Tube boost + overdrive running off a 9 volt battery

[Jdansti]

You might want to try it without the tone control. It sucks - literally!

[Dongle]

Hi guys - I obviously missed some parts of this thread...
Still I am quite satisfied with my Valvecaster. I modded it with an TL072 in front of the tubes for some extra drive and run the tubes with apprx. 50-60 V supplied with a charge pump.
Now I want to add a cab Sim (maybe the condor from ROG) and a headphone out - and I have no idea how to do this... Did anyone try this?
I guess, I can just put the cabsim right behind the valvecaster - but do I need an additional headphone amp behind this circuit?
Can I go directly into the condor (powered with 12V), after my valvacaster, which puts out about +/-10V?!?

[zambo]

You can go right into the cab sim. just turn the volume on the VC down. It functions as a master volume in the position that it is in.you may have to turn it down quite a bit if your running 50v on the plates but no big deal. Headphones would be after the cab sim to get you the sound your looking for. Would love to build the condor cab sim.

[Dongle]

Thanks for replying!
I tried - and failed... I think I made some mistakes while building the Condor. Have to try again...
Ok, you think I can just put the volume down - that means, I would lower my outpout from some 10 V to something, the cabsim can handle... Sounds logical to me
I tried putting the headphones directly to the valcaster - first with volume all the way down. Than I pulled it slowly up. Also with full volume, I only get a very quiet signal.
Why is this not working, but is supposed to work with the cabsim?

[zambo]

its a impedance mismatch. you could try a resistor in series or even a 1 meg pot wired as a variable resistor. I dont know how much R you would need thus the pot. Ive tried it before and had it worlk like a transformerless amp of sorts, but it didnt work well or sound overwhelmingly good or loud for whatever thats worth. Try the cab sim and just put your out put volume around 1 or 2on the vc and it should be fine.  you may need to run the cab sim into a headphone amp if it doesnt have a headphone out due to the impedance mismatches. it seems to be an issue.

[mth5044]

You will need a headphone amp after the cab sim to drive the headphones. The condor cab sim will not drive headphones effectively.

[pappasmurfsharem]

You will need a headphone amp after the cab sim to drive the headphones. The condor cab sim will not drive headphones effectively.

This.^^

A ruby amp works well for this

[Dongle]

Ok. So its much more effort than I thought, but I will try. I will try and see, what I get for an output signal from the cab sim. Maybe a one stage headphone tube is sufficient.
Is there any good simple cab sim? Maybe even driven by tubes and not by Op amps?

[DoktorGonzo]

Please, in advance, excuse my noobish ignorance.

This will be my first attempt at building something beyond a simple fuzz circuit using a transistor and clipping diodes on a breadboard.  Using the Beavis Audio layout (http://www.beavisaudio.com/Projects/ValveCaster/MatsuminValveCasterWiring.gif), I cannot figure out how to add a DPDT bypass switch. 

I have scanned each of the 150+ pages in this thread and, obviously, seen the physical examples of those who have done it, but no one seems to have posted how it is actually done. 

Can I assume that the wiring of a bypass switch is fairly universal from box to box, or am I missing something?

Once again, excuse my ignorance, this is my first time out of the gate, and I'm anxious and excited to build this thing.

If someone could post a simple schematic or layout, or point me in the right direction I would be greatly appreciative.

Thanks, and thanks for such a killer site and forum!

DG

[stallik]

Welcome.
Yes a bypass switch is pretty universal and can be introduced to this circuit however, my experience is that such a switch is not always necessary with this circuit. It's an overdrive which appears to me to work better by overloading the input of your amp. The overloading increases the volume so you end up turning down the output volume to compensate. A switch will, in this case give you a big drop in volume when the valvecaster is bypassed. Lowering the guitar volume however is magic. Everything cleans up nicely

Perhaps others experience something different so please wait for them to chime in.

Anyhow,  enjoy your build.

Oh and the circuit you linked to is simply built on the base of a valve socket. Just wire it up as in the picture.

[Isak]

Hi there.

If you mean to a foot switch, here you go...(not DPDT but works)
http://i47.photobucket.com/albums/f191/krinor/Valvecasternylayoutmkabler.jpg

Another link...
http://i25.tinypic.com/1zpp3r6.jpg

Hope it helps yaa.
Cheers,
Isak E.

[zambo]

                       bypassed side
                            0---0
from input-----------0    0----- to output
               to C1---- 0    0-----from volume

                     circuit side

Hope this makes sense. 0 are the pins of dpdt. 3pdt is best to use as you should ground the volume ( silence the tube side ) when bypassed ( stops the ringing/oscillating  that occurs when you eventually put two or three of these in a row to make a distortion pedal like most of us do..lol..) and hook up the led. welcome to the darkside lol

[DoktorGonzo]

Thanks for your replies and help!  Sincerely appreciated! 

DG

[sgmb]

Hi... First post.... Yay!!!
   I have spent a considerable amount of time reading this whole thread and pasting all my favourite tips and bits into a reference document. I then built 2 amps inside some old tube radio enclosures. ( I was given then empty so I haven't destroyed any cool old radios).
   I built the ValveCaster as a preamp into a TDA2003 chip amp in both radios. Radio 1 is an old Ekco using it's original 5x7 Rola speaker. I really like it a lot. Radio 2 is a bigger Rolls Radio that I have put a 12" Peavey speaker in. I built that one for a friend... with a clean boost version of the VC.
   I had collected a small choice of tubes and have settled on a Philco 12AE7 in the Ekco and a Russian ECC99 in the Rolls.
   I am really happy with both of them and would like to thank everybody who has contributed to this thread over the years. I would never have made it to this stage without you. I have learned a lot and am planning a twin VaveMaster + Tremolo + Delay pedal to follow up.

I'll post Photo's of the radios as soon as I take them
   Yay!!!!..... Cheers!!!!

[vigilante397]

Firstly, welcome to the forum

Secondly, that sounds awesome! I'm currently working on a hybrid amplifier build (trying to get my feet wet before jumping into all-tube amp building ) and my preamp section is based on the valvecaster. I'd love to see your pictures when you get around to it 

[sgmb]

Thanks for your comments. Pictures will be forthcoming

[sgmb]

OK, I took some pictures. My photography skills however are almost as lacking as my electronics skills.
  I haven't posted pictures on a forum for a long time so I hope this works.





OK.... So I am a bit scared of showing these cos I know the workmanship here is not exactly fantastic. However it really does sound good and is a great little at home practice amp. The cardboard is a simple reflector to illuminate the radio dial in the same way that the original radio did, except this one is using leds. The voltage reguator in front of the tube is there to bring the led voltage down to 9v, everything else is running at 12v. I had a few of these 12v power supplies lying around. They are way overkill but very low ripple. It cleaned up even more with the extra cap across the terminals.
  I like using the aluminium tape as a ground bus and shield. The TDA 2003 amp was a kit from evilbay. It looks like they have stopped selling the kit but you can still buy the assembled board for about $10... How?... I don't know.
  The tube socket is mounted in the smallest enclosure I could find and the Valvecaster is assembled on the socket. This has no tone control and the volume control was replaced with a trimpot. I've tried a few different tubes before I settled on the Philco 12AE7.
  I left the original radio labelling on the front but even though it says TONE - ON/OFF VOL - TUNING - RADIO/GRAM, It is actually INPUT - VOL - GAIN - ON/OFF
  It's pretty obvious really. I don't think anyone would get too confused.
I know it's not that pretty inside with the cardboard reflector and everything but it wasn't really meant to be inspected. I am really happy with it in any case.
  I haven't taken photo's of the one I made for my friend cos I haven't seen him in a while. Perhaps I will take some soon.

  Oh well, let me know what a mess I've made and how stupid I have been... Cheers

[sgmb]

[sgmb]

Hmmm... my photo's aren't showing up

[sgmb]

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