbase=ib*rb
vcc-vcollector=ic*rc=hfe*ib*rc
since the collector has to be close to the base then
ib*rb=hfe*ib*rc
that is,

rb=hfe*rb

that simple. you note that this condition is independent of the diode and vcc, so you add a tirmmer at collector and fine tune.
enjoy.

mac