Tube Sound Overdrive build.... I got questions.

[Strat68okc]

In keeping with the philosophy I was taught as a child... "keep your mouth shut and your ears open, you might learn something" I've been reading and reading lots of threads here. Mr Photon's B-17 got me intrigued. I found MarkM's gallery. Wow. All kinds of neat stuff.  Plus he seems to be a country guy too.

So I built a tubesound od. I did it on perfboard.

http://www.aronnelson.com/gallery/main.php/v/MarkMs-Gallery/album15/album76/Tubesound_Overdrive_LAYOUT.gif.html

I had to do one substitution. For R3 I used two 100k resistors in series since I didn't have a 220k. I'm hoping that's part of the problem I've got with it.

I really like the sound of it over all. But.

First, its NOISY. I might possibly have a ground issue, I dunno. I'll mess with it more tomorrow when I'm awake. Its really treble-y. Which is okay, except it seems to kind of... eh, dampen my bypass tone. Like a blanket over my amp. I'd like a bit more tone control. Or maybe I should darken the thing a bit. When I turn up the treble on my RP250, its icepick time. ( I use the RP250 as a speaker/amp sim mostly, just to run in to my sound card to play at home. My amp is at the jam room.) The 20k trim pot only seems to do anything in the middle of the range... up til about halfway, it's silent. At say.. 1/3, it has a godawful static fuzz sound. Right at half, it sounds pretty damn good. Past that, you get more fuzz, then silence as you turn it up. Is this normal?

I really want to figure out how to get this thing right. Its pretty close to exactly what I was looking for OD wise. Its really transparent, and responds pretty well to my pick attack, even with a compressor on. It seems to have some compression of its own. Any suggestions? I'd really like to learn anything I can.

Thanks.

[Strat68okc]

Here's a sound clip. Audacity is lagging for some reason. I had no idea how difficult it was playing with a delayed monitor....
I start out with just clean and compressed and then turn on the OD. The end of the clip is the buzz...

http://db.tt/AJPNsRUJ

[pinkjimiphoton]

hey bro,
didn't build the original ever, but the behaviour of the trimmers are normal. right about half way up is where you'll find the sweet spot.

if you're on a breadboard that's probably where all the noise is coming from. when you bias it up to a sweet spot, and box it in metal, it should be ok.

my b-17 is pretty quiet..but if i crank the trimmers too much, i can get some gawdawful fizzy noise, for sure.

best bet is to find where it feels best, and then just leave it there i guess. that's what i did with my thing.

you may be having an impedance problem with the rp250 too...the original "tube sound od" is basically a transistor version of the driver stage of a fender/marshall/etc amp...

it's more current amplification than audio amplification i think...but i'm a rank newb, so take that for what it's worth.

and i'm jimi or pink or f-tard, bro, no mister photon's here.

[Strat68okc]

Right.. gotya Jimi. I knew you hadn't built the original. I just had to try it. Thanks for the info on the trim pot. I'm a hella noob at this. I'm finding that my previous CB radio hacking has pretty much made me just knowledgeable enough to be dangerous.

Basically, where do I change values to effect the treble/bass on this thing? Can I get just a little more gain? Just a little. If so... how?

[pinkjimiphoton]

if you want it to break up more, try a bigger input cap...if you go with .01, you'll get twice as much bass in there, and should up the gain some.
i'd imagine if you change the r4 10k resistor to a trimmer, you may get more balls out of it too..i bet if ya changed r4 and r2 to about 4.7k it would have a bit more gain, too...
but i don't know for sure, bro, i didn't build this particular circuit, i just kinda molested it a little and mutated it some.

the bigger input cap will allow more bass and mids..

you could also try using a ge for the pnp.

hopefully some peeps more knowledgeable than me will chime in!

[Strat68okc]

Cool. Thanks for the ideas. A .1uF is pretty wild. It becomes almost distortion, almost fuzzy. Really saturated. With a .01uf Input cap, its more gainy than the .0047 but still the treble is... slashing.

@*&^%#$ Rat Shack closed before I could get any more resistors. I'm gonna have to try another idea I think. I'll come back to this in a few days.  I can't see the forest anymore.

I do think it has potential. Its so close, I just don't KNOW enough yet to figure it out.

[Strat68okc]

I learned some neat stuff about this little circuit today. One, my Tele has pretty hot pickups. I kinda knew that, but I plugged one of my Strats in and I had WAY less gain. I built a COT last night, and these are kinda similar sounding. The Strat had less gain there too. I've been reading some, and I've decided to add a capacitor to the volume pot of the TSO to see if I can cut just a touch of treble. If that fails, I'm gonna add a tone stack to it, and probably up the input cap. I figure I'll use the Stupidly Simple one, or maybe the Muff one. I ain't sure. I still have to go get more pots.

I really need to get a breadboard. I've been perfboarding the things so far... so it makes modding things a little difficult. I gotta order more of those sockets too.

[superbriggs]

The TubeSoundOverdrive is a nice sounding little circuit. There are a few mods I make to this thing when I build them;

1 - I add in a 100kB (Linear) pot wired are a variable resistor in series after the input cap, this allows you to smooth the tone out, reduce the gain a little and take away some of the cutting highs (in some builds where I don't want too many knobs I just use a 10-15k resistor instead of the pot),

2 - I raise the input cap to 22/33nF (depending on how much bass is wanted),

3/4 - I add in a 4n7 cap in parallel to a 500kA (Log) volume pot, this further reduces the overpowering top end,

5 - Instead of using a 10uF bypass cap on the 10k resistor from the NPN transistors emiitor I use a 470nF cap as the bypass, I then wire up a series configuration of a 10uF cap with a 4k7A (Log) pot, this is then wired in parallel to the 470nF bypass cap. This mod allows you to control the overall gain/low end saturation of the build. With this mod you can go from treble boost right through to a full range boost.

Hope that helps,
Briggs..

[Strat68okc]

Oh yeah. That helps. Thank you Mr super guru kind sir.

[superbriggs]

No probs, I think it's an underrated/underbuilt circuit that really sounds nice

You can add a simple buffer in front of the TubeSound OD if you like - it helps it get along with other pedals better by upping it's input impedance (http://www.muzique.com/lab/imp.htm; for more info on pedal impedance). I don't do this though as I like the way it interacts with the guitar when I play straight into it - it's low input impedance helps to cut down on the treble. If you wanted to put a treble cut control before the tubesound od I'd recommend placing a buffer upfront, for some buffer schematics check here; http://www.muzique.com/lab/buffers.htm. The simple jfet buffer will do fine.

[Strat68okc]

I hesitate to buffer the TSO also. I really liked the ability to clean it up with the volume knob on the guitar. Plus, its so bright, you don't lose much treble when it cleans up. I also realized I was thinking in a box. I took and followed the TSO with my compressor. Its still that nasty Behringer one, I don't have my compressor building parts yet. In any case, at about 3/4 volume on the guitar, I get a very "Brad Paisley" kind of clean boost. Dime the guitar volume and I get really good OD. Still a little hissy, so I'll try a few more mods.

The COT wasn't so grand. Compressor>COT>amp sim was okay. Seems to lose drive, but I can't get it to clean up with the guitar volume. It gets almost too squashed sounding. COT>compressor>amp sim is better, and I can clean it up with the guitar volume, but still, I think it should have more drive. I have to have screwed up somewhere, since the Bias pot now has drive on either end, but clean in the middle of the pot. All the demo's of the COT I've heard, it's pretty aggressive. It just doesn't sound as good to me as the TSO. I'm in the ball park with these two at least. I still want to build and test out a few more circuits before I settle on anything. Especially that Country Fried Overdrive a few threads away...

[tca]

Hi,
I've just breadboard the TSO (from the original circuit) and it sounds much more fat that your sound sample shows. I did not build the original but it sounds great.
These were my mods:
2n4401 and 2n4403 transistors (I have a few of these laying around) and used a 100k pot instead of the 20k pot to adjust bias. It does in fact sound like a tube amp and cleans well with the guitar volume. I'll post some sound samples later on.

Cheers.

P.S. (edit)

Just found this the other day!