Saturday, 7 April 2012

Sola Sound Tone Bender MkIII - 3 knob




46 comments:

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    1. I didn't specify anything because some of the PNP germanium transistors that people use in these are hard to find and expensive so really it's whatever PNP germanium transistors you want to use and have easy access to. If you can get hold of some OC81's or similar old Newmarket then great, if not use anything but try to aim for around 60-70 hfe for Q1 and Q2, and 110-120 hfe for Q3.

      2N404's seem readily available still from eBay so they may be a good choice, or I know shops like Small Bear sell Tone Bender sets that are around the correct gain and so may be worth considering.

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  2. Where the transistors measured back in the day? I really want to make a germanium fuzz but all the fuss AND expense of purchasing selected ones etc puts me off.

    I have 3 AC128's that I have no idea of the hfe!? lol

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    1. I've no idea whether they were measured, probably not but then they probably didn't all sound great either. But I'd always socket them and then just experiment with different transistors in different positions to see which combination sounds best to your ears.

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    2. I only asked because when I made the Fuzz factory I just threw 2 x AC128's in as I don't have the means to test them and it sounds fantastic... lucky I guess. I'll stick to all the distorions/silicons I think

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    3. Hey if you've got 3 x AC128's to use up, why waste em? :o) Honestly mate, your ears are a much more powerful tool than something that will measure gain and leakage. There's been lots of times when I've used the accepted "standard" and thought "meh", and then ignored the accepted "standard" completely and made what I thought was a good sounding effect. No one can say that certain gain ranges will sound better to your ear than any other gain ranges, and I only include them in things like this as a guide because they can be expensive, but they're also something where you could buy in a specific range from some sellers, and so you know it'll get you somewhere in the right ball park.

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    4. Well now I'm torn between this and the DAM Fleshhead... but I think I've had enough of DAM so I'll try 'em in this instead(When my switches arrive)... I suppose if it does sound bad at least it will be built and I'll just have to order a 'tonebender set'

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  4. Built it. Made it NPN (negative ground) - reversed electrolytics and used MP38As. 40-50 hFE for Q1 and Q2. 100 hFE for Q3. I got only one word. Amazing.

    So the circuit works right.

    This has been a very good day. :)
    +m

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    1. And another one bites the dust! :o)

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  5. Someone can teach me about positive/negative ground? I´ve done the circuit and it sounds amazing! even with random unmeasured transistors. I´ve built it with the GGG positive ground wiring diagram. The circuit works with the battery and with power supply too but I have a question. My power supply has a interchangeable jack to make positive-negative power. I use the same position to supply the board as my other pedals (NPN as usual) and it works, I swapped it and it doesn´t.

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  6. Can I use a 1n34 in place of the 1n270?

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    1. Yeah you can try any different diodes there, socket the spots and see what you like best.

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  7. Hmm...my 2nd germanium failure.I tried Dragonfly's MkII "reissue" lastnight and got only clicks out of it. This layout turns into a Atari punk console on me lol. All i get is a volume and tone sweepable "synth" sound out of it. Good grief I am frustrated. Using ac128's and a 1n34. Just want to make sure I have the non 3pdt wiring right.

    9 volt battery + goes to ground on the board/- goes to "-9" on the battery.

    Sleeve input jack goes to input on the vero.

    Volume 2 goes to sleeve jack output.

    Volume 3 can go to one of the tips (either in or output).

    9+ on the battery goes to one of the tips.
    Need some help here...Thanks.

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    1. I ment +9 from the battery goes to a sleeve

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  8. Volume 2 is the out of the vero (goes to 3pdt). Jack´s Sleeves are for grounding, for input and output you should use the tips.

    Try this http://www.generalguitargadgets.com/pdf/ggg_sw_3pdt_tb_pnp_dcj.pdf

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    1. Thanks...I assumed "+ ground " meant all the standard wiring got reversed (ie. sleeves and tips get reversed ect.).I think whats confusing me is seeing that red wire -9 volt and black ground on that layout. Will have it a go today.

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    2. http://tagboardeffects.blogspot.fi/2012/05/negative-voltage-inverter.html

      That's what i would use.. Relatively cheap daughter board, that gives the possibility to use the same wall wart as the other pedals.

      I've built my RangeFace (germ FF to germ RM) with that pump, and it is awesome.
      +m

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    3. Looks like a must build (thanks). BTW got it working this morning. I had the wiring all wrong.It sounds the part. Thanks for the help guys.

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    4. http://i1115.photobucket.com/albums/k543/jd_roost/IMAG1241Small.jpg

      http://i1115.photobucket.com/albums/k543/jd_roost/IMAG1242Small.jpg

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  9. http://mirosol.kapsi.fi/varasto/boxes/ryyppyputki.JPG

    As "bender" apparently means continuous drinking spree in some slang, i named this "Ryyppyputki" - which is the same thing in finnish. Paint became ugly, but i'm still quite happy with it :) This one's a keeper.
    +m

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    1. Ha ha, awesome. Yes a "bender" to me usually means any weekend. :o)

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    2. It did mean the same thing to me.. Until i found myself a new hobby :) I think i'll be trying some next friday though :D
      +m

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  10. So I've really been enjoying building fuzz pedals...I've had some issues with my first builds from here but that's been me learning the ropes. Made a Zvex SHO today and it turned out great so I'm building my confidence! Miro mentioned having reversed the electrolytics and using MP38As to make it NPN. I don't know what the MP38A is, but is all that really needs to be done to make a PNP circuit negative ground reversing electrolytic polarity? I prefer to power all my pedals from a PP2+ :)

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    1. MP38A is a soviet made NPN Ge transistor that has reasonable gain range. These are, sadly, rarely for sale on ebay..

      You can probably get more stable transistors in PNP, so another option would be to use a charge pump to invert the voltage. That way you can have the PNP transistors, but still daisy chain it with other boxes.

      If you can find good NPNs, then just reversing electrolytics and minding the power would suffice. Ground is still ground, and the board should be fed with +9V instead of -9V
      +m

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    2. Cool, gotcha. I just ordered a few NE555 and ICL7660S to try the two different voltage inverters on here.

      So a more general question - how does one determine a good transistor...silicon or germanium? I have a lot of transistors but I don't know how to test them as of yet or what might make one "good" and another "poor." Thoughts or resources that might be useful? Thanks!

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    3. Get one of these! Best investment I have made. It saves so much time hand testing transistors.

      http://www.amazon.com/Peak-Electronic-Design-Ltd-dca55/dp/B005NIR8G8

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    4. Sweet! I'll look into it - thanks Vince!
      Does the 1N270 need to be reversed as well?

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  11. I'm trying to trouble shoot this pedal today as I can't seem to get the signal all the way to the output. Q1 is processing signal from the CBE, Q2 from C and B, whereas Q3 only has signal at B...I don't know if that's normal or not but I've tried all combinations on the Qs to make sure nothing else is the matter since I had that issue with a previous build. Signal is going through Fuzz but not making it the volume. I tried metering the trannys but realized I had no idea what I was looking for...

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  12. I'm on a fuzz run... so with this I simply flip the elctros and chuck any NPN in there with some leg twisting and I'm done for a negative ground version?

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    1. Reverse the diode too. You'd probably want the transistors to be in hFE range or 70-120.

      For more volume, lower the value of 220K at volume 3 to something like 100-120K.
      +m

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    2. Thanks so much. Noted. :)

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    3. I recall using 200K pot for volume and lowering that resistor to 120K. That way the resistance between tone 3 and ground stays the same.
      +m

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    4. Just Found interesting thread in freestombox site . Optimum voltages for basing are q1-3.5 q2-3.5 and q3 1.9 D1 was also an Oc75 used as a diode in the earliest variants of the pedal.will try these changes tomorrow and report back .

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    5. Pedal sounds great but I'm really craving more volume. Is it necessary to sub a 200k pot or just lower the 220k resistor? Will lowering that resistor value affect anything else tone-wise? Anyone else find this thing pretty noisy? It's got the loudest hum on my board right now with single coils-silent with hb's.

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    6. I'd suggest doing both. Lower the 220k to 68k or 82k and swap the volume pot for 250k lin. That just takes the output closer to tone control and further away from ground without affecting anything in the frequency department. With 68k and 250k pot the resistance between tone control and ground (this being the volume control) stays close enough to the original spec (68k+250k=318k as opposed to 220k+100k=320k).

      I've built quite a few of these and i even have an original (in form of OEM built as Carlsbro Fuzz). I've never had issues with noise. You should probably try another power supply..
      +m

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    7. Thanks. I'll do some tinkering today. It was also my first time using a 555 voltage inverter. That wouldn't be a source of hum would it?

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    8. Haven't tried one since i'm stocked on 7660Ss for the rest of my life, but that could be it. You could try adding a little more filtering to see if it helps.
      +m

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    9. Using this circuit with a 7660scpa chip, can anyone please confirm what their current draw is? I've measured appx. 30mA even w/out an LED and wondering if this is normal?

      Also, Collector biasing of Q3 at less than -2V seems low when comparing to other fuzz circuits where it's usually recommended to be at least 1/2 supply voltage or more has been mentioned (between -4.6v to -6v). Anyone experiment with something different than the usual 10k + 18k resistors to put more voltage on Q3's collector?

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  14. Amazin fuzz - I build one today - Leave out the last resistor 220 K ( or put in on a Switch it makes it louder - Will the gain on the 3. transistor mean anything to how loud it is ( I used 3 Germaniums with around 100 - 110 hfe.. )
    And the tone control is very good - it can get really brigth and sharp -
    Once again thanks for sharing -
    Greetings from Ole - Staalfx - Copenhagen Denmark


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  16. hi is tonebender also named fuzz unit?
    it seems to have a similar circuit
    and i am building a fuzz unit with a layout in freestompbox

    http://www.freestompboxes.org/viewtopic.php?f=19&t=7055

    buti cant get any sound out of this
    i have try BC184 and BC549

    http://i.imgur.com/w2zfMUCl.jpg

    but when i use my finger touch the red circle area
    there are sound with volume and tone knob working but not the gain

    http://i.imgur.com/twi7bEUl.jpg

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