Saturday, August 15, 2020

EARTHQUAKER DEVICES: Plumes

The Earthquaker Devices Plumes is their take on a Tube Screamer, and it's quite a good one.  It's somewhat simpler than Palisades, which is probably about as far as anyone would want to take a Tube Screamer.  

I'm not one that really likes Tube Screamers a great deal, as I never got the mid-boost and bass cut...  I quite like this one though.  Also, check out the Nobels ODR-S if you like Tube Screamers that don't sound like Tube Screamers (if that makes sense).


EARTHQUAKER DEVICES PLUMES - VERO LAYOUT

This is my second layout for Plumes, the first was a little cramped, so I spaced things out a bit.  Need a bit of room for the 1uf caps.  

Now, if you did want to head towards something more like a Dunes / Palisades, you could quite easily make daughter boards for the voice and bandwidth controls.  It's just diodes and caps on rotary switches.
 


earthquaker devices plumes vero layout

And a smaller layout, with all the connections for pots and switches on one side.

earthquaker devices plumes vero layout




ON THE SCOPE / FFT

INPUT SIGNAL:  440hz sine wave, approx 130mv TRMS
 
volume varies to suit.  note: B25K used for tone control, as I didn't have a W20K
 
 
 
Clean boost - no diodes.  There's a lot of level on tap.
 
 

Full gain - no diodes.  Again, just cranked and headed into square wave territory.  note:  even though it looks a bit square on the scope, it's nowhere near fuzz - clean boost with some dirt at the end of the range is the sound.  Meant to hit your amp with some level.
 
 
 
  
Silicon diodes - looking very much like a Tube Screamer now (tone 50%, gain 100%).
 
 
 
LEDs - similar to the silicon diodes, but with a bit more hair and more level (tone 50%, gain 100%).  Like anything diode related and clipping - it's a less compressed sound, more open due to the higher forward voltage of the diodes.
 
 





39 comments:

  1. Thanks for this! Regarding "note: B25K used for tone control, as I didn't have a W20K", I'm having a similar problem getting a W20K.

    Would a linear 25K pot be wired up the same way?

    Also is this a workable substitute, or should I try and find somewhere that supplies W20Ks?

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    1. Yes, they are wired the same way. W pots have a slightly different curve, which means that the sweep will be different, but you can still get the same sounds. You can always make a 20k pot from a 50k pot by placing a 33k resistor across the pins (resistance in parallel). This explains it better than I can http://www.geofex.com/Article_Folders/potsecrets/potscret.htm

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    1. It is pretty nice - hope you found the layout easy to work with.

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  4. Hi,

    Quick question, I thought the LEDs should be symmetrical? That's how Earthquakers describes that mode

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    1. Hello. The LEDs are symmetrical, meaning that there are two working together to clip the signal equally. Usually asymmetrical clipping involves an uneven number of diodes.

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  5. Ok thanks. I've tried to build thos today so I've just got a oscillating noise.

    Seems like pots work as they do change the tone a little, did a probe too and signal only gets as far as Tl074 pin 3 then becomes the noise after.

    I am using a MAX1044EPA+ instead of a TC1044, could it be that? Tried the usual check components, jointams, shorts etc.

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  6. MAX1044 EPA
    8.14
    6.95
    0
    6.4
    6.39
    7.63
    7.22
    8.13


    TL074
    7.60
    7.60
    5.94
    8.13
    5.74
    5.74
    6.39
    7.44
    7.36
    5.87
    6.37
    5.89
    7.56
    7.56

    If I've measured right

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    1. Pin 5 on the 1044 should have -9v The TL074 is not going to work with this happening. I’d investigate the inverter.

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    2. I checked mine. Voltages are approximate

      8.5 8.5
      5.3 1.5
      0.01 2.8
      -2.7 -8.5

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  7. I'm not really sure if I'm honest. I've checked the board so many rules now for bad joint, shorts etc I think I can't see the wood through the trees now.

    Can I just double check how you've read the voltage for the pins (and negative voltage) case I'm doing it wrong? I got those readings by probing the pins with positive, negative on ground?

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    1. Yes, negative to ground, then positive to the pin you are measuring. As a suggestion, take the TL074 out and see what you get for voltages on the 1044. If you get the right voltages on the 1044, then you know the issue will be elsewhere (probably around the TL074 area).

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  8. Voltage is the same without the TL074 in. Just to test too with the 1044 removed pin 5s area is now discharging to 0V.

    Any ideas why the chip is outputting positive voltage in pin 5? I have tried two different ones and same in both. Does this chip need pin 1 cut maybe?

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    1. I added a photo of my build - are the electrolytic caps definitely the right polarity?

      Not sure if it’s the IC as I’m not familiar with the version you mention. It looks ok on the data sheet. You could trying putting a cut there and if it does nothing you can always bridge it.

      Are you in any of the Facebook groups for pedal builders where you can post photos? Might be a good place to ask - and I’ll also be able to see some pics.

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    2. Just tried a cut between pin 1 and 8, hasn't made a change to any of the voltages coming out the chip. Checked the elec caps too, C11 going into pin 1 is positive facing and going to ground, C13 (the one between pins 2 and 4) is positive facing pin 2 too. C14 (pin 5)s is negative facing going to ground.

      I checked resistance against them too. All caps are slowly rising in resistance when measured with no voltage, BUT when voltage is on C13 is still rising in resistance whereas C11 and C14 are now holding steady. Maybe it's a problem with C13?

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  9. Pin 5 is the negative side of the capacitor, with positive going to ground. Is that what you mean?

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    1. Yes, that's what I meant. Pin 5 goes into C14 (which faces it negative, and the positive going to ground).

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  10. Think I've found it but can't try until home from work..... got a 10uf and 100uf the wrong way around, DOH

    Pin 5 has a 100uf instead of a 10uf, and the final cap before the output has the 10uf instead of the 100uf.....gonna guess there's my problem?

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    1. Fingers crossed that’s it.

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    2. Alas its not. With both caps both changed around still reading something like 6v there. Tried with pin 1 and bridged back too.

      I'll look at joining a Facebook group, but I might just bin the circuit at this point, I'm getting to the point where I'm starting to fix broken wires from inspecting it again and again now.

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    3. Fair enough - DIY stomp boxes is also great for this kind of thing

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    4. Right, I think the answer is these chips are total s**t and to not use them.

      This morning I made just the inverter section on a small piece of strip (pic below) with new parts. I have 3 of these chips all from the same order.

      one measures 8.5V pin 5.
      Another measured about 5V
      The third did - 3.5V.

      https://drive.google.com/file/d/163uw5EjMVezN_9w8VD7V3pn0SdqCMODQ/view?usp=drivesdk

      Nothing else on the board to interfere with it and all I did was swap the chip each time.

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    5. Yeah that’s not a good sign. eBay purchase?

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    6. R they were, rest all off bitsbox who I normally go from (they didn't have any inverters in stock at the time)

      I'll order off them, I can assume the TL074s prob been killed too?

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  11. https://electronics.stackexchange.com/questions/336704/dual-power-supply-two-9v

    You could make a dual rail supply with batteries and then attach the matching polarity voltages to the board to see if it is still ok - or just wait for new ICs

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  12. For the pennies it is I'll prob just get another now. If its been having positive voltage being sent into negative for a while I can imagine it's not gonna work right now

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    1. I have just tried the chip that did a negative voltage in the circuit. With the Tl074 in it read 9V (or thereabouts), with the TL074 removed it read -0.04V.

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    2. Well I hope you eventually get one going - it’s a pretty nice sounding overdrive. Very useable.

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    3. New chips cane today, built from scratch and worked a charm. Thank f**k. The MAX chips were duds, tried the one that did negative voltage in this board and it didn't work either. I haven't tried the news chips in the old board yet but I suspect it'll now suddenly work if I did.

      The TL074s were fine too so I got 2 spare now, got any cool suggestions to use them in (no inverters... I don't think I can cope with another!!!)

      And thank you, I know I must have done your head in but I wouldn't have figured it without having somewhere to grumble about the whole ordeal.

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    4. That’s great news. No problem re grumbling, we’ve all been there.

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  15. Andy, my apologies for leaving verified comments on wrong blog .I have noticed it yesterday..Sorry

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