Sunday, 28 May 2017

Darkglass Microtubes B3K

"The Microtubes B3K is an unusual tool - a perfect combination of brutality and clarity. It delivers defined and powerful saturation in an intuitive format. There are no rules and no limits, so dig in and unleash your tone.

Controls
Level: Sets the volume of the overdriven signal.
Drive: Sets the amount of saturation in the overdriven signal.
Blend: Mixes the clean input signal with the overdriven signal. The clean signal remains at unity gain while the volume of the overdriven signal is set by the Level knob, allowing for fine control of the blend ratio.
Grunt Switch: Sets the amount of low frequency content to saturate by selecting between three different bass boost levels before the clipping stage.
Attack Switch: Sets the amount of treble content to saturate: The œBoost setting emphasizes the treble content extra clarity and presence. The œFlat position leaves this register untouched while the œCut position will reduce the amount of high frequencies being saturated. This new addition helps to keep the treble portion of the signal under control, specially useful when playing with new strings and/or cabinets with tweeters.
"

You can find the original FSB thread and schematic here.

The layout (like the Friedman BE-OD) has been verified as "working" in the forum section but the original has been built using SMD components and there's been some "guessing" in some of the values.
I don't know how close it is to the B3K (it may be 100%) but this is the best schematic we can get at the moment.



53 comments:

  1. Alex you are the best!!A thousand thanks!!!

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  2. I was just reading up on this last week. Due to inaccurate values, i deemed it "unclonable" for the moment - for myself. But now i'd be quite interested to hear if someone builds one and compares it to the original. Chances of that happening just multiplied on a logarithmic scale. Good work Alex! Nice and tidy layout!
    +m

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    1. Thanks Miro. I wasn't sure if the schematic was good or not but I'm not sure we'll get a better one. Gavin has verified the layout in the Forum but he doesn't have an original one to compare it to. It sounds good though. I've thought by putting it on the main page (like the Friedman) someone may be able to build it and tell us how close it sounds to the original. I've worned people in the introduction but (like the schematics' links) some people won't read it and then complain about it ;)

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    2. Most likely :) However, like i said - the chance of getting more info and comparison test is now way higher since a lot of competent builders may take this on.
      +m

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  3. Awesomes! Thanks for posting this one.

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  4. Pretty new to the site and I'm already hooked after building my Sunn Model T preamp. Looking forward to building this but I can't seem to figure out which are the two transistors types used here? I apologize for my beginner's question in case it's something super obvious.

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    1. They're both J201s it's a JFET transistor.

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    2. Thanks for the quick reply! Now the shopping list is complete.

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    3. Watch out for shitty JFETs, there's lots of fakes out there, especially on eBay.

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    4. Got the pedal up and working and I have to say I like it a lot. The only issue I can't seem to wrap my head around is that turning the Drive pot up past 90% leads to lower sound and slight cutting out. Turning it back a bit gives the proper sound without any issues. Is the drive pot somehow letting the signal get pushed too hard? Can this be solved by adding a resistor somewhere or using a pot with a different value?

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    5. I have similar issues with you. Mine has a loud popping/crackling sound while the clean sound is present, I will check on it if my Drive pot is past 90% though.

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  5. Hmmmm. I wonder if this was taken from my blog. Traced this out a while ago. I now have PCBs that do both versions

    Initial trace
    http://peperspedals.blogspot.co.nz/2017/02/a-brief-guide-into-tracing-out-pcb-to.html

    Second post
    http://peperspedals.blogspot.co.nz/2017/03/b3k-clone-update.html

    Been meaning to do a new post with my newest versions. Also Currently designing a tone stack. So far I've tried a few different things and I'm not happy yet. Better keep tinkering.

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    1. Get some SMD JFETs and little adapter boards from diyguitarpedals.com.au and you won't have those sourcing issues! Paul rules.

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    2. Charles. I'm using SMD J201s for everything now.

      Alex. I did share this with Miro a while back over facebook but at that stage if hadn't verified it. No dramas I'm not that worried. At least it's out and about and making the rounds. Just a word of warning Doug has contacted a few people and threatened legal action against clones of this effect. I'm sure if the schematic is slightly different and you don't use the trademarked names if will be ok.....well ok ish.

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    3. I'm sorry Tony. I didn't know that. I've deleted my previous post. :)

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    4. Hey.. No problems at all matey. Keep up the great work.


      Love the work of you guys. So many great layouts. I have built at least 60 different veros from this site.

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    5. This comment has been removed by the author.

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    6. Hello Tony,
      I have compared my schematic, which is the one in the fsb thread, with yours, and they are exactly the same. I drew mine tracing the guma drive board.Where did you get your shematic?

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    7. Hey Miguel. Yeah I traced out a GUMA. Also made some PCBS that do both effects on the same board with a few component changes. I found the VMT needs a 1M pull up resistor on the second to last opamp stage otherwise it sounds horrible and farty. Will do another blog post on my blog about my new versions at some stage.

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  6. Is the 4049 buffered or unbuffered? And will this fit into a 1590B? I'm not sure what the max board size is that will fit one. Thanks!

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  7. Hi. I write here, because I don't found another place. Only want to tell you that I don't see a search form in your site to find post faster. It will add to your page the final 1% to reach the 100% of perfection.

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  8. umm, in Chrome there's a search bar on the top left cornere here.

    And as an alternative - go to Site map and CTRL+F ;)

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    1. Hi. It's not the same. Ctrl+F is for make a search in the active page of the site. An embeded search form, is for make a search in the entire site.
      This other search bar, I didn't found it the first time. Now I see it. Thanks.

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  9. I have one of these and honestly don't see what all the fuss is about.

    I don't think it's any better than the Boss ODB-3 or Fulltone Bassdrive...

    I'll be putting it up on Ebay soon, unless one of you would like it?

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    1. Just based on the demo, I really don't get the hype with this one either. Maybe it's like the Timmy of the bass world or something :)

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    2. I have a original Bassdrive as well but I find the B3K to be a completely different animal than Bassdrive with my setup. The B3K really makes my Rick & Ampeg growl in a way the Bassdrive just can't. Still like the Bassdrive though and it's been on my pedalboard for over a decade. Now it's got a B3K next to it.

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    3. Hi Jonas! Would you call it verified?

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    4. Well I've never gotten to try an original, and I have a slight issue with the Drive pot starting to cut out after being turned past 90%, but I might chalk that one up as some kind of beginner error (third thing ever soldered together). I would certainly say it sounds extremely like what is being said about it and the sound clips I've heard. And like I said, I will be using it as a permanent fixture on the pedalboard since it really has a "zing" and growl to it. Will just try to sort out the Drive pot issue at some point. I would wait for someone with more building experience or access to the original to truly verify it.

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    5. Thanks Jonas. I will build one of this and check if I'll have the same result. On FSB they didn't mention any problem with the Drive pot but...

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    6. On another subject: we need to verify 3 more circuits to reach 1000!!!

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  10. I'll verify Jonas' post and confirm that it's a working layout. Finally finished mine today and it's a GREAT pedal.

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    1. Thanks Paul! Had no time to build one yet! Is your Drive pot working 100% (Jonas had some problems)?

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    2. No issues with the drive control to report, not really had a proper play with it yet though.

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    3. Ok. I've built this and (although the Drive pot is working correctly) it doesn't sound as gainy as the videos. Also the Grunt switch isn't working correctly in the middle (Off) position. Do you have the same problems?

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    4. Did you use SMD or through hole Jfets?

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    5. Mine does the weird thing when the gain gets past 3 o'clock, but I'll keep it as it is as I rarely go past noon. Sounds great.

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  11. I also have a problem with the Grunt switch in the middle position Alex.
    If the drive pot Is on 85% or more I get some strange oscillations. (but the oscillations disappear when I turn down the drive pot)

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    1. It's exactly the same (J201's are good). I'm 99% sure the layout is correct. In that case there must be something wrong with the schematic or some other issues that I can't see. Does your gain sound as strong as in the original's videos?

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    2. No the gain isn't as aggressive as the video and I think that the switches does very little compared to the video. ( I have never tested the original)
      I used J201 from musikding that should be good but I have ordered SMD-ones and adaptor boards to test with.

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  12. Built this last week (much to the delight of my bass player) and it works great. No problems whatsoever when the gain is dimed, nor with any of the switches. All seems to work as it should. Absolutely top job guys!!

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    1. Mine has the same low gain/ switch problem that other people have experienced. And I've built 2 different layouts! Does it sound like the videos?

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    2. Yes matey, or as close as could be expected given rig differences. Both switches seem to work as they should (low saturation boost on switch 1, treble boost on switch 2, straight gain when both centred), and an abundance of gain with no unwanted noise. Maybe I just got lucky? Only notable diversion on my part is that I used a linear 100k for the drive pot, since I had no rev logs in.

      It works to a degree that my bass player is more than happy with at any rate.

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    3. In fact, now you mention it you're right. Should have paid more attention to the video. It sounds great once you start flicking the switches, but is actually decidedly lighter on the gain with them both set to centre. All the gain hits when the pot is at about 75%. Bizarre, I could have sworn it was working as it should. Serves me right for not spending more than a few minutes with it.

      Case reopened.

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  13. Mine has low gain for some reason

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    1. And low volume too, I dont think the switches work right either.

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  14. Wow...Thaks
    Please another Darkglass pedal and tc electronic spectra compressor bass.....

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  15. Hello guys!
    Just saw this thread! It was me that drew the circuit in fsb thread! Very proud that you used it here! :D
    Unfortunately is not perfect! but well, I done my best!

    I built it using tone transfer (you may find my tone transfer in the fsb thread). I used a Guma drive board to trace the circuit and compared it side by side they seems exactly the same. My thought about it:
    I tried it with a sadowsky metro bass that allows me to turn on and off the active preamp. And it's a huge difference. The passive sounds so much better! When I use in active mode I have to turn the knobs at full to have a some nasty drive that is not even close to what I want. But in passive, I get that sound with Blend, drive and Level at 1 o'clock. When I turn to full rotation the Blend and Drive is nasty, gritty and awesome. If you put the level at full rotation it becomes very very loud compared to your clean sound, something that does not happen in active mode.
    The grunt switch is very subtle in both, but also on the B7k that I tried. So, does not surprise me.
    For the JFETs I used the smd version, MMBFJ201. I think they are way more consistent then the through all version. I found a nice adapters in Musikding that coverts to through hole footprint.
    Cheers

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    1. If you are interested you may also find the VMT circuit in this thread.
      http://www.freestompboxes.org/viewtopic.php?f=1&t=25589
      It is more consistent when comparing with active and passive basses and it sounds better in active basses. But In passive I prefer the B3k.

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  16. Help a scrub out?

    I'm assuming the brown circles (22n, 220p, etc) are capacitors, yeah?

    What are the yellow rectangles (2n2, 1u, etc)?

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    1. Also, where it says DSG, I take it those are J201s as indicated at the side of the diagram?

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    2. Those are also caps, different markings because of the different spacing. And yes the DSG is the J201.

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  17. Hi guys, I have posted on FSB and I will quote it here:

    "I am sorry if I might be off-topic but since Guma Drive was mentioned here, I have done both the Drive (B3k) and Antique (Vintage).


    https://scontent-sin6-1.xx.fbcdn.net/v/t1.0-9/20374772_10213241516734053_2388814588029743446_n.jpg?oh=949843401576376530912738628f0d5b&oe=59F5B392

    https://scontent-sin6-1.xx.fbcdn.net/v/t1.0-9/20431333_10213241516774054_1214977167890671195_n.jpg?oh=899d0b05bdd6a6db42e570d72d94338a&oe=59EE21AE

    https://scontent-sin6-1.xx.fbcdn.net/v/t1.0-9/20596989_10213241516694052_8321330643929150071_n.jpg?oh=70346f9848e3ed4dc05caccf8eb3f2e3&oe=5A30B121

    The Antique works fine but I am having a problem with the Drive (B3k) because I got a cutting out sound, it seems that the distortion sound will get disconnected and all that's left is the clean sound, but it sounded great when the distortion kicks in. It feels like something is wrong with the switching, I always got a loud pop or the best way to describe it is like when you are playing a clean sound and then someone was messing or plugging/unplugging a cable to your distortion (parallel) sound, or when you hit the tip of your cable/plug to your guitar jack when your amp is turned on, or it's like a crackling sound (my pots don't crackle when I rotate them). Both the clean and the messed up sound varies in time, maybe milliseconds away. One thing I noticed was that after several minutes of fiddling with the pots and toggle or just by leaving it untouched, the messed up sound disappears slightly but it is still there waiting to happen."

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