Testing Tantalum vs Electrolytic Cap in GGG DOD 250

[afrogoose]

Hey Everyone,

So I built the General Guitar Gadgets DOD 250 (with more than a little help from DIYstompboxers!), and in the bill of materials it lists C6 as either being an electrolytic or tantalum capacitor.  I "scoured" the internet to see what the differences might be.  I decided that I should just run a little test for myself to see what was happening, so I recorded a quick video comparing the two caps. 

I recorded a loop into my TC Ditto Looper and then recorded it playing through the DOD 250 clone 4 times.  Once each with Ge diodes and the tantalum and electro cap, as well as once each with Si diodes and the caps.  I thought I would share it in case anyone else was curious.

note: There might be a better circuit to test out this premise.  From looking at the schematic it seems that the 22uf capacitor in the DOD 250 is really the only cap where you could do a tant / electro swap.  All the other capacitors seem to be either very small, or not in the signal path.  I'm not sure how reasonable it is to expect a significant difference from changing one lonely cap in a circuit.  But then again who knows...

[armdnrdy]

I think that any sonic difference that you might hear is due to the slight variation in capacitance between the two.....not the type of capacitor.

[PRR]

I would not expect a difference in a double-blind test (or any form of compressed audio file).

The capacitance is extra large for the application, so cap differences would be extra small.

Historically, Tantalum electrolytics were smaller and lower leakage. But in the last 30+ years Aluminum electrolytics have improved a LOT, smaller size/uFd and also much lower leakage. And other "flaws" much less also.

I would use good Al electros everywhere and not think about it.

History shows that you do NOT want Tants in power systems, across the supply. When they fail they explode. Al can also burst but it is usually much less dramatic for the size. A pea-size Tant can scorch a hole in a PCB, the Al will just ooze goo.