Valvecaster standard Shopping List at Small Bear

[lowend]

When SB says mF I'm presuming they really mean uF? I'd hate to be ordering millifarads by mistook.

Edit, I renamed the topic in the interest of it possibly being useful to someone else

[slacker]

yeah.

[smallbearelec]

Hi--

Since I was a teenager, uF and mf have been used interchangeably (in the U.S.) to mean "microfarad." I still use that convention.

Regards
SD

[wavley]

Considering I've never actually seen a cap marked as millifarad it's a safe bet.  In the olden days you used to see caps marked as mF or MMF, rarely with a u (which is actually a mu not a u) most likely because nobody had ancient greek fonts to print caps.

[lowend]

That clears that up.

Now I can't find any 47nF caps that do 100V, 50V I think was the spec for the valvecaster but someone said if I want to ramp it up into more of an amp then 100V would be the go. The only ones I find are 16V

Edit:
Quoting Zambo, who builds some kickarse valve pedals ...

.50 volt caps should be fine..... Small Bear Electronics is a great source as well. 16 bucks for a tube and 2.20 for a socket. They have all the caps enclosure etc. A good one spot shopping place to be sure. I recomend using 100 volt caps on these as once you build it you may want to start running on higher voltage.....it gets kind of addicting imho...good luck and hope this helps.

what I got so far for two pedals:
2    1220D    Capacitor, Mallory 150 Series .01 mf. 630 Volt
2    1301G    Capacitor Silver Mica 500V 1000 pf.
2    0611    Jack, DC Power, 2.1 mm All-Plastic, Round(All-plastic Round)
2    0708    Socket, 9-Pin With Shield(9-Pin Socket w/ Shield)

already have boxes, 3pdt, valves

[wavley]

What kind of power supply are you planning on using?

If you are planning on running at full plate voltage, then I might consider using a design meant for this, like a Hot Box clone or something. 

I thought that the beauty of a valvecaster was that it sounds good running off of wall wart power supplies at powers ranging from 9 to 24 volts.

I guess if you buy that Puretube designed EHX tube series power supply stuff you can pump that kind of voltage, I have an English Muffin that does it and it sounds great.  Somebody used to sell that stuff but I can't remember who.

[zambo]

you can use 16 volt caps if you want. Anything over 9 or 12 is fine. If you are ever going to up the voltage to something higher than that then its nice to have all the higher rated stuff already in it and it only costs a couple bucks more. 1/2 watt resistors and 100 volt caps are cheap enough that its easier just to use those. SB also sells the chip for making voltage multipliers. You can turn 9 volts into 45 pretty easy and cheap. Remember the dc jack , 1/4 inch phono jacks, 100k a and 50k b pots and cool knobs etc. ( thats what I always forget). If you add a few extra caps to your order and a dpdt mini toggle for input caps you will be happy to. A .002mf and .022 for the input caps on a valvey is nice mod. Imho.....good luck sorry if i added any confusion about voltage ratings. 

[nomorebetts]

add a few extra caps to your order ...  .022 for the input caps on a valvey is nice mod.

I Agree! 
Throw maybe a 22nf or 33nf cap or both onto your order. To try in place of C1's 47nf cap as the ValveCaster is sometimes to bass heavy with humbuckers. This will save you making another seperate order again if you're not happy with the sound.

[smallbearelec]

Nobody ever tells me anything!...(growl!, grunt! snort!!)

Seriously: I did not know that this project had become popular. After I'm done confessing my sins on Yopm Kippur (sigh...) I will put together a spreadsheet parts list for my library so that I can assist others.

Regards
SD

[lowend]

I take it you spotted the 92 page thread then?

If you had a search engine that let you search capacitors by capacitance and voltage that would make it easier for noobies like me. It takes forever sifting thru them by style.

[lowend]

And thanks for the suggestions fellas. Being that I'm ordering from New Zealand I liked the idea of future proofing it against the 100V tube mania setting in. I saw Zambo's desktop deathtrap vid. I'll add those tuning caps, maybe by the time I get it all sussed SB will have the 100V ones online and a spreadsheet done.

Still unsure about the power supply side of things. I have a 9v switching one which should do fine but I need to suss the filtering that may or may not be needed. Please comment on the big thread http://www.diystompboxes.com/smfforum/index.php?topic=63479.0

[lowend]

Haha, I set google onto SB, much easier, not as easy as inbuilt dropdrown menus!

[smallbearelec]

Here is the shopping list I came up with:

Matsumin Valvecaster                                                    Resistors
9-Volt Schem at Beavis Audio Research            
                                                               SKU              1 x 1 Meg
4   Resistor 1/4 watt, 5%                                                 1 x 220K
1   Pot, Alpha 16mm 50K Linear                     1005A      1 x 100K
2   Pot, Alpha 16mm 100K Audio                     1005A      1 x 470K
1   Capacitor Poly Film .01 mf. 50 Volts             1101B      
2   Capacitor Poly Film .047 mf. 50 Volts             1101B      
1   Capacitor Poly Film 1 mf. 50 Volts minimum     1107      
1   Tube, 12AU7                                             7002      
1   Tube Socket, 9-Pin                                     0708

Clearly you can substitute any of the Xicon or Sprague film caps if you are doing a 45-volt build. I'm not a tube amp shop and can't support builds at still-higher voltages.

As far as power for this version, my Small Wart 200 would do well:

http://www.smallbearelec.com/Projects/SmWart2/SmallWart2.htm

though please note that if you want to use the transformer in 220-volt environments, you'll have to work out the mains power entry on your own. A safer and less-difficult way to go would be a 12-volt DC wall wart followed by filtering and an LM317 as dano shows in one of his schems.

[lowend]

Thanks, that helps a lot. I found some 600V overkill caps which added a bit to the cost so your suggestions will reduce that.
Most would want the 3pdt switch plus LED, jacks and a power jack, I've got them on my shopping list saved at the moment. I'll post it all up when I have it sorted.

btw, what's with having to order vero board thru a 3rd party?That stripey stuff looks so dang handy it's not funny but I didn't go to the link as it seemed like a pita to make a special order. Or did I miss an acceptable substitute somewhere?

[smallbearelec]

btw, what's with having to order vero board thru a 3rd party?

I had the stripboard made-to-order because many standard layouts are available for it (see the Gallery,) and I chose to give Aron Nelson, the founder of this Forum, an exclusive on selling it through his Store. It's my contribution to helping him maintain this amazing resource. It has inspired countless DIYers and professional builders over many years, and it's been Small Bear's most important venue for word-of-mouth advertising.

Regards
SD

[Govmnt_Lacky]

May be a noob question but is the 12AU7 different from the 12AX7? I am assuming it is but, could they presumably be used in place of one another?

[lowend]

btw, what's with having to order vero board thru a 3rd party?

I had the stripboard made-to-order because many standard layouts are available for it (see the Gallery,) and I chose to give Aron Nelson, the founder of this Forum, an exclusive on selling it through his Store. It's my contribution to helping him maintain this amazing resource. It has inspired countless DIYers and professional builders over many years, and it's been Small Bear's most important venue for word-of-mouth advertising.

Regards
SD

ok I get it, not happy about it though, what say I donate 5 bucks to the forum and you add some to my order? Can you work out another mechanism for supporting the benefactor that doesn't entail a separate package being posted halfway round the world?

May be a noob question but is the 12AU7 different from the 12AX7? I am assuming it is but, could they presumably be used in place of one another?

yep that would be a noob question, I'm a noob too so so I'll humour you. They have different names because they are different valves and no, a 12ax7 doesn't do the sme thing in the valvacaster. That hasn't stopped people from trying it out and if you know what you're doing it can be used for sure in a similar circuit but that's for another thread ta. Go to the 90 page one and read yourself crosseyed.

[lowend]

Here is my list, enough for two valvecasters.

There are no enclosures, valves or 3pdt switches, wire as I already got them. Vero from the forum shop.


2    0611    Jack, DC Power, 2.1 mm All-Plastic, Round(All-plastic Round)
2    0708    Socket, 9-Pin With Shield(9-Pin Socket w/ Shield)
4    1005A    Alpha Single-Gang 16mm, Solder Terms, Linear & Audio Taper(100K Audio) tone and vol
2    1005A    Alpha Single-Gang 16mm, Solder Terms, Linear & Audio Taper(50K Linear) Gain
1    2303B    LED 8mm High-Brightness Clear, Colors(Orange)
1    2303B    LED 8mm High-Brightness Clear, Colors(Blue)
4    0600A    Jack, 1/4 in. Mono Neutrik #NYS229(Jack 1/4 in. Mono Neutrik NYS229)
6    0825A    Knob, Fluted, Miniature, Black Pointer(Fluted Miniature Black Pointer)
1    1405    Capacitor, Electrolytic, Radial 16 V 220 mf. - 470 mf.(220 mf.) didn't know which to get for power filter so I got one of each
1    1405    Capacitor, Electrolytic, Radial 16 V 220 mf. - 470 mf.(470 mf.) ditto
2    0902    1.1K to 6.2K - Individual(4.7K) R5 on the vero scheme
2    0904    43K to 220K - Individual(100K) R3
2    0904    43K to 220K - Individual(220K) R2
2    0905    240K to 1 Meg - Individual(470K) R4
2    0905    240K to 1 Meg - Individual(1Meg) R1
2    0900    1 Ohm to 100 ohms - Individual(20 ohm) my own mod to get 9v down to 6.3V for 12AU7 heaters in parallel
4    1101B    Capacitor, Panasonic ECQ-V .01 mf. - .1 mf.(.047 mf.) C1, C2
2    1101B    Capacitor, Panasonic ECQ-V .01 mf. - .1 mf.(.01 mf.) C4
2    1107    Capacitor, CDE DME Series, 1 mf. 100 V C3

must add tuning caps

comments welcome, please see also the big valcaster thread for some queries I have unanswered

[smallbearelec]

Careful regarding the power for the heaters! The heater current for that tube is 150 ma. at least, so any resistor in that part of the circuit would have to be able to dissipate 2 watts or so. I don't stock anything above 1/4 watt, but Mouser.com and other sources do.

SD

[lowend]

Ha, thanks, I already spotted that myself. I messed up the calculation but caught it at work. However it seems I still haven't got it right as your figure is way over mine still. Please check my assumptions:

Pretty big one I guess is to assume that the power supply is regulated. I put a voltmeter on it with no load and it reads 9.2V so seems fair but open to education.

The heaters need 6.3 V to make their power at 300mA. Pretty sure on that.
I need to disapate 2.7 Volt at 300mA if the supply is 9V in order to keep the current at 300mA. Educated guesswork so far....

I worked out the heater resistance at 21ohm for parallel config. In parallel the supply is 6.3 V @ .3A
V=I*R follows that 6.3/0.3 = R = 21ohm

9V @ .3A is then 30 Ohm so I need a 9 ohm worth of resistance in series to bring the heater circuit up to 30 ohm total.

Power = V * I = Isquared * R by substitution from V=IR
0.3*0.3*9= 0.81W which is a way shy of 2W even at twice the current you were talking about. So either I got it all wrong or made a poor assumption or you made a bad estimate.

Thinking I'd put 4 x 39ohm in parallel on the vero so they'd get about 0.2W apiece and still form 9ish ohm