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Projects => Tech Help - Projects Page => Topic started by: just1more on April 25, 2018, 04:30:18 AM

Title: Aquaboy V2 - repeats too prominent with mix at full CCW
Post by: just1more on April 25, 2018, 04:30:18 AM
I finally got picked up an MN3005 for an Aquaboy V2 (02/10/10) board I built years ago. Built to instructions - no mods, single BBD, no modulation.

It's sounding great but the wet signal is still too prominent with the mix at full CCW for my taste. Is there any way I can further attenuate the volume of the repeats at the lowest mix setting?

(With mix at full CW the repeats sound very slightly louder than the dry signal. I'm prepared to live with that).

Thanks

John
Title: Re: Aquaboy V2 - repeats too prominent with mix at full CCW
Post by: chordball on April 25, 2018, 01:12:23 PM
With the way the mix pot is set up you should be able to completely kill the wet signal. I'd check the pot to make sure that pin 1 is at ground, and that pin 2 goes to ground at full CCW.
Title: Re: Aquaboy V2 - repeats too prominent with mix at full CCW
Post by: just1more on April 25, 2018, 10:04:27 PM
Thanks for the reply. I've got the pots connected to the breadboard so a suspect connection is entirely possible. I'll play around with it some more tonight.
Title: Re: Aquaboy V2 - repeats too prominent with mix at full CCW
Post by: just1more on April 26, 2018, 10:32:27 AM
You were spot on chordball  :)

The ground connection for the mix pot was loose on the breadboard.  Don't I feel silly :-[

There's a bit of clock whine at longer delay times so I'll do some tweaking with the trim pots to see if I can reduce it. Other than that I'm just about ready to box up a project that was all but working in 2010. I think this is officially my longest build ever.
Title: Re: Aquaboy V2 - repeats too prominent with mix at full CCW
Post by: chordball on April 26, 2018, 06:33:57 PM
Cool! Glad you got it worked out. I spent quite a long time on an analog delay myself so I know what you went through. It's usually the simplest mistakes that take the longest to catch.

Do you have a scope? If not, I can send you some info on how to calibrate the delay using a signal generator on your phone and a free scope program on your computer. At the very least, I'd use an audio probe to set the cancel trimmer, then listening to the full output adjust the delay time so that the whine just barely starts and then back off a tad to eliminate it.
Title: Re: Aquaboy V2 - repeats too prominent with mix at full CCW
Post by: just1more on April 26, 2018, 11:19:13 PM
I don't have access to a scope. I've calibrated using an audio probe and ears.

I thought I was being clever by using multi-turn trimpots - easier to make fine adjustments. Never again - it's impossible to know how far through the travel you are. Think I'll replace them with regular trimpots.

If you can send some info about a scope app that would be great. I'm using a Mac but have access to a Windows machine too.

Thanks