#1
Well here's the thread for the build I want to do. It may be a pipe dream, but it's worth an attempt of research and brainstorming.

I want to attempt to build a battery powered tube amp... That sounds good!
Now the power source on most schematics for most portable amps is a 9 volt cell. It doesn't have to have that. So that frees up some options.
Now I'll admit I really don't know a lot about tube amps, but I am really good with solid state amps. So I've been lurking around, looking at diagrams and other post by other users to try to understand how this could be possible to build. Though as you can apparently see by me making this post. I have not figured it out.

So here's the meat of this thread.
If you have any suggestions, comments, or idea's Please post them. They are very much appreciated. I'll be posting updates on my progress, until it's built. Or until the idea is murdered and thrown outback, or fails.

Thanks for taking the time to read this, and have a jolly ol' good day
#2
The start.

Ok, Only portable tube amp I have been able to find after hours of searching is the tube cricket, which was stated before by S.R.V. Seems this isn't a popular idea.

Stated in another thread...
Quote by Losenger
You could use batteries to power an inverter that would power a more classic circuit. There exist some tubes that are designed to be used with lower voltages: http://www.duntemann.com/12vtubes/12vtubesindex.htm

Something that I never thought of, thus is why i'm asking for brainstorming idea's.
In the same thread "I accidentally hijacked it for a min."
Quote by motorcycleboy
i wonder if a rechargeable battery like in a dewalt 18 v power drill could be used to power a small amp.....the flashlight that comes with most kits could be sacrificed to provide a socket for the battery and im sure way could be found to match voltages........we use these batteries to drive screws into hard wood all day on one charge and would probably outlast the current designs out there.....or do tubes have to run on 110vac..........i think even so, solid state practice amps and the like could benefit from the extra juice

I never thought of using a rechargable battery like that, but the question still remains. Would it be enough juice to push the tubes?
#3
i wouldn't MAKE a tube amp and make it portable. if i make a tube amp (ever), then i'd make it big, loud, and awesome with lots of money and effort put in.

making the cheapest tube amp, i'd assume $150+. tubes are $25ish even if u use a 12AX7 and an EL84 (probably one of the cheaper combinations). then, a speaker. get a 12" speaker (because i don't like it smaller), and spend $50 on it (nice spekaer used. if not, $100 for a good one, bit less for eminence). there u got $75. now get the metal chasis. u're lucky if u get it $20. that's $95. now u forgot all the resistors, components. that i'll say $5. now, if u get ALL those things from one place, shipping would be like $20 (speaker is heavy). OR, if u get it from different places, even worse. approximate around $50~60 for all the shipping.

there we go. u can just buy an epiphone valve jr for $150 and be happy with it. they're quite portable too.

and if u need it to work on batteries, i'd advice not looking tubes.
Call me "Shot".

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Custom Hand-wired Amplifiers and Effect Pedals.

Est. 2007


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#4
Quote by ECistheBest
i wouldn't MAKE a tube amp and make it portable. if i make a tube amp (ever), then i'd make it big, loud, and awesome with lots of money and effort put in.

making the cheapest tube amp, i'd assume $150+. tubes are $25ish even if u use a 12AX7 and an EL84 (probably one of the cheaper combinations). then, a speaker. get a 12" speaker (because i don't like it smaller), and spend $50 on it (nice spekaer used. if not, $100 for a good one, bit less for eminence). there u got $75. now get the metal chasis. u're lucky if u get it $20. that's $95. now u forgot all the resistors, components. that i'll say $5. now, if u get ALL those things from one place, shipping would be like $20 (speaker is heavy). OR, if u get it from different places, even worse. approximate around $50~60 for all the shipping.

there we go. u can just buy an epiphone valve jr for $150 and be happy with it. they're quite portable too.

and if u need it to work on batteries, i'd advice not looking tubes.


Lol, always gotta rain on a parade ^_^

I don't really need it, I'm just really doing it for a learning aspect.
I have most of the parts, along with a random celestion speaker laying around.
about the only thing I don't have, is the tubes. the Chasis I was going to make mostly out of wood. But I have a nice size sheet of metal for a grounding plate.

Kills your budgeting doesn't it ^_^
#5
I find the idea interesting.

The ZVEX Nano already runs on 12V, so that would be a good starting point.
#6
eh well. for a learning aspect, i'd recommend something like a lie detector (/joke) but like... building an amp. it's practical. and u can use it. but wouldn't u kill if u mess up?


i'd recommend building a ruby. it's asolid state 1/2 watt or something amp. i've heard it's been sounding pretty good, so i said i'd give it a try. so i have parts here to make it hahaha.


i've been wondering tho.
http://zvexamps.com/guts.html
zvex nano has so many transistors. wtf is up with that? i see a mosfet IRF470, three in a TO-92 case, and one in a metal can...
Call me "Shot".

ShotRod Guitar Works

Custom Hand-wired Amplifiers and Effect Pedals.

Est. 2007


Source to everything I say about Guitars, Pedals, and Amplifiers: I make them.


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Last edited by ECistheBest at Feb 8, 2008,
#7
Don't you think that if it were possible to run a tube amp off a small battery to make it portable, it would have already been done by now?

Tubes take a lot of power to run properly. Even the ZVex Nano, thought it can runs off 12v power or whatever, would drain a battery quick, I bet.
Last edited by forsaknazrael at Feb 8, 2008,
#8
Quote by ECistheBest
i've been wondering tho.
http://zvexamps.com/guts.html
zvex nano has so many transistors. wtf is up with that? i see a mosfet IRF470, three in a TO-92 case, and one in a metal can...
You didn't think they were gonna run the plates from 12 volts, did you?
And you can't put DC through a transformer, to step up the voltage. (hint, hint)
Meadows
Quote by Jackal58
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Quote by SK8RDUDE411
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#9
Quote by forsaknazrael
Don't you think that if it were possible to run a tube amp off a small battery to make it portable, it would have already been done by now?

Tubes take a lot of power to run properly. Even the ZVex Nano, thought it can runs off 12v power or whatever, would drain a battery quick, I bet.


Hmm... It's rated at 1.5A at 12V. The relatively small battery in my motorcycle is rated 9AH, and is roughly the size of the Nano. So, 6 hours of operation, assuming a sine wave input?
#11
... back to my inverter idea, ahem. If you want true portability in a tube amp, it would have to be battery powered, yeah? If you're going to use conventional tubes, you would be required to step the voltage up, which would require an inverter circuit. Basically, you change the DC to AC with an oscillator, then step up the voltage with a transformer.

If you have an oscillator, you can run it through something like a toroidal power transformer: http://www.hoffmanamps.com/MyStore/perlshop.cgi?ACTION=enter&thispage=parts1.htm&ORDER_ID=!ORDERID!

After that, you can have the conventional power supply and tube circuit. Doing it this way is rather inefficient, though, since every time you convert the power, some is lost as heat due to different types of energy resistance. Efficiency doesn't matter as much when you're plugged in to an outlet. It matters more if you're relying on a battery.

If you want to keep it all 12VDC, mess around with those space charge tubes. They don't get very loud, but some configurations sound pretty good. Plus, you don't have to worry about high voltages.

Just as an aside, does anyone here think that portable tube amps have a real world market? I mean, do they have an advantage over solid state portables in any way? Would anyone want or need a tube amp while camping?

Oh, and I'm sorry, WickedBeast, but I have to correct you. It's not a 9 volt cell, it's a 9 volt battery. Cells consist of one anode and one cathode. Batteries consist of two or more cells. Yes, I'm anal
#12
The Nano uses a pretty tricky method of ramping the voltage up WAY higher than 12V with no induced noise in the system. I've read the notes on the power supply construction for the amp and it's rather ingenious/complicated - something like 17 components to get the B+ voltage at around the 250V mark without inducing noise into the system.
"Everybody, one day will die and be forgotten. Act and behave in a way that will make life interesting and fun. Find a passion, form relationships, don't be afraid to get out there and fuck what everyone else thinks."
#13
Quote by the_random_hero
The Nano uses a pretty tricky method of ramping the voltage up WAY higher than 12V with no induced noise in the system. I've read the notes on the power supply construction for the amp and it's rather ingenious/complicated - something like 17 components to get the B+ voltage at around the 250V mark without inducing noise into the system.
Do you recall if either the phrase "charge pump" or "Cockroft-Walton" was used?
Meadows
Quote by Jackal58
I release my inner liberal every morning when I take a shit.
Quote by SK8RDUDE411
I wont be like those jerks who dedicate their beliefs to logic and reaosn.
#14
Don't you think that if it were possible to run a tube amp off a small battery to make it portable, it would have already been done by now?



I don't know... but with your logic, lets look at the world.
If it was possible to have the wheel, why did it need to be invented? someone should of already invented it before it was invented.
If it was possible to have flight, why did that need to be invented? someone should of already had it invented before it was invented.

Now lets bring this to the guitar world...

If it was possible to have a tube amp, why did someone need to invent it? It should of already been invented.
If it was possible to have a solid state amp, why did someone need to invent it? It should of already been invented.

Now lets take this a step farther. Why did someone invent the electric guitar? we already had acoustics... and if it was possible to have an electric guitar, then why did it need to be invented?
#15
Portable (very small) amp: doable;
Battery powered amp: not so doable.

But don't be discouraged. Learn as much as you can about tube amps, then try it. Imagine if you did manage to make a good-sounding, small amp with decent battery time. It would definitely be something to be proud of.


Quote by ECistheBest
i wouldn't MAKE a tube amp and make it portable. if i make a tube amp (ever), then i'd make it big, loud, and awesome with lots of money and effort put in.

making the cheapest tube amp, i'd assume $150+. tubes are $25ish even if u use a 12AX7 and an EL84 (probably one of the cheaper combinations). then, a speaker. get a 12" speaker (because i don't like it smaller), and spend $50 on it (nice spekaer used. if not, $100 for a good one, bit less for eminence). there u got $75. now get the metal chasis. u're lucky if u get it $20. that's $95. now u forgot all the resistors, components. that i'll say $5. now, if u get ALL those things from one place, shipping would be like $20 (speaker is heavy). OR, if u get it from different places, even worse. approximate around $50~60 for all the shipping.

there we go. u can just buy an epiphone valve jr for $150 and be happy with it. they're quite portable too.

and if u need it to work on batteries, i'd advice not looking tubes.


You're forgetting the most expensive parts: transformers. They add another $50-$100 (or more) easily.
Last edited by mr_hankey at Feb 8, 2008,
#16
Damn... ie crashed, and I had something good said lol. ^ but i agree, You never know what you can do, until you try. Then once you reach your limit.. push harder lol...
#17
Quote by WickedBeast666
Quote by forsaknazrael
Don't you think that if it were possible to run a tube amp off a small battery to make it portable, it would have already been done by now?



I don't know... but with your logic, lets look at the world.
If it was possible to have the wheel, why did it need to be invented? someone should of already invented it before it was invented.
If it was possible to have flight, why did that need to be invented? someone should of already had it invented before it was invented.

Now lets bring this to the guitar world...

If it was possible to have a tube amp, why did someone need to invent it? It should of already been invented.
If it was possible to have a solid state amp, why did someone need to invent it? It should of already been invented.

Now lets take this a step farther. Why did someone invent the electric guitar? we already had acoustics... and if it was possible to have an electric guitar, then why did it need to be invented?

Um...Your argument doesn't make ANY sense.

The wheel needed to be invented because man needed a more efficient method of transporting things. It's called necessity.
Flight WAS possible before man could achieve it. They're called birds. It wasn't invented.

It's not that things needed to be invented because they were invented (Whatever the fuck THAT means. )...You read my point wrong.

What I'm saying is, you're not an electronics genius. There are, however, MANY electronics experts out there who tube build tube power amplifiers. Yet they either have not created a portable tube amp. This means one of two things, or both:
- no desire to make a portable tube amp.
- it's not possible.
#18
Quote by SomeoneYouKnew
Do you recall if either the phrase "charge pump" or "Cockroft-Walton" was used?


I'll try and find the original article, but it was touted as being very original and ingenious. I'll have a look tomorrow morning, there's a schematic that goes with it too.
"Everybody, one day will die and be forgotten. Act and behave in a way that will make life interesting and fun. Find a passion, form relationships, don't be afraid to get out there and fuck what everyone else thinks."
#19
Quote by forsaknazrael
^well, how small is small to you? If it's something that isn't comfortable to lug around, I'd cross it off the list.

Even then, I think what SYK was saying is that you can't run DC through the transformer.



It would be less than 1/4 the size of my Valve Jr, although I think I would hesitate to strap it to my waist.
#20
Quote by mr_hankey
Portable (very small) amp: doable;
Battery powered amp: not so doable.

But don't be discouraged. Learn as much as you can about tube amps, then try it. Imagine if you did manage to make a good-sounding, small amp with decent battery time. It would definitely be something to be proud of.


You're forgetting the most expensive parts: transformers. They add another $50-$100 (or more) easily.

they just discussed you can't put DC through transformers...?
Call me "Shot".

ShotRod Guitar Works

Custom Hand-wired Amplifiers and Effect Pedals.

Est. 2007


Source to everything I say about Guitars, Pedals, and Amplifiers: I make them.


UG's Best DIY PedalBoard
#21
Quote by ECistheBest
they just discussed you can't put DC through transformers...?


That was after your post, mr. smartypants.
#22
If you want it to be battery powered, the best I can think of is to use one of those emergency things that you can plug into a cigarette lighter in a car and have an outlet.
Will says:
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- SmarterChild - says:
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#24
I don't think it was like that, but I'm not too sure.

Maybe something like this would also work.
http://www.canadiantire.ca/browse/product_detail.jsp?PRODUCT%3C%3Eprd_id=845524443289558&FOLDER%3C%3Efolder_id=1408474396673606&bmUID=1202513301358&deptid=1408474396672395&ctgrid=1408474396672406&subctgrid=1408474396673606
If you need to enter a postal code to view it, use b3f 1g6.
Will says:
DON'T FEAR THE REAPER!
- SmarterChild - says:
I don't know if I can help it.

Member #6 of the "I play my guitar as high as Tom Morello does" club
#26
Now they're catching on! I thought of using a small inverter with a sealed lead acid battery, but haven't tried it yet. The UPS is an inverter with a battery included.

So nobody has an opinion about whether or not completely portable tube amps would be attractive?
#27
Quote by Losenger
Now they're catching on! I thought of using a small inverter with a sealed lead acid battery, but haven't tried it yet. The UPS is an inverter with a battery included.

So nobody has an opinion about whether or not completely portable tube amps would be attractive?


I might have an opinion.

It could be attractive, but it becomes borderline portable.

Making something the size/weight of the Crate Taxi (in the photo) would still allow for a speaker large enough to appreciate the difference between a tube amp and a solidstate.



Something as small as an original pignose just won't cut it,
unless you get some genius like Amar Bose to design the speaker and enclosure.
(Check out the Bose Acoustic Wave Music System, if you want to hear something amazing)

12.6 volts for the batteries would be a good choice.
You can run the heaters directly from them.
Either Gel Cells, AGM, or NimH.

Forget about even an EL-84 for the output tube.
Too much current for the heater (760 mA)

Both sections of a 12AX7 in parallel, or push-pull could get you about 1~2 watts output.
Both sections of a 12AU7 could get you about 2~4 watts
Using two 12AX7s, or a 12AX7 and a 12AU7 would require a total of 300 mA

If you found an inverter that was designed for 240 volts,
you wouldn't need a transformer to get your plate voltage.
Just use a bridge rectifier on the output, and filter it.

Since you're running only the plate supply through that, it could be EXTREMELY small.
We're talking 7~10 watts.


... How's that for an opinion?


...
Meadows
Quote by Jackal58
I release my inner liberal every morning when I take a shit.
Quote by SK8RDUDE411
I wont be like those jerks who dedicate their beliefs to logic and reaosn.
Last edited by SomeoneYouKnew at Feb 10, 2008,
#28
Hmm, something like the Ax84 Firefly? It's drawing 450mA, which isn't too much all things considering. I suppose you could redesign the pre-amp stage to cut it down to only using two tubes throughout if you were keen.
"Everybody, one day will die and be forgotten. Act and behave in a way that will make life interesting and fun. Find a passion, form relationships, don't be afraid to get out there and fuck what everyone else thinks."
#29
zvex has a tiny half watt tube amp. I'd look into that.
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#30
What I actually meant was, would anyone buy a portable tube amp, and spend more money on it, or settle for the current solid state completely portable amps such as Pignose? Would anyone want a truly portable (camping in the woods) tube amp, or just buy a nice solid state they could play through?
#31
Quote by Losenger
What I actually meant was, would anyone buy a portable tube amp, and spend more money on it, or settle for the current solid state completely portable amps such as Pignose? Would anyone want a truly portable (camping in the woods) tube amp, or just buy a nice solid state they could play through?


doubt it, not many people even want portable amps in the first place.
#32
Making something the size/weight of a Taxi would still allow for a speaker large enough to appreciate the difference between a tube amp and a solidstate.


.... I don't quite understand what your saying.... If you mean Taxi as in car... well umm, normal tube amps are not that big anways, lol. I think i just lost your meaning.
#33
Quote by WickedBeast666
.... I don't quite understand what your saying.... If you mean Taxi as in car... well umm, normal tube amps are not that big anways, lol. I think i just lost your meaning.
And I think you're just giving me a bit of a wind-up. lol

Just in case you're not, the picture of the Crate Taxi battery powered portable amp is in the post you took the quote from.

For those mentioning the Zvex, it's 100 miliwatts clean, 500 miliwatts distorted.
That's probably enough for an efficient 4 -12 cab,
but it's a bit light to drive an single 8 with any bottom end.
Meadows
Quote by Jackal58
I release my inner liberal every morning when I take a shit.
Quote by SK8RDUDE411
I wont be like those jerks who dedicate their beliefs to logic and reaosn.
#34
here are some tube amp schematics

here are some more

one link or the other has to be helpful or if all else fails you could make a solid state then make one of the tube pedals or a tube cricket
#35
Quote by SomeoneYouKnew
And I think you're just giving me a bit of a wind-up. lol

Just in case you're not, the picture of the Crate Taxi battery powered portable amp is in the post you took the quote from.

For those mentioning the Zvex, it's 100 miliwatts clean, 500 miliwatts distorted.
That's probably enough for an efficient 4 -12 cab,
but it's a bit light to drive an single 8 with any bottom end.

Ah, I havn't fully looked at crate amps... thus i didn't know it was called a taxi thus is why i was confused lol.
#36
^ Okay, cool. I edited that post to make it clear, so no one else might get confused.
Meadows
Quote by Jackal58
I release my inner liberal every morning when I take a shit.
Quote by SK8RDUDE411
I wont be like those jerks who dedicate their beliefs to logic and reaosn.
#37
Quote by SomeoneYouKnew
^ Okay, cool. I edited that post to make it clear, so no one else might get confused.

Yah i thought you were talking about Taxi's as in the CAR... like a new york taxi cab lol.