Substitutes for parts for the Ultimate

[Antimon]

So I'm checking my local suppliers for components to put together the Ultimate. A good tip is to check Raymond's prefilled basket on Mouser, since he's put in a couple of comments there on components that he needed to replacement with what Mouser has in stock. I'm also checking the SoundLab component replacement sticky here for clues.

I'm a but stumped concerning LF444 (which Raymond has changed to OPA4137 in the Mouser cart). When I built the SoundLab I used TL074 instead, but since TL074 is alo on the parts list for the Ultimate I guess that there is some special need that the LF444 fulfills. It's part of the sample/hold circuit. I can find LT1058, but that's a pricey one. I'll probably stay with tl074 - it's cheap and i'll use sockets - but if anyone has a tip I'd be grateful.

Then there's the PN4391 - I can't find this locally. I'm going to try 2N5457 after a suggestion here: http://www.electro-music.com/forum/topic-35244.html

1N5239B 9.1V Zener Diode - my knowledge in electronics doesn't reach as far as to actually know what this is. I can find a BZX55CC9V1 DO-32 9.1V Zener Diode (0.5 W), which fits everything except the serial name, I'm going to try that one.

c54 (for the VCA) should be a non-polarized aluminium electrolytic capacitor. I am guessing this means there should be non +/- distinction for the connectors? I have a hard time finding this one... might an other kind do?

c7,c17,c29 is a 0.005 µF Polycarbonate or polystyrene capacitor, for temp stability (used in the oscillators). Any tips for other materials - I can find stuff like polyester, polypropylen, polyfenylsulfid (possibly swedish spelling), but I don't see much info about whether these are stable regarding temperature. I took a chance and ordered a polyfenylsulfid, see how that works.

Any helpful hints ad tips would be appreciated. I've built the SoundLab mini-synth, but that's about the only successful project involving soldering components to a PCB that I've had. Looking forward to having some fun this autumn.

/Stefan

[magman]

Stefan,

I found quite a few suppliers of the LF444 using this web tool that I can't remember where I got it from:

http://burnit.co.uk/sdiy/part_search.php

This is obviously UK and USA biased, but you should find some of these suppliers will deliver to Sweden.

I suspect that the BZY88 should work OK, as a replacement for the 1N5293B, it's just a Zener diode after all.

For the non-polarized cap, these are relatively easy to find from the suppliers shown in the link above (I've just ordered some from Rapid for example). You can use any non-electrolytic cap as a replacement, but you tend not to get the high values that are available in the non-polarized electrolytics.

For c7, 17 and 29, you do want to aim for a polystyrene capacitor of 5000pf. If you can't get the precise value, you can parallel caps to get closer, but I suspect a 4700pF [4.7nF](one of the standard values) would be OK here. These may also be listed as film capacitors by your local suppliers. These are expensive but have a very good temperature stability.

If you struggle to find polystyrene caps, you could try a multi-layer ceramic cap, aim for theC0G/NP0 type though (this is the best temperature stability type of ceramic capacitor). These are much cheaper than the polystyrene, so it might be worth trying them anyway and only replace them if you have temperature stability problems.

Hope this helps

Magman

[Antimon]

Great tips - thanks!

That search page is pretty neat, I'm sure I'll be able to get one of those UK stores to ship here.

/Stefan

[magman]

Stefan,

I like that search page myself, I use it quite a lot. I think I picked it up from the Synth-DIY list if I recall correctly.

Good hunting on the parts. I've dealt with most of these suppliers and you shouldn't have any problems with them. I wouldn't be surprised if RS haven't got a Swedish division anyway.

I must admit that the Ultimate is on my long term project list, hence my interests in this part of the forums.

Magman

[Antimon]

Ordered stuff from Rapid - thanks again for the tips!

I bought the clincher pacage which included the wallwart to power supply PCB, but I think I'm getting cold feet about making that. I have a pile of 15-20 wallwarts and I was hoping that at least one of them was AC, but no such luck. I don't understand all the info I see on the local sites, and if I buy a UK or US I need to add a mains adaptor.

Is there some place where I can order a ready-made power supply that I can use directly (with possible connector cable mod) with the Ultimate? Preferably european.

/Stefan

[magman]

Stefan,

I'm not sure what type of mains plugs are used in Sweden, nor what the power consumption of an Ultimate will be, but I've found this AC wallwart PSU that might fit the bill from CPC:

http://cpc.farnell.com/_/mb120a050u-d/adaptor-eu-12vac-500ma/dp/PW01877?Ntt=pw01877

If you are looking for a complete PSU module, it might be worth looking at the All-In-One power supplies from Elby, here:

http://www.elby-designs.com/shopping/index1.html (Just click on the Power Supplies Link on the left hand side of the screen).

These are quite a bit more expensive (about kr900) but it does appear to be a good quality PSU that you could build into your Ultimate cabinet, with a suitable adaptor plate, and it uses standard IEC mains leads.

Most of the other Power supply modules I've found are for +/15V, for example Curetronic have a unit for 65 Euros. It just depends if they could be modified to provide +/-12V you need for the Ulimate.

Good hunting.

Regards

Magman

[Antimon]

Actually, now that you mention it, I do have a new Curetronic modular unit here. I remember it being mentioned that you can take the power supply for one cabinet (that's what I have) and use it for more modules - I only use it for twelve modules currently, there's room for 20 on the bus and it supplies 2A. All I need is a connector... I think I'll check with Matthias at curetronic and see if I can buy that from him.

Thanks again for good advice.

Re: power connectors, I think most of the EU except the UK uses the same kind of mains plug - two small cylinders with optional ground connectors on the side of the plugs. I actually don't think it would be a big deal to add the UK/Sweden converter - it's a common enough thing to do for stuff bought from the UK.

/Stefan

[magman]

Stefan,

You need to watch out as the Curetronic PSU is probably 15V and I believe the Ultimate is 12V as standard. You may be able to modify the Ultimate to run off 15V though.

Also, the AC PSU I linked to from CPC is a Euro version, so should fit the 2 pin version of a Euro socket (you don't want it earthed anyway), without a UK/Euro adaptor.

Regards

Magman

[Antimon]

From the main page, the left column a couple of screens down:

[magman]

Sounds like a plan then.

You'd only need a seperate PSU if you want to take the Ultimate elsewhere.

Have fun building it.

Regards

Magman

[Antimon]

Thanks! I tend not to move stuff too far from my bedroom anyway, and the Ultimate will make nice bedfellows with the Curetronic stuff I think.

/Stefan

[Uncle Krunkus]

You could always put a 7812/7912 pair of regulators into the SoundLab, and then you'd be able to power it from your +/-15V supply and it would actually use +/-12V inside.