Tycobrahe Octavia Transistors???? PLEASE HELP!!!!

Started by brokenstarguitar, July 27, 2015, 12:42:24 AM

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brokenstarguitar

I need some advice/help. I'm building the General Guitar Gadgets "Tycobrahe Octavia" ( http://www.generalguitargadgets.com/effects-projects/octave/tycobrahe-octavia/ ) and the transistors it calls for, 2N6519, I can't seem to find. I do have the MPSA18 though. I've been cross referencing it but what I come up with I have the same problem, I can't find them. Can anyone help me out? I do have an order I'm placing with SmallBear as soon as I find a replaceable transistor, maybe someone can look through what SmallBear has and give me an option? Thanks Guys, I'm forever in your debt!

http://smallbear-electronics.mybigcommerce.com/

MaxPower

The 2n6519 has an hfe about 200/270 max (according to the fairchild datasheet). Transistors with an hfe in that area should work fine. The 2n3906 looks like a decent candidate.

You could always try the modern npn version which uses available transistors. Or you can try to find substitutes at this site:

http://www.alltransistors.com/
What lies behind us and what lies before us are tiny matters, compared to what lies within us - Emerson

Elijah-Baley

I'm going to build the Tycobrahe Octavia, too, but I want it negative ground, modern style.
Did you have decided to build it like the original?

If you change it from positive ground (old fuzzes) to negative ground (modern pedals), and you can find the instructions on GGG, you should find other transistors, mybe more available. Further, GGG "says" transistor are not critical components, so maybe the sound will be the same or so.
«There is something even higher than the justice which you have been filled with. There is a human impulse known as mercy, a human act known as forgiveness.»
Elijah Baley in Isaac Asimov's The Cave Of Steel

Cozybuilder

Check out the Retrograde schematic on MadBean for a negative ground version of the Tycobrahe Octavia.
Some people drink from the fountain of knowledge, others just gargle.

brokenstarguitar

Steve (SmallBear) recommended a few for me. Thanks for your thoughts and opinions, it helped a lot. You guys rock as usual!

JimSalabim

Look here: http://www.generalguitargadgets.com/pdf/ggg_toct_bom.pdf
Q1: 2N5087 or 2N3906
Q2: 2N5088 or 2N4401

Where did you read about 2N6519?

I built mine with a 2N5087 and two 2N5088, and it sounds amazing. I have used this layout:
http://tagboardeffects.blogspot.de/2013/04/tycobrahe-octavia.html
It’s negative ground already.

If you already have a PCB with positive ground, I would recommend to built a negative voltage inverter (http://tagboardeffects.blogspot.de/2012/05/negative-voltage-inverter.html) right into the enclosure.

Elijah-Baley

Quote from: JimSalabim on July 27, 2015, 01:44:17 PM
Where did you read about 2N6519?

Here:
http://www.generalguitargadgets.com/pdf/ggg_toct_sc.pdf
Original schematic Positive ground.

I'm going to use sabrotone layout. There's in the page some instructions to add the octave off switch.
I suppose every layout is goof for positive or negative ground, but careful to the polarize. Search on fuzzcentral this info.
«There is something even higher than the justice which you have been filled with. There is a human impulse known as mercy, a human act known as forgiveness.»
Elijah Baley in Isaac Asimov's The Cave Of Steel

LightSoundGeometry

I have two transformers for the octavia I will sell if anyone needs them - if you want them I can send a paypal invoice for them to you

pinkjimiphoton

don't ever get "hung up" on transistors. if they are the proper pnp/npn and in the proper gain range, the name doesn't mean poo.
in some cases, with germanium, you WILL get different tones... but with silicon, pretty much as long as your gain is right and ya have it biased properly you can use damn near anything. the "mojo" aspect of the exact parts may or may not be relevant. personally, my ears ain't that golden.

personally, i prefer the roger mayer transformerless version tonally myself.  the bobtavia is close too.
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Elijah-Baley

I chosen Tycobrahe because have less components, I was curious because of the transformer, (I never tried to solder it), and it has been used by a guitarist, one of my favourite guitar tone. So I wanna try it.

Bobtavia? ??? What is it?
«There is something even higher than the justice which you have been filled with. There is a human impulse known as mercy, a human act known as forgiveness.»
Elijah Baley in Isaac Asimov's The Cave Of Steel

pinkjimiphoton

bobtavia is bob star's simplified octavia, it's chip based, totally easy, and sounds great.

you newbies need to learn to use the search function. ;)






way way easier, and frankly sounds pretty close. if ya lift the transformer, you get a decent (if slightly muddy) overdrive, too.

but better than all the others is gus smalley's ousb aka octave up sick box. them suckers will track most of the way down your neck, have a screaming octave and are insanely fun to play with.





here's the vero i did for mine years ago. i would check it as i don't recall if this was the final one or not:



my dipshit thread from days of yore: http://www.diystompboxes.com/smfforum/index.php?topic=97944.0



http://tagboardeffects.blogspot.com , IvIark and Miroslav's site has some of the best vero layouts available. you should get to know them guys better. ;)

you should use the search function to find layouts and schems and info etc. you will be amazed at the unfathomable wealth of info on this website.
i reccomend starting at the end of the forum, and working forward in time. by the time you get back to the beginning, you will likely know more than many EE's do, and will be able to do some amazing things. believe me. i was once a beginner just like you. i STILL am "but an egg"...but there's a world of knowledge in this site from some of the greatest names in effect devices of all time.

there's a literal ass load of videos of various fuzzes and weird things on my youtube

https://youtube.com/666pinkster

happy building dude... get down with the sickness, and never look back.

stock up on every day components at tayda, and get all your good bits from small bear and you'll be out of your mind in no time.
peace

  • SUPPORTER
"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr

Elijah-Baley

Quote from: pinkjimiphoton on July 29, 2015, 09:54:20 AM
[...]
you newbies need to learn to use the search function. ;)
[...]

You're right! I search quickly on google, with "bobtavia" I got not concerning stuff. I have to search "bobtavia pedal". ;)
Now I found this: https://www.youtube.com/watch?v=HrhRjSFjHok.
:D
«There is something even higher than the justice which you have been filled with. There is a human impulse known as mercy, a human act known as forgiveness.»
Elijah Baley in Isaac Asimov's The Cave Of Steel

pinkjimiphoton

Quote from: Elijah-Baley on July 29, 2015, 10:54:06 AM
Quote from: pinkjimiphoton on July 29, 2015, 09:54:20 AM
[...]
you newbies need to learn to use the search function. ;)
[...]

You're right! I search quickly on google, with "bobtavia" I got not concerning stuff. I have to search "bobtavia pedal". ;)
Now I found this: https://www.youtube.com/watch?v=HrhRjSFjHok.
:D

i meant use the forum's built in search function. you'll find shit that ain't on google.
  • SUPPORTER
"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr

Elijah-Baley

«There is something even higher than the justice which you have been filled with. There is a human impulse known as mercy, a human act known as forgiveness.»
Elijah Baley in Isaac Asimov's The Cave Of Steel

pinkjimiphoton

  • SUPPORTER
"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr