What's the most ridiculously clean booster you know of.

[skiraly017]

I mean super clean. So clean that you can hit it with a Seymour Duncan Invader and not have the circuit break up.

[R.G.]

A 1.5kW Crown power amp.

[davidallancole]

Good one R.G.

How much of a boost do you need?  You will need something with wide supply rails on it if you don't want it to distort at all.  There are a few op-amps out there that will handle +-45V.

By the way skiraly017 thats one of my favorite Homer quotes next to this one:

Homer: Kids, there's three ways to do things: the right way, the wrong way, and the Max Power way.
Bart: Isn't that the wrong way?
Homer: Yeah, but faster!

[Nasse]

I had an old small sized 50 watts Marshall head in the old days, no master volume. It was loud and clean, no distortion at all, perhaps they had doctored it at repair shop or something. Other channel was very bright and i think it had treble and precence control too. It is not just me but people few blocks away too told me it was loud.

[R.G.]

Back on the serious side, find yourself a high voltage opamp. It is quite difficult to find a cleaner boost within its power supply range than a well set-up opamp. The issue then is just how big the power supply rails can let the output signal go.

The OPA454 from TI has a total maximum power supply of 100V. Will that be enough?

[skiraly017]

The OPA454 from TI has a total maximum power supply of 100V. Will that be enough?

More power! Agh! Agh! Agh!

Any suggestions for existing layouts? Thanks.

[davidallancole]

Do you plan on using an op-amp?  If so the layout should be straight forward.

[Mark Hammer]

Basically ANY gain stage, as long as it isn't set for much gain, isn't fed anything particularly high level, and has a reasonably wide voltage swing from the available supply.  You can do that with a one transistor stage run on 1.5v and fed a voice mic, or you could do it with one of the suggested op-amps that can run off super-high voltage supplies, makes not matter.

You can get ANYTHING to be clean. Clean is not a problem.  Clean plus gain, and clean gain feeding an amplifier that threatens to break up...THAT's a challenge.

[earthtonesaudio]

A volume cut, when bypassed with a piece of wire, results in a perceived volume boost.  No distortion, and the battery lasts a long time.

[petemoore]

  RG beat me to it.
  I tried a Mackie sa1530z, 3-way, powered speaker, has respectable 'clean' specs.
  Wider range frequency response and very close reproduction clarity is a revealing way to compare guitar pickups.

[Mark Hammer]

I should not be so snarky.  The thing of it is that many people think they want a boost, and know they want something that still allows them to hear the amplifier sound, yet the intended use is to deliberately introduce coloration to the amplifier sound.  Does a simple high-headroom gain stage necessarily do that?  Not necessarily.  I know that I used to have a simple x4 preamp in my guitar and drove my little tweed amp with it, and the results were pleasing; more clean loudness at low volume settings (important in my case because the volume control had a treble bypass cap that would have diminishing effect on tone as the pot was set higher), and more grind at higher volume settings.  Would ANY of that "cleanliness" be audible were the gain set higher than x4?  I strongly doubt it with that particular amp.  If one had an amp designed to accept steel guitar or piano input signals (typically very high levels with wide dynamic range requirements), then perhaps more gain in the booster would still retain a "clean" tone, but this would be unlikely with an amp intended for guitar use.

"Clean" gain absolutely requires that everything after it in the signal path be equipped to handle the increased amplitude.  If not, then there WILL be clipping.  Sometimes, that clipping is leasing, but more often it requires some form of pre-shaping the dynamics and tone of the input signal in order to elicit desirable sound from the amp.  I used to use my compressor as my booster, even going so far as to hook the compressor volume control to an EHX Hot Foot pedal for real-time control over level.  That allowed my to adjust the dynamics of the boosted signal so that the amp behaved the way I wanted to.  A simple gain stage will not do that.  One of the reasons why many people find that an overdrive pedal helps them to get the tone they want from their amp is because the distortion produced by the pedal results in compression of dynamic range.  A tube screamer is a case in point.  The boost in level pushes the amp to a point in its range where it starts to behave non-linearly, and the natural compression of the overdrive keeps the amp right in that zone, without falling too far above or below it.

This is why I would recommend a compressor as "clean booster".

[isildur100]

This is why I would recommend a compressor as "clean booster".

I totally agree. My favorite booster right now is the Flatline compressor.

cheers

[skiraly017]

What prompted this?

The LPB-1 is my favorite booster hands down. I've been a single coil guy up until a few months ago when I was loaned a '64 ES-345 that had an unreal set of humbuckers in it. With my Tele, the LPB stays "clean" until the point where the pedal starts to drive the amp but with the 345 the LPB doesn't seem to hold together as long and I get an ugly gated static like sound. It doesn't sound like the amp is being pushed, it sounds like the LPB is breaking up (or trying to). So what I was hoping to find is a booster with the same tonal characteristics of the LPB that doesn't suffer if hit by higher output pickups.

Did any of that make sense?

[davidallancole]

If you are wanting to build something, you could just build a LPB-1 with a higher supply rail.  Instead of a 9V battery, you could use 2 batterys in series for 18V.  You would have to adjust the bias then.  If you can handle less gain, you could keep the same 9V rail and change the collector and emitter resistor to get a higher input voltage range.

[DUY1337GUITAR]

The only clean boost I tried was the Super Hard On so I don' t really know what's the most outstanding.  But doesnt break up clipping from boosting is also determined by your amp's headroom?  When I boost the Super Hard On onto my small Roland amp, it breaks up (but into crappy solid-state clipping), but on my Crate GT120R it barely even clips at max boost.  It has a lot more headroom than I thought (but the volume got from tolerable bedroom level to INSANELY EAR-PIERCING LOUD).

[petemoore]

  Clean = 0.0 distortion. The shape of the input signal wave is identical to the shape of the output signal wave.
  To get perfect-wave flat response [such as the impossible] requires the bandwidth of everything electro-mechanical exceeds the bandwidth of the source [could be guitar].
  To do that [well, get closer] requires...well, a clean PA, or a reference monitor, not turned up, so in general boost isn't recommended for clean.
  There actually is no 'clean', but boost tends to take you farther from it.

[Mark Hammer]

Glad you provided some perspective.    The LPB-1 has a fixed gain and variable attenuation on the output.  The 9v supply only allows so much amplification of the input signal before the circuit runs out of clean headroom.  You could increase the supply voltage, but maybe all you need to do is reduce the gain in the circuit and turn up the output level.