Dan Echo wet only question

[Michael2]

Hey all,

I would like to make an optional stereo feature on an old DanElectro Dan Echo. Does someone know which lead I have to bypass in the schematic?
https://www.dropbox.com/s/mnp42vknn9wb61a/Dan%20Echo%20Schematic.pdf?dl=0

[Mark Hammer]

IF the pedal used true bypass switching, it would be a simple matter of lifting one end of R22 - the resistor that mixes dry signal in with wet.  Unfortunately, as is true of so many pedals that use electronic switching to combine a clean and effected version of the input signal, this one also uses that same logic.  The "bypass" never removes the buffered clean signal from the output; it only cancels the delay signal.  So, if you lift the dry signal from the output mixing stage, all you get in "bypass" mode is silence, rather than clean.  That is, the unit has no native capacity to alternate between delay only and dry only.

I have one of these units in my collection.  While I might otherwise suggest drilling another hole for a separate wet-only output, we both know that drilling any additional holes in that chassis is going to be especially difficult. 

[Michael2]

Thanks Mark!

I understand. I was thinking of adding another input buffer as described here: http://www.tdpri.com/threads/dan-echo-input-buffer-fixed-nice.266647/
to eliminate the tonesuck. There is more than enough space left in the hole where the battery is supposed to go. My idea was to put a simple dual buffer in there where one output  goes to direct out and the other into the circuit. A small stereo jack output chassis will might fit in without drilling. My aim is to make a switch somewhere to switch  between stereo/mono.

Does this give any possibilities to wire it in such a way that it is doable? I do not mind to sacrifice if a true bypass switch is necessary but rather not. On Circuitbenders is a very interesting report about a modified Dan Echo with a wet only switch. The writer mentions there is a little bit original signal present. That would be okay.  Unfortunately there is no mention of how he did it.
https://www.circuitbenders.co.uk/newsarchive/danecho.html

[Mark Hammer]

The question I have to ask, that will set the direction for what changes would be approriate, is "How are you intending to use it?".  As noted in my earlier post, eliminating the dry signal is easy, but regaining it in bypass mode somewhat harder.  So, if the intention is to be able to use the pedal in a gigging context, we have a challenge that is not present if the intent is simply tobe able to tap the delay signal for home studio purposes.  If the goal is to send wet and dry to separate amps, or separate processing, the question prompted is what the objective is for the delay signal output when NOT using wet.  Is it to be cancelled outright, or converted to clean, such that the pedal now has two dry outputs?

[Michael2]

Hey Mark,

Good questions. The goal is to be able to switch between a stereo wet/dry setup for live purposes. One amp dry (original) signal and the other amp wet only.

I was thinking about adding a toggle switch to choose between original mono setting and the stereo setting. The most  cosmetic  way to do the splitting is to replace the mono output jack with a stereo jack. So when in mono mode a mono jack can be used and a stereo jack for the stereo mode. There are small stereo jack chassis on the market so I don't worry if that will fit. But I'm not sure if it will work out the way I have in mind.

I understand that the issue is that if the pedal is in bypass mode in the stereo setting the wet channel will be silent if there is a cutoff at R22. That's of course not what I'm looking for. Is there a way to get around this? Or is a 3pdt instead of the relay switch the easiest way to go? In that case the effect needs an "always on" mod I'm afraid? I hope there is an easier way to get the dry signal instead of the wet channel when the bypass relay is active.

Thank you for thinking along!