True bypass mod for Exar FL-03 (buffered stock bypass)

[Rethfing]

Hey. Here's the thing. I bough an Exar FL-03 Flanger a while ago (it is said that Exar were copies of BOSS effects) because I was using Exar CS-03 Chorus for more than a year. The issue with the flanger was volume boost when engaged. So I putted a Volume pot as suggested by Paul (chromespherecom http://www.youtube.com/watch?v=dyfFHO2XeKY). After testing it I realized, that because of the buffered bypass in the pedal the new pot affects the volume also when the effect is turned off, which makes it useless, because the volume boost is still the same it was before modding.

So I though I make it true bypass. I drilled a hole for 3PDT, disconnected the board with microswitch from the main board (photos at the end of this post), and wired the True Bypass as I always did (madbeans offboard wiring). Of course the pedal doesnt work now, because of the removal of stock bypass board. Is there any way to fix it? I need to make some connection on the main board so the effect is always on, but I have no idea how to do it. Here are the photos, maybe some of you know how this stuff works

http://www.flickr.com/photos/98853273@N07/

There is also possibility of applying the true bypass to the whole effect along with buffered bypass microswitch always turned on, but I can barely fit that stuff into the enclosure, so I would like to omit that switch board.

[Rethfing]

Mike told me, that speedyshare is considered dangerous by some antiviruses, so I posted the photos on flickr Hope now someone will look into it!

[mistahead]

You put your volume control between the output of the board and the out-jack?

It needs to tuck in between the output of the effect and the buffer loop (consider the buffered bypass a big loop around the effect, you've volume controlled that loop, not the effect inside it).

[Rethfing]

That seems logical, but I would like to omit the buffered bypass. Anyone know how I can get rid off of that PCB with switch?

[mistahead]

That's a bigger question that I realised, sorry about that, it would be a little different and I've not worked on that brand, even if its a Boss clone the buffer/bypass could be implemented differently.

Have you got a schematic? I could have a crack at it but would also trust others to check my work.

[Rethfing]

The thing is that I dont have the schematic :/ To company doesnt exist no more as I believe, so there is no way of getting hands on schematic

[mistahead]

Is it possible to compare it to some Boss buffered bypasses?

Come on guru types - all we're trying to do is seperate the buffered bypass from the effect...

Have you looked over at Geofex... I vaguely remember an article similar to this issue (possibly about the TS though).

[Dave W]

http://www.geofex.com/Article_Folders/bosstech.pdf
the search function is your friend
more reading....
http://www.diystompboxes.com/smfforum/index.php?topic=65818.0

[mistahead]

Sorry, who are you suggesting uses the search - the guy asking the questions or the guy prodding him along the right path in between tasks while at work?

Thanks for turning those up Dave.

[Dave W]

both. we are all in this together...

[mistahead]

So true... its sinking under the weight of all of our best efforts here...   

[Rethfing]

I see some talking but dont see any solution Im not really good at reading and understanding electronics in my own language, not to mention english, so if anyone has some clear fix for my issue I would be very pleased to hear it

[Rethfing]

bump...

[slacker]

What's the chip on the bypass board?
I would measure the voltages on the pins 1 to 7 on the bypass board when the effect is on and bypassed, some of those will probably turn the effect on and off and so will change depending on whether it's on or off. Post the results here and we can figure out what you need to do to make it always on.

Or one of the transistors on the main board is probably a switch that turns off the delayed sound in bypass, if you use an audio probe to find which one you may just be able to replace it with a jumper.

[Rethfing]

Wow its been a long time My job was succesfuly keeping me away from pedal-related stuff.

The chip on the bypass board is HCF 4007 UBE.
I also measured the voltages, here are when the pedal is off (I ensured that by watching LED):
1.   4.08   8.   9.00
2.   4.46   9.   0.00
3.   8.14   10.   9.00
4.   2.60   11.   9.00
5.   2.60   12.   0.00
6.   9.00   13.   0.00
7.   0.00   14.   0.00

And when the pedal is on:
1.   4.50   8.   9.00
2.   4.50   9.   9.00
3.   0.00   10.   0.00
4.   2.60   11.   9.00
5.   2.60   12.   9.00
6.   0.00   13.   0.00
7.   0.00   14.   9.00

What I am trying to achieve is to remove the buffer board completely, because with it its extremely hard to mount true bypass witch in the stock enclosure.

[Rethfing]

Measured the voltages on bypass board (this photo: http://www.flickr.com/photos/98853273@N07/9282218169/in/photostream/)
OFF:
7: 9.0V
1: 4.08V
2: 4.46V
6: 0.0V

ON:
7: 9.0V
1: 4.46V
2: 4.46V
6: 0.0V

And also I measured the transistor on the bypass board - C547B (http://pdf1.alldatasheet.com/datasheet-pdf/view/354321/MCC/BC547B-AP.html)
OFF:
C: 5.3V
B: 0.0V
E: 0.0V

ON:
C: 0.15V
B: 0.0V
E: 0.0V

Any ideas how to get rid of the bypass board now?