Why are the feedback diode pairs connected in the middle?
(https://i.postimg.cc/23sLF6sV/tream2ed5.png) (https://postimg.cc/23sLF6sV)
There's no trick. Put it on a switch and see if you can hear a difference.
Seconded.
There's no trick at all. The connection is pointless - no current can ever flow through it.
Think about it: If the current is flowing one way through the diodes (the top pair, say) then the middle connection does nothing because the lower diodes block the flow. If the current is flowing the other way through the bottom diodes, the middle connection does nothing because the top diodes block the flow. So either way it's pointless.
Cosmetic, more than anything.
Technically I'm with Electric Driud but the reason it's there is Paul Cochrane (the designer of Timmy) said he could hear a difference and decided on the cross connection. You could probably find a quote on the web somewhere.
You know, map makers put nonexisting roads or villages in their maps to catch others who copy their maps without licence instead of making their own map. I feel like a lot of pedalmakers, especially the boutiquish kind add pointless connections and the like and then pretend they do something so that they know when someone just plain copied their design. Not sure what the point of that would be, though. No copyright on circuits. Or having the connection just made the layout more convenient, I've had similar cases. Or maybe he actually thought he heared a difference, who knows.
Quote from: Fancy Lime on February 01, 2025, 05:18:08 PMI feel like a lot of pedalmakers, especially the boutiquish kind add pointless connections and the like and then pretend they do something
Well the thing is he did it before anyone knew what he did. So there was a decision process.
Just the same there's plenty of "bad electronics" in pedals.
something I've learnt on this very forum is - no matter what you know of the theory and practise, you can point out the error, but you can't argue with someone who has done the experiment.
This looks like a trick used with series LED lights where the source voltage can exceed the peak reverse voltage of a single LED. Where you have a double string of LED's operating from an AC source with one string that illuminates in one direction and the other that illuminates in the other direction, connections between diodes can be used to ensure all diodes are driven by the same reverse voltage as the forward voltage of the LED's.
But this would not be necessary with 1N4148 diodes in a 9-volt circuit since their allowable reverse voltage is much higher at 75 volts. There may be a slight voltage difference due to leakage or capacitance in the reverse direction, but that should be negligible.
Quote from: duck_arse on February 02, 2025, 08:54:04 AMsomething I've learnt on this very forum is - no matter what you know of the theory and practise, you can point out the error, but you can't argue with someone who has done the experiment.
"...can't argue with someone..." sounds like a challenge. Hold my beer!
One thing that may play a role in this arrangement, is reverse leakage. Although, admittedly, I don't find the question at hand intersting enough to actually calculate if leakage would matter at all or enough to be audible. Just an idea.
It's basically running two diodes in series, in antiparallel with another pair of diodes in series. The result is the usual antiparallel diodes, but with twice the threshold voltage.