Tube boost + overdrive running off a 9 volt battery

[stallik]

Tried out some different power supplies, none of them made the same sound.
Anyone know why a power supply for a laptop is making a hi frequent hum? Looked at the current in a oscilloscope, can't see anything.

My best guess is that most power supplies for computers and laptops are switched-power supplies, which operate at a high-frequency

I Make my own power supply using a transformer and a Velleman 1Amp PS board. It's cheap and stable. Never had any problems with noise no matter which pedal I'm using. Nice thing is that the board allows you to modify the output voltage to taste

[Big Dan]

Had the thread bookmarked for a year now. Finally built this thing today!!! I used the basic layout in the first few pages and added a switchable input cap. Here are few pics:

[Big Dan]

Has anybody build this Twincaster layout? Is it correct?

Dan

Based on the Twincaster schem, seen some pages ago and developed by Dano (again) I'd like to show you my Twincaster VERO version...
Here is my vero (should be correct, but hey...)

[Renegadrian]

Checked it again, still seems correct - I guess you'd have 99% of getting it fired up alive and kicking arse right away...
Still haven't built it myself tho'

[siore]

Hey guys!  Here's my valvecaster.  Also my first post, although I've been lurking (on this thread specifically) for quite some time.  It all started when I had this unused 9v power adapter from a modem/router.  Was gonna use it for my pedalboard, but it already had a working power supply, so I thought I'd use this for a pedal build.  Switched polarities and it's good to go.  Regulated also, as far as I can measure.  Then an abandoned pedal build came into my hands (some guy trying to build a jcm800 emulator?), complete with the enclosure, DPDT footswitch and some other stuff.  At the time I was most interested in building the valvecaster, so on to it!

First I used a perfboard (or veroboard??) just to see if it was a pedal I'd like.  Also took the time to experiment with components.  First was input cap values, after a while I found out I was very happy with a .010 uF, and that it's all I need to rawk!  I just use it to boost my amps.  Amp slightly crunchy, valvy tone and vol always maxed out, and just adding a bit of gain on it to taste.





My mistake right here... is not following any of the layouts already posted.     Each component had a spot on the board so... TOO MANY HOOKUPS!!  Then I tried the vero layout on aronnelson.com's summary PDF file (I believe the proper credit to this is Renegadrian's?).  Then at this time I got the enclosure (from the abandoned pedal build) delivered to my doorstep.  Following the new layout, and admittedly rushing to put it all together in the box, I ended up with this monstrosity.    





So I took a few steps back, removed everything once again, and re-housed with some decals and "label plate" (which I just put there to cover old holes from the previous build).  At this point, I felt like I still had way more wires than needed, so I decided to go point-to-point, but I did some modifications to the layout, basically just switching ground here and there so they follow a more separated ground route.  E.g. dedicated heater ground route, switch grounds, signal grounds, lead twisting, routing, then leading them all back to the jacks.  Not that it matters at all    as it worked fine as shown on the layouts, but I wanted to prep myself for an amp build in the future, so I figured I'd have fun with it that way.






Oh, in the end I replaced the formal looking 'valvecaster' plate and put in something more personal.  I chose him, because I dunno if you guys play mortal kombat........ but the dude just WINS.   





I'm liking it a lot.  Thanks to matsumin-san, dano, renegadrian, that frequencydude, and all the others who have made this pedal build possible.  Yes, I'm still using it with 9v (and a 12au7 tube), and for boosting purposes, it's epic.


siore

[juansolo]

Checked it again, still seems correct - I guess you'd have 99% of getting it fired up alive and kicking arse right away...
Still haven't built it myself tho'

I built your 0.11 version of the Twincaster, works perfectly. Uses 12DW8 12V tubes, so pin 9 is connected to ground as it's a separate diode on these.  They draw nearly 1A as a pair, but sound great.

[Renegadrian]

siore, I really enjoyed your build report - it seems you already learned a lot, trial and error, and so on...
I like the first boxed version, looked "cyberpunky" somehow...
Glad you like your pedal!!!

juansolo, thx for using my layout!

[DPV]

OK guys... this is my first post here, please don't kick me for my bad English

I'm reading this tread from about 2 months, and this week i built a twincaster, with 12Au7 + 12ax7, i followed this circuit:



i corrected the error in the middle, and exchanged connections on second tube from lug 4 to lug 5, as suggested in the first pages (cit: "12ax7 and Au7 are pin to pin compatible except pin 4 and 5 that got inverted in grounding and heating"). Is this practice correct or i had to leave the lug connections as shown in project?

i added also a 3PDT switch, so i have a full bypass pedal. I added also a "always on" blue led that lights up when the power plug is connected and a green led that lights up while the switch is not in bypass position. The leds are working correctly.

I'm using a 3-12 volt 400ma DCa, but the stompbox is not working. Tubes are not lighting up, and when i connect it to the amp i get only a big hiss in bypass mode and nothing in work mode. Can u guys help me checking the circuit?

[Renegadrian]

Hi there, and welcome! Your english is also quite good!
First, if you have no sound when bypassed, there must be something wrong! I believe that you should use a PS with more power, 400 mA for 2 valves couldn't be enough...But hell, before that you must see why there is no bypassed sound!
I dunno about the pins 4 and 5, AFAIK you could use them both ways and get no difference...
The circuit you posted should be correct, let us see your work then, post some pics and we'll check!
A.

[DPV]

as reneg suggested by chat, i checked the tubes... i connected them directly to the power plug (i used a 2000ma 9v DC this time) and it happens something strange... The 12AX7 lights up but remains cold, and the 12AU7 remains dark but becomes warm.

I'm a bit confused The Tubes are new, bought them 3 days ago.

This is a (bad) shoot of the circuit. It's just a trial, i must fully rewire it i guess, but all connections appear good.



Center resistors heats leds, the two red cables who starts from center heats the tubes, the two red cables going from 3dpt to jack plugs carry audio signal.

Except 2 cables (i had not enough blue one ) i used blue for audio, red for DC and black for ground.


This is the outside... 4mm MDF painted with no-gloss nitro puliurethane. Looks good

[frequencycentral]

@ DPV

C3 should be connected to pin 2 of the third stage, not pin 1. You also need to add a grid leak resistor (or a pot) from pin 2 of the third stage to ground - so it looks similar to C1/R1.

R3 of the second stage is just floating in that schematic, it should be connected to +ve.

12v/400ma should be just enough for this circuit, but 12AX7 really don't perform at such low voltage, maybe try a 12AU7 instead.

Pins 4 and 5 are interchangeable, some tube designs use AC for the heaters.

Don't expect the tubes to glow like light bulbs - you may just get two small pinpoints of glow in each tube.

[DPV]

C3 should be connected to pin 2 of the third stage, not pin 1. You also need to add a grid leak resistor (or a pot) from pin 2 of the third stage to ground - so it looks similar to C1/R1.

Ok i already corrected that pin, pin6 of first stage is connected with a cap to pin2 of second stage. I'll try adding that resistor.

R3 of the second stage is just floating in that schematic, it should be connected to +ve.

No, is connected to +v

Don't expect the tubes to glow like light bulbs - you may just get two small pinpoints of glow in each tube.

I was just wondering about the different reaction of the tubes... thx for help.

Any Other suggestion?

[differo]

You might start with sorting out the bypassed sounds or should I say no sound; this should be the starting point as this is only wiring problem has nothing to do with the circuit. It happens sometimes that these simple (yet annoying) problems cause another problems like circuit not working in 'work' mode.

[siore]

DPV, check your pin 4 and 5 connections maybe?  Sure they're interchangeable, but know that one pin takes DC, the other shunts to ground.  So if you have other connections that use one of the two pins for ground, then suddenly you interchange them, you just connected a component to the +9v supply.  IMO, heater grounds should be isolated from signal grounds, but it also works as shown in the layouts.  You may have already done this, but still, work your way from the schematics.  The layouts could have a slight error (for instance the tone pot functioning in reverse in one of the original layouts), but the schematic will show you which pin or component connects to which.

[zambo]

I have also had 1 12ax7 that worked in a valvecaster but 3 that didnt. That wouldnt solve your bypass issue but if you dont have sound in "work" mode I would try 2 12au7 s .

[Virtue]

Also decided to lay out my creations on this scheme. That one I did for the first time http://virtue-harp.narod.ru/lam2.JPG, bypass mode with cold bypass. That one made my friend http://www.gb-music.ru/george/walvecaster_2.jpg, inside looks http://www.gb-music.ru/george/walvecaster_4.jpg. Tremolo pedal combined with a tube http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=40279&g2_serialNumber=1

My second pedal http://virtue-harp.narod.ru/0918191018.JPG
Third http://virtue-harp.narod.ru/1020015147.JPG
Type in the second and third http://virtue-harp.narod.ru/1020200749.JPG

Fourth
Type in http://virtue-harp.narod.ru/0212233845.JPG

Subject to the Russian forum about the tube-like pedal http://www.forum.harmonica.ru/viewtopic.php?f=19&t=127115

[snickers_163]

First post. Built a Valvecaster a few weeks ago, and it sounds great! Really warms up the front end of a SS amp.

I FOUND OUT WHAT THE TONE KNOB IS FOR!!!!

Ok, so I thought I agreed with the tone knob delete, but I already built the valvecaster, so I left it on. Then while fooling around with it and my Peavey Bandit, I found out why it's a good thing. I've been trying to find something smaller to take to gigs, as I am SICK of lugging around my 5150 and Marshall 4X12 of HEAVY celestion V30s... So I decided on a Peavey Classic 50. I don't have the cash for that right now... but I do have a 80w Peavey Bandit 112 that's loud enough for bars, just doesn't sound right. Putting the valvecaster in front of it sounds great, just turn the knobs up all the way and it sounds smooth and creamy, but at higher volumes it starts getting all twitchy. But I found that I could get really respectable gain and tone out of the Bandit if I put the valvecaster in the fx loop, play through the lead channel with the pre at about 5 and post at about 8, t dynamics at 10 presence at 7 and on the valve caster turning the gain and TONE down somewhere between 40% and 80%, and use the volume knob as a power brake. Great tone at any volume! PERFECT! Well, as good as a Bandit is going to sound, anyway.

Note: I'm using a early 90's LP studio, playing punk, and I have the gain and thrash buttons pushed in.

Edit: I'm using the Dano layout - on the socket build.

[Renegadrian]

Right, thx for the report and welcome! Feel free to post some pictures of your Valvy!!!

[Rewind]

Hi,
I discovered a cool thing. If you do your own vocals, try hooking the Valvecaster to your regular DI-guitar input. And THEN use a Whirlwind Little IMP impedance transformer to hook a SM57 microphone (or any other mic that doesn't need 48V phantom power) to the input of the valvecaster. Nice tube saturation and vocal fattener!

For some reason I get less static and hum using the impedance transformer, suggesting a little impedance transforming would to the valvecaster some good for guitar also. If anyone has a spare transformer that doesn't do to much with the signal feel free to try it out.

[siore]

First post. Built a Valvecaster a few weeks ago, and it sounds great! Really warms up the front end of a SS amp.

I FOUND OUT WHAT THE TONE KNOB IS FOR!!!!

Ok, so I thought I agreed with the tone knob delete, but I already built the valvecaster, so I left it on. Then while fooling around with it and my Peavey Bandit, I found out why it's a good thing. I've been trying to find something smaller to take to gigs, as I am SICK of lugging around my 5150 and Marshall 4X12 of HEAVY celestion V30s... So I decided on a Peavey Classic 50. I don't have the cash for that right now... but I do have a 80w Peavey Bandit 112 that's loud enough for bars, just doesn't sound right. Putting the valvecaster in front of it sounds great, just turn the knobs up all the way and it sounds smooth and creamy, but at higher volumes it starts getting all twitchy. But I found that I could get really respectable gain and tone out of the Bandit if I put the valvecaster in the fx loop, play through the lead channel with the pre at about 5 and post at about 8, t dynamics at 10 presence at 7 and on the valve caster turning the gain and TONE down somewhere between 40% and 80%, and use the volume knob as a power brake. Great tone at any volume! PERFECT! Well, as good as a Bandit is going to sound, anyway.

Note: I'm using a early 90's LP studio, playing punk, and I have the gain and thrash buttons pushed in.

Edit: I'm using the Dano layout - on the socket build.

Hey man, I think the valvecaster sounds great with the peavey transtubes.  I tried it on my peavey blazer, I have the gain around 1'oclock, and use the valvy with all the knobs turned up except the gain knob, which I keep low.  It definitely adds top end sparkle to the cleans when you roll back the guitar volume, compared to rolling back with just the amp on full.  Wish I could try it on the effects loop, but I (stupidly) sold my bandit years ago.  But in front, I agree with you that the peavey takes it well.