Devi Ever Karaoke Party

Revelation · Post by **Revelation** » 24 Sep 2010, 22:15

This is unverified scheme of the Devi Ever KP. Can somebody check it?

: karaoke party unverifed.png (4.62 KiB) Viewed 3308 times

jrod · Post by **jrod** » 24 Sep 2010, 22:54

Revelation wrote:Can somebody check it?

Some gut shots of the circuit, both component and trace sides, would help tremendously.

salocin · Post by **salocin** » 24 Sep 2010, 23:49

Revelation wrote:This is unverified scheme of the Devi Ever KP. Can somebody check it?

Did you trace this yourself?

IvIark · Post by **IvIark** » 25 Sep 2010, 00:31

There you go, I'm sure someone will give it a try and let you know. I included a filter cap because there was a gap and I figured it was going to need all the help it could get:

squrl · Post by **squrl** » 25 Sep 2010, 00:38

IvIark wrote: I figured it was going to need all the help it could get

teej212 · Post by **teej212** » 25 Sep 2010, 01:37

no. the karaoke party only has one transistor.

this might help
http://www.etsy.com/listing/50620272/pu ... dark-boost

IvIark · Post by **IvIark** » 25 Sep 2010, 01:43

It sounds like two from this description. Even though it only says Q2 it says that the 3M3 goes "from middle of Q1 to IN1":

>>> Karaoke Party

INPUT - IN1
GROUND - GND (either one)
9volt + - 9v (either one)
OUTPUT - OUT

3.3m resistor from middle of Q1 to IN1

R1 - jumper
R2 - 2.2M (red red green)
R3 - 10K (brown black orange)

C1 - .1uF (104)
C3 - .1uF (104)

Q2 - MPSA18 (same orientation as Q1 screen print)

Greenmachine · Post by **Greenmachine** » 25 Sep 2010, 01:44

squrl wrote:
IvIark wrote: I figured it was going to need all the help it could get

Revelation · Post by **Revelation** » 25 Sep 2010, 10:09

Thanks guys.
I made this scheme using the description on the website. You can see that it is very similar to Silver Crank (viewtopic.php?f=7&t=3704), but uses 3.3m resistor and Q2 is MPSA18 (from description).
I'm not sure about "3.3m resistor from middle of Q1 to IN1". If it's true, all should be ok.

bajaman · Post by **bajaman** » 25 Sep 2010, 10:20

you have a dc bias path to the input

- I would add a 33n input coupling capacitor to avoid dc coupling to your guitar (and loud bypass switch pops

cheers
bajaman

Revelation · Post by **Revelation** » 25 Sep 2010, 15:42

Ok, i'll try this when the parsel with transistors arrives from ebay

celadine · Post by **celadine** » 25 Sep 2010, 18:39

I agree with a previous poster, you would need pics of the circuit board to know whats going on. There's a pic of the top on etsy. Shots of the bottom would be nice.

teej212 · Post by **teej212** » 25 Sep 2010, 21:59

im pretty sure it only has one transistor. see how the 33 directions say "Q1 - MPSA18
Q2 - 2N2907A"

the karaoke party only says Q2- she would have specified if there was another transistor in there i believe.

Revelation · Post by **Revelation** » 26 Sep 2010, 10:46

In my mind it will be booster with only one transistor.

mictester · Post by **mictester** » 26 Sep 2010, 12:30

teej212 wrote:no. the karaoke party only has one transistor.

this might help
http://www.etsy.com/listing/50620272/pu ... dark-boost

Errr... No - I can see two transistors in that kit!

HEAD · Post by **HEAD** » 26 Sep 2010, 12:34

... just to mention it: Don't give a f*** for the "right" transistors. I tried several Devi "designs" with mostly BC type transistors. They all sounded the same - whether this ist good or not.

celadine · Post by **celadine** » 26 Sep 2010, 17:52

There are multiple things you can build with the kit. The instructions are on the etsy page. Some only use one of the transistors. The Karaoke Party instructions are confusing, as they tell the builder to put the one transistor required in the place the second transistor would be.

Revelation · Post by **Revelation** » 26 Sep 2010, 19:23

I built this with two BC550C transistors. They have a lower hfe than mpsa18, so the sound was like a low-gain fuzzy drive.
Honestly i didn't hear the differense between variation with the 3,3M resistor and without it.

Also i replaced the bias resistor with 150K pot. This option can add some crackle to the sound.

teej212 · Post by **teej212** » 26 Sep 2010, 19:24

ill ask someone on her forum for the pcb layout and that will lead to the schem i bet.

papercutnoise · Post by **papercutnoise** » 03 Dec 2010, 10:52

this is what I came up with based on the descritions on her site and given that it's of a similar design to some of her other pedals....

Any comments are appreciated.