Page 1 of 2

Devi Ever Karaoke Party

Posted: 24 Sep 2010, 22:15
by Revelation
This is unverified scheme of the Devi Ever KP. Can somebody check it?
karaoke party unverifed.png
karaoke party unverifed.png (4.62 KiB) Viewed 3309 times

Re: Devi Ever Karaoke Party

Posted: 24 Sep 2010, 22:54
by jrod
Revelation wrote:Can somebody check it?
Some gut shots of the circuit, both component and trace sides, would help tremendously.

Re: Devi Ever Karaoke Party

Posted: 24 Sep 2010, 23:49
by salocin
Revelation wrote:This is unverified scheme of the Devi Ever KP. Can somebody check it?
Did you trace this yourself?

Re: Devi Ever Karaoke Party

Posted: 25 Sep 2010, 00:31
by IvIark
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:

Image

Re: Devi Ever Karaoke Party

Posted: 25 Sep 2010, 00:38
by squrl
IvIark wrote: I figured it was going to need all the help it could get
:lol:

Re: Devi Ever Karaoke Party

Posted: 25 Sep 2010, 01:37
by teej212
no. the karaoke party only has one transistor.

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

Re: Devi Ever Karaoke Party

Posted: 25 Sep 2010, 01:43
by IvIark
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)

Re: Devi Ever Karaoke Party

Posted: 25 Sep 2010, 01:44
by Greenmachine
squrl wrote:
IvIark wrote: I figured it was going to need all the help it could get
:lol:
:mrgreen: :mrgreen: :mrgreen:

Re: Devi Ever Karaoke Party

Posted: 25 Sep 2010, 10:09
by Revelation
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.

Re: Devi Ever Karaoke Party

Posted: 25 Sep 2010, 10:20
by bajaman
you have a dc bias path to the input :shock: - I would add a 33n input coupling capacitor to avoid dc coupling to your guitar (and loud bypass switch pops :( :wink:
cheers
bajaman

Re: Devi Ever Karaoke Party

Posted: 25 Sep 2010, 15:42
by Revelation
Ok, i'll try this when the parsel with transistors arrives from ebay 8)

Re: Devi Ever Karaoke Party

Posted: 25 Sep 2010, 18:39
by celadine
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.

Re: Devi Ever Karaoke Party

Posted: 25 Sep 2010, 21:59
by teej212
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.

Re: Devi Ever Karaoke Party

Posted: 26 Sep 2010, 10:46
by Revelation
In my mind it will be booster with only one transistor. :roll:

Re: Devi Ever Karaoke Party

Posted: 26 Sep 2010, 12:30
by mictester
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!

Re: Devi Ever Karaoke Party

Posted: 26 Sep 2010, 12:34
by HEAD
... 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.:D

Re: Devi Ever Karaoke Party

Posted: 26 Sep 2010, 17:52
by celadine
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.

Re: Devi Ever Karaoke Party

Posted: 26 Sep 2010, 19:23
by Revelation
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.

Re: Devi Ever Karaoke Party

Posted: 26 Sep 2010, 19:24
by teej212
ill ask someone on her forum for the pcb layout and that will lead to the schem i bet.

Re: Devi Ever Karaoke Party

Posted: 03 Dec 2010, 10:52
by papercutnoise
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.