Boss Slow Gear

[Malius]

Hi guys, I'm new to the forum and I hope this isn't posted in the wrong place.

Basically, I'm attempting to build a Boss Slow Gear clone for a university project. I have a couple of schematics and all the components I need. I'm fairly sure I will be able to start putting it together.

However my main problem is, I don't really understand quite what all the components are doing for me in the circuit. My electronics knowledge is beginner/intermediate as I work as a sound engineer. But I need to be able to write about how it works.

So I was wondering if anyone would be able to give me at least a brief walkthrough of how the circuit works.

Any help is greatly appreciated.

Thanks

[vendettav]

i'd say take another project. don't want to be a bammer but slow gear is a complicated circuit from what i remember!

[Malius]

Unfortunately it's a bit late for that now. I've already submitted and had the proposal approved. I have just under two months left to get it done. Oops.

[vendettav]

well 2 months aint that bad. but at least mind dropping a aschematic here?

[Malius]

Here is a schematic I've been working from. http://www.montagar.com/~patj/bosssg1.gif

I have the service notes at home, but I'm at work at the moment.

[geertjacobs]

http://www.geofex.com/Article_Folders/bosstech.pdf
http://www.geofex.com/Article_Folders/ECFtech/ecftech.htm

[geertjacobs]

You can also download a copy of LTSpice (it's free) and simulate the pedal to see what exactly it's doing.
It will take some time to learn, but it's time well spent.
BTW the simulation subforum is on top of the "building your own stompbox" forum.

[Mike Burgundy]

Start out first and foremost with the entire beginners' section on this forum. Find the links to basic electronic circuit theory and take it all in. Start with Ohm's law, it all starts and ends there, basically.  With two months, there might still be enough time to build a couple of small circuits as a warm-up, say a fuzz and distortion?
Good luck, and be careful you don't get hooked

[Galego]

I've built one. I can supply my layout if you need it. PM'me and i'll send it to you later. As said, it's not the easiest of effects to build, and to setup. Even when the trimpot is properly tuned, it's a weird pedal. The knobs are basically set and forget, because you'll only find one position that makes it work properly for the whole guitar fretboard.

[dthurstan]

I'd get rid of the flip flop switching system to make it easier.
There is a circuit description here with a nice figure;
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=9191

[MikeH]

Also check out the Slow Gear project files at generalguitargadgets.com

[Thomeeque]

I'd get rid of the flip flop switching system to make it easier.
There is a circuit description here with a nice figure;
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=9191

Nice one, I'd yet interrupt wire leading from input to output buffer (between Amplifier and FET branches) by (22k) resistor, as it forms voltage divider with FET.. T.

[Hides-His-Eyes]

In words:

If the input signal is over a certain voltage threshold, the circuit "triggers"; the audio volume is controlled by some voltage (or is it a current in this one?) which, upon the trigger, increases from zero to its maximum value. One could easily redesign the circuit today to take advantage of the wonderful VCAs you can buy from CoolAudio or THAT corp, which would make the whole thing at least easier to understand on inspection!

So you need to identify which bits of the circuit are to do with the trigger, which is the controlled amplifier and which is producing the "swelling" voltage. 2 months is plenty and it's an interesting circuit, it will make a good essay!

[geertjacobs]

Another layout
http://topopiccione.atspace.com/PJ03BossSG1.html

[Malius]

http://www.geofex.com/Article_Folders/bosstech.pdf
http://www.geofex.com/Article_Folders/ECFtech/ecftech.htm

Thank you very much, they look like really helpful links!

You can also download a copy of LTSpice (it's free) and simulate the pedal to see what exactly it's doing.
It will take some time to learn, but it's time well spent.
BTW the simulation subforum is on top of the "building your own stompbox" forum.

I'll give that a go. Anyone got any experience of iCircuit?

I'd get rid of the flip flop switching system to make it easier.
There is a circuit description here with a nice figure;
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=9191

Thanks. I was going to take the switch out of the circuit and just add it before so that it's either straight to the output or to the FX circuit.




And thanks to everyone else, you've all been really helpful.

I'll let you know how I get on!

[benfox]

you are lucky to make it work !!
mine doesn't !!
Could you please give your voltages ? i think it would help a lot of people debugging this  one !!

Thanxs !!

[Skruffyhound]

http://www.bossarea.com/loadpage.asp?file=boxes/SG-1.xml

Did you read this?
The slow gear is in fact the Boss NF-1 in reverse. There is some story about the engineers having to come up with something fast etc..
http://www.bossarea.com/loadpage.asp?file=boxes/nf1.xml

[Billy_Jim]

I just picked up an NF-1.  Does anybody know how to do the conversion to an SG-1 or know where I can find some info?  I'd really like to give this a shot.  Thanks.

[tiges_ tendres]

http://www.bossarea.com/loadpage.asp?file=boxes/SG-1.xml

Did you read this?
The slow gear is in fact the Boss NF-1 in reverse. There is some story about the engineers having to come up with something fast etc..
http://www.bossarea.com/loadpage.asp?file=boxes/nf1.xml

I have one of those NF-1's  It's more useless than the Slow Gear was!

[Skruffyhound]

There's a video on youtube IIRC, possibly with some links. Long time since I looked at it though.