madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: gitaar0 on April 29, 2012, 06:49:21 PM

Title: Dirtbag extra delay chip
Post by: gitaar0 on April 29, 2012, 06:49:21 PM
Is it possible to use a double delay board pcb intended for the aquayboy to add an extra mn3005 chip in a dirtbag?

Title: Re: Dirtbag extra delay chip
Post by: gitaar0 on May 02, 2012, 08:28:59 PM
Bump
Title: Re: Dirtbag extra delay chip
Post by: BraindeadAudio on May 02, 2012, 10:02:00 PM
Im not sure it would get enough power?
Title: Re: Dirtbag extra delay chip
Post by: Scruffie on May 03, 2012, 04:10:40 AM
It's not power to worry about so much, it's the clock managing to drive that much capacitance.

Yes it will work, although you might not get quite all the delay out of the 3 without a buffer... you greedy BBD whore ;D
Title: Re: Dirtbag extra delay chip
Post by: gitaar0 on May 03, 2012, 08:21:12 AM
I read in an earlier post that Josh did something like this. I PM-ed him.
I would like to know if the exact pcb for double delay that was made for the aquaboy can be used in the dirtbag with the same components.
It can be found here:http://www.freestompboxes.org/download/file.php?id=6062 (http://www.freestompboxes.org/download/file.php?id=6062)

And yes I have one spare BBD ;D
Did you get yours scruffie?
Title: Re: Dirtbag extra delay chip
Post by: wolfingsworth on November 18, 2012, 05:49:26 AM
BUMPETY BUMP BUMP! I am trying to find a good solution for doing the double BBD thing on my Dirtbag. I feel like I have spent quite enough money on this project and hopefully I can make something work with what I have. Has anyone tried the FSB layout on the Dirtbag?
Title: Re: Dirtbag extra delay chip
Post by: Scruffie on November 18, 2012, 10:31:14 AM
Yeah that PCB should be fine for 4 x MN3008.
Title: Re: Dirtbag extra delay chip
Post by: LaceSensor on November 18, 2012, 11:43:55 AM
I've done the Double delays on the dirtbag so it does work.
I used DIY pcb and vero layouts, the sabrotone one.
Title: Re: Dirtbag extra delay chip
Post by: wolfingsworth on November 24, 2012, 12:59:40 AM
I have everything soldered and connected and no delay. Each sets of SB fakes work and produce delay when put directly on the Dirtbag board. I substituted 25k trimpots for 100k but I don't think that would make the double chip board unusable... Either the board itself has a short or I screwed something else up along the way. Any tips would be much appreciated!
Title: Re: Dirtbag extra delay chip
Post by: LaceSensor on November 24, 2012, 01:32:19 AM
I was able to make  a 4 x mn3008 (SB fake 3005s) using double delay boards.
I would say I got about 400-450ms out of it, with the stock 220pF clock cap.
No other mods.

You have  a build fault somewhere, most likely
Title: Re: Dirtbag extra delay chip
Post by: Scruffie on November 24, 2012, 01:53:10 AM
Quote from: wolfingsworth on November 24, 2012, 12:59:40 AM
I have everything soldered and connected and no delay. Each sets of SB fakes work and produce delay when put directly on the Dirtbag board. I substituted 25k trimpots for 100k but I don't think that would make the double chip board unusable... Either the board itself has a short or I screwed something else up along the way. Any tips would be much appreciated!
Voltages  :)

I think 25ks will make biasing a bit harder though.
Title: Re: Dirtbag extra delay chip
Post by: wolfingsworth on November 24, 2012, 02:37:16 AM
I guess I was a bit unclear. I used 100k trimpots where the FSB build doc called for 25k. Later on, Ill check the schem against my BBD board. Hopefully its just a bad solder joint. FWIW, I am getting a boosted dry sound when the effect is engaged, but that is controlled by the Blend pot, so I guess that means either the portion of the circuit with delay chips is open somewhere, or I am not biasing it the right way.
Title: Re: Dirtbag extra delay chip
Post by: LaceSensor on November 24, 2012, 02:43:29 AM
Well you said the fakes work when directly in the DB board, so its the dual delay board(s) which are confounding stuff.

FWIW I found it best to bias the ICs in the main board first, then do the first double delay board, with the IC you just biased in there, and get it working with that, then do the other one.
It hard to bias all 4 trimmers for sure.

Title: Re: Dirtbag extra delay chip
Post by: wolfingsworth on November 24, 2012, 05:52:45 PM
After doing some probing last night, I found that I am getting voltage on all four 3005's when the Dbl Delay board is connected, but for some reason I am only getting signal on one of the chips for each set. I am thinking I just may need to scrap this layout and do one of the perfboard layouts that have been verified.