Ideas for my first Tube project

[pudelko]

Im looking to find information for building a tube based guitar pedal.

This all started when I found an old 1960s tube amplifier in the garbage which also came with a seperate module which was used to convert mono radio signals into stereo (multiplex adaptor) The schematic of which I will post a link to, I can provide a larger version if this one is hard to read:


I would like to use at least the tube(s) from this in the creation of my first stomp box. The 3 tubes in it are all 12AU7A which ive actually found ideas for boxes already online. The transformer has no model number, but I found a site that lists it as 110/220, which im guessing are the input/output voltages?

the most interesting was this one, but it has no schematics posted:
http://www.olcircuits.com/olc_eclipsevalve.html

Another one using the 12au7 tube, which also doesnt have a schematic:
http://www.diyguitarist.com/DIYStompboxes/RealMcTube.htm

Right now I think the original mctube will be my best bet, but Id like to see if there is anything else out there.

Ive also got a few broken computer power supplies that im thinking I could grab a few parts out of as well. Maybe the transformers? I also have a bunch of pots and other electronic components that ive scavenged.

The type of box doesnt really matter, I guess Id like an overdrive/distortion pedal most, but will consider all ideas.

If anyone could help me find something that would be great! I realize that I still have to do a ton of research, which I will continue to do and post more information as I find it.

Thank you!

[frequencycentral]

Valvecaster http://www.beavisaudio.com/Projects/ValveCaster/

Tube Town Pepper Shredder http://www.tube-town.net/diy/lov/lov02-peppershredder-eng.html

Tube Town Vanilla Overdrive http://www.tube-town.net/diy/lov/lov01-vanillaoverdrive-eng.html

[wavley]

Valvecaster http://www.beavisaudio.com/Projects/ValveCaster/

Tube Town Pepper Shredder http://www.tube-town.net/diy/lov/lov02-peppershredder-eng.html

Tube Town Vanilla Overdrive http://www.tube-town.net/diy/lov/lov01-vanillaoverdrive-eng.html

Those look like some fun kits for not a bad price.

[pudelko]

Thank you for your posts. Looks like there are quite a bit of choices for me to look at

The main thing that Id like to figure out is if I can use any of the transformers that I have for a power supply. Im thinking that the power supply in the multiplex would be my first choice, but if its setup for high volts, can I still use it for any of the low volt plans? Or would I have to modify the plans to make use of it?
If I cannot use that then could there be a way to use the computer power supplies to create a 12-14v supply? I will look for plans for something like that now.

Also, Thank you to the person who PMd me the plans for the Eclipse Valve!

[petemoore]

  Pretty sure this is the best page to understand the ''hard part'' of tube circuits:

  http://geofex.com/Article_Folders/Power-supplies/powersup.htm
 
  Not sure every brick wall has been hit with the various alternatives to power supply for audio circuits made from old computer blocks, if you can dig some workin' plan up we'd like to take a look at it.

[GibsonGM]

Keep those 12AU7's!! Great tubes for lower-voltage applications.  You could look up "Tube Star' on here, too, it's a neat circuit and not too high voltage to get ya started...

[lunchie]

Also check out valve wizard web site - it helped me to actually understand tube circuits ...

http://www.freewebs.com/valvewizard/

[sean k]

When you first start out with tubes it seems incredibly practical to jump in and work with what you find, and some good stuff can come your way. Some of it seems easy to pull apart to serve your purposes while some seems so arcane you swap it out for stuff thats easier to understand and use.

Hold your fire! That little box may be worth more to you to sell on Ebay and just start from scratch with a few transformers and a tube or two.

I kinda started out with Fred Nachbaurs, may he rest in peace, little single 12AX7 preamp and though its simple and fairly cut and dried... it's a great place to start.

I just think that piece might be intereting to the radio brigade, interesting enough that you could get all the parts to build an AX84 PI... a complete amp, or buy a kit. Who knows!

Found this link last night looking for info on 6BM8's and I love how he has guitar amps, stereo amps and even radio stuff... not to mention vertical hold amps using tubes for TV's! Who knows where you'll go in the future and I recently saw two of something I just about gave away go for 450 bucks... meaning I got bugger all for it.
http://www.freewebs.com/cameramanlink/electronicsprojects.htm

One of my favourites, on another search, was an EL84 SE amp that'd been constructed on an old radio chassis using as much of the same era stuff as the radio... it was beautiful and kinda like an old tractor in the aesthetic.
http://www.stoetkit.nl/tubes4all/content/hall_of_fame/EL84.php

[petemoore]

 Cool stuff, I like 'em like that too, fine cooling respiration that way.
  Put a cabinet w/faceplate [maybe another switch or knob] on there, nice speakers under it...
  looks good-sounds great !

[charbot]

Dude, please  sell it and buy parts!  Most  hifi components  (especially Heathkit )are valuable and collectable.  Did you check ebay or some hifi sites to find out what it is and generally what its worth?  I suggest picking up a old Bogen or similar PA amp and converting that.  I have a CHB 35-A (or is it cha35b?) Just Replace the paper and elec caps (you will have to do this with any tube conversion/restoration) The two mic inputs can easily be cascaded into gain stages and then you can twiddle with the tone section til your heart's content.  Its a good, managable first tube project, likely to produce good results....and it sounds totally rad. Sounds similar to a 18W Marshall, i think.  It distorts awesomely when both stages are cranked. Rich and creamy.
You can can probably get one   for maybe $60 or less. Less than what I bet that multiplex is worth. They were very common for chuches, schools etc and built to run ALL DAY.  Mine was $10 from a junk shop.  (It has all original working tubes!) There is a bit of DIYer demand for this particular amp so Ebay will be the most expensive.

[pudelko]

Well, ive got some bad news, I started ripping the multiplex adaptor apart last night, I did have a look on Ebay earlier and didnt find anything before so I didnt think it was worth much. There are 2 on Ebay now, one ends in 5 hours, but its too late for that now I think, unless I sell it with a missing tube and a few resistors I do still have the Heathkit Amplifier and FM tuner which I will sell on Ebay after I receive a replacement tube that is bad in the amp. The funds will go towards the purchase of an Epiphone Valve Junior amplifier.

As for this project, I was anxious to get started and I almost have a working valvecaster. I still have to diagnose it as seems to pass audio for a second then dies. I havent had a chance to play with the knobs while it works, so I dont even know if its doing anything, but I will look over my connections tonight and hopefully fix it.

Thanks everyone for the tips. I hope the multiplex on ebay doesnt sell for too much, Thinking back, I probably should have kept it in good shape and sold it with the rest of heathkit stuff, but oh well.

[charbot]

The tuner would demand far more if you had the multiplex with it. It essentially provides stereo signal for FM reception.  You have the schematic, think you could put the resistors back? Consider it your first tube restoration.   
Also you might want to check  out  wht those old tubes are selling for. Even used but working tubes of certain brands fetch a mind blowing price on the hifi market. Telefunken for example. a single power tube could be woth more than a whole bogen with tubes at ebay prices.
Sorry to rain on your tube parade, but I thinkthat you will make out far better($$)  if you take this stuff straight to ebay...or you can keep it and have an amazing vintage tube stereo.

[wavley]

The tuner would demand far more if you had the multiplex with it. It essentially provides stereo signal for FM reception.  You have the schematic, think you could put the resistors back? Consider it your first tube restoration.   
Also you might want to check  out  wht those old tubes are selling for. Even used but working tubes of certain brands fetch a mind blowing price on the hifi market. Telefunken for example. a single power tube could be woth more than a whole bogen with tubes at ebay prices.
Sorry to rain on your tube parade, but I thinkthat you will make out far better($$)  if you take this stuff straight to ebay...or you can keep it and have an amazing vintage tube stereo.

This is very true.

I'm a BIG fan of a tube stereo, it warms up cds and it's how LPs were meant to be listened to.  Maybe you should just fix it and enjoy it.  Over the past few years I've upgraded with a McIntosh MX-113 (which is solid state) control unit into a tube power amp that I built from a kit and modded.  It really breathed new life into my record collection and I heard things I've never heard before on records I've owned for years.

[sean k]

If your still into finding old gear to rip up and build tube amps for guitar then those big old boxes they called stereo grams from the early to late sixties, and even into the early seventies in countries like mine that are so off the beaten track, are ripe for the picking. Old radios have weird old setups taht harken back to the thirties in the way things are done but these stereograms had phone preamps and usually two outputs set up in SE class A. And the fact that they were big and boxy and set on spindly legs meant they are easy to put in the garage and store things on top of them means they are floating around and cheap as people try to fit bigger and bigger SUV's into the garage.

The chassis are a fair size, the tube sockets are usually nine pins and the pt's and OT's can be used along with the phono amp tube and the preamp and output amp tubes...even the speakers can be interesting with that funny coney thing cut out of the centre, given they're usually alnico as well... you've got a goldmine of parts. Sixties reel to reels as well but they're more Ebay fodder for the nuts who think that kinda stuff shouldn't be made into reverbs and tape dalys for recording studios so the music they listen to is evn better...

[pudelko]

I got the valvecaster to work! I used an old input jack from a strat copy I had and didnt look carefully enough and wired the input connections backward. I also used caps that were not 47nF but much smaller, after fixing these it works! But if I turn the volume up past a quarter or so there is a loud humming sound, so some more work needs to be done, Im only on page 20 of the 80 page thread. I want to read through the whole thing before I decide what to do next.

But it sounds Amazing! Especially with the Valve Junior tube amp that I also picked up today. Really fat sounds coming from my Epiphone Les Paul Standard. I also have a tube compressor (ART Levelar) which I put one of the multiplex tubes into as well, its not a very good compressor, but its going through another tube so its all good Its a bit late tonight, but tomorrow I will make a demo video.

I will definitely look into trying to fix the multiplex, I only took out 1 tube and 3 resistors, but I did cut a few other parts out of the way. Hopefully I can get it back to working order.

I will definitely be giving the tube amp a try once its working, and based on my experience today with the guitar amp I may end up keeping it, but then again Ive seen this same amp sell for $400 on ebay (its the Heathkit AC-151), so its very tempting to just sell it. I have the tuner, now busted multiplex and all 3 original manuals that go through step by step for building everything so it should go for some good $$$.

Ill post tomorrow when ive made the video. For now here is a pic of the box on top of my new valve junior:

[sean k]

You'll never look back. Welcome to the real gentlemans club. The church of the glass bottle where the word of God is in the second harmonic!

[puretube]

You'll never look back. Welcome to the real gentlemans club. The church of the glass bottle where the word of God is in the second harmonic!

[sean k]

Funnily enough it's kinda true.

One of the places I used to frequent, and may again as I get into valves agin, is an old kinda clearing warehouse for old electronics and electrical stuff thats located mid city, still in the old wooden building, and it was taken over by a young chap of alternative leanings and (he takes a breath) he told me about a registered church they have that is about the thermionic valve being the new prophet of God. In the same breath he said that some of the disciples take it seriously while others not so seriously but they all meet up and listen to, look at, and talk about valves. Kinda neat huh!

I think every democracy in the world needs a registered church that sees God in liquid silicon envelopes that contain no gaseous elements but plently of densely packed metallics... and need high DC voltages to exist.