BF-2 Flanger Build? Anyone?

[shadowmaster]

I was planning to build DC-2 Dimension C as a long term project but was unable to purchase a compander chip (NE570/NE571) locally but was able to secure MN3207 and MN3102. BF-2 flanger uses MN3207 and MN3102 so I thought of doing this instead as a long term project. I just want to ask has anyone built BF-2 flanger, performed mods to it and how was the turnout?

[343 Salty Beans]

I haven't built it, but our guitarist has it, and wants me to mount pots on the outside instead of trimmers. It's easily the best guitar flanger I've ever heard. Has a huge sweep range, great versatility...it's just all-around great. Just for reference, we play a lot of different stuff, but my be described as radiohead-ish with a lot of J-tree style U2 mixed in.

Out of curiosity, why don't you search around for both the MN chips, then buy 2 of each at the same time? Then you can do both builds 'long-term'.

[Rafa]

In my country these are the only chips available for flangers  MN3207,  MN3102 (the mn3007 and mn3005 are not vailable)
so I wanted to build a chorus maybe something like boss ch-2, Does anybody know were can I find a chorus that uses only these chips??
If it exists It would be wonderful to have the need the PCB layout because Im pathetic at designing them.
Thanksssssss

[John Squire]

I don't mean to hijack the thread, but what do the trimpots on the BF-2 do? I have one, but I never ever messed with the trimpots.

It's an amazing flanger, though I only use it for the big swooshy airplane sound.

[shadowmaster]

I don't mean to hijack the thread, but what do the trimpots on the BF-2 do? I have one, but I never ever messed with the trimpots.

It's an amazing flanger, though I only use it for the big swooshy airplane sound.

Check out the BF-2 schematic in here.
http://www.godiksennet.com/default.asp?main=Schematics

[John Squire]

I don't mean to sound stupid, and thanks for trying to help, but the schematics don't help me at all.

[Mark Hammer]

We'll start at the top left and work downwards.

VR5 sets the maximum regen.  Typically it is set up by setting the regen control to max, and trimming back with this until the howling stops.

VR6 sets the DC bias that the signal going into the delay chip has to ride on.  When that DC voltage is set too low or too high, you will hear nothing coming out of the BBD.  As the DC bias gets closer to the optimum, you will hear distorted delay, and when set right you will hear clear delay.

VR7 sets the fine-tuning of the high-frequency clock so that it can be adjusted to compensate for all the little variation over the many 5% tolerance components comprising the clock circuit.

[shadowmaster]

I don't mean to sound stupid, and thanks for trying to help, but the schematics don't help me at all.

Well on the right side of the schematic diagram are the instructions on how to properly set-up the trims. I was hoping that this would answer your question.

Nevertheless, a resident expert has already shed light to this. Thanks Mark!!!