Dirtbag Troubles

[tenwatt]

You're not getting the problems he is with not getting oscillation unless the trims are so high the delays are gritty?

That's exactly my problem.

[MadeByMike]

You're not getting the problems he is with not getting oscillation unless the trims are so high the delays are gritty?

That's exactly my problem.

I guess we need to hear more from Brian, but it sounds like we're not out of the woods as regards the v3205 version yet.

[Seiche]

who needs oscillation anyway? 

[LaceSensor]

Seeing as how confident the fix appeared to be I didnt socket C14, I just put the 100k resistor in. I do have r21 socketed however.

Well, if it appeared confident it's because it worked for me. I'm doing my best to help you 

Can you address my point above to confirm how completely it worked for you?
I dont wanna sound ungrateful I do appreciate the help, but big statements were made with regards this fixing it, and Im saying yeah it does for 1 or 2 repeats but not with gain trims set to allow the effect to work correctly.

[MadeByMike]

I got it! Pin 12 of the Compander, it's set to bias the output of the Compander and it's still set for 15V so the compander is putting too much signal back into the feedback path and clipping your delays!

Well at least I think that's what's going on and i'm not about to be an idiot when you both say that didn't help at all.

Right, try half the value of 11k (5k6, 4k7, something round there) and then try again.

I'm wondering about this, is this still the case that R42 is incorrect for 9V operation or was this a red herring?

[LaceSensor]

I got it! Pin 12 of the Compander, it's set to bias the output of the Compander and it's still set for 15V so the compander is putting too much signal back into the feedback path and clipping your delays!

Well at least I think that's what's going on and i'm not about to be an idiot when you both say that didn't help at all.

Right, try half the value of 11k (5k6, 4k7, something round there) and then try again.

I'm wondering about this, is this still the case that R42 is incorrect for 9V operation or was this a red herring?

For what its worth to reiterate I have a different value here, and it definitely helps*, with and without the c14/r21 @ 100k fix.

I will try to find time to experiment with r21 tonight.

*on my build, and to my ears, with a strat through an amp, not an oscilloscope.


I wanna take a minute to state

1 - I am genuinely sorry if any comments have been construed as overtly negative. I am passionate and perhaps that is coming across as me being ungrateful or angry. All my input has ultimately been with the goal of driving towards a fix for everyone, not just me.

2 - I am trying to help. Based on what I have experienced in this process, I think there is a combination of fixes here which can help get everyone where they wanna be with the performance of this effect. I am no expert however and hold my hands up. However, from the evidence it seems that there isnt (yet) a one stop "simple fix" - see * above..

3 - it would be most useful if we could have some transparency with regards the boards from development / testing / debugging. What are the voltages of the ICs? If the test boards work fine, why was it necessary to do the "100K Mod" on those boards? Or do I have the wrong end of the stick somewhere.


With respect

LS

[jubal81]

I just got mine mostly working after making the fixes Brian suggested. However no matter how much I adjust the delay bias I can't get all the buzz out.

[madbean]

I just got mine mostly working after making the fixes Brian suggested. However no matter how much I adjust the delay bias I can't get all the buzz out.

Can you elaborate on "buzz"? I would categorize buzzing and distortion as two different issues, the first being usually more of a grounding or noise issue and the second being more about excessive voltage or gain. Would you say it is more like the first or second category?

[jubal81]

I just got mine mostly working after making the fixes Brian suggested. However no matter how much I adjust the delay bias I can't get all the buzz out.

Can you elaborate on "buzz"? I would categorize buzzing and distortion as two different issues, the first being usually more of a grounding or noise issue and the second being more about excessive voltage or gain. Would you say it is more like the first or second category?

Sorry, it's distortion. I've screwed up enough to know grounding hum when I hear it
Also, I didn't see today's posts. The fix I did was the original 100K/100K.

[madbean]

Got it, thanks. I've been tweaking some more this morning so I'll hopefully have some more ideas later on today....mostly just dealing with the compander right now.

[jubal81]

Awesome.
I also have to add that this thing sounds amazing. The warmth is incredible. To my ears it sounds like what I would imagine playing through a hi-fi reel-to-reel would sound like.

[MadeByMike]

Got it, thanks. I've been tweaking some more this morning so I'll hopefully have some more ideas later on today....mostly just dealing with the compander right now.

Any news on this? I'm still waiting for the result of your investigations before I continue populating my board

[Seiche]

bump.