Is the Matsumin Valvecaster similar to...

[superferrite]

...the preamp in an old tape-delay unit?
I want that slight thickening boost like Blackmoore and Reine Fiske (Dungen) get in front of their amps and I was wondering if this is a suitable option.

Opinions, suggestions, etc?

[Caferacernoc]

There is one big difference. The Valvecaster is at low voltage. 9-12 volts. The echoplex is over 100 like most tube preamps. If you copy the echoplex schematic and run it at 12 volts it will sound flabby and buzzy. However, you can make a fat clean boost out of a Valvecaster. Lower the plate resistor sizes until you get the desired level of clean to overdrive balance.
If you copied the input of this schematic. I would try R16 at 100k or less:

http://www.schematicheaven.com/effects/ep2_5939-9067.pdf

[petemoore]

  I built a "Valvecaster 38".
  It has a printer supply [38vdc] and an LM317 running near it's max V to regulate that [no heatsink].
  And a tap for 7812 regulator [for the heaters] which runs extremely hot and had to be heatsinked to the enclosure [~large Raco].
  If you want a cleaner preamp you'll need to run higher voltage on the plates..I opted to buy that instead though. The Valvecaster 38 didn't cost much [I had to go buy regulators], mind that RS has very tricky markings on their regulator packages draw the pinout with their rediculous numbers 1,2,3 eliminated, write output / input / adjust [or ground on the 7812], save yourself a few burnt chips and a scorched thumbprint from trying it their way.
  I decided I had to bump the voltage [was originally 12v on plates] because my 12aU7 wasn't cooperating, and the 12at7 sounds.
  The Valvecaster made recent move to my pedalboard, it quickly became like an old friend.
 

[superferrite]

Dude, that sounds like gibberish to my NOOB ears, but I am willing to learn!

[km-r]

are printer supplies clean enough?

i might wanna try my HP printer supply wc has 30vdc and 15vdc [+ 7812] for heaters...

[petemoore]

  Higher voltage supply = higher output/headroom.
  12vdc is a small amount of potential for any of the 12a_7 tubes to work with, that's why they sound cool/distort/compress. 12au7 has the low Mu [gain] so it doesn't try so hard to exceed the power rail potential like a higher mu tube would. I had a 12at7 working, not sure about my 12au7, didn't seem to like the V-caster.
  At 12v the sound was constrained, the tube was running out of juice much too soon.
  I decided to increase the supply potential, and found a 30vdc printer iron put out about 40v, which happens to be the Max V input of an LM317 adjustable regulator.
  To answer a couple questions: the regulator smooths out the ripple, for quiet operation you need either regulated or filtered supply, regulator is easier, if I had say 45vdc to start with I think I'd scrap the regulator 45v is beyond it's max rating.
  That takes care of the HV for the tube supply, nice quiet DC for the tube to use when amplifying.
  Now, to supply the filament with suitable power, another regulator...the 7812 gets hotter than heck if not super-heatsinked, in this application it's dropping about 25v, that creates a lot of heat to dissipate, larger heatsink didn't see to do as well as bolting the smaller one to the box, I bolted the smaller one to the box, the box gets warm.
  The circuit itself is a bit like an 'addendum' to creating the power supply and getting everything secured.

[km-r]

another thing...

gainwise, or distortionwise, does higher voltage give more distortion?

[Salvatore]

another thing...

gainwise, or distortionwise, does higher voltage give more distortion?

No, it gives more clean headroom, and higher gain.
Low and high voltage circuits can distort just as well when you push them beyond there specifications.
The biggest advantage of low voltage is , lower cost, less hassle, and no mortal dangers.