Boss BF-2 Flanger

[chance]

Time to make use of those MN3207's you have laying around. I have made this layout against the factory schematic available here: https://www.hobby-hour.com/electronics/s/boss-bf2-flanger.php.
I have substituted some components for more common/popular substitutes but have also listed the original parts if you like to use them. Check your transistor pinouts if you use anything other than the susbstitutes I have used in the layout as the may be need twisting. Sorry if you don't like standing resistors but I wanted to make sure it fit in a 1590BB. I don't mind standing resistors at all, a lot of other components are standing anyhow. Ah, thanks groovechampion, I have now fixed that typo, MN3204/MN3207, same pinout, grab the updated layout.

[GrooveChampion]

Err dude, the layout says MN3207 but the notes say MN3204

[chance]

Cheers buddy, layout updated

[GrooveChampion]

Aint no chance in hell I am building it without my brain blowing a fuse but you are a saint for doing this.

[chance]

Yeah it's not for the faint-hearted but I promised at the and of last year that I would start putting out some flanger layouts (that weren't too big). The first 2 on this site only appeared last year. If you think this is nuts you should see the layout I did for the EHX Deluxe Memory Man (Madbean Total Recall), I would be surprised if it ever got built, I don't even know if I will ever build it, as compact as it is, it's still a behemoth. Not to mention the outrageous price of MN3005's.

[GrooveChampion]

That werent too big....is there an actual compact flanger layout? As in compact compared to this?

[chance]

From what I've seen as far as stripboard layouts go, this might be the smallest.

[aruberus]

Has anyone completed this Build?
Im building one up at the moment and am hoping to hear of any gotchas.

Notes:
I might be going blind but I cannot find one of the IN4148 diodes in the Vero Image. I count 3 instead of 4.

The board needs to be finely shaved to fit into a BB enclosure in a way that can fit the 1/4" Jacks and Stomp switch. Its possible tho.

Thanks,
A

[Sphere80]

It's "D6" at P-12.  They correspond to the labeling on the factory schematic which has about 10 diodes, but the rest are for switching.  

 Please let us  know how the build goes.  I have a real BF-2 and a Behringer clone of the HF-2, which is subtler.   I wonder if that one can be built on this layout also?  

[aruberus]

Thanks Sphere80,
Understood - Noting for future reference there should only be 3 Diodes at (not 4)
D4  G-14
D3  G-15
D6  P-12    

Thanks,
A

[aruberus]

Build is complete but I have a problem in that the Res pot does not appear to change sound.

Rate And Depth work and Manual has a vague effect. The result definitely sounds chorus, flange like but it does not have the Spacey Resonance/Feedback.
Audio Is present on Q1, Q2 and !Q3 as is IC1 (pins 1 and 7) IC2 (1 and 7) and IC 3 (378).

I used TL072's for the 4558's and a cool audio v3207 for the MN3207.

I dont have a scope to set up the VR7 or VR5 , Is there a way of doing this with a multimeter or by ear?

Please help with any Recommendations to assist with problem solving.

Thanks
A

Voltage readings below.
IC1   TL072
1  4.13
2  4.13
3  4.13
4  0.0
5  4.13
6  4.13
7  4.13
8  8.39

IC2  TL072
1  4.13
2  4.13
3  4.13
4  0.0
5  4.13
6  4.13
7  4.13
8  8.39

IC3    Coolaudio v3207
1  0.0
2  @ 2.0
3  2.6
4  4.7
5  5.08
6  @ 2.4
7 @ 3.5
8  @3.4

IC4   MN 3102
1   5.08
2  @ 2
3  0
4  @2
5  @ 4
6  @ 0.5
7  @4
8  4.74

IC5  TL022
1  @ 2
2  2.5
3  2.5
4  0.0
5  @4
6  2.5
7  4.4 - 0.6
8  5.08

IC6
1  8.4
2  0.0
3  5.04

Q1
E  2.7
B  3.29
C  8.4

Q2
E  3.45
B  4.08
C  8.4

Q3
E  2.8
B   3.4
C   8.37

Q5
E  5.08
B  @4.7
C  @ 1

Q6
E  0.0
B  0.56
C  0.56

Q7
E  0.0
B  @0.6
C  @3.6

[aruberus]

Update - Did a solder re-flow on the board and Resonance control is working.

The Resonance is however now a little distorted, Adjusting VR5 reduces the 'sibilance' of the feedback but it remains a little thinly metallic distorted.

Any ideas?

A

[IvIark]

Nice job mate

chance wrote

Time to make use of those MN3207's you have laying around. I have made this layout against the factory schematic available here: https://www.hobby-hour.com/electronics/s/boss-bf2-flanger.php.

[aruberus]

Some WIP shots of the BF-2

Still need help identifying where the 'tinny metallic distorted' sound is coming from.

[aruberus]

Ok, So tracing the Audio signal Im finding the Following.

Q1   Output sounds Clean

IC1  Output pin 1 Sounds Clean but slightly tinny

IC2  Output pin1  Sounds like an Phased/ Chorusy version of the above

Q2   Output Sounds like a very tinny (Fizzy) version of IC2's output.
 If this is what is being sent to the BBD im not surprised it sounds so metalic and Fizzy (slightly distorted).


On IC's 1 and 2 If I audio probe pins 2,3 or 5,6 I hear nothing. (This is a little unexpected)


Does this sound normal?

A

[aruberus]

Build Verified.

Current Draw 34 mA


Voltage readings below.
IC1   TL072
1  4.13
2  4.13
3  4.13
4  0.0
5  4.13
6  4.13
7  4.13
8  8.39

IC2  TL072
1  4.13
2  4.13
3  4.13
4  0.0
5  4.13
6  4.13
7  4.13
8  8.39

IC3    Coolaudio v3207
1  0.0
2  @ 2.0
3  2.8
4  4.7
5  5.08
6  @ 2.4
7 @ 3.5
8  @3.5

IC4   MN 3102
1   5.08
2  @ 2
3  0
4  @2
5  @ 4.7
6  @ 0.5
7  @4
8  4.74

IC5  TL022
1  @ 2
2  2.5
3  2.5
4  0.0
5  @4
6  2.5
7  4.4 - 0.6
8  5.08

IC6
1  8.4
2  0.0
3  5.04

Q1
E  2.7
B  3.29
C  8.4

Q2
E  3.45
B  4.08
C  8.4

Q3
E  2.8
B   3.4
C   8.37

Q5
E  5.08
B  @4.7
C  @ 1

Q6
E  0.0
B  0.56
C  0.56

Q7
E  0.0
B  @0.6
C  @3.6

[chance]

Nice work, I'm glad it worked out in the end! Sorry I haven't been on the forum for a while to work/travel but you verified it, thanks  There is also a layout for the Boss HF-2 if you are interested, similar layout with component changes. Nice enclosure by the way mate!

[chance]

Happy to contribute  I have also posted a layout for the Boss HF-2 flanger if anyone is keen. It looks like this one has been verified!

[chance]

How does this one sound, comparable to the Boss original?

[chance]

Sphere80, if you search this forum for Boss HF-2 Hi Band Flanger I have already supplied a layout. Yes it is similar to this BF-2, some component changes