Boobtube and beavis audio tube overdrive stompbox [HELP]

Started by Will.mendil, April 24, 2014, 05:16:12 PM

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Will.mendil

Hi guys.
I have tested the beavis audio tube pedal but it sounded terrible. I don't really understand the 9v on the filament thing plus the bias gain knob hence terrible hum and sound. Though I am sure it's my tube that is rubbish. I still undertook to build the boob tube. With the murder one s charge pump

http://juansolo.demon.co.uk/stompage/btbuild.html

But it does not seem to be working.I have a couple ideas on why, mainly the tube. Has anyone tested this circuit?

How fragile is a tube per say? I substituted the max1044 for what people said was better ( I cannot remember the name ). I get between 60v to 80v in the 1 and 6 pins and between 12 v and 14v on the filament.

I think I need assistance as it is my first tube. ie very poor experience.

Cheers
Don't know what to do with a paritculare transistor? Check this website where stompbox pedals are listed by what transistors they use

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vigilante397

My very first pedal build was Matsumin's Valve Caster (I believe that's what you are referring to from Beavis), and I ended up building two, as well as a couple twin casters. The quality of the tubes will obviously make a difference, but unless you use an absolute garbage tube I can't imagine it sounding "terrible." Though I will admit I think running it at 9v is a mistake. I always ran mine with a 12V 1A power supply and I loved the tone. I found that the higher the current rating of the power supply is the better the pedal sounds and the less hiss you get.

I've never tried the boobtube though I've heard good things about it. Do you have any other tubes to try to make sure it isn't a problem with the tube? Tubes aren't always the problem, but they are a good place to start if you're sure you're getting voltage that far. I usually use JJ/Teslas for my builds (depending on my budget), but you can get decent 12AU7's on ebay for around $5.
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"Some people love music the way other people love chocolate. Some of us love music the way other people love oxygen."

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mth5044

I'd imagine if you are using a charge pump for the filaments you aren't getting enough current. Split the 9V power source to a 7806 for filaments (or just use the 9V) and to the voltage multiplier. Don't feed the filaments 14V.

Will.mendil

Thanks for your feedback. I didn't think o running it at 12v simply because I don't have a 12v supply :s need to get one I know. I guess I'll follow what you said and try the beavis again ( indeed that is the one you mentioned). I am awaiting two new tubes. But when I tested the only tube I have I realised it was miss wired and I wonder if I have not broken it when testing it :(.
Do you have a link for your 5$ tubes? I do worry about the shipping cost to France.

Could it be the amperage of the my 9v box that is not enough. I haven't got the value exactly but would this be a problem especially when charge pumped?
Cheers
Don't know what to do with a paritculare transistor? Check this website where stompbox pedals are listed by what transistors they use

http://scfxguide.wordpress.com/

Will.mendil

I was typing when I got the answer from mth5044. I'll sort out the filament since it does not even warm up the tube. I'll do all that tomorrow
Don't know what to do with a paritculare transistor? Check this website where stompbox pedals are listed by what transistors they use

http://scfxguide.wordpress.com/

vigilante397

It seems the posting I was using expired, but I have bought tubes from this guy in the past (not sure about France shipping) but you could try.

http://www.ebay.com/usr/antique-radio-picker?_trksid=p2047675.l2559
  • SUPPORTER
"Some people love music the way other people love chocolate. Some of us love music the way other people love oxygen."

www.sushiboxfx.com

mth5044

I think I read somewhere that a filament at 12V needs 150mA? Something like that. The LT1054CP can put out 100mA max. The MAX1044 can only do about 20mA.

Will.mendil

Ok next on the to buy list is a high current 12v transformer then
Don't know what to do with a paritculare transistor? Check this website where stompbox pedals are listed by what transistors they use

http://scfxguide.wordpress.com/

vigilante397

  • SUPPORTER
"Some people love music the way other people love chocolate. Some of us love music the way other people love oxygen."

www.sushiboxfx.com

Will.mendil

Wow 1$ ... That is do cheap. I can only find minima of ~10$ for France ( including shipping) will keep searching
Don't know what to do with a paritculare transistor? Check this website where stompbox pedals are listed by what transistors they use

http://scfxguide.wordpress.com/

Will.mendil

Stupid thing!!! Just delete my mile long post :(.
So as I was saying. It is finally alive. I ve connected the pins in series to the 9v though I think my brick I getting old as it goes up to 12v by its own.

Any way I think I'll add a SHO on the end with a master boost switch.

Plus I think the pots are not right lin vs log. On the boob tube schematic. Would you expect to have a log on the volume and Lin on both the gain and tone?
Anyway it does not sound finish but I am very happy especially since all my other pedals sound great I. Front of it.

Thanks for your help
Don't know what to do with a paritculare transistor? Check this website where stompbox pedals are listed by what transistors they use

http://scfxguide.wordpress.com/

juansolo

#11
I really should update that page to simplify it to just cover a 9v source. That way there's only one way to do things. As it is:

Essentially the heaters are the high current draw, these want to be either 12v wired in series or 6v wired in parallel. So if you're using a 12v regulated supply run it from that. If you're using a 9v supply you'll need to regulate it down to 6v. Do not try and run them from a charge pump going up to 12v, it won't work.

The plates are high voltage but low current. As far as things go, the more power the merrier. This is the charge pumped bit.

That supply on that page is Renegadrians layout fettled with all the bits you need to run a tube effect. IE. You put a decent 9v supply on the front (1A will be more than sufficient) and out the other side you get about 6.2v for the heaters and 60v for the plates.

If you want to live dangerously, I've since fettled another of his layouts to do something similar and use a beefier inductor:



Please note the yellow link under the board. Do that first and continuity check the crap out of it before continuing :) It just keeps the board as small as possible. Also don't go over 190V on the HV, it can get a little unstable beyond that. Oh and it needs two heatsinks...

FWIW, I've built multiple pedals with both supplies.

Here's one using the big one:



If you want to make your life easy, TH Custom does a PCB that's a boobtube with the other supply built in:



Neither are my prettiest builds...

Will.mendil

What an honour to meet the holy creator!! Thanks for your advice. I have ordered the 12v 1A  power supply and the 7806 so I can try both on different project. (I have preserved a Russian ute than only runs on 6v)
Since this is my first use of these 78xx how hot do they get when turning 12v or 9v to 6v does it depend on the current?

I have accidentally put the 9v on the filament in parallels, they glowed red hot :s  did not damage them well might have shorten they live-span but the tube still works.

Do you have an updated website?  All I know is that the schematic is going on my blog (if you don't mind)

But now that I got you ( sort of speak) what type of pots did you intended to use log vs Lin.

Anyway thank you mate. Always wanted to make one of these.
Don't know what to do with a paritculare transistor? Check this website where stompbox pedals are listed by what transistors they use

http://scfxguide.wordpress.com/

juansolo

#13
Just caught the post by chance. ;) I don't stick my head in here that often these days. The tube build thing hasn't been updated in ages. I should simplify it... I'll get around to that shortly. The rest of the site is pretty up to date.

Heaters. 12v or 6v (actually 6.3 if you can) are the voltages they really want to run at. If you're using a 12v supply, run them at 12v. If you're using a 9v supply, take a regulated feed from that and run them at 6v. Running them at 9v in series will not be running them as optimally as 6v in parallel. Heat wise, yep they'll get hot. Depends on the tube and it's current draw as to how hot. But that's what they do ;)

Log on vol/tone and lin on gain IIRC. Long time since I've built a straight boobtube. Plus I wasn't really the inventor, it's just a valvecaster with a proper gain control running at higher voltage. ...and if anyone asks, Cleggy came up with it. He's the one who keeps deciding to do these valve projects, I just tend to assemble them ;)

Also try and get your hands on a 12AU7A (RCA cleartops are nice). It works nicest in there in terms of how it sounds and current draw.

Will.mendil

Cool. Does clergy have a website?

I got line on tone which explains the malfunction.


About your website, I've found the general page with a table with pictures on the left hand side a description in the middle and the guts on the right hand side though I cannot figure out how to get the doc on each pedal, schematics etc... ( maybe a demo)
Don't know what to do with a paritculare transistor? Check this website where stompbox pedals are listed by what transistors they use

http://scfxguide.wordpress.com/

Will.mendil

Ps: I preference the hand wire stuff it is more trouble but if I have to build stuff for pedal it can be sold at a higher price :p
Don't know what to do with a paritculare transistor? Check this website where stompbox pedals are listed by what transistors they use

http://scfxguide.wordpress.com/

juansolo

Righty. I've simplified that bit. The site is mainly just a showcase of DIY stuff I've built (and car stuff if you're interested in that sort of thing, just go back to the top). Cleggy is the guy I build the pedals with. His stuff is on the same page (top right).

There aren't really that many guides on it. The valve guide is there because I kept getting asked about it (likewise the finishing tutorial). Most of the other stuff I build will be from other peoples projects. If I mod them I tend to note the mods in the text next to the build. There are also a couple of other things floating about in there that we've done. Again there should be links to the schematics/layouts for those in the text next to them. There's not that many of those.

Main Stomp Page is here: http://stompage.juansolo.co.uk

It's a bit slow as it's just sat under my desk on the end of an ADSL line (that everything else uses too. It also has a tendency to drop when the house phone rings...). So bear with it.

Will.mendil

Lol. I like that last bit.
Well thanks again. I'll be making a next tube pedal for my brothers birthday. I need a proper overdrive. The valvecaster has not got the overdrive I'm/he's looking for.  But he really what's a tube stompbox. I could/might add a SHO in the enclosure before the valvecaster. Though has anyone got a better idea?
Don't know what to do with a paritculare transistor? Check this website where stompbox pedals are listed by what transistors they use

http://scfxguide.wordpress.com/