Behringer UF-100 modifyable?

[finkfloyd]

Just got one of these today, Heres a pic:




Has the usual capacitors, and uses 3 trimpots instead of fixed resistors

and also uses a 3-Terminal Positive Regulator.

EDIT: I am STUPID! theres loads of surface mount resistors on the back and 2 more IC's A TLO64C (opamp??)  4558 (opamp) but a lot smaller than the usual 4558's

The IC on the left is a CD3207GP

Some info:

The  CD3207GP is a 1024-stage long delay low noise BBD that provides a signal delay of up to 51.2ms and is particularly
suitable as a device for generation of reverberation effect in audio equipment such as radiocassette recoder,car radio
,portable radio,portable stereo,echo microphone and pre_taped musical accompaniment,etc.

Variable delay of audio signals :2.56ms ~51.2ms
Wide supply voltage :4~10v
No insertion loss :Lj=0dB typ.
Wide dynamic range :S/N=73dB typ.
Low distortion: THD=0.4% typ.(Vi=0.25Vrms).
Clock frequency range :10KHz~200KHz.
N-chanel silicon gate process
8-lead dual-in-line plastic package.

The IC on the right is a CD3102GP

Some info:

CD3102GP is a clock driver suitable for CD3207GP.The circuit is constited by the oscillatation ,frequency dividing circuit and reshaping  circuit  ,driver and VGG generator .The circuit generate two phase opposite clock to driver CD3207GP and provide suitable gate voltage for CD3207GP.

Direct driving capability 4096-stage low voltage BBD
Self oscillation and separate exitation are abled
Two phase clock output
VGG voltage generator for low voltage BBD
Single supply source:4~10V

----------------------------------------------------------------------------------------------------------------------------------------------------------

Any idea if theres other chips like these which I could experiment with, as it sounds pretty weak to me as it is.

And with it being cheap, and simple looking it could be fun

[Mark Hammer]

Can you say "BF-2 in a plastic case"?

In principle (and we're talking about principle far far removed from reality), any mod you might do to a BF-2, you could probably do to this unit.  The trouble is that the use of surface mount won't let you add parts or easily replace them.  Sweating a new chip to an existing set of pads isn't THAT difficult, but installing resistors or tiny caps is a whole other ball of wax.  Worse, the pads available would not permit you to add "nromal-sizedP parts, and there aren't any holes in the board to insert wires for connecting to switches.

As dead-ends go, it's not bad for $35 or so, but I suspect it IS a dead end.

At least one thing we can tell from the picture: you can't buy SMT delay chips, even if you're Behringer.

Incidentally, without that bottom plate, these things weigh less than some rice crackers I've eaten!!

[petemoore]

  There still could be one or more 'less intrusive' mods to the circuit, if any of the suitable connections are accessible, such as pot tapering etc.
 

[finkfloyd]

Hi thanks for the replies, Im not sure about the boss pedal,
but this version I think copies both the boss and ibanez flanger, it has a switch with 2 modes, which makes thinks a little more complex, it is 2 flangers in one box.


http://www.behringer.com/UF100/index.cfm?lang=ENG

[Mark Hammer]

I gather they had an extra op-amp available so they threw in an inverting stage to get negative OR positive feedback.  Expands the tonal range.  Two flangers in one? Not so sure about that one.

[finkfloyd]

Hi, yeah thats right, in the manual it says,

1. the MODE switch lets you choose between negative feedback (mode1) or positive feedback (mode) flanger modes. Negative feedback means that the delayed signal is inverted before it is fed back into the original signal. In positive feedback mode the delayed signal is not inverted. In this case the effect has a more detuned character perfect for vibrato effects... blah blah..

What would you suggest for a workable tweak, I havent touched the varible resistors yet.. shame I dont have much experience

Thanks

[Stompin Tom]

I don't have any mod suggestions, but I was wondering, how does it sound?  Do you have another flanger to compare it to?  I'm always in the market for cheap pedals...

[Mark Hammer]

Hi, yeah thats right, in the manual it says,

1. the MODE switch lets you choose between negative feedback (mode1) or positive feedback (mode) flanger modes. Negative feedback means that the delayed signal is inverted before it is fed back into the original signal. In positive feedback mode the delayed signal is not inverted. In this case the effect has a more detuned character perfect for vibrato effects... blah blah..

What would you suggest for a workable tweak, I havent touched the varible resistors yet.. shame I dont have much experience

Thanks

The trimpots are likely to be for the same things they are in other flangers:

• one is for setting the bias, which will be pretty much the same across all chips but can use some fine tuning to get optimum clarity in the light of component tolerances.
• one is used for setting the balance between the two complementary outputs from the BBD.  Here, again you could simply use two same-value resistors as many companies do, or use a trimpot to nail it perfectly.
• one is used to set maximum regeneration.  Component tolerances, again, may result in acceptable maximum regen in one unit but runaway oscillation at max regen in another unit.  Typically, the regen knob is set for max, and the trimpot eased back until the howling stops.

As such at least 2 of the trimpots ought not to be played with since they are not adjusted to taste but rather to functional goals.  The thrid MIGHT be worth toying with but the largely SMT construction makes it hard to easily tell which one is which.  I'd leave it alone, personally.

[Paul Perry (Frostwave)]

At $35, one 'mod' might be to get TWO of them & then you can get thru-zero flanging! by mixing the outputs from the two delays, rather than the delay & the original signal. Sometimes 'more' IS better

[troubledtom]

At $35, one 'mod' might be to get TWO of them & then you can get thru-zero flanging! by mixing the outputs from the two delays, rather than the delay & the original signal. Sometimes 'more' IS better

that's cool paul!
       peace,
           - tom

[Mark Hammer]

Good idea, but of course it assumes you can actually FIND the appropriate parts to alter!

Ideally, one lifts the dry signal from each unit, sets one for zero depth and manual delay adjust to taste.  The other is allowed to sweep.  Probably neither should have any regen whatsoever. The two outputs get mixed together in a 2-input mixer.

[Roobin]

Sorry this isn't really any help to your question...

I haven't had the chance to try one of these out but could you please clarify some things for me? 1) is it made out of 2.5mm plastic, and if so, does it feel like it would crack and 2) are those jacks attached to the sides with a nut, or just to the PCB?

Thanks

[petemoore]

 but I was wondering, how does it sound?  Do you have another flanger to compare it to?  I'm always in the market for cheap pedals...
  if 20 worth of flanger would make me happy for a time...that'd be cool.

[Aharon]

At $35, one 'mod' might be to get TWO of them & then you can get thru-zero flanging! by mixing the outputs from the two delays, rather than the delay & the original signal. Sometimes 'more' IS better

Sometimes you find that rare breed of people that THINK LOGICALLY,Paul Sr.......you are one of them!!!!!

[finkfloyd]

Hi,

Sorry to bring this thread up again, Im bored & I left some unanswered questions

Posted by: Roobin 

Sorry this isn't really any help to your question...

I haven't had the chance to try one of these out but could you please clarify some things for me? 1) is it made out of 2.5mm plastic, and if so, does it feel like it would crack and 2) are those jacks attached to the sides with a nut, or just to the PCB?

Thanks

Hi Robin, (1) the plastic case seems pretty sturdy, and wont break unless you really stamp on the thing like you want to kill it and it has a heavy metal (no - pun intended) base plate on the bottom, (2) the jacks are PCB mounted.

Posted by: petemoore 

but I was wondering, how does it sound?  Do you have another flanger to compare it to?  I'm always in the market for cheap pedals...
  if 20 worth of flanger would make me happy for a time...that'd be cool.

Hi I dont have another flanger to test it against except the one in a software program called Native Instruments Guitar Rig, Which I like better, but isnt no Electric Mistress
Infact I dont even own an real amp, I have to use Amp emulation software like the above, so I cant really tell, I would really like an old soundcity amp head, they are like the hiwatts, but cheaper, but still expensive.

I wonder how different my setup would sound when routed through a decent amp?

Thanks all for your help.

[loscha]

one is used to set maximum regeneration.  Component tolerances, again, may result in acceptable maximum regen in one unit but runaway oscillation at max regen in another unit.  Typically, the regen knob is set for max, and the trimpot eased back until the howling stops.

What if I don't want it to stop!

seems like Behringer have made a modifyable pedal in my books, even for the circuit bending kiddies.
Maybe with some time and some more skill, I could turn it into a voltage controlled Karplus/Strong generator (one day, I WILL make one of those!)