Unidrive & Sixteen OD sound samples :-)

[MartyMart]

Yup i understand now, I just remember you saying to use a 1M resistor
rather than a pot  !
So ..... jumper it for full gain then !!  yummie

M.

BTW: those damm trimmers, had them both at 4.56v then went back to check no 1 and it jumped to 6,5 !!!  aarrgghh

M.

[vanhansen]

Yup i understand now, I just remember you saying to use a 1M resistor
rather than a pot  !
So ..... jumper it for full gain then !!  yummie

M.

BTW: those damm trimmers, had them both at 4.56v then went back to check no 1 and it jumped to 6,5 !!!  aarrgghh

M.

Yup, I did put a jumper there once and Q2 went nuts and wouldn't stay biased.  I found 1M to 1.5M fixed helped that out.

I know what you mean about the trimmers.  They can be a PITA sometimes.

[Doug_H]

Hey Marty,

I breadboarded the unidrive last night. Very cool...

It is very tunable and tweakable and I love the sound of it. This one is definitely going on the build list.

Doug

[MartyMart]

Hey Marty,

I breadboarded the unidrive last night. Very cool...

It is very tunable and tweakable and I love the sound of it. This one is definitely going on the build list.

Doug

Great Doug, I'm glad that you like it
I have mine in a cheap "Wah" shell, but I'm not sure that's required ?
It's more of a "Booster" but mine has a lot of character and some break
up of its own.
Makes a small valve amp sound terrific IMO !!
Is there an optimum place to insert a "gain" pot, to cause a little more
break up internally ??

Marty.

[Doug_H]

Is there an optimum place to insert a "gain" pot, to cause a little more
break up internally ??

Marty.

The way to get more gain/internal breakup is to play with the 8.2k feedback resistor. Try a bigger value or remove it. It gets quite wild.

Doug

[petemoore]

this looks like a good place to try out a 10k pot...with say a 2k2 stop resistor?
 The way to get more gain/internal breakup is to play with the 8.2k feedback resistor. Try a bigger value or remove it.

[MartyMart]

Photo:
http://www.pbase.com/image/48928301


WOW !!
This worked a treat guy's :
Hang a 1k resistor off Q1's 10uf ( where the 8k2 link was ) connect that
to lugs 3&2 of a 22k pot ( lin is all I had )
Connect lug 1 of said pot back to Q3's junction of 10ufcaps ( 1uf NP in my case )
Great ! a nice amount of extra "crunch" when set high, even at lower
boost levels .....  
I'm digging this A LOT   :twisted:
Maybe even a 50k log would work well and get more raunch going !!

Thanks to Doug for the heads up

Marty.

[Doug_H]

Marty,

I was looking up some old threads on the Colorsound Overdriver/Power-Boost and noticed that you built one of those as well. I had noticed some similarities between the overdriver and the unidrive. Obviously there's the tone control, and the overdriver has less negative feedback and the last stg is a gain stg (to recover from the bax tone stack), etc.

But I was wondering: how do their sounds compare? Do they sound similar?

I really *love* the sound of the unidrive. It really adds a big thick tone to my amp that is hard to describe- very unique.

Doug

[MartyMart]

Marty,

I was looking up some old threads on the Colorsound Overdriver/Power-Boost and noticed that you built one of those as well. I had noticed some similarities between the overdriver and the unidrive. Obviously there's the tone control, and the overdriver has less negative feedback and the last stg is a gain stg (to recover from the bax tone stack), etc.

But I was wondering: how do their sounds compare? Do they sound similar?

I really *love* the sound of the unidrive. It really adds a big thick tone to my amp that is hard to describe- very unique.

Doug

Doug, your right, there are similarities and the eq is useful on the colorsound.
I would say that the unidrive is a bit "fuller" sounding ( not mike! ) where
the colorsound is a bit more "edgy/harmonics" sounding and has less low
mid/bass in it.
Close, but both have some nice tones and are worth building for sure.
I see the Unidrive as a "booster with grit" and the colorsound as a true
"overdrive" pedal .... that's my 2c's worth  :wink:

Marty.

[petemoore]

I put parts on the board for this and tested it over a week ago.
 Tried to fix it a couple days for a little while, built my guitar and messed with that much.
 I got it going tonight, it boosts, but also has a definite Fuzz in it.
 I forewent the 100ohm, and used a 6k8 instead as Q1ER to ground with bypass cap. Ii do that, stick sompin' in I think'll work when I'm getting tired of it and wanna see if I can get it poppin'.
 Tho I don't have a CSOD around to compare, it's funny you mentioned that Doug, for some reason I was hearing a touch of that.
 The thing has nice highs if you let them through, maybe that 6k8 is messing things up for the .001 across B/E junction of Q1, when installed it squeals...haven't messed with it except to eliminate it or run it straight to ground.
 Thick Bass and Mids.
 Of course I see a "FF" in it or at least influnce of FF...the 100k feedback resistor and setup of at least the top half of Q1/Q2 looks FF-ey.
 It feels like a FF set up to be a nicer OD. Cleanup at guitar volume or big drive sound, more stable/less wierd as a FF, great sound on full chords. Leads sound is OD.
 I know I should build it as shown before reviewing it, but since it sounds great and at least works now, I decided to bring this thread back up.
 I figured reducing the 7k5/100ohm to a 6k8 would give Q1 more room to swing and add drive the circuit, maybe this is why I'm 'feeling more Fuzz than the other reports lead me to see.
 Another funny thing, I had a ton of 4u7's, and built all the 10uf's from them, as it looks like the schematic is showing bipolar caps for the 10ufs, I got wise on the Q1E bypass cap [toward ground, mine Is grounded], and used a polarized cap for that.

[MartyMart]

Pete, glad to hear that you got it "fired up" !!
Turning the 8k2 feedback resistor into a 22k pot is 100% worth doing
You still have the "touch of fuzz" settings and can get a nice bit of extra
crunch going if required .
I left some of the 10uf's in mine, bit the last pair @ Q3 are 1uf NP's.
I'm going to remove it from the "wah" enclosure and re-fit it into a standard box.
I can use the enclosure for something that "needs" a vol/wah pedal arrangement more .

Regards,
Marty.

[petemoore]

Well I had a few of the 'extra twists' in the circuit to straighten out, like the output coming off Q3C, which happens to be V+ also [made an ouchy Clak when powered].
 Darn cool sounding circuit, and different clipping sound that "X" circuit's that I have.
 Thanks for bringing it up M.M., I'm glad I built this one. :wink:

[Doug_H]

I think it's pretty unique sounding - very thick in the mids in a good "vintage/classic" way. The bass response is fantastic- no loss at all when you switch it in. Try rolling your guitar volume down. It cleans up real nice and has pretty and clear clean sound.

Doug

[petemoore]

Good and interesting sounding enough to get into a 'probationary' box, all looks good and access to the parts I *think I want to mess with will be there.
 I feel it has great potential so I'm preparing a box to see what that does to the noise floor and how it fares...upstairs.