low wattage all tube

[Papa_lazerous]

Evening all,  at the risk of this being in the wrong area fo the forum, but also the busiest.

I am looking to build an all tube amp it needs to be ultra low power.  thinking 1/2 or 1watt

any ideas or seen any projects or schematics floating around on the net?

[JonFrum]

Try the Firefly at 18watt.com


http://ax84.com/bbs/


I built a similar 12AU7 amp, but I made it push-pull. I built it into a Peavey Rage 158, and put in a Weber Sig series speaker. It's nice to have for bedroom practice so I dont' have to use my higher power amps with the more expensive tubes in 'em.

[infinitemonkey]

People say good things about the Gilmore Jr. from Guytronix.  It's sold as a kit, though, so if you want to build completely  from scratch, it may not be quite what you're looking for. Site is here: http://www.guytronix.com/

[alextheian-alex]

Evening all,  at the risk of this being in the wrong area fo the forum, but also the busiest.

I am looking to build an all tube amp it needs to be ultra low power.  thinking 1/2 or 1watt

any ideas or seen any projects or schematics floating around on the net?

Aer you looking to run it off batteries a'la stompbox, or are you just looking at building a plaiin old small tube amp?  Also, what kinda sound do you have in mind?

[Ronsonic]

I built one using a single 12DW7. The 12AX7 like side is the first gain stage and drives the low gain side which uses a Fender style reverb driver tranny for an output tranny. There was plenty of output power, relatively speaking, but it really needs more gain. I couldn't drive close to full power with any normal guitar pickups.  Next time, I'll use two whole tubes, a 12AX7 for drive and maybe a tone stage to burn off some gain and a paralleled 12AU7 for an output. Could also use 12BH7 for a power tube. If you designed something like a champ using a paralleled tube like that for the output you'll be just about there.

Ron

[MartyMart]

Search at 18watt.com for the "Heavy Watter" that's approx a 1.8 watt fairly high gain
all valve amp.
Mine is still 3/4 finished !!

MM.

[JonFrum]

I built an amp similar to the Gilmore Jr, but I designed it myself. It has a 12AX7 input, a 12AT7 phase inverter, and a 12AU7 power tube. No tone stack, no indicator light, just a volume pot. I used Randall Aiken's articles to design the preamp, and guessed at the power tube. It works, but i wouldn't use it to show off my skills.       It definitely breaks up like crazy.

[Papa_lazerous]

Aer you looking to run it off batteries a'la stompbox, or are you just looking at building a plaiin old small tube amp?  Also, what kinda sound do you have in mind?

Nope not planning on running stompbox stylee' (I've got a matchless Hotbox clone in the pipeline for that  )

I am thinking of buildng a small combo, for the main reason I cant take my 50Watt Laney TFX-1 with me when I move its just too loud.  The Kinda sound I am after, Creamy sustaining compression distortion, the kind that you only get from driving the output stage to the max, not the crunchy clipping distorion you get from over-driving the pre-amp tubes.  I'm looking into the FireFly at AX84.com right now, not too sure on what sounds it sill be good for thats why I am looking around and asking anyone who'll stand still long rnough what they recommend.

The Gilmour Jnr.  Hmmm its not cheap for the Kit.  The thing is I work in a machine shop on nights I have a clear pass to make whatever I want as long as my proper work is done by morning so I can and will be doing my own chassis and face plate and probably do all the wood work on a mill too, beats the hell out of using hand tools.  So a kit is going to be a waste of money.  I am looking for schematics only really

[JonFrum]

I was happy to get out of the machine shop years ago. but i really miss being able to do "home projects". I worked second shift, and I was alone in the room, so I made a lot of goodies over the years.

There should be some firefly clips available. Creamy is a lot to ask for, but it does distort pretty good.


Here's the schem for the Heavywatter:





I can't vouch for it, but someone mentioned it above.

[Papa_lazerous]

Thanks for the schematic I'll print it off before it gets buried under a 1000 posts.

I can see me building and selling off a few dozen things before finding what I want 

You used to be in the machine shop JonFrum?  What was your trade?

I'm a CNC miller, well programmer/setter.  can do the manual stuff too.  Try and keep away from sheetmetal unless its 'homework'  likewise with turning

[Papa_lazerous]

Just done a bit of googling (has that officially become a word yet?  Its bound to)  and I came up with this.....  Its a nice adition to the previos schematic

http://www.sonicdeli.com/ThunderTweakWeb/images/HEAVYwatter_boardV351.pdf

[alextheian-alex]

A few here too:http://www.ricktone.com/schems.shtml

and here: http://amps.zugster.net/projects

[Papa_lazerous]

Cheers, the adams amp site is good especially like the sutff on sub-minuture valves   

The first link I am still sifting through, nice find

[JonFrum]

Thanks for the schematic I'll print it off before it gets buried under a 1000 posts.

I can see me building and selling off a few dozen things before finding what I want 

You used to be in the machine shop JonFrum?  What was your trade?

I'm a CNC miller, well programmer/setter.  can do the manual stuff too.  Try and keep away from sheetmetal unless its 'homework'  likewise with turning

I did maintenance machining and tool and die in a sheet metal shop and a foundry. The sheet metal shop made chassis for the computer industry - when we had a computer industry in Massachusetts - and the foundry made boxes for electrical construction - like the ones people here use occasionally. I liked the work, but you start doing the same jobs over and over. We never had CNC machining - it was all "old school".   

[phil]

Here's the schem for the Heavywatter:

Here's  links to the site with a layout for The Heavywater as well as sound clips:

Layout: http://www.sonicdeli.com/ThunderTweakWeb/images/HEAVYwatter_boardV351.pdf
Sound Clips: http://www.sonicdeli.com/ThunderTweakWeb/heavywatter.htm

I've been looking at it as well as the Firefly since I'm going to gut one of my Epi Phone Valve Juniors to convert it. Off hand it's very tempting as I can use both the PT and OT from my Valve Junior and  90% of the parts remaining part are in the Valve Junior to do the HeavyWater, but the clips that I've heard of the Firefly sound better to me so I'm probably going to buy another OT and do the Firefly.

Ebay has quite a VJRs for sale fairly cheap.

Here's a link to a schematic for the stock Version2 Head in case you want to see what parts might be reusable. You'll see that most the parts are in the Vjr including the Power Filter Caps. (The PT is not Center tapped, so you'll need to use 4 diodes to do full wave rectification - but that's already how it's setup in the Vjr anyway):
http://mercurymagnetics.com/images/pdf/schematics/wiring/E-VJ-Schem2a.pdf

[Papa_lazerous]

Phil you been posting over at AX84??  There is a current post about gutting a VJ to do exaclty what you after I am alos thinkng along the same lines.  I figure buy a cheap VJ probably from the US and get someone I know to post it to the UK (US prices are VERY cheap and the PT has windings for 230V)  play with it then rip it apart and possibly go the firefly route but then the heavy watter is also an option.  I hate choices!

[brett]

Hi

but the clips that I've heard of the Firefly sound better to me

My Firefly is very low output. 
So I'm going to convert my Firefly output section to the one in the HeavyWatter.
Also, the cascode input option of the Firefly has too much gain for my tastes.

The HeavyWatter looks exzcellent
cheers

[phil]

Phil you been posting over at AX84?? 

Yes that's me - I'm planning to post my progress in converting my now defunct Valve Junior (the stock PCB is finally falling apart from all the modding) into a real low power amp (2 watts or less). I really had it in mind to convert it to a Firefly, but then I saw the 1 watt HeavyWatter and am so tempted to build that since I can use the PT and OT unlike in the Firefly where I need to get a different OT as it is Push/Pull.

One thought is, if you don't mind spending the extra time, you could buy the VJR and build the HeavyWatter and if that's not the sound you are looking for, you could tear it down and build the Firefly - The only thing you would be out is about $5 worth of resistors, caps, and pots since you don't have to get new Iron for the HeavyWatter ...

[phil]

My Firefly is very low output. 

Thanks for the info! In my case low output is exactly what I want so I can get tube saturation at bedroom volumes ...

[Papa_lazerous]

My Firefly is very low output. 

Thanks for the info! In my case low output is exactly what I want so I can get tube saturation at bedroom volumes ...

+1  But in my case its because I am moving to a new flat where the noise isn't going to make me many friends 

Phil you say I can use the same PT & OT from the VJnr in the HeavyWatter??  I wasnt aware of that.  I am very interested in being able to make a heavywatter on the cheap and then as you say there is the possibility of making a firefly also..

I think if its something you are serious about we should combine forces on it a little would seen silly for two of us to be working on the same project and not sharing brain power