[ginettaman]

Can I just use a 1n400x diode for the mint power section, and leave out diodes for the amplification section?

I have used the forum to search for these answers, but are just getting more confused - and I can't locate 1n5822 / 1n5298 in the U.K. also if I leave out the diodes in the amplification section, I don't need to jumper them, just leave empty, is that right?

thanks in advance.
Alan

 

[Pars]

I think from Tangent's parts selection guide for the MINT, that the crowbar diode is discussed (the 1n5822). I think that you can use a std. 1n4xxx, with some deficiencies. Check the docs on http://tangentsoft.net/audio/mint/pguide.html.

The bias diodes (CRDs) you would not jumper but leave open (these are tied from the opamp outputs to ground, so jumpering them would effectively short the outputs out... probably not what you want). Farnell or RS in the UK does not carry them? I know here in the US that Digikey does not have them but Mouser does.

Chris

 

[tangent]

Quote:

Can I just use a 1n400x diode for the mint power section

That depends on your power supply's current ability, doesn't it? A 1N400x is rated for 1A continuously. If your power supply goes into current limiting before that, the diode will be fine. With alkaline batteries, a short across their output can deliver 5A for a short while, and it doesn't drop to under 1A for many seconds. I think you'd burn a 1N400x with an alkaline. The situation is even worse with rechargeables, since their effective impedance is lower, hence output current is higher. That's why they can use NiCds to run cordless power tools, after all.

I've settled on a 3A diode for space reasons; a 5A+ diode would just be too big for the MINT. I've tested it, and a 3A diode seems to survive short-term use here, even though the specs say it is allowed to die under these conditions.

It's a question of risk management: a 3A diode is the balance between risk and space+cost that I'm willing to tolerate. By that same logic, you might be able to tolerate using a 1A diode here. But personally, I would rather use no diode at all, because a 1A diode smacks of false security. At least if you leave out the diode, you remind yourself that you have no backup plan if the power supply is hooked up backwards.

The exact diode type you use here isn't critical. If I were you, I'd search out an alternative that meets the spec. For instance, the 1N540x series is a similar 3A barrel diode; it's a silicon type rather than a Schottky, but it'll work for this purpose.

Quote:

leave out diodes for the amplification section?

It's absolutely fine to leave D2 out. It's only a tweak, and an expensive one at that.