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Volume/Blend Stack?

Discussion in 'Luthier's Corner' started by C-5KO, Jul 20, 2005.


  1. C-5KO

    C-5KO

    Mar 9, 2005
    Toronto, Canada
    Has anybody seen a Volume/Blend stacked pot before?

    If anybody would know, it would be somebody here at TB.
     
  2. I've never seen one. I would imagine it is because that would have a triple stacked bottom on it. I'd be interested if there was one though.
     
  3. Sonorous

    Sonorous

    Oct 1, 2003
    Denton, TX
    No, but I've seen a volume/volume.
     
  4. C-5KO

    C-5KO

    Mar 9, 2005
    Toronto, Canada

    just found one. now i have to see if first it will work for me, and if they'll sell it to me. i could do with out the push/pull factor. just one more thing to break.

    http://www.warwickbass.com/schematics/sch_images/dolphin1.pdf

    if anybody else finds one, please, PLEASE, reply. this warwick pot may not work for me.
     
  5. Scott French

    Scott French Dude Supporting Member

    May 12, 2004
    Grass Valley, CA
    I have some Noll parametric preamps that have stacked volume/blend pots. I've never seen them for sale before but Noll might sell them individually (or at least know a source).
     
  6. ArtisFallen

    ArtisFallen

    Jul 21, 2004
    you know, fundementally, a Volume volume stack would work in almost the same way, you'd just have to contemplate how important it is to have a master volume controll. i've always felt more comfortable with the vol2x, but if you're set on the blend, i'd be interested to see if it works the way you want it to. it'll be hell to solder though...
     
  7. I'd love to get my hands on a couple of those. Push/pull stacked volume/blend pots are a great idea.
     
  8. C-5KO

    C-5KO

    Mar 9, 2005
    Toronto, Canada
    So here's the whole plan:

    Ordered some pickups from Carey.

    I was going to replace the Barts with the Nords, but now, I want to try and have both sets of J's in my bass.

    I was trying to figure a way to do it, without having to add more knobs, or switches. And would also be fairly simple to operate.

    Volume/Blend stack for Barts and Volume/Blend stack for Nords, sort of makes sense to me. I'm able to select any set of pups, any combination of pups, or even just individual pup.

    Volume/Volume stacks would work, but I'm not as comfortable with that setup. When I play, I usually just adjust blending here and there. With two volumes, I would have to raise/lower levels. With blend pot, it just one turn.

    One thing that I did wonder though... with a standard volume/volume set up, if i had bridge at 100%, and neck at 0%, then dialed in neck, wouldn't the overall output increase? ie: if the neck were at 20%, the bridge is still at 100%, that's more volume! Where as a blend, if the neck were at 20%, the bridge would be at 80%.

    Sorry if the direct of this thread is heading towards "pickups". I don't want it to go there. I just want help finding these pots. I thought that Luthiers would have a better idea of sources for parts. Plus I've received alot of help from everybody here already. Mod please don't move yet! :help:
     
  9. C-5KO

    C-5KO

    Mar 9, 2005
    Toronto, Canada
    Thanks! I just sent them an email.

    Are the pots "regular"? By regular I mean, not connected directly to some sort of circuit board? I've taken a look at the J-Retro website, and they have a pot there, but it's mounted directly to the circuit, which I'm guessing my repair guy couldn't use.

    edit:

    also sent Warwick an email. in the warwick manuals the pot actually has a part number! very encouraging news! M88552 listed as 500K, 2x25K. I know the numbers have something to do with ohms? but still not sure if they'll do the trick for me. I'm going to pass the specs on to my repair guy and see. I'll let everybody know if they'll ship spare parts!
     
  10. ArtisFallen

    ArtisFallen

    Jul 21, 2004

    That idea of yours is actually really cool. i now understand your need for the blends as opposed to four volumes. two swings of a knob to get one pickup is a heck of alot easier than trying to turn four of them.

    as to the quote up above, that's a misconseption. the output doesn't increase because most pickups wired with two volumes like a standard J bass are in paralell, therefore the output can only really be as high as the lowest powered pickups.

    for example, my P-J bass is slightly unbalanced. the J has a slightly weaker output than the P, so when i futz with both at the same time, my volume goes down slightly. not much, but just noticeable. so when the P is on full, the J knob acts like half a blend.
     
  11. C-5KO

    C-5KO

    Mar 9, 2005
    Toronto, Canada

    Thanks for the kudo's. Now if I could only get it to work. :D

    Also, thanks for the explanation of the blend vs volume/volume. You lost me after misconseption, but I'll take your word for it. I really need to brush up on my basics... :scowl:
     
  12. ArtisFallen

    ArtisFallen

    Jul 21, 2004
    i'm sorry bout the whole electronics thing... i tend to go overboard with my wiring: always trying to get the most options you can fit without making your tone controls look like a minefield.

    if you would rather i could shorten it to "You're not right about that" :D
     
  13. FBB Custom

    FBB Custom TalkBass Pro Commercial User

    Jan 26, 2002
    Maryland
    Owner: FBB Bass Works
    I bet the Noll pots are low-impedance. Just a guess.

    That Warick pot sounds odd. Is it really 500k stacked with a 25k dual taper? I can't imagine what that would be useful for. 25k pots are matched to low-impedance sources and 500k are matched to high-impedance.
     
  14. C-5KO

    C-5KO

    Mar 9, 2005
    Toronto, Canada
    Bad news.

    James Landry just got back to me, and he says that he's never heard of such a pot.

    Scott, I'm guessing it's like the J-Retro preamp, where it's a special pot connected directly to the circuit board, and the circuit board takes care of all the complicated connections? Can you let me know what item it is exactly you received from them so I can get back to James on it?

    Not exactly sure what FBB is saying? The connection I'm trying to make is for two sets of passive J's (Barts and Nords), connecting to a Bart preamp. Does the 500K, 25K mean it won't work for me? This is so frustrating.
     
  15. FBB Custom

    FBB Custom TalkBass Pro Commercial User

    Jan 26, 2002
    Maryland
    Owner: FBB Bass Works
    Depends on which part of the pot is 25k and which is 500k. If the volume is 25k then you can do it but you'll need a preamp after the blend stage. If the blend part is 25k then I have no idea what the pot is good for. Passive Bartolini and Nordstrand pickups are high impedance and are rated to be matched with 250k volume/blend pots.
     
  16. C-5KO

    C-5KO

    Mar 9, 2005
    Toronto, Canada
    This looks like even more bad news....

    http://www.warwickbass.com/schematics/sch_images/dolphin1.pdf

    this is a pdf link of how they wire it up. It actually says 500K, 2 x 25K part#M88552 in the Dolphin Pro I user manual. So if two of the pots are 25K most likely they'll be the parts that attach to the pups?

    Is there anyway to tell from the pdf wiring diagram?

    I will be connecting both sets to the existing Bart preamp.

    If the pots are a standard size, is there a way to modify/switch their 25K pots, with 250K pots?

    edit:

    so just called Long & McQuade (Canadian music store chain), and as luck would have it, they have 6 of them in stock!!! Of course he doesn't know how much they are, he guessed around $30 each. He said that they ordered half a dozen of everything on the Warwick spare parts inventory. I'm dropping down there after work to grab one. I still don't know if it will work until I pass it on to my tech - he'll have to check out the 25K vs 500K deal - volume 25k? blend 25k?

    If it does work, I'll need one more, and will probably grab an extra 2 or 3 for backups since they're so hard to get.

    Geoff, I'm not sure if there are any L&M's near you, but if you want I could mail out some to you. Maybe a trade for the covers ;)

    thanks Mod's for not bumping this to Pickups - everybody's help here has been great, I'll post with an update as so as i grab them.
     

  17. There's a L&M here, but if the pots are in fact any part 25k, then I'd have no use for them. My Nordstrands need a 250k minimum and I'm planning to use 500k on them so that there's less high frequency attenution.
     
  18. C-5KO

    C-5KO

    Mar 9, 2005
    Toronto, Canada
    After reading through a bunch of threads about Pots, I think you're right.

    I don't think these will work for me. From the description 500K, 2 x 25K. It would make sense that the 25Ks are both for Active Pups, and the 500K is the volume? I don't know what sort of rating a blend would have... But why have a single 500K for one pickup? Doesn't make sense, unless this pot is ONLY for actives going to 25K.

    edit: tech at L&M says that the Volume is 500K. Which means that it won't work. 25K is too low for Barts or Nords. I need Volume 250-500K, and Blend 250-500K.

    My repair guy did say that he could take out the 25K's and replace them with 250-500Ks blends. I just have to find a size that will fit. he said there's about a 2% chance of finding them.
     
  19. Keith Guitars

    Keith Guitars

    Aug 25, 2004
    Woodstock, NY
    Builder: Martin Keith Guitars, Veillette Guitars
    Hi Guys,

    I dealt with one of these pots for a "1-knob" bass I built a while back.

    They are indeed a 500K volume, with 2 ganged 25K blenders. They are made by Alpha. They also have a DPDT switch on the bottom, and some pretty small shafts.

    They are not your usual construction - they're more like "military" style, box shaped pots, riveted together at the four corners. Taking these apart and replacing the resistive element would be exceedingly difficult to do.

    On the stock Warwick installation, the ground wire actually ran *inside* one of the long corner rivets...interesting.

    If you really wanted to use this pot, a simple buffer circuit on each pickup would do ya - that would bring the impedance to a level that would work for a 25K blender. The EMG PB-2, RMC BUF-2, or similar item would work fine. There's also a preamp on the MIMF forum that you could probably modify, or extrapolate to a 4-parallel-channel version.
    I used EMGs on my bass, so no problem...

    These pots are available as replacement parts from Dana B. Goods...I think they want a lot of money for them, though.

    Peace,
    Martin
     
  20. C-5KO

    C-5KO

    Mar 9, 2005
    Toronto, Canada
    Thanks Martin,

    My repair guy was going to see if he could find Warwick blend pots with 250K, and tear them out. He was very concerned that the Warwick pots would be proprietary, and difficult to modify. I'll check the Dana website and see if they have anything else. If they have these, then who knows what else they have. BTW, L&M wanted $30 Can for them.

    I think I would pass on putting a buffer circuit in. First, I don't want to make it exceedingly complicated for somebody other than my tech to fix. Second, the more work he has to put into it, the more this project will cost me. I may have found an alternative though....

    Warwick has stacked Blend pots that are 220K. Instead of the Volume/Blend, Volume/Blend, - I may go with Volume/Volume, Blend/Blend. Not exactly my original plan, but it is close enough. I won't need any extra controls, it's still a simple layout, and easily controllable for me. I'm guessing that 250K blend and 220K blend won't be much of a difference. If it is, again it's another compromise I would make for this to work.

    On to Dana!