Volume Boosting or Sucking

[nickbungus]

Hi guys.

Haven't posted for a while and been a bit lazy building of late since I've moved house but I'm back in the game.

I'm having issues boosting for solos.  My basic set up is guitar - tube screamer (modded for extra gain) - vox ac30 cc normal channel.

It sounds great but if I use a boost before the amp I don't get a volume boost just more clipping.  I then tried the boost in the effects loop and that was the same. I then tried using the boost to be a lesser volume when engaged before the amp.  That did give me a boost but sucked the tone.

I'm yet to try a volume choke in the effects loop but I am hopeful.

To boost I'm just using a crap behringer graphic equaliser but I do intend to build something one knobby, more robusty.

Anyway, does anyone have any suggestions on the best way to get my boost and also recommend any builds to use?

Thanks, Nick.

[Plexi]

It's hard to push and bump over a AC30, due the design of their preamp and characteristic voice.

I would use something that push the mid/highs.
A treble booster could be a good start: maybe some LPB1 with reduced value over input cap (1/2 would work).
Or why not the Catalinbread Naga Viper: an improved/inspired Rangemaster, NPN.

[antonis]

if I use a boost before the amp I don't get a volume boost just more clipping.

Volume is the audible expression of signal voltage..

If you can't get more volume it means your signal is already hitting the power supply rails..
(so with more voltage gain you only get more distorted waveform..)

Try to use your - modded for extra gain - TS at mid Level settings... 

Or use a Booster (now its time/place for sir Mike..  ) with 12V PS..

[GibsonGM]

Or use a Booster (now its time/place for sir Mike..  ) with 12V PS..

I had the same problem.  So I got a new amp. 

I use a Fender Hot Rod Deluxe - nothing fancy, it has a few mods but nothing remarkable.   What IS good about this amp/many Fender amps, is that there is a lot of headroom in the first stages - they are not pushed to the max off the bat.

So I use an AMZ MOSFET BOOST (!) at the regular 9V to boost my signal level for solos, just before the amp input.  This doesn't change my tone very much at all, but makes it louder.  The amp can handle the additional input.   

I'm not the greatest fan of my amp, it's just a generic Fender, but for this use it's great. I had the same problem as you for years, Nick...that's why I am a big fan of the mosfet boost.  It made my life infinitely simpler on stage!   

If your amp is (as said) already on the edge of clipping, then pushing the front end will just make things fuzzier.   Maybe in the AC30 there's a place this could be done, but as I understand it, that type of rig (Marshall 18W too) doesn't take boosting all that well... 

[pinkjimiphoton]

i bet ya like the toob skreemer cranked.

here's the thing. you cannot get more distorted than when ya hit a square wave.  if you try to "boost" something that's already clipped, all you can get is more compression, not more volume.

there's only two ways to do this. well, three.

1: turn down the preamp of the amp for more headroom
2: turn down the amount of gain on the pedal so its not so saturated it just compresses your amp more
or my fav which works well,
3 : attenuate the bass of the pedal so that you can push the range harder with less mud. less bass = more mids and highs, which will cut thru and seem louder. they aren't really, but by not wasting amplification to boost mud, the percieved volume will be higher.

or just build my pink's clipper and put it after everything noisy and boost your pesky guitar output up to a few volts. you'll get more distortion, more volume (way more volume) but still, if there's no headroom on the amp, it will just compress it more.

everything is a compromise. a lot depends on the amp and the rest of the chain, but like i said, once you hit square wave, all you can get trying to pummel it is more compression... not volume.

hope that helps.
peace!

[antonis]

I use an AMZ MOSFET BOOST

Can you see the astonishment on my face, Sir.. ??

[blackieNYC]

Hold on - you're saying the behringer works for you?  Maybe you are clipping the booster. If the eq can give you you a solo boost (what's that, 10dB or so) when it is set flat, somethings going on with the booster, no?. I have a booster that required me to attenuate the input to avoid clipping, but I could still get enough gain for a solo.
Is it really possible that you are already crushing the amps input stage so much that you aren't hearing boost?  Try other pedals with capability for clean gain. Got a second EQ?

[pinkjimiphoton]

blackie, most of the guitarists i've known literally peg the preamp volume, then peg a fuzz or drive into it and turn the master way down. it gets quieter and more saturated the more they turn the fuzz up, and don't understand why.
but yep, once ya reach square wave, whether by clipping valves or transistors or whatever, it can't get louder. no headroom left.

thats why "stacking" a couple pedals can be good. one to overdrive the amp, one to boost that or drive it. less preamp saturation and more power amp always makes for a phatter more dynamic tone, and yeah, you will have to "sacrifice" some distortion somewhere or other.

turn the preamp down a little and the master up. let that shit sing. and then boosts and drives and dirts can actually do their things.

jmo ymmv

but i've gotta rep as the loudest mother@#$%er on the planet round here 

[blackieNYC]

Hey PJP
He said he's getting the same thing on the effects loop. Wondering of something else is going on.

Used to be loud. Miss it occasionally.

[GibsonGM]

* Slave another amp that is louder....use a volume pedal to bring it in for leads.

I knew a guy who had 2 Music Man heads, and used 1 for leads this way...it was DAMN cool!    

[pinkjimiphoton]

wait a minute... fx loop in an ac30? huh?

weird.

but again, the same thing. you're probably already about maxed for drive, and to add more, you just squash the signal down more.
there's also the possibility that cheap behringer's buffer is causing you issues.

but i have a feeling you've reached your headroom limit a long time before you thought ya would

[mth5044]

Is this the vox with a top boost channel? Could you build a splitter and switch between channels?

[nickbungus]

Thanks for all the replies guys.  So much to take in!!

Yes I did think about the splitter between the channels but would I get more volume from that method?  The AC30cc has a shared master volume and for me, that seems to be the thing I am trying to increase/decrease.  I already have the normal channels volume on about 7 when it starts to break up and any higher just saturates so I cant see how switching channels would give me anything more.

How about modding the amp and do something with the master pot?  The master never gets past 1 and a half otherwise its too damn loud.  It is a really loud beast but adjusting that doesn't really change the overall tone too much.

Next rehearsal I will try using something like this to decrease the volume in the loop for rhythm parts and then taking it off for solos and see if that works and keeps the tone.

[antonis]

How about modding the amp and do something with the master pot?  The master never gets past 1 and a half otherwise its too damn loud.

Pot acts as voltage divider..
What matters is only its setting (ratio of lower/upper resisctance) and not its total value..
(i.e. a 10k pot set at middle should divide signal voltage at half, which is exactly the same result with a 100k pot of same setting..)

So, altering your master pot value shouldn't result in any volume increase/decrease..
(but it should result in impedance matcing disturbance between preamp and power amp..)

In practice, depending on the way master pot is wired on AC30, lowering its value maybe result in volume decrease..
(in the way of heavy loading previous stage significantly lowers gain thus leaving space for further volume increase..)

[GibsonGM]

....but hacking into the MV may allow you a way to 'turn it up or down' dynamically, rather than having to turn a pot.   That's another whole topic!

Could be done with a switch, an expression pedal...but it WOULD require surgery on your amp...

[nickbungus]

I don't mind a bit of amp surgery if it gets me what I need.   I'll never sell on this amp as I'm really happy with it.

I'll see if I can find the schematic online for my model ac 30, if not I'll get a screwdriver and have a look at the pot

[Plexi]

...I'll never sell on this amp as I'm really happy with it....

So... if it ain't broke, don't fix it 

Imho

[nickbungus]

What I mean is I dont mind a minor change (especially is I could do and undo it myself)

[pinkjimiphoton]

well, you answered my question.

with the master on 1.5, you are effectively strangling the amp.

instead of cranking your preamp up to 7, crank your master up to about 4 or 5 and put the preamp on about 4. then you'll have some headroom.

there is a volume control on your guitar for a reason.

you'll never get half the tones available to you the way you're doing it. i mean, to each their own, but when i see someone trying to get something out of gear that is a physical impossibility, it makes me grin a little.

your tone will improve ridiculously. let the @#$%in amp sing!!

then your boosts/fuzz/distortions will actually WORK instead of just squishing your signal.

if it's too loud, you're either too old, or you need a smaller amp.

or ya should learn to use your guitar knobs. seriously. you're missing out.

there's a reason they put so much gain in amps... for the guys who don't use pedals to be snobs and say they just use the amp to generate everything (forgetting of course that diode clipping is solid state and maay as well be a fuzz).

its not for pedal guys. that's what the pedals are for, to enhance the amp.

you're looking to bump it up in headroom,
BUT
you run out of headroom at about 4 on an ac30 if your guitar is cranked. by 7, you've added enough clipping compression to destroy any chance of a boost doing anything other than adding more compression and more saturation.

and you're not letting the el84's which is where ALL the magic with vox amps comes from sing at all.

seriously. put the preamp on 4, the master on 4, and i'll bet ya suddenly you have headroom and picking dynamics,
and if ya slam it with a dirt box or boost, it WILL get louder.

turn the guitar down if you need cleaner tone. that's the way all us old guys did it and still do.
i often turn on a fuzzface at the beginning of the nite and control EVERYTHING from clean to scream right from the guitar knobs.
that preamp gain shit is fine for metaloids. but in a vox? i dunno why they do that to them amps.

good luck mate

[nickbungus]

Thank you pinkjimiphoton

I'll play with the amp more next time we have a practice.  I am really happy with the tone with my current settings but I'll certainly give it a shot.