Delay self oscillation Question

Plug in here for info tips and strategies for your Moogerfooger Analog Effects. Connect more than one for plenty of fun!
Post Reply
matt the fiddler
Posts: 231
Joined: Tue Jul 11, 2006 6:07 pm

Delay self oscillation Question

Post by matt the fiddler » Thu Jun 05, 2008 10:10 pm

I am trying to figure out some stuff about the delay.

Is the 104z supposed to oscillate on it's own if there is no input, when it is fully cranked?

the feedback level is very hard to get it at a place where I can control with accuracy the difference between either the "net zero gain" delays as well as the positive gain into self oscialltion. sometimes it screams at 8, sometimes 10 is not enough to self oscillate the pedal, even at a fast repeat setting....

ideas? does this sound like the delay problems that were happening with the 104sd recently? or am I just not one with the delay yet.. The delay I am working with has a serial in the first 100 of the 104z line.. and probably since it is under 300 is built the same time period as the104sds.
Electronic Violinist here

EricK
Posts: 5975
Joined: Fri Apr 09, 2004 2:09 pm

Post by EricK » Fri Jun 06, 2008 12:24 am

I think that I have noticed sometimes that mine is a little "Wierd".

Sometimes Its like it wants to oscillate just fine and then sometimes I can't get it to cycle.

I have noticed too that when I play some of the highest 8 keys of so on the 73 key Rhodes, that they don't even delay. Maybe if the input signal is low then it will be less likely to feedback the screaming way we woudl expect.

After reading the threads lately I have looked at my delay and I haven't had any problems with it that ive noticed. WHen i noticed these things its almost like it depended on the instrument that im trying to delay but I didn't really take note of that.

I will report back on this if I even notice it again.

Eric
Support the Bob Moog Foundation:
https://moogfoundation.org/do-something-2/donate/

I think I hear the mothership coming.

Bryan T
Posts: 812
Joined: Mon Mar 06, 2006 4:23 pm

Post by Bryan T » Fri Jun 06, 2008 2:21 pm

I don' think that my delay pedal will oscillate with no input, but I'll check.

When the pedal goes into self-oscillation definitely depends on both the position of the feedback knob and the delay time. The amplitude of the input signal also affects this.

Eric's problem with the highest keys on his Rhodes not repeating is probably due to the frequency response of the delay circuit. You'll notice this more in the long setting, as the frequency response is halved.

Bryan

matt the fiddler
Posts: 231
Joined: Tue Jul 11, 2006 6:07 pm

Post by matt the fiddler » Fri Jun 06, 2008 2:27 pm

Yea, i understand that... even on short, there is a Lowpass effect on the delay.


I guess, on some softer stuff with internal loop switched to 10- some of the softer parts fade out... Maybe it is the nature of the beast... a threshold needs to be reached before self oscialtion..


It just rememnded me very music of some of the SD woes I read about... and want to double check everything is peachy.
Electronic Violinist here

Bryan T
Posts: 812
Joined: Mon Mar 06, 2006 4:23 pm

Post by Bryan T » Fri Jun 06, 2008 5:36 pm

I just tested my delay. It will not feedback if there isn't a connection made to the input. Mine goes into runaway feedback at 8 or higher on the feedback knob, though I do need to set the feedback level a bit higher if I am using a very short delay time.

Bryan

EricK
Posts: 5975
Joined: Fri Apr 09, 2004 2:09 pm

Post by EricK » Fri Jun 06, 2008 8:15 pm

Thanks for the feedback Bryan.

Compression on the delay will keep it from running too far away.
Support the Bob Moog Foundation:
https://moogfoundation.org/do-something-2/donate/

I think I hear the mothership coming.

matt the fiddler
Posts: 231
Joined: Tue Jul 11, 2006 6:07 pm

Post by matt the fiddler » Sat Jun 07, 2008 12:43 am

are you running the compression in the loop (which makes sense), or before the input?
Electronic Violinist here

EricK
Posts: 5975
Joined: Fri Apr 09, 2004 2:09 pm

Post by EricK » Sat Jun 07, 2008 1:53 am

Actually I discovered this by accident and It didn't occur to me what had happened until after I noticed that the feedback didn't get as loud.

I have this roland cube 30 bass amp that I have used in the past as an effects processor for vocals sax and other instruments. It has amp modeling and flange, chorus, auto-wah, delay and reverb. In this instance I was using it IN the effects loop with a long delay time on the 104 so that each delay would have a fast delay from the amp. It created this throbbing type of effect. I moved the Moog delay feedback to 10 and I noticed that it peaked out and it was tolerable to the ears....no speaker damage. It maxed out and was contained.

It is a nice safety measure when recording so it won't clip or startle you into turning the feedback way down.


Eric
Support the Bob Moog Foundation:
https://moogfoundation.org/do-something-2/donate/

I think I hear the mothership coming.

godzilla
Posts: 418
Joined: Fri Feb 06, 2004 9:00 am
Location: Australia

Post by godzilla » Thu Sep 11, 2008 4:29 am

i've noticed that on my SD, it won't self oscilate at the shortest settings, and yeah high freq audio won't get much either, if playing synth it can be really fun to counter that by sending the CV out of the KB to the feedback in, makes the high notes really scream and gets rid of a lot of that muddy feedback.

when i want to have really fast delay and more feedback (or a greater control over feedback) i use the ext feedback loop and run a whole of of extra gain through it.

Post Reply