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Weber Mass Pedal

Discussion in 'Effects [BG]' started by BassJunkie730, Jan 5, 2007.

  1. BassJunkie730


    Feb 3, 2005
    I just ordered this


    I'm going to build it stock first before I start tweaking.

    I'll try in in front of the amp and in the loop.

    I'm dropping in an RFT12ax7 and A Mullard 12AT7

    finally power tube overdrive in a circuit with a british voicing.

    running into the B1500

    here we go folks.
  2. nad

    nad 60 Cycle Humdinger Commercial User

    Sep 22, 2005
    Not Mars
    The Overlord of Nordstrand Pickups
    Looks awesome, and much cheaper than those wee Z.Vex amps. Looking forward to a review. :)
  3. Zeemno


    Feb 15, 2006
    Warsaw, Poland
    Color me very excited!!

    I guess you'll have to make some modifications to the circuit, so it can work with bass guitar well. Like tuning the tonestack, changing the input tubes configuration (if you want more gain) , maybe even changing the output transformer for a more hi-fi one if this one lacks lows.

    One thing leaves me curious, what made you say this circuit has a british voicing? It's taken from a Fender amp after all...

    Good luck building this and watch out for those high voltages!
  4. BassJunkie730


    Feb 3, 2005
    just the output circuit is taken from a fender reverb driver.

    But if you look at the power supply filtering and preamp circuit it resembles a more vow/marshall lineage.

    i asked the same questionin the weber forum and that's what they told me.

    either way, I'm anticipating the lack of lows so I'll be looking at the input caps and the caps for the bass section of the tone stack as primary culprits.

    Luckily I have both an eq pedal and the super powerful B1500 pre to change this.

    However - if I can get a great bass sound from this mother, whats to stop me from creating a dream rig.


    this pedal into an AI Focus2 SA

    think about it folks

    and all tube bass amp (or just enough tubes for the "all tube" sound)

    at 900W

    and about 5lbs :eek:

    needles to say i'm f***ing excited.
  5. Zeemno


    Feb 15, 2006
    Warsaw, Poland
    Power supply filtering is pretty basic, I'd be worried here. Such tube configuration is indeed common for marshall/vox amps, but I guess it's a lot more factors which decide on the voicing, like the output transormer. I'm affraid the one you get with the kit won't be exceling at bass frequencies. :meh:

    Check the '70 SVT for a bass orientated Baxandall Tone Stack, change C6 for something higher, experiment with C5 and C2. And that's all I can think off now.

    But trust me, if this can work with bass, then I am as much excited about this project as you are! :hyper:
  6. BassJunkie730


    Feb 3, 2005
    Looks like I'm going to send this guy off to Electrosonic Amps.

    Take a good look at the circuit. i think we're going to implement an EF86 in the front and keep the 12AT7 in the poweramp. ultimately what I want to end up with is a CLEAN CLEAN CLEAN amp with the ability to drive the hell out of the poweramp and get a great natural compression without excessive grind.

    if we can get the voicing right then a simple, yet very powerful tone control will be the only shaping tool on the unit, along with a volume (for power amp grind) and another volume (for controlling the voltage of the line out so I can use it with any power amp)

    I'm still very excited. If this amp works then it will be applicable to both passive and active basses. You can run any number of pedals in front of the thing - which opens up the floor for any type of eq to be used in front of the pedal.

    We'll see - but spirits are high.
  7. Zeemno


    Feb 15, 2006
    Warsaw, Poland
    Ooh, Electrosonic Amps' stuff look cool! Is it worth the expense though?

    That Supernova preamp with a EF86 looks even cooler. So you are going to put a tube like that in there? That will be kinda ackward: a pentode in the preamp, a triode in the poweramp section! :D

    Bad news is that we won't be able to build a unit exactly like that ourselves, but anyways it will be great to hear how the triode poweramp will work!

    I keep my fingers crossed! :hyper:
  8. BassJunkie730


    Feb 3, 2005
    So no go on the ef86 as the voltages were skew. but here's an email from Josh at Electrosonic amps he's finished the pedal and made some tweaks.

    all in all the price of the pedal, and the work, and shipping comes out to just under $300 - cost prohibitive for some - but if this really is the ticket for solid full tube amp sound - then it's worth it at any price.

    here's the email

    I'm not sure if you got my last email, but I have the pedal finished now.
    I eliminated the footswitching, increased filtering, changed the values to better suit the bass range, and added a mid control in the hole of the footswitch controler. I also changed the setup that the tone controls had, to a more classic fender circuit. The whole thing is pretty much clean all the way up the volume knob...its got a pretty big sound, dynamic, not compressed.

    yeah he says clean but wait til I throw a boost pedal in front and change the 12ax7 out for an RFT ecc83!

    What's nice is you can always make a clean amp dirty but not a dirty amp clean - so this might just be the ticket for many of you out there.

    of course for a fee I'm sure josh wouldn't mind selling you his revisions. - or perhaps we could pester weber to offer the new schem as an alternativea for bass players.

    I should get it by friday or tuesday. - then i'll let you all know
  9. SpankyPants

    SpankyPants That's Mr. SpankyPants to you.

    Aug 24, 2006
    Brooklyn, NY

    I'll want clips, of course ;-D
  10. Zeemno


    Feb 15, 2006
    Warsaw, Poland
    Cool! But didn't it became a whole different pedal than intended? Or did the basic construction stay unchanged?

    " big sound, dynamic, not compressed." :hyper:

    I'd love to try this thing as a 'tube enhancer & booster' before a good overdrive pedal. mmmmm..... :smug:
  11. BassJunkie730


    Feb 3, 2005
    That's right the Weber/Electrosonic Bass Mass pedal is sitting under my desk. Just got it today.

    So I'm chomping on the bit to go home already (not good for being only 11AM!)

    The pedal is BIG though. - 7" x 7" by about 3"

    I fully intend on throwing it in the effects loop of my amp and will use the Loop's remote switch to bring the amp in and out of the circuit. So obviously my biggest concern is will the output of the pedal fit seamlessly into the loop (I do not have level controls on the B1500 loop - nor do I have a global volume control on the pedal) well see. perpahs I can add a trim on the line out signal on the pedal.

    The bad boy needs some rubber feet too.

    What's nice is that I have a few tubes to try it with I'm hoping the RFT ECC83/ Mullard 12AT7 combo will be the best sounding for natural grind.

    What I am hoping for is a pedal that will have an even volume level when set at it's lowest as when it's dimed. The tonestack - which has been modified to a TMB should be able to give me all sorts of overdrive options at different frequency points.

    Having a Full Tube Amp pedal has been something of a dream of mine since I started playing guitar when i was 15 - and now that I play bass - having the attributes of an all tube amp leaves me salivating even more.

    So let's all keep our fingers crossed. With the big flexible EQ of the B1500 - not to mention the power and this all tube pedal, I hope to get some big hairy vintage driving sounds.

    I'll keep everyone posted with pics and sounds.
  12. The BurgerMeister

    The BurgerMeister musician.

    Apr 13, 2006
    Big Bear, CA
    my fingers are crossed. i hope it turns out great! let us know!

  13. BassJunkie730


    Feb 3, 2005
    So moral of the story is no prototype is without bugs first time around.

    With that being said - the tone of the unit is very clean and punchy.

    I'm having issues with the line out (the only output on the unit - in my version) being very very weak.
    In order to drive a power amp with it I'll need to adjust the gain of the line out signal considerably. - even running a buffer after the amp (a boss GE7) I had to dime the output of the both the pedal and the Boss pedal to get a workable signal.

    I'll post sound files when the issues are sorted out.

    Other drawback is - the bass isn't very authoritative when I slam the front end with gain. I attribute this to an ill equipped output transformer for really strong bass frequencies.

    BUT with the unit run wide open (all controls at full) the sound is very punchy and noise is relatively low.
    The magic happens with the mid control installed - I can dail it back just a bit and get a great round warm tone.

    Again - I think for this thing to be useable - the output gain needs to come up considerably.

    Pics to come soon.

    Ahh the proto-typing process.

    I'll keep you guys posted.
  14. SpankyPants

    SpankyPants That's Mr. SpankyPants to you.

    Aug 24, 2006
    Brooklyn, NY

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