Recoomend A Clean Boost

[Voodoo Blues]

Hi guys,

Can someone recommend a good clean boost.  I built the beginners project but I'd like to build a boost that has no gain and if it has a tone control it'd be great.

Thanks!

[gutsofgold]

try the Runoffgroove Omega. It has a Range control that is far more useful than a tone control IMO.

[Ben N]

... I'd like to build a boost that has no gain...

If by "gain" you mean distortion, I find that the so-called beginner boost is quite clean. If you want cleaner, make an opamp based booster/preamp, like a Microamp, with an 18v power supply. For an opamp boost with tonestack, look at the ROG ToneMender or Boss FA-1.

[The French connection]

Craig Anderton frequency booster! IC based and you can slect between different frequency to boost (Low, mid, high mid...)

Dan

[Voodoo Blues]

If by "gain" you mean distortion, I find that the so-called beginner boost is quite clean.

Maybe it's the transistor I'm using.  I tried a 4401 and the distortion was crunchy, changed it to a 2222 and it more fuzzy.  Maybe I'll try the 5088.  Does anyone know of a low gain transistor?

[kurtlives]

If you do a search there are about 1000 more threads just like this one with loads of good info.

[Ben N]

If by "gain" you mean distortion, I find that the so-called beginner boost is quite clean.

Maybe it's the transistor I'm using.  I tried a 4401 and the distortion was crunchy, changed it to a 2222 and it more fuzzy.  Maybe I'll try the 5088.  Does anyone know of a low gain transistor?

You have to get around the confusion over the word "gain". Technically, gain means the amount of voltage increase the device is capable of. That may or may not translate into distortion (especially on peaks) depending on a variety of factors, but basically whether the signal as so boosted exceeds the headroom of the circuit. This depends on the design of the circuit, but also on how hot a signal you are feeding it in the fist place. So a higher gain transistor may clip the signal as you turn it up, or may overdrive the next device in your signal path, but it is not inherently any dirtier than a lower gain transistor. For a clean boost you generally want a medium to high gain device, because those are typically not as noisy. I have used MPSA18 and 2N3904, and my boost has been quite clean and transparent (if I may use the term).

[jacobyjd]

Usually in these threads, everything the OP wants out of a booster tends to look exactly like a tube screamer. Turn down the distortion, has a tone knob, has a mid hump that does good things. Just an observation...

What do you plan to use it for? to get more distortion out of your amp, or as a solo booster?

[Al Heeley]

I made this recently for our guitarist, looking for a volume boost for solos, the AMZ mosfet boost - good clean boost and plenty opf extra volume.
http://www.aronnelson.com/gallery/main.php/v/MarkMs-Gallery/album15/album76/MosfetBooster_LAYOUT.gif.html
Use it between your preamp and power amp for boosting solo levels.
Use it before your preamp to tip the amp into overdrive mode for some good, natural break up.
Really simple and effective little circuit.

[Paul Marossy]

I personally like the AMZ Mini-Booster.

[Voodoo Blues]

Usually in these threads, everything the OP wants out of a booster tends to look exactly like a tube screamer. Turn down the distortion, has a tone knob, has a mid hump that does good things. Just an observation...

What do you plan to use it for? to get more distortion out of your amp, or as a solo booster?

As a solo booster... I use a tubescreamer for those other things.  

[Voodoo Blues]

So a higher gain transistor may clip the signal as you turn it up,

OK, I've read it a million times so I have to ask... what do you mean by "clip the signal"? I'm picturing a standard compressor wave diagram that goes from peaks to squares... as in it clips the peaks.

[Mark Hammer]

Your unadulterated guitar signal may be about +/-40mv on average, and over +/-200mv on peaks.  Your booster pedal may be able to swing to within a volt or two of each rail (so, lets say that it can go from 3.5v below the reference to 3.5v above the reference - 7v "swing" altogether - with a fresh 9v battery).  Okay, now divide that 7v swing by 400mv.  You can't really divide it by 400mv very many times (17.5, to be precise) before you run out of capacity to produce a higher amplitude output with the exact same waveform.  And I was being generous in my ratings.

One of the things that is not well understood is that there is clipping and there is clipping.  What we call fuzz or overdrive, is something that has seriously exceeded its headroom limitations for enough of the lifespan of the note/chord that it acquires a new and characteristic tone.  When the clipping is restricted to only very short segments/bursts, (or worse, is intermittent) the tone is not necessarily desirable, or evokes the most desirable sounds out of whatever is next in line.

So, when people want a booster, they either need to have a clear plan of action that will not exceed the operating limits of the pedal or what comes after the pedal, or else they need top productively anticipate the behaviour of the pedal and/or whatever comes after it.  That's one of the reasons why a sensible booster will either introduce some soft clipping on peaks, and/or wil include a treble cut control in order to anticipate how the next thing in line will behave when faced with such a massive input signal.

[aron]

>Does anyone know of a low gain transistor?

I will be adding some lower gain transistors soon.

[petemoore]

  Often enough boosts are intended to increase the output of an amplifier.
  Any of them will probably do that to some degree, especially if some type of distortion is tolerable or desired.
  Some amps are already ''boosted'', to cleanly boost volume with the least difference in tone, a doubling [signifigant increase] of the output wattage and speakers is sometimes the only true answer.
  Treble boosts aren't known as 'clean' by nature, but some cutting of bass frequencies and boosting of signal may allow signifigant increase in the SPL's of higher frequencies, allowing the sound to 'cut through' before the onset of distortion.

[jacobyjd]

ok--knowing that you're looking for a solo booster (i.e. not for more distortion), probably in your effects loop...I'd suggest an orange squeezer.

It adds a slightly crisper attack to your notes, plus it has plenty of headroom--I've found that these two things combined can make for a fantastic solo boost (in fact, I actually use my Black Finger tube compressor for my solo boost at the moment...). It's certainly worth a try!

[Top Top]

Hi Mark,
I am just wondering, what boost are you referring to in this post - the beginner project one?

I am personally looking for a boost circuit that just boosts volume (to use on the inputs of a passive ring modulator), preferably using discrete components. A gain of 17.5 would probably do it for my purposes, I think.

It should be a simple enough thing, but searching, I have had a hard time finding this because it seems that most people want a boost that will have some overdrive or will boost treble or some other tonal characteristic.

Thanks

Your unadulterated guitar signal may be about +/-40mv on average, and over +/-200mv on peaks.  Your booster pedal may be able to swing to within a volt or two of each rail (so, lets say that it can go from 3.5v below the reference to 3.5v above the reference - 7v "swing" altogether - with a fresh 9v battery).  Okay, now divide that 7v swing by 400mv.  You can't really divide it by 400mv very many times (17.5, to be precise) before you run out of capacity to produce a higher amplitude output with the exact same waveform.  And I was being generous in my ratings.

One of the things that is not well understood is that there is clipping and there is clipping.  What we call fuzz or overdrive, is something that has seriously exceeded its headroom limitations for enough of the lifespan of the note/chord that it acquires a new and characteristic tone.  When the clipping is restricted to only very short segments/bursts, (or worse, is intermittent) the tone is not necessarily desirable, or evokes the most desirable sounds out of whatever is next in line.

So, when people want a booster, they either need to have a clear plan of action that will not exceed the operating limits of the pedal or what comes after the pedal, or else they need top productively anticipate the behaviour of the pedal and/or whatever comes after it.  That's one of the reasons why a sensible booster will either introduce some soft clipping on peaks, and/or wil include a treble cut control in order to anticipate how the next thing in line will behave when faced with such a massive input signal.

[jacobyjd]

also something to note---the beginner project's volume control doesn't go from silent to loud. It goes from loud to louder. If you want to use that circuit, I'd recommend using a fixed resistor in place of the existing volume control, then adding a standard voltage divider volume pot to the output. This makes it a little more flexible.

[Ben N]

It goes from loud to louder.

That's why it's called a booster! 

[The French connection]

It goes from loud to louder.

That's why it's called a booster! 

Nah! That's a burst box!