Help Me Read This Schematic

Started by fuzzymuff, March 13, 2013, 03:49:37 PM

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fuzzymuff

Ok......I'm attempting to learn how to read schematics.  I would like to breadboard this Sola Sound Tone Bender MK1.  Q1 Collector, R3, R6, and R8 are connected directly to -9 rail of the breadboard or only the Q1 collector is?  Also, since this is a PNP circuit would I have to reverse the power connect, black battery lead as -9v and red battery lead as ground/negative?

LucifersTrip

Quote from: fuzzymuff on March 13, 2013, 03:49:37 PM
Ok......I'm attempting to learn how to read schematics.  I would like to breadboard this Sola Sound Tone Bender MK1.  Q1 Collector, R3, R6, and R8 are connected directly to -9 rail

yes 

Quote
Also, since this is a PNP circuit would I have to reverse the power connect, black battery lead as -9v and red battery lead as ground/negative?

yes, black to Q1 Collector, R3, R6, and R8, red to ground
always think outside the box

fuzzymuff


smallbearelec

#3
Be aware also that this circuit will sound poor with a "good," i.e. low-leakage, device for Q3; 2G38x sometimes don't leak enough to turn the transistor "On". Even Q2 should be somewhat leaky. You may well have suitable devices in your "remainders" bag, or someone on this forum may want to sell you some, or we can match a set for you, or you can buy a few PNP bulk devices and sort your own. The MK I works a lot like the FZ-1/1/A:

https://www.smallbearelec.com/Projects/FuzzE-One/FuzzE-One.htm

But it is powered at 9 Volts rather than 1.5. That's why the output stage has the 2.2 Meg resistor--reduces the output voltage to what will reasonably drive an amplifier. I usually do this kind of pedal as NPN/negative-ground because then it plays nice with other gear on the board, so you have choices.

Regards
SD

LucifersTrip

also, be aware that even though the MKI is very close to the FZ-1/1A, it is much, much, much more difficult to get to sound good.  probably not the one to tackle until you've build a bunch of other ge fuzzes

either way, good luck!

http://stompboxes.co.uk/forum/viewtopic.php?f=10&t=37
always think outside the box

fuzzymuff

#5
Quote from: smallbearelec on March 13, 2013, 11:37:32 PM
Be aware also that this circuit will sound poor with a "good," i.e. low-leakage, device for Q3; 2G38x sometimes don't leak enough to turn the transistor "On". Even Q2 should be somewhat leaky. You may well have suitable devices in your "remainders" bag, or someone on this forum may want to sell you some, or we can match a set for you, or you can buy a few PNP bulk devices and sort your own. The MK I works a lot like the FZ-1/1/A:

https://www.smallbearelec.com/Projects/FuzzE-One/FuzzE-One.htm

But it is powered at 9 Volts rather than 1.5. That's why the output stage has the 2.2 Meg resistor--reduces the output voltage to what will reasonably drive an amplifier. I usually do this kind of pedal as NPN/negative-ground because then it plays nice with other gear on the board, so you have choices.

Regards
SD

Hey SD,

Glad you dropped in.  I actually purchase a couple of your TB transistors, http://www.smallbearelec.com/servlet/Detail?no=12 that I will be using for this tonebender MK1.  Would that work or you have some PNP Germanium set that would work with the tonebender MK1?


UPDATE:  I found a couple of TB MK1 transistor set from your site.  I ordered one and a set for a future TB MKIII build.  Thanks JD for having those available.


fuzzymuff

Quote from: LucifersTrip on March 14, 2013, 01:35:33 AM
also, be aware that even though the MKI is very close to the FZ-1/1A, it is much, much, much more difficult to get to sound good.  probably not the one to tackle until you've build a bunch of other ge fuzzes

either way, good luck!

http://stompboxes.co.uk/forum/viewtopic.php?f=10&t=37

Thanks for that link!!  I actually breadboarded the Gary Hurst TB MK1 and it sounded great, but was a bit noiser and brighter than the MK2....  It had more of a gated effect aswell.  I was using a smallbear PNP germanium tonebender set.
http://www.smallbearelec.com/servlet/Detail?no=12

LucifersTrip

a MKII set most likely won't work well since the MKI is a totally different circuit and is very picky.   you can't even take a set that works great for an FZ-1A and expect it to work well in the MKI.

the MKI shouldn't be noisier since Q3C voltage is up near 9V and gating.  You've probably seen this before, but check it out to see him tune out the noise, AFTER he picked a good trio. As I mentioned in the other thread, you can only expect to tune it well once you're close.
http://www.youtube.com/watch?v=jkn29p1aLdI
always think outside the box

fuzzymuff

Quote from: LucifersTrip on March 14, 2013, 02:18:06 AM
a MKII set most likely won't work well since the MKI is a totally different circuit and is very picky.   you can't even take a set that works great for an FZ-1A and expect it to work well in the MKI.

the MKI shouldn't be noisier since Q3C voltage is up near 9V and gating.  You've probably seen this before, but check it out to see him tune out the noise, AFTER he picked a good trio. As I mentioned in the other thread, you can only expect to tune it well once you're close.
http://www.youtube.com/watch?v=jkn29p1aLdI

Yes, the Q3C voltage was indeed hoovering around 9v and when I compared a MK2 that I breadboarded, its Q3C was around the 4-5v range using the smallbear set of PNP transistors.   Is the Q3C voltage much lower on the MK2 Pros?

LucifersTrip

Quote from: fuzzymuff on March 14, 2013, 09:21:52 AM

Yes, the Q3C voltage was indeed hoovering around 9v and when I compared a MK2 that I breadboarded, its Q3C was around the 4-5v range using the smallbear set of PNP transistors.   Is the Q3C voltage much lower on the MK2 Pros?

not really...but it can be a wider range, usually 7.5 - 8.5V and even higher
always think outside the box