Mini booster completed. Not clean boost?! (compare to mosfet booster)

[madball]

Hi,

I've bulit the minibooster, I use a electrolytic 4.7uf cap to replace the non-polarised 3.3uf cap. It works, but it doesn't sound clean, it sounds like a
mild overdrive, compare to the mosfet booster that I built. Is that normal? The overdrive sound is coming from the mini booster but not the pushed amp
because with the same volume boost by the mosfet booster, the sound is relatively clean compare to the sound from the mini booster

I am using THD univalve which is a SE amp with EL34 if that matters.

Thanks!

madball

[newbie builder]

That's how it sounds- I don't think of it as a booster, it's more of a 1 knob overdrive pedal. Wasn't what I expected at first, but I like it a lot- it has a lot of good tones in it. I'm thinking of building a mosfet booster and a mini booster in the same box with the mos running into the mini and a mod so that both mos and mini have two seperate volume controls that are foot switchable and also I think i'll stick a buffer in there too.....it's gonna be a big box

[madball]

Wouldn't it will blow your amp and cause damnage to your speaker if you stomp your mosfet+mini booster with both volume knob turnned up?

madball

[newbie builder]

IF I had both of their volumes at max...maybe through a low wattage speaker. But I don't plan on doing that, just slight boosts.

[d95err]

Nothing that you can build that is powered with a 9V battery can do any damage to your amp or speakers. No matter how many boosts you use, you can never get more than a 9V peak-to-peak signal. All you get is more distortion.

So, boost away as much as you want!

[newbie builder]

I though you could damage your speakers if the amp is cooking and you boost it beyond what the speaker can handle....

[plucky]

I guess the power of the amp is limited by the output power... so if you try to get more power with boosters you just will get more distorsion at the max level of the power state of the amp and nothing else more, that's why you can crank your tubeamps without burning the speaker....

[DuncanM]

My Minibooster isn't what I'd call clean - sounds pretty good though...
Adds a really nice sheen - a "quality" sound to your guitar.

As far as destroying your speakers goes, you CAN damage loudspeakers by driving your amp distorted for long periods BUT it usually applies to transistor amps which clip, rather than valve amps which saturate.
The reasoning goes like this:
If you overdrive a transistor power amp you get relatively long periods of DC appearing across the speaker as the signal hits the rails and stays there until the signal heads back towards zero... Close to maximum power is transfered to the speaker - and not in a good way.
This causes heat to build up in the speaker coil which will eventually cause damage of some sort - flames are the most spectacular...

Strangely, you're more likely to destroy a high power speaker using a low power amp, than a low power speaker using a high power amp... Well, maybe not - but the type of damage will be different...... Ever seen a speaker cone fly? 

The same does not apply to valve amps as the output transformer prevents DC produced by clipping from reaching the speaker (the magnetic field saturates.

I hope I've reasoned this correctly - it's been a long day with not enough sleep.....

[kvb]

As far as tooooooo much boost is concerned, all I can say is I had the mini going into the amz presence control and then into a fetzer valve - all of this was at max, as was the 5w amp.  I noticed the bass response in the amp die as if someone flipped a switch.  Then I smelled something like hot vinyl.  I turned the volume down and a little while later the bass kicked back in.

[amz-fx]

Why are some boosters cleaner sounding than others?   

http://www.muzique.com/lab/boost.htm

regards, Jack

[jrc4558]

Miniboost is not meant to be a clean transparent volume booster. If you want a clean clean - build a MXR microamp.

[d95err]

I though you could damage your speakers if the amp is cooking and you boost it beyond what the speaker can handle....

If you use an underrated speaker, it can be damaged regardless if you use a booster or not. However, if the amp had a marginal OT and speaker to begin with, you may want to be a bit careful about cranking it, booster or not.

[Pushtone]

it doesn't sound clean, it sounds like a
mild overdrive,

I you sub-out the J201 with a lower gain 2N5457 it gets a lot cleaner.
With 5457's my Mini-booster sounds much more like the Fetzer.

I've built a couple MBs. The one with J201s I call "True Grit"
If your looking for a clean boost... my vote is for the Stratoblaster over the MosFET boost.