Kit for Tube-preamp stompbox ?

  • Hi,
    I just think about offering a kit for a tube-preamp stompbox (à la Bad Cat 2-Tone) What are your favorite features / major requirements for this kit ?

    - single channel preamp
    - two channel preamp
    - usage as effect between guitar and amp
    - usage as preamp between guitar and power amp
    - True Bypass (when designed as a effect)
    - Stereo output (two volume controls)
    - symmetrical output for mixer
    - what's the upper limit for pricing ?

    Just post, what you think and want, I will try to design a kit for a reasonable price based on this.
    Regards, Martin

  • Re:Kit for Tube-preamp stompbox ?

    Something in the style of the Mesa or H & K Eg: 2 Channel + Bypass

    Clean /Drive /Dist. But more "Tube", less "Angry Bee" than the other ones on the market.

    Built in pover supply? Hmmm... Thats another inportant aspect!

    I think the whole stereo thing is something of the past.
    People prefare the traditional stuff (Atleast in Sweden)
    I should know,.. I work in a guitar store that sells loads of new and old stuff, but hardly any rack effects at all these days.

    The price should stay around 150Eurous

    True bypass isnt that inportant if it has a transparent buffer.


  • Re:Kit for Tube-preamp stompbox ?

    - single channel preamp
    - to be used as effect between guitar and amp
    - having good buffering, even useable as booster when in bypass (an output level always active)
    - Stereo output (two volume controls) to drive two amps would be a welcome plus...
    - no symmetrical output for mixer (require cab-sim)
    - the pricing depends upon the features...


  • Re:Kit for Tube-preamp stompbox ?

    This sounds realy cool! If it´s going to sound as well as the ampkits? Im going for one, thats for sure. My suggestion looks like this;
    - two channel preamp
    - crunch/rythm and lead and of course real tubedrive
    - good eq possibilities
    - usage as effect between guitar and amp
    - True Bypass (when designed as a effect)
    - external powersupplie
    - what's the upper limit for pricing ? €150 maybe?

  • Re:Kit for Tube-preamp stompbox ?


    This looks (sounds ;D) very interesting. My requierement would be:

    - Built-in power supply
    - single chanel
    - crunch/distortion and clean-boost modes
    - phase neutral (for use in one path of an a/b/y setup)
    - as "pedal" before the amp
    - as "preamp" before any power stage (including SS (berk...))
    - DI and headphone outputs with speaker emulation
    - leave enough room (or option for a bigger chassis) to add a
    bedroom "power amp", with sth like a 1.5W 12AU7 or 6N1P push pull or
    SE. This might in fact be combined with the headphone and DI outputs.
    - This "Trettmine" should be built like a tank.
    - Kit price below 100€.

    That was my 2 cents.


    Daniel F.

  • Re:Kit for Tube-preamp stompbox ?

    Here is my reaction:

    - two channel preamp
    - usage as effect between guitar and amp
    - True Bypass (when designed as a effect)
    - mono output
    - symmetrical output for mixer: not required
    - what's the upper limit for pricing : quality comes first
    - easy access to tubes
    - 2 tube setup
    - internal power supply
    - different volume settings for two channels
    - indicator leds for 2 channels. for each leds two settings:
    intensive if channel is engaged,
    not intensive if the channel is not engaged (true bypass) but
    selected ... e.g. see king of tone pedal of analogman ...

    This would be a nice project for a beginner (like me) because
    of the even more limited complexity (no power amp required)
    which is beneficial if you do not have any experience and little
    spare time !!!! like me ...

  • Re:Kit for Tube-preamp stompbox ?

    - single channel preamp
    - two channel preamp (like jcm800 and fenderish, each channel it's own volume, tmb, gain)
    - usage as effect between guitar and amp
    - usage as preamp between guitar and power amp
    - True Bypass (when designed as a effect)
    - Stereo output (two volume controls) (small chorus effect?)
    - symmetrical output for mixer ->marshall speaksim
    - what's the upper limit for pricing ? =>good sound doesnt have to have a price

    idea: use a normal 12v walwart adapter for powering this pup, then inside the box use a 12v to 240v trafo (so a regular trafo wired backwards)
    use 2 preamptubes

  • Re:Kit for Tube-preamp stompbox ?

    Very interesting, especially for people who may not want the trouble of building/aquiring a cabinet. Probably a good startup project to get into the tube "business".

    I would want to be able to use it either as a stompbox, or direct into the poweramp (FX Return) on my regular amp. I can't see any particular difference between those two.

    If it is to be used as a stompbox, it would need to be very durable (for safety reasons) and have very good protection for the tubes. In this case, channel and bypass switching could be made with simple stomp switches.

    However, most people would probably not want their tube "babies" stepped on and prefer to keep it on top of their amp (rack-mount perhaps?). In this case relay/opto switching and a dual footswitch input (channel, bypass) would be good.

    Ideally, the two channels would be independent, each with a switch for clean/crunch/lead. I.e. it should be possible to use 2 lead channels, one clean one lead etc. If relay/opto switching is used, this should be relatively easy to achieve.

    Stereo would be useless unless the input was stereo, but then were basically talking two paralell tube preamps and this is simply too complex.

    A balanced line out could be useful for direct recording, but then it should probably have a speaker sim as well. This would make things a lot more complex and expensive, so for those who want to direct record it is probably easier to buy (or build) a separate DI box/speaker sim.

  • Re: Kit for Tube-preamp stompbox ?

    This would be a good kit.

    I think mainly useful as a something between guitar and preamp. Definately 2 preamp valve, 12a*7 type.

    Maybe 2 version: 1 pedal type and 1 rack type to maybe go between guitar and poweramp section?

  • Re: Kit for Tube-preamp stompbox ?

    - Built-in power supply 230V
    - One channel
    - Sounds from literock to deathmetal
    - Op or transistor boost with switch (for ubermetal)
    - pedal and preamp
    - headphone output with speaker emulation
    - Analog VU meter and lots of bright leds :D "lightshow"
    - built in tuner :D
    - predrilled chassis (must)

  • Re: Kit for Tube-preamp stompbox ?

    Most importantly I would like it to sound better than the Bad Cat 2-Tone. I have owned one of those, and despite its good reputation I think it sounded too harsh, too much like barb wire, especially with single coil pickups.

    I have a Madamp J5Mk1, which I really like the sound of, and having the preamp of that one as a stompbox would be very nice, being able to stomp it On and Off and also the extra gain stage In and Out.

    I guess it would be a rather easy task to modify this kit and offer it as a preamp stompbox - just another box and omit the OT and poweramp.

    /Mats D

  • Re: Kit for Tube-preamp stompbox ?

    I've given some more though to this, and this is my new suggestions:

    * Relatively simple design (no advanced switching, no speaker simulator...)
    * Basically an overdrive/booster
    * High voltage (no 12V design)
    * All tube (no opamps or transistors)
    * 2 Footswitches: "On/Bypass" and "Boost"
    * Baxandall tonestack
    * Perhaps a "Fat" or "Bright" switch to make it a bit more flexible.
    * 2 tubes (12A_7) to make it easy to experiment with different tubes

    It should be something you could set fairly clean just to get a bit of tube magic if you have a solid state amp. Or you could set it for a nice overdrive, and then hit the "Boost" switch to really make it scream.

    I'd like the Baxandall tonestack, because it's very effective and does not have the mid cut of a typical FMV stack.

  • Re: Kit for Tube-preamp stompbox ?

    Based on my experience of building these kind of things, here is my opinion:
    -Two channel Clean/Dirt
    -Some voicing switchs like high/low, countour,etc.
    -It would need only one tone stack (in order to keep things simple) but independent volumes are very important
    -Maybe two versions, one pedal and one rack, both of them should have lots of spare space for upgrades
    -Rack version with remote switching (relay) and the pedal one of course, switch on the chassis. Or maybe the relay switching could be an optional add-on for both
    -Power supply internal of course with a small toroidal transformer, otherwise only a switching PS can be used but thats not practical at all. (I don't even consider 12V operation) ;(
    -Stereo operation is more 80s fashion (don't get me wrong, the 80s were great for guitars, but not for some little things) than useful. And most effects processors can get a mono input and the output in stereo.
    -Speaker simulation would be cool but no necessary, maybe as an optional add-on (if one consider the Marshall incorporated in the JMP1).
    -Option between true-bypass and buffered bypass should be left for the builder by connectiong things differently by with (almost) the same parts.
    -A must will be an level type selector for the output, to select between line level and guitar level signal (1Vrms and 100mVrms)
    -If only two tubes are used, (4 triodes are required to get a standard high gain dist) it should use a solidstate output buffer.

    Some of my options are made looking for prices and simplicity. To keep the price low it could be done some other things. By taking some of the funcions and making them as "optional" upgrades. In the rack version by using the same case with the same layout as the Mad Bass preamp (layout due to the vents for the tubes), bigger quantities, lower prices. The same power supply PCB as the bass preamp, and maybe making this preamp on a pcb with some extra pads for mods in place of a terminal board.

    I never bought a amp/pedal kit, I usually make them from scratch but if the price range goes under 100€ (its a hard goal, but not impossible), I will get one as sone as I can.

    Regards from Portugal!
    Tiago Pires.

  • So, anyone else still interested in pushing forward to make this happen? If Martin can make a Tube-preamp kit, I really think a lot of people would buy one. I will buy at least three, and that is a promise Martin!

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