Saturday 21 May 2016

CmatMods Butah

Here is a slightly modified version of the Marshall Bluesbreaker that is supposed to sound very nice.



20 comments:

  1. Awesome to see such an organized layout, this one is going on the To Build list for sure!

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  2. Wow, talk about low gain indeed. This one seems to be almost no gain at all.

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    1. If you mean volume, I think that might be related to the 250k tone pot which is originally 25k in the BluesBreaker. The sound would be darker too, and the tone pot would affect volume noticeably.

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  3. If you want more gain, increase the 220K resistor to 680K. For more crunch, use germanium diodes in the feedback loop instead of the 1N4148s. If you want something similar but with more of a distortion flavor, build the BBE AM64.

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  4. Looks like a completely original BluesBreaker except for one thing - a 250k tone pot instead of 25k. I think that has to be a mistake - right?

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    1. That was a mistake.
      It's been corrected.
      Thanks!

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  5. I have a double supply, which parts should I leave out? Or is there a schematics to post please? Thanks

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  6. Why is it Unverified ? It Works - I Used A ( C 1oo K )for drive - and put D 1 and D2 on a Switch so you can turn them off - Thanx for all the great layouts - Greetings from Ole Staalfx Copenhagen Denmark

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    1. Nobody had verified it yet.
      Thanks Ole!

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  7. Just built one and put the clippers on a switch (on-off-on) with the quad as in the layout, lift and two blue diffused LEDs. Pretty usable Bluesbreaker upgrade.
    +m

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  8. I'm a bit confused. Why do you have two different symbols for the 10n? Aren't they both 10nF capacitors? (the red and the yellow) I'm trying to understand the logic behind the different symbols, but I could use a little help. I've been looking for a legend to these diagrams, without success...

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    1. Yes, they are both 10nf. I would say that the program there using. The box type 10nf would be big in the layout where the other one is. Just a guess though. Otherwise, it is no big deal just use what you have.

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  9. What is the dot at coordinates (10,10) from top left?

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    1. That's a double link. Meaning you have two link wires soldered together at that spot. Usually, you'll need really thin wire to be able to get them through the same hole, like resistor legs.

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  10. When you say pot are B100k, you mean linear?

    regards
    Allan

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    1. Yes, A: logarithm, B: linear and C: anti-log (AKA reverse-log).

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    2. Thank you, i just bought log pots :-(
      What different will it make?

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    3. Basically, you'll need to crank an A pot a little further to get the same amounts of volume/gain/tone a B pot would give you at the half-way position - so, it's a feel thing. Sometimes a B pot works better for a specific circuit/control, sometimes it's A, sometimes C...

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  11. BTW, built this one this morning. Can't say I love it, but having never owned/built a bluesbreaker-type pedal I had to try it or my life wouldn't be complete. This thing is really friggin bright, so I upped the 51pf cap to 330pf to roll off the treble some more, and experimented with a few op-amps (NE5532, LF353, LM1458, TL072CN and JRC4558). I'm using a JRC4558D for now, it seems to have a little more compression on the top end and a little more midrange - with a TL072 this thing is very upper-mids/treble heavy, almost like a treble booster. All in all, this is an interesting alternative to a regular TS. Another observation: most of the gain is bunched up at the end of the pot, like a fuzz face with a B pot for gain. I think that a 100K C pot would work better here.

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  12. So it's basically another Blues Breaker clone of the worst version 2, with only 2 changes: linear volume pot to try to fix the volume drop, and one more diode in the loop...

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