A little help pls...

[rx5]

anyone got any ideas for a simple MN3007 delay circuit?? i only need info on how this chip operates and how to get adjustable delay from its output.... just the circuit of MN3007.... in short,how to utilize it...just gonna use the output as a delayed signal from the orig signal... :roll:

thnks

[Rob Strand]

There's many example around, look through the schematics.

A good starts is to use the delay and filter from the Boss CE-2 and the clock generator from the Boss DM-2.  You can tinker with the filters if you find the CE-2 has too much HF roll-off, but really it should be OK.  If you don't want to use a MN310x clock chip perhaps look at the 4046 from John Hollis's designs.

[jeroen_verbeeck]

Is there a replacement for the MN3007 ?

[rx5]

ok.... got one here from hammer.ampage site.... a delay using MN3007 and MN3101...  my qeustion is: is the output signal the same in amplitude with the input?? considering i just use MN3007 and MN3101 circuit without signal buffers on the input and output side of the BBD?

[Joep]

That's not gonna work, you need at least some input buffering and lowpass filtering at the ouput.

If you want something simple, use the PT2399 delay chip. The Rebote 2 delay works nice and it is a simple build. You can find it at Tonepad.

Regards,

Joep

[rx5]

then ill add buffers to the input and ouput.....  i dunno if im gonna use lowpass filter... im really just getting the delayed signal to drive an envelop rectifier in mutronIII which would serve as my LAG control.... what do you think bout it?? :wink:

[Rob Strand]

i dunno if im gonna use lowpass filter

The output low-pass filter isn't an optional component.  Delay lines are not continuous analog devices they are actually sampled devices and they need the filter to restore the sample pulses to continuous analog signal.  The output filter also removes a lot of unnecessary noise from the output of the delay lines.   The input filter is used to stop aliasing problems, you can get away with a simple filter here for guitar signals.

If you look at the Boss DM-2 circuit, you will see the delay chip in there, which is the component doing all the work, and the large amount of stuff around it is all the baggage to make it work.  That's the thing with these delays the idea is simple but there's a lot of baggage.

[rx5]

ok ill try to search for a lowpass filter....  what should be the cut-off freq for the input filter?? how about the output filter?

[Rob Strand]

It depends on the amount of delay you use, longer delays imply low cut-offs.  Something in the 3kHz to 8kHz region should be OK - it's a trade-off between noise an high-end loss.  The DM-2 uses around 3.3kHz, the CE-2 uses about 7kHz.  3rd order input and output filters would be a middle ground, a minimal filter would be first order in and 3rd order out.  There's usually no need to go higher than 5th order on the output filter.

[rx5]

so a simple ouput filter will do....then what would the anti-alliasing input filter cut-off freq?

btw, i used 5th order output filter for my flanger and non for the input (anti-allias) of the BBD....

another, what is the maximum -USABLE- delay for an MN3007?

[Rob Strand]

It's somewhere in the order of the numbers I gave earlier.  If you want a number then use 6 to 7kHz.

There isn't really a maximum useable delaym it is a trade of high-frequency loss and noise.  A rough guide would be say 20ms, I wouldn't want to stetch it much above that.