# Could you turn this into an amp?



## traynor_garnet (Feb 22, 2006)

I have been loving my Eh LPB-2ube pedal. It has a ton of output and can actually drive a cabinet all by itself. Of course, it's very very quiet when it does so. So this got me thinking…

What would it take to switch this pedal into an amplifier? I know it already runs the tubes at a very high-voltage, so perhaps it wouldn't take as much as it would with other tube pedals. On the other hand, maybe it would be a complete rebuild and not worth the trouble.

any thoughts or ideas?

TG


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## traynor_garnet (Feb 22, 2006)

Hmm, either this is a ridiculous proposition or I should have posted this in the effects section.


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## greco (Jul 15, 2007)

Do you not just need some type of power amp? 
You could then put both in one large enclosure, if you felt that was something you would like.

I could be very wrong here..it might be more complicated.

Cheers

Dave


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## traynor_garnet (Feb 22, 2006)

I would want want this to be very low output and know there are several amps using just 12a_7 tubes. Not sure if just an output tranny would be necessary, a full power amp out put in, or what . . .

I used to have a Stephen Stage Hog which was a "pedal amp" so I know these things exist.

thanks for chiming in

TG



greco said:


> Do you not just need some type of power amp?
> You could then put both in one large enclosure, if you felt that was something you would like.
> 
> I could be very wrong here..it might be more complicated.
> ...


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## jb welder (Sep 14, 2010)

Any pedal/amp that can drive a speaker will either have an output transformer, or some little solid state "chip amp".


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## greco (Jul 15, 2007)

jb welder said:


> Any pedal/amp that can drive a speaker will either have an output transformer, or some little solid state "chip amp".


Could one run the output signal into "some little solid state "chip amp" " and then to a speaker cab? 

Something like this.....









Would the tone form the pedal be lost/altered by doing this?

Cheers

Dave


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## traynor_garnet (Feb 22, 2006)

jb welder said:


> Any pedal/amp that can drive a speaker will either have an output transformer, or some little solid state "chip amp".


When I say it can "drive" a cab, I mean that fully cranked with humbuckers you CAN hear it through a cab! but that singe extent of it.

let me see if I can find a schematic.

TG


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## greco (Jul 15, 2007)

traynor_garnet said:


> When I say it can "drive" a cab, I mean that fully cranked with humbuckers you CAN hear it through a cab! *but that singe extent of it.*
> 
> let me see if I can find a schematic.
> 
> TG


TG...I'm getting lost here.... or I am totally "missing the boat". 

How much louder do you need/want it to be?

Cheers

Dave


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## traynor_garnet (Feb 22, 2006)

I have though of pairing it with a .44 magnum amp but wondered if I could do an all in one solution.



greco said:


> Could one run the output signal into "some little solid state "chip amp" " and then to a speaker cab?
> 
> Something like this.....
> 
> ...


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## greco (Jul 15, 2007)

traynor_garnet said:


> I have though of pairing it with a .44 magnum amp but wondered if I could do an all in one solution.


I now feel better knowing that I am at least "on the boat".

Cheers

Dave


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## mhammer (Nov 30, 2007)

The answer is more or less "yes", but you would need to swap out one of the tubes for a 12AU7. See here: http://www.ax84.com/index.php/oldprojects.html?project_id=firefly

I suspect there would need to be an output transformer integrated into it, though. I can put you in touch with the designer if you want.


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## traynor_garnet (Feb 22, 2006)

greco said:


> TG...I'm getting lost here.... or I am totally "missing the boat".
> 
> How much louder do you need/want it to be?
> 
> ...


Stupid voice dictation software. I meant my post to read, "but that is the extent of it." You can hear this pedal powering a cab but it's barely audible.

- - - Updated - - -



mhammer said:


> The answer is more or less "yes", but you would need to swap out one of the tubes for a 12AU7. See here: http://www.ax84.com/index.php/oldprojects.html?project_id=firefly
> 
> I suspect there would need to be an output transformer integrated into it, though. I can put you in touch with the designer if you want.


Wow that would be awesome! I'm thinking this pedal could serve double duty as a very low wattage practice amp, and also a dirt pedal on my mainboard with my big amp. Obviously, you would need some type of switch to go back-and-forth for different uses.

tg


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## greco (Jul 15, 2007)

traynor_garnet said:


> Wow that would be awesome! I'm thinking this pedal could serve double duty as a very low wattage practice amp, and also a dirt pedal on my mainboard with my big amp. Obviously, you would need some type of switch to go back-and-forth for different uses.
> 
> tg



Very cool concept!! 

Please keep us posted. 

I am especially interested in what is involved from an electronics perspective....along with the results, of course.

Cheers

Dave


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## mhammer (Nov 30, 2007)

I popped Doug a note, and directed him to this page. Hopefully he'll show up at some point in the not too distant future. He's good folks.


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## traynor_garnet (Feb 22, 2006)

mhammer said:


> I popped Doug a note, and directed him to this page. Hopefully he'll show up at some point in the not too distant future. He's good folks.


Awesome! Thanks so much.

I currently run the pedal with 12av7s so if I have to go to a 12au7 it won't be a huge deal for me. 

The he only other mod I would consider is a bass eq knob (set up like a Timmy's bass knob).

Could be a very cool project, but I cannot seem to find a schematic.


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## nonreverb (Sep 19, 2006)

Better yet, see if you can find a 12BH7 tube. Same pinout but will do about 3 watts...It's basically a 12AU7 on steroids.


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## Lincoln (Jun 2, 2008)

nonreverb said:


> Better yet, see if you can find a 12BH7 tube. Same pinout but will do about 3 watts...It's basically a 12AU7 on steroids.


would a 12BH7 have even more gain than a 12AX7?


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## nonreverb (Sep 19, 2006)

No, the 12BH7 is approximately the same gain as a 12AU7. Not huge gain but can deliver hefty current for it's size.


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## bolero (Oct 11, 2006)

I used a pedal into the FX return of a marshall 4203 amp a while back, it basically went right into the power section of the amp

worked well


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## mhammer (Nov 30, 2007)

Lincoln said:


> would a 12BH7 have even more gain than a 12AX7?


What Richard said, but I'll simply add that wattage is a function of how much current can be pushed/pulled/fed to a load of a given impedance. More current delivery = greater output. The NE5532 and LM833 are both dual op-amps, not all that different from the 4558 you find in Tube Screamers and loads of other pedals, but the 5532 and 833 are both capable of much higher current delivery to low loads than something like a 4558 or TL072...which is why they are often used for headphone amps. Indeed, Elektor magazine had a project just a few years ago that used a fistful of 5532 op-amps to make a 20W/channel power amp!


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## mhammer (Nov 30, 2007)

I got a response back from Doug, and his verdict is that it would probably be easier to just make an amp from scratch than convert the pedal into one.


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## traynor_garnet (Feb 22, 2006)

mhammer said:


> I got a response back from Doug, and his verdict is that it would probably be easier to just make an amp from scratch than convert the pedal into one.


Ah, that's no fun LOL

Thanks for the info. Looks like an Eh power amp may be easier in the long run. If anyone sees a used one kicking around please let me know.

does anyone know how thoses little "smokey amps" put out so much power? They are really loud and run off a battery!

TG


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## greco (Jul 15, 2007)

traynor_garnet said:


> If anyone sees a used one kicking around please let me know.
> 
> TG


I will be going to a guitar/music "swap" type event this coming Sunday. I can look for you.

How much do you want o pay for one? 
Would you be OK with either the .22 or the .44 model?

Cheers

Dave


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## traynor_garnet (Feb 22, 2006)

Thanks Dave. I would prefer the 44 but the 22 would interest me.

i would say my interest decreases as we start moving above $95; at a certain point it just makes sense to go new and return it if it doesn't work.

Please let me know and thanks for offering.

TG



greco said:


> I will be going to a guitar/music "swap" type event this coming Sunday. I can look for you.
> 
> How much do you want o pay for one?
> Would you be OK with either the .22 or the .44 model?
> ...


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## greco (Jul 15, 2007)

Does your preferred upper limit of $95.00 include the ~ $15.00 it will cost for me to ship it to you?

Cheers

Dave


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## mhammer (Nov 30, 2007)

traynor_garnet said:


> Ah, that's no fun LOL
> 
> Thanks for the info. Looks like an Eh power amp may be easier in the long run. If anyone sees a used one kicking around please let me know.
> 
> ...


Got another note from Doug (I guess he lurked a bit). Seems I misunderstood him, so I'll quote, rather than post a botched paraphrase: "you would have to make a determination whether it's worth converting the pedal or not. I have no idea what that pedal circuit is."

So, we're back to the drawing board, and placed at the choice-point. I'll see if I can score some usable technical info from the designer of the LPB2ube, who is also a semi-regular at the DIYstompboxforum.


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## traynor_garnet (Feb 22, 2006)

Ok, I am confused. I assumed "Doug" _was _the original designer . . . 

At any rate, any info is great so thanks so much.

TG



mhammer said:


> Got another note from Doug (I guess he lurked a bit). Seems I misunderstood him, so I'll quote, rather than post a botched paraphrase: "you would have to make a determination whether it's worth converting the pedal or not. I have no idea what that pedal circuit is."
> 
> So, we're back to the drawing board, and placed at the choice-point. I'll see if I can score some usable technical info from the designer of the LPB2ube, who is also a semi-regular at the DIYstompboxforum.


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## mhammer (Nov 30, 2007)

Doug designed the Firefly amp (and some terrific pedals, too). The "other guy" is Ton Barmentloo, the fellow who designed the LPB2ube (and many other things for EHX). Doug's in the USA, and Ton is in Germany. If Doug needs more info about the insides of the LPB2ube to make any sort of recommendation one way or the other, then it behooves me to find out more about the insides. I expect Ton to guard his I.P. closely, since it is his livelihood as an independent designer. But perhaps he'll be willing to disclose a few tidbits that might suggest a suitable course of action. He's also good folks.


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## mhammer (Nov 30, 2007)

And here is what Ton said: 

" _No-I can`t recommend to alter the pedal into an amp: power-supply probably too weak...

( although I was able to assist ZVEX in his attempt to use the E-H trafo for his:
http://www.diystompboxes.com/smfforum/index.php?topic=32861.0 )

The circuit itself (designed by Loy Dang of E-H), doesn`t lean itself to be turned into an amp...
And: where to put the OT?
Better start from scratch, and leave the pedal as-is... _"

Ah well, it was a sweet dream while it lasted.....
I thought Ton had designed the pedal, since the basic form factor used for EHX tube-based FX is his, but apparently, as he notes, this was not his baby.
http://www.puretube.de/


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## greco (Jul 15, 2007)

mhammer said:


> ......"_Better start from scratch, and leave the pedal as-is... _"


Back to the drawing board.

Cheers

Dave


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## traynor_garnet (Feb 22, 2006)

Ok, thanks for all your help. I looks like it is just better to wait and find an EH .44 Magnum amp pedal.

The interesting news is that the LPB-2ube has kicked my Timmy off my board. Nothing has done this in almost a decade. I was kind of shocked, but I would be happy with either; they are kind of like different takes on the same flavour of ice cream. I won't be selling my Timmy but for now it is sitting off my board.

The 2ube is just a great pedal once you switch tubes and keep the gain down. Now I am really interested in trying the EH English Muff'm from the same series.

TG


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## WCGill (Mar 27, 2009)

This might be easier than turning this thing into an amp. :smile-new:


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