recommend me a clean boost circuit

[Al Heeley]

Can anyone recommend me a good, simple clean boost circuit?
Use is for boosting signal for soloing on an already pretty overdriven amp.

[liddokun]

AMZ mosfet boost.
It is capable if giving a large boost (if desired) and colors your tone very little.

[Al Heeley]

Thanks for that - would you normally use this before or after a distortion pedal in a chain?

[Der Groovemeister]

I just built the Gus NPN Boost (aka the Beginner Project. from the vero layout floating around here) and I like it very much. It hardly colors your tone and it kind of expands the dynamics of your playing. I also built the Fetzer Valve, which i also like because it adds a little tweed to my sound. I like the booster best at the end of the pedal chain for solo boost. If you put it before an overdrive, fuzz or distortion pedal it will increase the gain of that pedal. Can be cool, can be too much...

[rousejeremy]

I'm a fan of the LPB when used with single coil pickups. It's a little darker than some other boosters and goes well with a twangy guitar, taking away a bit of the piercing high end edge at that can happen while soloing on the higher strings.

[BAARON]

From the other end of the spectrum, I'd recommend a booster that emphasizes upper mids and highs, rather than the full-frequency or smooth/darker boosters we've seen recommended so far.

Simple reason: if your amp is already overdriven and you boost the bass along with everything else, it can tend to get pretty mushy and icky.  If you just boost the upper mids and the highs, you still get a boost to the upper range where you do most of your lead playing, but the bass stays nice and tight.

This is why a Tube Screamer (which is normally thin-sounding as a stand-alone overdrive) makes a nice booster into a dirty amp: it only boosts the upper-mid and high frequencies, though admittedly not by very much because it's not a very loud pedal with the standard clipping diodes.

[roseblood11]

But he asked for a CLEAN booster...

I´d recommend the AMZ mosfet booster or the mxr microamp - that´s a really good sounding booster if you run it at 18V and use quality parts

[petemoore]

  Nope, sure can't.
  I like dirt sound of clean, pure clean just sounds dry in comparison, good clean sound for me has dirt in it, not big loads but enough that the non-linearities add some character...
  For that...anything, a purely clean booster distorting say an amp that distorts nice when the front end pushes it's back end around.
  OR...a boost with a little 'hair', NPN Boost cleans up real nice @ the guitar volume though, but a 'glancing' test would likely have you believing its an overdrive.
  LPB...Jfet...anything.

[BAARON]

But he asked for a CLEAN booster...

So?  He said clean, not transparent.  There are some clean treble boosters out there...  And for the application he intends to use it, I thought that a treble booster might be more appropriate than a full-range booster.  Obviously, it's going to depend on the amp and the guitar.  With my amp's overdrive channel (Dumble clone), a full range booster just gets too mushy.  With a thinner sounding amp, a full-range booster might be more appropriate.

[mrslunk]

+1 AMZ mosfet booster
i just tested it as part of my wasitpack linedriver/heaphone amp that i'm building, subbing the gain control with a fixed resistor.
it's an exceptional clean boost.

[roseblood11]

But he asked for a CLEAN booster...

So?  He said clean, not transparent.  There are some clean treble boosters out there...  And for the application he intends to use it, I thought that a treble booster might be more appropriate than a full-range booster.  Obviously, it's going to depend on the amp and the guitar.  With my amp's overdrive channel (Dumble clone), a full range booster just gets too mushy.  With a thinner sounding amp, a full-range booster might be more appropriate.

The MXR Microamp adds just a little treble, it "opens" the sound, I really like that in front of an overdriven amp. A Rangemaster or other treble boosters sound also great, but they really change the sound...

I think, boosters are so easy and cheap to built, that it´s worth to try some different circuits...
http://aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/album14/

Often overlooked, but very good sounding, is the booster section in the Electric Australia Tremolo:
http://aronnelson.com/gallery/main.php/v/Renegadrian/ea+booster+vero.gif.html

[gena_p1]

SHO
if you don't like crackling, then put trim (or 150-330 Ohm resistor) at source and 100K pot to the output (like big muff).

Microamp - i think it need to change input cap to higher value, for example 0.1u  especially with humbackers and mahogany, or bass guitar

[Al Heeley]

Some useful comments and opinions. I'll put together the AMZ Mosfet as its a simple little circuit and see how it sounds with my friend's guitar and overdriven amp. if I need something more treble-biased to cut thru for solos I'll have a look what else is around. For now we are purely talking a lift in dB for soloing, he drives his amp pretty distorted all the time. What i didn't tell you was that this is being worked into a Tubescreamer pedal so he can have the Tubescreamer for the overdrive tone but have a reasonable volume boost as well built in as a 2-in-1 stompbox.

[BAARON]

Something to keep in mind, then, is that if your volume boost comes before your overdrive (which you say is already pretty heavy), you won't hear a Lot of a volume boost.  It'll sound more like a gain boost without much extra volume.  It'll be more of a volume boost if you can put the boost after the overdrive, where the boost isn't just going to end up being clipped.

[liddokun]

Something to keep in mind, then, is that if your volume boost comes before your overdrive (which you say is already pretty heavy), you won't hear a Lot of a volume boost.  It'll sound more like a gain boost without much extra volume.  It'll be more of a volume boost if you can put the boost after the overdrive, where the boost isn't just going to end up being clipped.

Agreed. You beat me to that post, Baaron. When I'm using a clean boost, I have it at the end of whatever I want boosted. If I put it at the beginning, it might just overload the input gain I'm throwing into whatever else is in the chain, and clip. Which is why after all your gain based pedals would be the best place for a volume boost circuit like the AMZ. 

[Al Heeley]

Yep that confirms what i asked in the 3rd post in this thread - to clarify about position in the chain, so the signal route will go into the t/s, then into the booster box before coming out and going into the amp.
The other option would be to make a vol-cut pedal, just a passive resistance with low tone-suck which supresses the input/gain for rhythm playing, then setting the amp vol right so that stomping on the boost removes the vol cut for solo work. This would require even less components i'm guessing. Just need to control the treble bleed issues.
There is another alternative, that's to teach him to use the vol knob on his guitar but i suspect he's superglued it on 10.
Thx guys

[R.G.]

Just clarifying things.

People say clean boost, then proceed to talk about the degrees of dirt and tone coloration they get with one- and two-transistor circuits.

==> If it distorts or colors the sound at all, it's not clean boost. <==

You want clean, use an opamp with a big power supply voltage for boost. Done properly, opamps produce larger signals which are simply bigger, and largely indistinguishable from the original without instrumentation.

[jacobyjd]

Further clarification needed:

What purpose is the booster supposed to serve? You mentioned that it's to increase the signal to an already-overdriven amp, but then you ask if it should come before or after a distortion pedal. This makes me wonder why you'd want a booster AND a distortion into an already-distorting amp...

Meaning...if I was going to use a booster to push my overdriven amp harder, then that IS my distortion--no real need for a distortion pedal if that's the case.

Can you clarify what's actually going on in the signal chain?

[liddokun]

Josh, I think the OP mentioned above that the overdrive is coming from the distortion pedal, the clean boost is just being used after the dirt box for a volume boost for soloing, not so much to drive the amp.

[petemoore]

  First and second of all, 'clean' doesn't seem to mean 'linear', the two should be about synonomous, technically speaking.
 TS's output certainly doesn't equate to 'clean'.
 Hitting the input of any booster 'hard' [the TS's signal is hotter in one or more ways than the guitar output], doesn't necessarily lend itself to being described as 'clean'.
 Post TS booster that doesn't add much distortion seems like it'd have been an appropriate title for this thread...I don't know of a booster that can accept a 'hot 'n spikey' signal and perfectly replicate it [with some volume boost, the heat and spikes will always end up being altered in some way or other, whether the booster does this or not.
  volume cut isn't a bad way, you 'could' even add that to the TS's volume pot, but there's no room for the switch and etc. in there.