This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Tuesday, April 3, 2018

Lovepedal Tchula

Another Electra variation from Lovepedal. It's described as a two-stage COT50... I guess the "stages" are the different ways to bias the transistor off the emitter. The stages are switchable via footswitch in the originals, but if you put it on a toggle switch you should be able to fit it in a 1590A. Here's the schematic (this was traced from a cream box Tchula):




49 comments:

  1. Verifield. Yeah.
    But i try TR 2n3904 and dioda is 1n4148.

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    1. jauh ga mas perbedaan soundnya dibanding pake BAT46?

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    2. You did exactly like me, how did it sound?

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  2. Also verified, and with 4148's. Thanks for a great layout D!

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    1. How does the sound of 4148's compared to the stock?

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    2. Probably like a much warmer COT50! :D

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    3. I have 1N270 Ge, 4001, BAT05 and 4148, I thinking something with the Ge and one of these.

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  3. Does anyone have the wiring schematic of sw1 and sw2 to 3pdt switch ? What if i connect sw1 and sw2 cable to spst switch (2 prong toggle switch) (On and On side both of them) ,will it work ?
    Sorry i'm just newbie, have a nice day everybody :))

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    1. An spst on/on would work. To wire to a 3pdt, just use 1-2, or 2-3 or 4-5 or 5-6 or 7-8 or 8-9. Any of those should work.

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  4. Does anyone have any reference to how I connect the 2 switches? thank you

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    1. Wire the on/off switch (3PDT) like the diagram in the General Layouts Notes tab. For the other switch, use a DPDT footswitch and wire lugs 1 and 2 to the corresponding pads on the board (reference the switch diagram in the General Layout Notes for lug numbering). Then wire an LED like you would with a 3PDT with the other side of the DPDT (4.7k resistor from +9v to LED+, lug 4 to LED-, lug 5 to ground). Hope that makes sense.

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  5. My very first build of a guitar pedal ever! Did it on protoboard with a few changes from the original. Highly recomended for beginers!

    Just a thing, by my thoughts, I can run this babe with a higher voltage (12v or even hihger) for more headroom Is that right or am I wrong?

    Pretty neat site btw. Cheers!

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    1. Yes, higher voltage should give you more headroom. Just be sure your components are rated at a high enough so nothing blows up! haha

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  6. I suggest adding a 47ohm resistor between the 47uF capacitor and the switch (on/off), because if it stays that way, when the gain is at its maximum it will have an excessive treble with too much bass loss.

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    1. Can you or anyone else confirm this? I'm building this and drew up the 47uf resistor in between the 47uf electrolytic cap and sw1. I'd just like confirmation since I will be sending the files to a fab house.

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  7. Hey all,
    So I built this thing this week and am getting extremely low output - tried swapping out the transistor (socketed) and still getting the same issue. Don't see any blatant solder bridges. Any suggestions on what I should look into? Should I be seeing specific voltages at the transistor? Thanks!

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    1. Double check you've got the right values for the resistor between the base and collector of the transistors, the resistor from voltage to the collector... That last one you may need to adjust to bias the transistor correctly.

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  8. Does the bias potentiometer only work if SW 1 E 2 Are actuated?
    When it is off, the bias potentiometer does not work.

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  9. PT: excelente layout e um timbre impressionante para stratocaster e lespaul :) coloquei um resistor de 47ohms entre o capacitor de 47uF e a chave on/off como indicaram e adicionei mais duas alterações; troquei o potenciômetro por C1K, inverti as pernas 1 com 3, para o efeito ser crescente da esquerda para a direita e adicionei um trimpot para volume. abraços!

    EN: excellent layout and an impressive timbre for stratocaster and lespaul :) I put 47ohms resistor between the 47uF capacitor and the switch on/off as indicated above and added two more changes by myself; I changed the potentiometer by C1K, inverted the legs 1 to 3, for the effect to be increasing from left to right and added a trimpot to volume. hugs!

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  10. Built this with the BAT46's. Great pedal, many thanks!

    Has anyone tried a Ge NPN in theirs? If so which transistor and what were the results?

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  11. I try russian TR КТ3102ГМ, sound very nice!)

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  12. Hi,
    I've just built the Tchula, sounds very nice.
    About the 47ohm resistor, I don't understand where exactly to put it in...
    Can anyone help me out?
    Thanks!

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  13. So i have a quick question. can i just used a black marker with a strip board an then use etching solution? i seem to be cured to fail, with both the alcohol+acetone transfer or using the iron. i only get 40-75 percent tranfer. iv watched both videos, im following steps. thanks

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    1. You can definitely try. It will depend on what kind of marker you use. I know people used to use Sharpies for this, but Sharpie has changed formulations, so they may not work anymore. But definitely worth experimenting with.

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  14. If you have to choose another potentiometer which value would you choose?

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  15. It works, the drawing is good. I built a few pedals from the drawings here. Thanks for them.

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  16. Great pedal, I used 4148 and a trimpot to adjust the output volume. Congratulations for the work !!!

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  17. As I use most of my pedals in a looper, I think about building it into a 1590A as a "always on" pedal and use the primary footswitch to turn the bias switch on/off

    But I am still worried that this circuit has no volume control - would someone who already build this recommended that? Did you use a A100k or what works well?

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  18. Yang di maksud sw 1 sw 2 kita pasang di pin mana??saya pakai switch dpdt

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  19. I breadboarded this and it sounds very nice. I finally realized when building this, that Lovepedal has manv variations of the electra distortion and so I modified the Tchula according to the other ones - recommended for a good learning curve :-)

    But - what makes me wonder in general: How could this pedal be "loud" really - as some stated? When using BAT46 (and even with 1N4148 as the original electra uses, AFAIK) to limit the output directly, you never get a real boost of the signal (at least compared to some already higher output pickups). BTW, even without the diodes the sound is already nice - and much louder ;-)

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  20. Hey everyone. I’m gearing up to attempt this pedal (my first build) but missed the 5817 diode when I did my BOM since I created it based off the schematic. Is the 5817 on the schematic somewhere and I just missed it? Also, what is the purpose of this diode? Appreciate anyone who helps.

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    1. The 1N5817 is for polarity protection so if the wrong polarity power supply is applied it won't fry the rest of the circuit. Other diodes will work like the 1N4001, 1N4148, and the BAT46 already used in this circuit will work well.

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    2. Thank you! I appreciate you taking the time to clear that up for me.

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    3. Hello there, another quick question regarding this polarity protection diode. In the schematic, would this diode go in between the 9V+ pin and the 330Ω resistor? I'm trying to use eagle to do up this board and want to get it right. Appreciate your help.

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    4. Yes. If you look at the PCB layout, you'll see power comes into the anode side of the 1N5817 diode, out through the cathode and on to the 330Ω resistor.

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    5. Thank you. I wanted to be certain. I appreciate your help!

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  21. Ok, total newbie question(again), but can I wire the two switches up with two 3PDT switches? Or do I have to do one 3PDT and one DPDT switch? I ask because I have some 3PDT switches but no DPDT ones. I already soldered them both to some little daughter boards from guitarpedalparts.com. I appreciate your help. Your eagle video tutorials and this site are how I learned everything I know so far, so thank you!

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    1. You can use a 3PDT. Just ignore the unneeded column

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  22. Hey there, I have a weird issue and was wondering if anyone could help me troubleshoot it. I have the board wired up and with stomp 1 engaged I get a maxed out gain signal. Engaging the second switch gives me the normal "side 2" signal with a functioning bias knob. If I max out the bias the two sides sound the same. Basically I don't have the low gain portion of this pedal as of now. Any idea what I did wrong?

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    1. This comment has been removed by the author.

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    2. I think I know what the issue is. Where do I route SW1 and SW2 to? I am doing a build with two 3PDT switches. I routed SW1 and SW2 to lugs 1 and 7 of the second stomp switch. I believe this is the problem. How should it be wired? I have 1 and 7 of stomp 1 going to in and out on the board.

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    3. Correction: I had lugs 1 and 2 of the second 3DPT going to sw1 and sw2.

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    4. I'm basically confused as to where I run the fx in and fx out on each 3PDT.

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  23. Is there a trick to make sure the pcb layout is sized correctly when you print it onto acetate or is it trial and error?

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  24. Built it today, sounds great. Lovely layout too, nice and compact. Cheers!

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