hi all. I finished the slow loris today. I'm actually a lil disappointed in the result. It works fine and all buts it's so trebly. And lacks gain. And I have issues with all rats bc of my active pickups. I'm thinking that it cuts out my low end resulting in a crackling sort of sound when I get to chopping. Is there a value I can change some where to help with this? I also put germaniums in place of the led clipping and it sounds so dull. I'm wondering if I have a bad cap in the circuit or somthing. But.. It's not a defect. I think it's just a matter of taste. But if I could mod it to handle a little more low end that'd be great. I used the 33pf silver mica and LM308n
Rats are not really known for their bass. It is a more mids/treble type drive IMO. Depending on your guitar/amp setup this could result in what your describing. I would switch the germ diodes to the LED's which will increase the gain, but I'm not quite sure what you mean when you say it lacks gain. Are you talking volume or available distortion?
Josh
well, it's just kind of harsh. Not as smooth as my chinese modded rat 2. I mean it's extremely middy. And is the ruetz (sweep) supposed to be a faint effect? Almost like the filter on a smaller scale? Will 5mm leds be ok or do I have to use the small ones?
and this may be a dumb question but the up position is the leds?
You can use 3mm or 5mm. I'd use diffused LED's(not the high bright waterclear)
after looking again I think that the up position is the leds(i have germaniums) this sounds more metal/big muffish. The proco rat has the 4148 diodes just like my clone but the whole thing sound so hollow and the sillicon clippers do not sound right. (very weak)
I don't know anything about what you already have. Maybe the circuit is a little different on your proco. There is a pretty good Rat site on the net. I forget the address but it goes through the changes through the years. What do you have in the other diode spots on the slow loris?
Josh
can't remember off the top of my head. I think it's a 4001 diode. And in the clipping spots I have one 4148 and on the other side a germanium and 4148. This is what I did to my actual proco rat. The pedal sounds empty and it's because ALL of the lows are filtered out. Every thing works, everything acts right (im kinda noob). But it's straight mids. Is madbeans rat just not very low friendly? Or could it be my panasonic low voltage film caps. .. I did have to use a couple carbon film resistors when I usually use metal film. I'm just trying to make sure something not wrong. If some one said "nah dude my slow loris has alot of bass" or no bass I would no where to go.. Thanks for taking the time to read my question tho josh.
I think there may be something wrong. If your pedal is not working like a normal Rat would, that would indicate a problem. The Slow Loris is essentially the same schematic. There should/could be small tonal differences, like different flavours of vanilla, but if one is chocolate and the other vanilla - you gots problems I think.
Jacob
I have built a couple of these and they did not show the behavior that you are describing. Sounds like you've got something wrong somewhere.
ok.. I think your right.. This thing turned out to be an over drive.. Not even a very warm one at that. I know it's now my soldering. My joints are solid.. But if it were lacking lows/warmth where should I start? Could it be a bad ic? I have a few 308n's but I don't wanna blindly go into this. I do know I had it wired and had to rewire it.
Hey man, even the best of us with years of soldering under our belts, even we make mistakes and have cold joints on occasion. In fact, just the other day I did...
Unfortunately, I can't really recommend any in particular for you. If you've done debugging in the past you'll know you need to follow the same steps for pretty much any problem - careful inspection, double and triple checking, and then measuring things.
Check out the 'rules for getting tech help' thread, and if you have specific questions or want us to give you some help, feel free to make a post in the tech help area.
jacob
as I was looking through the parts list for this project I notice it calls for a 2n5457 jfet. Every other rat uses 2n5458 to my knowledge. So I had one left from my orange squeezer and poped that bad boy in and it actually beefed up the signal. Now my proco sounds funny. After I did the silver mica mod. I put the lm308n and added a Ge diode in the diode series the end result sounds decent but a little muffled. When I play the 2 a/b-ing they sound very simlar except the proco no has that muffled sound. But the 5458 did seem to sound better. I'm still fiddling with it tho. Thoughts on this?
Even batches of the same type of FETs can very a lot in their performance. It may be that the 5457 you had was at the weak end, but the 5458 was decent. 5458s tend to be a bit more beefy, there's a thread here that discusses it:
http://www.diystompboxes.com/smfforum/index.php?topic=16921.0
I buy a few FETs and then measure them with a DMM to get the better performing ones.
that's good info.. But I still can't figure why this thing sounds so hollow.. The jfet helped some but this thing is like blistering highs. It's like the same as rats with more highs. Could it also be the brand of the pots, wires, jacks, footswitch? I also yanked one of the caps of a different pedal (the box one). Also is my 33pf silver mica ok, or could that be contributing?
I doubt it's the compensation cap. Could be the actual IC. Some voltages would be good here. You may need to audio probe.
It should NOT be hollow. It's thick and creamy distortion without a doubt.
I looked around the board and noticed on C9 where it calls for a 1uF box cap and I had one that said 3n3 3.3 I'm guessing that I missread. I don't have that part :/ so now I gotta wait. Do you think think contributed?
heck yes.
I say it often, but most errors come down to three things, and this is one of them. Either a wrong or backwards part.
Good find though, it's always safe to assume you've made a mistake rather than getting it perfect.
Jacob
You could use a 1uF electrolytic in its place...or 10uF even.
I actually tried to use a tantalum and it just humed.. I tried it both directions... Do those not work?
on of the leads connects to one of the pot terminals would I use the - in that place?
Tantalums are sensitive to polarity and you may have killed it by hooking it up backwards. Use another one if you have it (or a plain electrolytic) and hook it up so the minus side faces lug 3 of the volume pot and plus goes toward R9.
With polarized caps, the "+" side always goes toward the higher voltage source.
hellz ya! It works! Sounds way better. Now.. One last question for the clippers I used on one side a Ge going into a 4148 and on the other side just a 4148.. Does anyone see an issue with this? Did I do it right? I put mosfets in my proco so when I A/B them the slow loris sound a little raspier. It's sloppy tho and I'm anal about this.. But madbean you rock. I used the 10uF tantalum.
Glad you got it working properly. You can do what your heart desires with the clipping diodes. I prefer the stock LED's but that's just me. :D
Josh
standard asymetrical clipping is to just add another 4148 to the series of one side? I LOVE mosfet but I already did that to my proco. And they won't fit in the enclosure. Do the BS170s sound similar to the irf520's or whatever they are?