Dirtbag repeats too dark

[harpplayer]

Hi!

I built the Dirtbag few months ago (MN3005 version), and played quite a bit with it.

It sounds really nice but quite warm - great for textures and modulation, but not so great for slapback or patterns. SInce I never tried the real one, I supposed it was ok...the whole analog thing...

I could compare it with a 90´s DMM a few days ago, and realized that the repeats had quite a bit more high end (bright content) to it. It was still warm, but with much more clarity.

I´ve tweaked the trimpots a bit, but I am positive it is not just that. I was thinking of modding some fix values to see if I can get a similar result.

The DMM v in is about 15.4 - 15.6 V. I use a 15V power supply (not the road rage).

I figure I should mess with the low pass filters, in order to allow more high frequencies on the repeats (there should also be a high pass filter to keep it less muddy too).

Does anyone have a suggestion where to try first?

Thanks very much!
André

[madbean]

Lower the value of, or remove, C34. This will brighten up the repeats.

[harpplayer]

Nice! Tks very much.

Will try that and let you know.

[harpplayer]

Hi!

It did provide me more repeats, but I believe the signal that gets to this point should not already be so filtered.

I understand this cap is acting on the regenerations (successive high cut), but it didn´t change what is before it.

Since I could get almost 600ms without the anoying high pitched whine, I figure I can compromise 50 ms for a tad brighter repetead signal. I see many filters on the schematic, but I am still not sure which could make the biggets difference here.

Any other suggestion?

Tks very much in advance,
André

[madbean]

Reducing C14 and C22 will also work to brighten it up without having to mess with the pre/post filters. Try half of C22 first and work from there.

[harpplayer]

This two helped a bit more.

I started to feel that maybe the problem was more related to the amount of low end. It was just so bassy that diverted from the fact that the bright content was ok. By ommiting the capacitors, the clock noise started to bother me, and it was still muddy after a few repeats.

I tried another approach then, by grouding a resistor (actually, a 500ohm trimpot) after to c32, so I that I have a high pass filter before the dry and wet signals meet again.

Though it messed with the balance, and the decay is faster, now the overall sound is not so cavernous, and closer to the original DMM. I was thinking of adding a swith to "stock" and modded, so I can switch faster for different situations.

André