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valvecaster

Started by 12bar13, May 08, 2008, 05:13:23 PM

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12bar13

i'm thinking of building a diy valve caster.  has anyone done one of these? i've never done anything with tubes before so any tips would be greatly appreciated.


frequencycentral

#2
Great build. You can mount most of the components on the tube socket. Get yourself a nice 12 volt regulated wallwart though - battery power is nice for portability but you'll eat through them. I'd never done tubes before either. Build an LPB-1 at the front end to drive it harder.

EDIT: Oh, and its quite safe to build this circuit wearing sandals!
http://www.frequencycentral.co.uk/

Questo è il fiore del partigiano morto per la libertà!

12bar13

Quote from: frequencycentral on May 08, 2008, 06:25:43 PM
Great build. You can mount most of the components on the tube socket. Get yourself a nice 12 volt regulated wallwart though - battery power is nice for portability but you'll eat through them. I'd never done tubes before either. Build an LPB-1 at the front end to drive it harder.

EDIT: Oh, and its quite safe to build this circuit wearing sandals!

i think this will be the "brown toe" especially with the tube sticking out.

what is the difference between the major types of tubes? there are so many out there and i have no idea what the difference is.

ambulancevoice

Quote from: 12bar13 on May 08, 2008, 10:07:25 PM
Quote from: frequencycentral on May 08, 2008, 06:25:43 PM
Great build. You can mount most of the components on the tube socket. Get yourself a nice 12 volt regulated wallwart though - battery power is nice for portability but you'll eat through them. I'd never done tubes before either. Build an LPB-1 at the front end to drive it harder.

EDIT: Oh, and its quite safe to build this circuit wearing sandals!

i think this will be the "brown toe" especially with the tube sticking out.

what is the difference between the major types of tubes? there are so many out there and i have no idea what the difference is.

well, alot of them have different characteristics
the russian electro harmonix tubes are cheap and work but have a few issues, but ive heard they work good in a valve caster, JJ  Telsa make good tubes, i hear good things about them, and i see them used alot
there are Mullard (the kings of tubes, they invented the 12ax7... i think) reissues built by New Sensor corp (same company who make electro h tubes and sovtek tubes) which are supposedly built to the exact specifications of the original Mullard tubes, but i havnt heard much about them though

usually, people get a few different brands and try them out (usually only with pre amp tubes, because power tubes need re biasing when different brands are used) and pick what they like

Open Your Mouth, Heres Your Money

12bar13

Quote from: ambulancevoice on May 09, 2008, 04:46:24 AM
well, alot of them have different characteristics
the russian electro harmonix tubes are cheap and work but have a few issues, but ive heard they work good in a valve caster, JJ  Telsa make good tubes, i hear good things about them, and i see them used alot
there are Mullard (the kings of tubes, they invented the 12ax7... i think) reissues built by New Sensor corp (same company who make electro h tubes and sovtek tubes) which are supposedly built to the exact specifications of the original Mullard tubes, but i havnt heard much about them though

usually, people get a few different brands and try them out (usually only with pre amp tubes, because power tubes need re biasing when different brands are used) and pick what they like



is there any values that i should look at? for instance "if value x is higher then it is more midrangy" or anything of the sort.  and if not would should i listen for when comparing tubes

thanks

Stellan

Hi, i have built the "stock" valvecaster, and its a very  nice sounding boost. I did end up doubling the value of C1 because it was too dark sounding, which is something others have noted too. I think I will try to fit a small booster in the same box before the Valvecaster, and I highly recommend doing so cause it just sounds beautifull with a boost in front. Run it of 12V that will give you some more volume, and to my ears sounds slightly better (not sure thouh if its just the added boost that give the perseption of an enhanced sound) Good luck

petemoore

  Pre boost makes sense, get the signal level up so the tube stage becomes more of an overdrive, solid state is a good choice for that.
  ...Preboost>~Valvecaster>~Valvecaster>?
  By '~' I probably mean revoiced and perhaps reduced gain of early valve stages [you could keep adding tube gain stages], voicing, and inter-stage [early~?] gain control.
  I can only imagine what that would sound like...probably pretty good.
 
Convention creates following, following creates convention.

frequencycentral

Quote from: petemoore on May 10, 2008, 09:35:00 AM
  Pre boost makes sense, get the signal level up so the tube stage becomes more of an overdrive, solid state is a good choice for that.
  ...Preboost>~Valvecaster>~Valvecaster>? 
Defo! I tried this:

LPB-1 > Subcaster > Valvecaster

Crunch!
http://www.frequencycentral.co.uk/

Questo è il fiore del partigiano morto per la libertà!

ambulancevoice

#9
Quote from: 12bar13 on May 09, 2008, 04:58:52 AM
Quote from: ambulancevoice on May 09, 2008, 04:46:24 AM
well, alot of them have different characteristics
the russian electro harmonix tubes are cheap and work but have a few issues, but ive heard they work good in a valve caster, JJ  Telsa make good tubes, i hear good things about them, and i see them used alot
there are Mullard (the kings of tubes, they invented the 12ax7... i think) reissues built by New Sensor corp (same company who make electro h tubes and sovtek tubes) which are supposedly built to the exact specifications of the original Mullard tubes, but i havnt heard much about them though

usually, people get a few different brands and try them out (usually only with pre amp tubes, because power tubes need re biasing when different brands are used) and pick what they like



is there any values that i should look at? for instance "if value x is higher then it is more midrangy" or anything of the sort.  and if not would should i listen for when comparing tubes

thanks

im not sure on the specifics of different tubes and the way they handle frequency or if they attenuate them or not, i dont even think they have those "if this value is high, the mid range is boosted" kinda thing, usually it is just the quality of the tube in how its built and what its built with that counts, but like i said, get a few different brands, cause what may sound good to you my sound terrible to someone else, everyone has there own preferences
and 12a-7's usually come at a good price
it it were me, id probably get a jj tesla tube


Open Your Mouth, Heres Your Money

Renegadrian

I tried several, a new EH and NOS RCA, GE, Raytheon, ecc...
Every single tube has its own tonal nuance, I'd suggest go get some different tubes thru ebay, you can get them cheap!
Done an' workin'=Too many to mention - Tube addict!