DIY Pedal for boosting volume

[Rethfing]

Hi!

Im looking for some pcb layout for something, that will boost volume while playing some solos on distortion. My friend is using JCM900, and DIY Tube Screamer in front of it, but it doesnt boost volume at all while playing on distortion (its headroom issue as I read somewhere). So I need something that will make his amp louder. Is that possible to do?

[Kesh]

AMZ MOSFET booster.

[FiveseveN]

I need something that will make his amp louder. Is that possible to do?

A louder amp, obviously. Or more speakers. Doubling the number of speakers adds about 3 dB.
Boosters don't make amps more powerful. See Jack Orman's article: http://www.muzique.com/lab/boost.htm

[madboy]

I used to just put a boost in the effects loop if I was using the amp's distortion.

[Rethfing]

A louder amp, obviously. Or more speakers. Doubling the number of speakers adds about 3 dB.
Boosters don't make amps more powerful. See Jack Orman's article: http://www.muzique.com/lab/boost.htm

Amp is loud enough, I want some volume boost just for soloing.

I used to just put a boost in the effects loop if I was using the amp's distortion.

Like clean boost in effects loop? MXR Microamp will do?
I tried once putting tube screamer in effects loop with drive on minimum settings and it just ate my amps distortion and turned it into a loud fuzz or something.

[Gus]

A JCM900 is not loud enough?
 
What speaker(s) and cab(s) are you using, one or two 4x 12s cab?

[Puguglybonehead]

The LPB-1 is a decent straight-up boost. I use one for the same purpose you're suggesting. Beware that it will still make things gainier (ok, spellcheck thinks that is not a word) and slightly more distorted when you use it. I'm using mine with an old Gibson G5 Crestline amp and am finding that it also makes the guitar sound much fatter, as well as louder, for solos. Sometimes a good thing, sometimes not. The Tonemender might also be a good choice. It has a decent EQ to fix things up. On my build list to replace the LPB-1.

[Canucker]

LPB gets my vote...it does add a bit of bass but to me it sounds great. You can always mess with the capacitor values to reduce the bass the screaming bird is the same layout with just the cap values changed to make it a treble boost...that a lot of people hate...so caps somewhere inbetween might just do the trick for you if the bit of bass bugs ya.

[diydave]

I've "designed"  a simple circuit just for such a problem: a buff 'n boost.
Two jfet 201's. The first to buffer and the second to boost. Clean, no hassle with staticproblems (like sho or mosfet booster), no frequency changes (unless you mess with cap-values), and a lot of volume boost.
Maybe worth a try?
http://www.diydave.be/wp-content/uploads/2012/06/buffnboost1.png
Oh, it's in Dutch. Maybe best to breadboard the thing first in order to get a 'nice' value for the second fet's drain-resistor.

[Rethfing]

A JCM900 is not loud enough?
 
What speaker(s) and cab(s) are you using, one or two 4x 12s cab?

You dont get it, read again. I need >>>volume boost for solos<<<. I want to hit a footswitch and get some volume boost just for the time of solo.

@Puguglybonehead and Canucker
Im trying to be careful with the amount of gain, because my friends rig is very noisy, so adding more and more gain will result in unwanted feedback and a lot of noise.

[Gus]

I did read the posts and noted you are using a JCM900

Hi!

Im looking for some pcb layout for something, that will boost volume while playing some solos on distortion. My friend is using JCM900, and DIY Tube Screamer in front of it, but it doesnt boost volume at all while playing on distortion (its headroom issue as I read somewhere). So I need something that will make his amp louder. Is that possible to do?

You posted a TS does not boost the volume.  Are you using the boost channel on the amp? is it this preamp schematic in the link ?
http://atomiumamps.tumblr.com/post/9235920015/mods-for-jcm900-4100

If so note the diode clipping used in the boost channel of the amp.  Once you clip diodes it is harder to get more output from the clipped diodes.  You are on the B side of the chips with the boost channel and the signal gets clipped by BR2 diode bridge and one 1N4007 (3 diode drops as shown) then to an EQ then.  The normal channel uses LED clipping in the feedback loop of IC4A this should have more output signal level before clipping.

Have you tried turning the amps boost control down and the master volume up and use a TS etc with the amp?

If you use the normal channel you can use a number of different boosts before the amp.  It is hard to tell you what to use different boosts distort and load the guitar in different ways.  A LPB can load the pickup if passive and reduce the highs at full guitar volume a higher input resistance boost will not load the pickup as much.  The cable cap can change the sound of passive pickups.  There are many thread here with boosts and bufffers.

[ghostsauce]

I use a clean boost in the FX loop on my JCM900 for this purpose. Boosts only volume. I still use 2 boosts out front though to boost gain

[Rethfing]

I did read the posts and noted you are using a JCM900

Hi!

Im looking for some pcb layout for something, that will boost volume while playing some solos on distortion. My friend is using JCM900, and DIY Tube Screamer in front of it, but it doesnt boost volume at all while playing on distortion (its headroom issue as I read somewhere). So I need something that will make his amp louder. Is that possible to do?

You posted a TS does not boost the volume.  Are you using the boost channel on the amp? is it this preamp schematic in the link ?
http://atomiumamps.tumblr.com/post/9235920015/mods-for-jcm900-4100

If so note the diode clipping used in the boost channel of the amp.  Once you clip diodes it is harder to get more output from the clipped diodes.  You are on the B side of the chips with the boost channel and the signal gets clipped by BR2 diode bridge and one 1N4007 (3 diode drops as shown) then to an EQ then.  The normal channel uses LED clipping in the feedback loop of IC4A this should have more output signal level before clipping.

Have you tried turning the amps boost control down and the master volume up and use a TS etc with the amp?

If you use the normal channel you can use a number of different boosts before the amp.  It is hard to tell you what to use different boosts distort and load the guitar in different ways.  A LPB can load the pickup if passive and reduce the highs at full guitar volume a higher input resistance boost will not load the pickup as much.  The cable cap can change the sound of passive pickups.  There are many thread here with boosts and bufffers.

Im not sure what I should write now because I cant understand what you just wrote
This is the amp: http://bimg2.mlstatic.com/marshall-jcm-900-4100-100w-hi-gain-dual-reverb_MLB-F-3359657547_112012.jpg
It has separate volume controls for each channel + master volume. I believe my friend has pre-set master volume set to some value, and then he regulates the volume with separate controls. He is using TS (with little gain) in front of his amp (distortion channel with max gain) and it doesnt boost overall volume. So when he switch it during solos I cant hear him any louder than before he switched TS on.

You are suggesting that he should lower the volume of distortion channel but increase master volume - that way he should get volume boost with TS?
I've read that if you use TS on distortion channel it wont boost volume because it boosts headroom, and it cant boost headroom on distortion because there is already alot of it. That probably sounds dumb but thats how I read and it is true.

[R.G.]

I need >>>volume boost for solos<<<. I want to hit a footswitch and get some volume boost just for the time of solo.

An amp+speakers setup has a fixed maximum loudness it can possibly do, determined by the power supply , power amp, and speakers.  We can use it at less loudness than that by turning down the signal level it's fed. All loudnesses less than maximum are obtained by feeding the power amp a smaller signal than would drive it to maximum loudness.

Amps without the confusing stuff of pedalboards in front of them get varying loudnesses with preamps that can make at least if not more signal than the power amp needs to be fully loud, then using a volume control - or possibly many volume controls, one per channel, one labeled "drive", one "master volume", etc. - to reduce the signal down to less than full maximum loudness.

If your amp, all by itself, inside the amp, is making enough signal to get to full loudness, then you can't make it louder ahead of the amp by boosting the signal. You may be able to reduce it by cutting signal ahead of the amp, and this is one of the solutions we'll get to. If the amp produces MORE signal than the power amp needs for full loudness inside the amp, then you have to cut the signal ahead of the amp by even more to get to less loudness. And in turn, if you rely on the amplifier for any distortion at all, changing the level of the signal ahead of the amp will change that distortion tone.

The simple way to do what you want is to have box ahead of the amplifier input with one or two volume controls in it, selected by a switch. The simple version with one volume control lets you select either no volume control or the volume control. That way the "no volume control" path is the loudest, the "volume control" selection in the pedal is "less loud". This signal then goes to the amp and the amp is fed a bigger or smaller signal. The way to set this up is to switch to "no volume control" in the pedal, set the amp to the maximum loudness you want for solos, then flip to the "volume control" in the pedal and set the quieter level for non-solos. This does what you say you want if set up that way.

There are some problems, and you mention one of them: noise. Any time you feed an amplifier a smaller signal by using a resistive divider (like a volume control), you introduce the noise of the resistors, and make that more noticeable by decreasing the signal. So you get less signal, more noise. Most of the time, this isn't a problem. But if the rig is already noisy, it will only make it worse. How much worse depends on what noise is already there and where it's coming from. It could be trivially worse, or noticeably worse.

Another problem is that if the amp is used for any distortion in the final sound, changing the signal level ahead of it will change that distortion. The lower signal level will have less distortion, which may or may not be a problem.

Finally, notice that you have the idea backwards. It makes more sense to make the signal level fed to the amp smaller most of the time, then UN-restrict the signal level for solos. This is a 'boost' by comparison. And it is far easier to do than some active circuit, probably with fewer problems.

[Ark Angel HFB]

let me break down what the people are trying to say...

Gain = compression... to much gain to start with and there is no way the signal can get louder.

So, if a TS isn't getting your louder.. ether that TS is messed up, or you need to back off the gain a bit and raise the master volume.

If the second thing works it will result in you having more head room and then you can push the amp harder with the TS during solos...

[slacker]

Like clean boost in effects loop? MXR Microamp will do?

You don't need a boost in the effects loop, something to reduce the volume will work just as well. Set the volume level you want for the lead sound, then switch in the something to reduce the volume to the level you want for rhythm. The something can just be a pot wired as a volume control on a switch like this http://brushpile.files.wordpress.com/2010/12/mrcleanschem.gif  probably better schematics out there, that was the first one I found.

EDIT: just realised that's basically what R.G. said, except putting it in the fx loop instead of in front.

[midwayfair]

You dont get it, read again. I need >>>volume boost for solos<<<. I want to hit a footswitch and get some volume boost just for the time of solo.

Maciek, I can assure you, Gus does "get it." You should think long and hard before saying something like this to someone with thousands of posts.

You say that you want a volume boost "on distortion." This is not a simple question. What people need to know before answering this is:

1) Is everything on your amp already turned up to 10? If so, you're likely driving your amp so hard already that adding more gain in front of the amp (via a booster) will never work. As RG noted, amps have a limited amount of volume output based on several factors.

2) If everything on your amp isn't turned up, turn it up and then turn down your guitar's volume. This is far easier than adding another pedal -- and another potential noise source, which you said was a problem in your rig.

There's an additional complication for an amp with a master volume like yours. Your amp distortion is created based on the amount of gain way before the master volume control is in the equation. It has a point at which it starts to distort -- and any extra volume you add will just make it distort more. This is why some of the first responses involved things like "adding more speakers." It's because your amp isn't going to get louder once it's distorting a lot. The only thing that will make it louder is turning up the master volume.

So basically, you either have deal with less distortion before soloing (in which case, you should mostly just turn up your amp's master and use your guitar's volume knob), use a distortion pedal to give you more distortion at a volume level below unity (you can then turn off the distortion pedal for a volume boost into your cranked amp), do something that involves multiple amps and kicking in the second amp when you solo, or creating ... some sort of mechanism on a pedal that turns up your amp's master volume for you remotely (and yes, this is a thing).

[ghostsauce]

More volume before your distortion creator(s) = more gain. Volume after distortion creator(s) = more volume.

Put a clean boost in the fx loop and you'll get the same tone just louder. If all your distortion was created by a pedal, you could put the clean boost AFTER the pedal and it'd do the same trick.

[Rethfing]

@Gus - sorry for my previous post, I just dont understand this topic as good as you or other people here, and thats why I think opposite

@midwayfair
1) Nothing is set up to 10, its just a band rehearsal, we're playing quiet compared to how loud our amps can be.
2) Yeah, rolling down volume might do the trick but... If I do that my amps distortion will sound thin + I will never be able to roll my volume the same amount every time I use it.

Im going to play with master volume and channel volume + TS, but I thought I would get simple advice which pedal I should build. I guess I've started a topic which is far more complicated than I expected...

[Canucker]

A JCM900 is not loud enough?
 
What speaker(s) and cab(s) are you using, one or two 4x 12s cab?

You dont get it, read again. I need >>>volume boost for solos<<<. I want to hit a footswitch and get some volume boost just for the time of solo.

@Puguglybonehead and Canucker
Im trying to be careful with the amount of gain, because my friends rig is very noisy, so adding more and more gain will result in unwanted feedback and a lot of noise.

understandable but I don't know of a boost that is cleaner then the LPB.