Yellow Shark: weird fizz sound around notes?

[B_of_H]

I built up the yellow shark finally and although it sounds really good there is almost a fizzy low octave noise around the notes.  I tried changing the value of c5 (I socket'd it due to the instructions) and it changed where it seemed to come out frequency wise.  

Anyone had this issue?  I'm going to scope it but I'm pretty sure I built it properly to spec.  

edit:

found this on fsb

http://freestompboxes.org/viewtopic.php?f=7&t=6083&hilit=honey+bee&start=100

seems the poster at the top found the same thing. 

[stevewire]

Not that I would know why, but which IC did you use?  My board is sitting waiting for a few more parts to arrive.  I have the CA3130EZ and some NOS green LEDs.  So you say the fizzy sound was there before you tried the different cap, and then it's frequency changed, yet was still there after you changed it?

[B_of_H]

Not that I would know why, but which IC did you use?  My board is sitting waiting for a few more parts to arrive.  I have the CA3130EZ and some NOS green LEDs.  So you say the fizzy sound was there before you tried the different cap, and then it's frequency changed, yet was still there after you changed it?

I used the ca3140 from small bear and 5mm green LED's.

The effect seems more noticeable in the lower range with a larger value for c5 but it's there regardless of what I put in.  I've tried as low as 1n and as high as 100n.  At 1n it's more noticeable on higher notes etc...

it sounds like a faint octave fuzz in the background of the note but it's definitely too loud to overlook. 

[stevewire]

I'm using 3mm, but what I have read, it shouldn't make a difference.  I'll look out for this in my build.  I wish some other people that have built this already would chime in about their experience.

[B_of_H]

i'm going to try to find a 3130ez today and see if that clears it up.

do you have a link handy where I can get one?

[stevewire]

Hey B_of_H,
How are you?  I finished up my Yellow Shark on Friday.  At low volume I thought I might have heard what you meant, but upon having an opportunity to turn it up I don't feel my has the same issue.  I wonder if it could be your 2N5457.  I did read on freestompboxes.org someone suggeting that multiple transistors be tried to find a good one.  I had ordered two from Small Bear.  I tried both and heard or noticed little to no difference.

I really do like my build.  Through my AC30's normal channel, it sounds alot like my Top Boost channel with the gain cranked.

Digikey has the  CA3130EZ - http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=US&WT.z_homepage_link=hp_go_button&KeyWords=3130ez&x=20&y=14

[B_of_H]

i'm doing great, thanks for asking


Well digikey is actually sold out but...

http://www.alliedelec.com/search/productdetail.aspx?SKU=9030071

found one.  I'm going to probe it an see if I can tell where it's coming from. 

[B_of_H]

I audio probed it and the fizzy octave below distortion sound seems to be coming from the ca3140 from what I can tell. 

The signal is fine coming into pin 3 of the opamp but pin 2 has the noise as does everything following the opamp.  I tried changing the transistor to a j201 and a different 5457 and it's still there. 

I've tried powering it with two different power supplies and from different outlets as well. 

So perhaps it is the opamp? 

[stevewire]

I was curious if it could be the power supply.  I know my Slambox does not like my daisey chain power at all, but sounds real clear with a battery.  My Yellow Shark seems fine with either.  Any chance you have another ca3140?  Maybe the problem is with that specific one.

[B_of_H]

got the 3130ez's in today and....the noise is gone.

Everything sounds perfect now. 

[camsna]

got the 3130ez's in today and....the noise is gone.

Everything sounds perfect now. 

Aaaah! Glad to hear it! I love it when things work out like that!

[stevewire]

Good.  I'm glad it worked out.  I still wonder if it was just that specific IC though.

[B_of_H]

Good.  I'm glad it worked out.  I still wonder if it was just that specific IC though.

yeah, i'm done buying 3140's from small bear though.