Strange behaivior amber overdrive

[hopdybob]

Hello out there.
please excuse my not so good english

i am a newbie in this stompbox building and am trying to build this stompbox using the following layout after practicing on a build of a little booster that turned out fine
http://tagboardeffects.blogspot.nl/2016 ... drive.html

somethings seems to go wrong.
* it works, but thinking this overdrive will boost the volume level, with volume on max i can get the same volume as when hitting the bypass switch.
it is not going louder, and if it is than nog much.
* i also can not get a sound like this,

a lightly overdrive sound, it starts with a strong overdrive sound
* soft attack will give me a sound of a bad connection/potentiometer with wobbly sound.
* turning down the sustain will result in no sound at all when i reach the end off the turn
All the parts are like mention't on the layout, only the Q4 is a BF256 instead of the 2N5485

what did i do until now
check't parts and polarity etc. if they would be on the right place
with a fine saw blade i cleaned up the space between the copper lanes
reconnected the pots, tested the leads.

at first i used this kind of true bypass

but now i am trying this on


what could be wrong here?

[hopdybob]

This is the schematic that i found


this is how it looks like now

[induction]

The 1u at the right edge of the layout is installed backwards.

Also, what brand of BS256 did you use? The pinouts from different manufacturers aren't consistent.

[hopdybob]

The 1u at the right edge of the layout is installed backwards.

Also, what brand of BS256 did you use? The pinouts from different manufacturers aren't consistent.

than you are looking with your nose almost on the board and miss this.
thanks for helping out.
but now activating the effect will give me a kind of soundgenerator kind of buzz that changes using the sustain pot.
(brand of the BF256 i don't know but at the data sheets i found i had to mirror it against the original 2N5485)

[hopdybob]

have renewed the elco and bf256 but have the same problem .

[induction]

Most datasheets I found say that BF256 is DSG, but at least one resource indicates that some are DGS.

Beyond that, I'd say it's time to do some work with the DMM and the audio probe.

[hopdybob]

Most datasheets I found say that BF256 is DSG, but at least one resource indicates that some are DGS.

Beyond that, I'd say it's time to do some work with the DMM and the audio probe.

i have bought some little socket pins that you can use to solder on the board and you can switcht de fets.
tried the old and a new bf256 placed them both ways, but still get a oscillating noise that changes bij turning the sustain and disappears at some point. but no effect sound.
maybe the wire is to long for this sustain pot, but i kept it longer because i do not know yet what kind of housing i will use

[induction]

You can't convert DSG to DGS by simply reversing them. You have to twist the legs. (Maybe you tried that, I can't tell from your post.)

If that doesn't help: voltages, audio probe.

[hopdybob]

You can't convert DSG to DGS by simply reversing them. You have to twist the legs. (Maybe you tried that, I can't tell from your post.)

If that doesn't help: voltages, audio probe.

me bad, on another forum they wrote that some BF256 have GSD so i had turn the fet to use it. but that did nog work.( i use a bf256C)
but the strange thing is,before being pointed out that the 1 uf elco was placed wrong i had a guitar sound with problems at soft playing the strings, but i had sound. now i have constant oscillating sound.

[hopdybob]

You can't convert DSG to DGS by simply reversing them. You have to twist the legs. (Maybe you tried that, I can't tell from your post.)

If that doesn't help: voltages, audio probe.

me bad, on another forum they wrote that some BF256 have GSD so i had turn the fet to use it. but that did nog work.( i use a bf256C)
but the strange thing is,before being pointed out that the 1 uf elco was placed wrong i had a guitar sound with problems at soft playing the strings, but i had sound. now i have constant oscillating sound.

i still have to try this but did some measurement: using layout names for the transistors
new Q4 bf256 placed housing like on the board layout i
D= 3.29v
S=2.52v
G=2.53V
Mirrored, whit the connections like most off the data sheets show to this fet
D=3.05v
S=2.92v
G=0V

Q1
C= 4.01v
B=0.64v
E=0.03v

Q2
C=4.3v
B=.67v
E=0.02v

Q3
E=0v
B=0.51v
C=9.01v

[hopdybob]

yesterday i gave it another try.
with a fine sawblade and stanley knife i cleaned op all the space between the copper lanes, and heyyyy it worked
but than i noticed that when the sustain was turned down complete, volume on max there was a volume loss in compare with the volume of the amp itself after switching.
i then put a 10 k pot in series with the 6k8 resistor.
sustain turn down complete, volume complete up and then turned the 10k pot slowly to a volume level that was just as loud as the amp without the effect.
measured the total of 6k8 with the 10k pot in series and came to about 11k.

is there something i have to check now ore can i replace the 6k8 with a 10k ore 12k?

[hopdybob]

been a while but i have some good news.
i bought on ebay some 2N5485 en tried it again
measurment with BF256c
D =2,98v
S= 2,85v
G=0

with 2N5485
D= 5,30v
S= 1,80v
G= 0
the amount off fuzz was better in control but soundwise i still had the money for nothing sound that i did not like and could not get rid off.
on a dutch site someone gave me the tip to change this

bring back R12 to 22K, en C7 to 4,7nF,and you get a more useful tone control

and this works fine for me.
so all i can say i thank you all for helping and don' t change the 2N5485 with a BF256C

[induction]

Cool. Good work.