Boss slow gear not wanting to go

sean k · October 10, 2009, 09:42:43 PM

Heres a link to the schematic with the DC voltages, no signal and trim at 50% with attack at the combined collectors end of the track (not halfway as written on the drawing)
http://i4.photobucket.com/albums/y115/quickkiwi/effects/bossslowgear.jpg

The parts used are the same as the GGG and the lazy sprocket... with a 2SK30.

How do things look. Signals coming off the end of the first emitter but not getting onto the end of the junction at the 22k and the neg end of the 1uf. The 2sk30 has the drain on the two electros and the source at the zener end.

My thinking is the fet might be round the wrong way as the 5.6 zener is always going to keep more voltage on that end so maybe it sohould be around the other way with the source at the top and the other thing is that maybe the second 1uf on the end of the fet should be around the other way as the fet side will always be more positive than the emitter side which sits at bias. Am I wrong and if I am whats wrong and why would be nice as well.

Excuse the missed connection on the drawing from the diode and 100k to the emitter on the upper leg of the outputs from the transistor in the middle at the bottom... it's actually there in my PCB but I just forgot to draw it in. Sorry 'bout that

sean k · October 12, 2009, 07:47:36 PM

Does having the drawing on the page make things easier. I hope so.

sean k · October 14, 2009, 01:55:31 AM

I got my schematic from the BYOC page and s far as I can remember the outpuffer transistor had the base resistor going to 4.5V but upon checking the GGG schematic it has the same resistor going to 9V so this may explain why the 1uf caps are orientated the way they are. Now I'll just go and pull the bias supply wire to that 1M resistor and jumper it to the 9V line which is right beside it.... hopefully then it'll all start working.

Paul Marossy · October 14, 2009, 10:37:18 AM

I built one and never got it to work, no matter what FET I tried to use. It's the only circuit I ever built that I couldn't get to work.

Hopefully you have much better success than I did!

aziltz · October 14, 2009, 11:07:40 AM

is this design supposed to pass sound if you play lightly? or does it gate sound?

gigimarga · October 14, 2009, 11:08:42 AM

Quote from: Paul Marossy on October 14, 2009, 10:37:18 AM
I built one and never got it to work, no matter what FET I tried to use. It's the only circuit I ever built that I couldn't get to work.
....

Same story for me...I've tried over 10 types of FETs with no luck

Paul Marossy · October 14, 2009, 07:52:29 PM

Quote from: gigimarga on October 14, 2009, 11:08:42 AM
Quote from: Paul Marossy on October 14, 2009, 10:37:18 AM
I built one and never got it to work, no matter what FET I tried to use. It's the only circuit I ever built that I couldn't get to work.
....

Same story for me...I've tried over 10 types of FETs with no luck

Bummer. I know your pain.

edd29 · October 15, 2009, 03:28:14 PM

I made this pedal about a year ago from this link http://topopiccione.atspace.com/PJ03BossSG1.htm
and it works but i was not really satisfied i used fet 2sk30 and changed the cap c6 to 1UF -4.7UF Tantalum
[img]http://topopiccione.atspace.com/pjimages/BossSG1Sch.gif/img]

but now I'm using the swell pedal this is I want to recommend for every body

http://www.diystompboxes.com/smfforum/index.php?topic=78203.msg645323#msg645323

http://www.youtube.com/watch?v=GWdWrgiCQoY
.

sean k · October 15, 2009, 04:13:37 PM

Well, I've got two things to try out, well three actually, make the 1M go to V+ and that'll raise the voltage on the base and make the electros look right then put a 470k instead of 220k, to the first base from VR... then raise C6 to something alot bigger. I hope I can get it to work as even though many haven't.... quite few have done so. Maybe I'll be one of the lucky ones

There was a thread a month or two ago about getting this thing to work with various fets and what changes were made to do so but I haven't found it as yet.

aziltz · October 15, 2009, 05:18:07 PM

i can't imagine that the BYOC kit has this much trouble as well?

sean k · October 19, 2009, 02:16:19 AM

I just got it going by doing as I said I would and also upping the tantalum to 3.3uf. Not exactly what I thought but maybe with a 6.8 tantalum it might be evn slower on the attack. I'll try that.
Actually quite a wide area that the trim works in but only one place where the attack is longest though the overall volume is down somewhat. Sensitivity... forget it. Only really works up at the least resistance so isn't really needed. Attack... works quite well but the time constant between long attack and just pinching off the first chop is not nearly as long as I'd want.

I'm gonna go out and change the cap then go out and perform

Gila_Crisis · October 19, 2009, 03:39:16 AM

I've built mine following the project from Topopiccione (really a nice DIY website, form there i've also built the DOD FX25 and the Clone Theory). I highly suggest to follow the mods reported at GGG.
On mine i've done them, plus used a 50k pot for attack and a 680nF in C6 (like the BYOC). I added also a switch to choose between a 2SK30 and a 2N5458.

sean k · October 19, 2009, 05:07:54 PM

Yeah, I ended up with two .33uf tantalums in parallel for the .68uf cap but it didn't work till I swapped those out for 1 x 4.7uf. Then I decided That because that made it go then putting even more capacitance in parallel would add up to even more attack time so I had a 6.8uf and added that to the 4.7uf for a total of 11.5uf but when I had it plugged in at my gig it wasn't doing , at all, what it was supposed to do.

I suppose I'll pull the 4.7uf, so I'm back down to 6.8uf, and then add some series resistance between the cap and the attack pot as I'm not so fond of the faster attack times anyways.

The top PCB is the SG and the bottom one is a surf noise thingy with inductors on the emitter of one of the trannies...it doesn't work at all...
yet!

solderman · October 20, 2009, 04:51:11 AM

Feels nice to be in good company...
I have also failed to get the SG-1 to work. I used the GGG schematics and the PCB layout and went to a lot of trouble to source the 2sk30 but it did not work or rather it did sort of work in a very narrow setup. Not the way I have heard it to sound. I supsted almot everything and also tried different voltage and everything I could think of but finaly I gave up. This is the only build (from like 75) that I have to trow in the towel on. So I agree with edd29. follow that link, that is a much better and more precise effect that sounds really cool.

edd29 · October 20, 2009, 03:49:26 PM

Quote from: solderman on October 20, 2009, 04:51:11 AM
Feels nice to be in good company...
I have also failed to get the SG-1 to work. I used the GGG schematics and the PCB layout and went to a lot of trouble to source the 2sk30 but it did not work or rather it did sort of work in a very narrow setup. Not the way I have heard it to sound. I supsted almot everything and also tried different voltage and everything I could think of but finaly I gave up. This is the only build (from like 75) that I have to trow in the towel on. So I agree with edd29. follow that link, that is a much better and more precise effect that sounds really cool.

thanks SOLDERMAN for the compliments.

update video is coming soon for this update swell pedal I love it so much.

solderman · October 20, 2009, 05:13:23 PM

Your welcome Edd. Thank's for the conductive pic idea.

Here is mine

edd29 · October 20, 2009, 05:28:57 PM

you welcome too solderman.
that's cool little things

Paul Marossy · October 20, 2009, 10:55:49 PM

Quote from: Gila_Crisis on October 19, 2009, 03:39:16 AM
I've built mine following the project from Topopiccione (really a nice DIY website, form there i've also built the DOD FX25 and the Clone Theory). I highly suggest to follow the mods reported at GGG.
On mine i've done them, plus used a 50k pot for attack and a 680nF in C6 (like the BYOC). I added also a switch to choose between a 2SK30 and a 2N5458.

That's what I used to build my failed Slow Gear. Maybe I need to get a 2SK30 and give it one more try...

edd29 · October 21, 2009, 06:48:27 AM

Quote from: Paul Marossy on October 20, 2009, 10:55:49 PM
Quote from: Gila_Crisis on October 19, 2009, 03:39:16 AM
I've built mine following the project from Topopiccione (really a nice DIY website, form there i've also built the DOD FX25 and the Clone Theory). I highly suggest to follow the mods reported at GGG.
On mine i've done them, plus used a 50k pot for attack and a 680nF in C6 (like the BYOC). I added also a switch to choose between a 2SK30 and a 2N5458.

That's what I used to build my failed Slow Gear. Maybe I need to get a 2SK30 and give it one more try...

its really important to use tatalum C6 the bigger one and 1k to 4.7k in series after the collector of T5 to pot (attack)
I read this somewhere in the forum and its work but not as good compare to swell pedal.

MarcoMike · October 21, 2009, 09:15:19 AM

I built mine with my onw layout and at the beginning it didn't work with the original transistor, I even mached the 2 "paired" trns. I started to check voltages, solder joints, polarity things...
then I swapped all transistors with common ones, like 3904 and others (now I really don't remember, I just used the ones I had in my transistors "bottle") and it works fine now.
It's a matter of luck probably, but I succeded with very little effort.

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Boss slow gear not wanting to go