freestompboxes.org

Who knows where to get those?

http://www.turretboards.com/guitar_ampl ... igrade.htm

They don't stock 2,2uF, 4,7uF and few other values I would like to have

Thanks
Pawel

For some of the lower value uF caps have you considered using something else like PETP? You can get them for peanuts and I'd prefer to use them than even super high grade electrolytics:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0427778109
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0425349797

The 4.7uF in particular is fairly big compared to a standard sized electro in the same value, but if you can accomodate them it may be worth a look.

Have a look at this write up someone did on them on the DIY Audio forum.

Wow! I'll try some for sure, I'm fancy with military spec caps, pots and others, but those are not electrolytic

No, but why use electrolytics if you don't have to? I'd always use something else if I could rather than a leaky, inaccurate, temperature unstable electro that may only work for a couple of thousand hours. The main advantage electrolytics ever had was price, but if you're looking at expensive ones then it doesn't even have that advantage.

I've been able to find most values I need in tantalum caps. And if you pick and choose at surplus sellers, you can get them very inexpensively.

culturejam wrote:I've been able to find most values I need in tantalum caps. And if you pick and choose at surplus sellers, you can get them very inexpensively.

Yes me too, in fact I've got very few electros now. I was the only bidder for a batch of 80 x 10uF and 80 x 47uF tantalums and ended up paying £0.99 plus postage!

that guy is really mixing up his shit. first of all, he realizes later that he didn't actually have caps with PETP on them, but PTFE.

you can see the poster admitting is PETP/PTFE screw up in this thread, post #9.

http://www.diyaudio.com/forums/tubes-va ... -mods.html

PETP is an abbreviation for Polyethylene terephthalate, which is just a fancy word for mylar. that's why all those people are poo pooing him all over the place. but the thing is, PTFE is an abbreviation for Polytetrafluoroethylene, which is in fact Teflon! so what you've got there, if these screwy audiophile wackos can be believed, are some really cheap, large sized, Teflon caps. which sounds great, but i didn't think you could find Teflon caps that big. who knows.

He may have got the PETP description off the Lithuanian seller he bought them from, I don't know, but it doesn't say PETP or PTFE on the actual caps, just the rating, value, tolerance, Russian military mark and a couple of codes which may be date codes or something. I don't know exactly what they are because I can't find a datasheet that includes the K73-16s, but they are very nice.

well it would definitely make a difference, but if it doesn't say so on the caps, i doubt if they are teflon. i've never seen teflon caps that big. but that's just my uneducated opinion.

I think they're right with PETP, if you look here, it even lists the series of capacitor as an example. And the seller sells Teflon caps too so I expect he'd know the difference. They're nothing like the mylar we're all used to though like greenies, the Mallory 150s that soulsonic likes so much are also PETP

I'm sorry to be late to the party, but I've been kidnapped by my family...

IvIark wrote:No, but why use electrolytics if you don't have to? I'd always use something else if I could rather than a leaky, inaccurate, temperature unstable electro that may only work for a couple of thousand hours. The main advantage electrolytics ever had was price, but if you're looking at expensive ones then it doesn't even have that advantage.

I don't know what electro caps I can substitute really I always use what layout is asking for

Is there any rule for that?

culturejam wrote:I've been able to find most values I need in tantalum caps. And if you pick and choose at surplus sellers, you can get them very inexpensively.

I have no problems to find some of those values in other brands, like Illinois, bc components, I think i have some of those in atom series of spunage as well... I just think they are fancy enough to try to get some more

I've managed to get those in close to values, like 5uF in place of 4,7uF, 2uF in place of 2,2uF and so on... I don't think it's a problem since caps have 10-20% of parameter drift (drift? is that English word? )...

sinner wrote:I'm sorry to be late to the party, but I've been kidnapped by my family...

.. and it's going to get worse!!

sinner wrote:I don't know what electro caps I can substitute really I always use what layout is asking for

Is there any rule for that?

I think they're ok for power supply filtering because they do have at least one advantage over tantalum in that they're more tolerant to voltage spikes, but other than that I don't think an electro is ever specified for any reason other than price and physical dimensions at larger sizes. It certainly doesn't have any advantages over other types in terms of temperature stability, leakage, accuracy or longevity. I don't think there's any real rules so it's just down to preference, but I'd use pretty much any type of capacitor rather than an electrolytic if I have alternatives in the same value. Even for PS filtering you would expect a 25 or 35V tantalum to work perfectly well in a 9V pedal and the tantalums will be more reliable and last longer.