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WIGGLING 'LITE' IN GUEST MODE

Component hunting
MUFF WIGGLER Forum Index -> Oakley Sound Systems  
Author Component hunting
catatemycaps
Hi, a new poster here.
I'm very happy to be here on this great forum.

Just recently I started planning on a small basic system and while browsing the parts list I encountered a few components that seem quite elusive.

BC 549, 550 and 560 are not carried in stock by very many dealers. I tried to find replacements for those, but I seem to get mixed results from different sources.

1nF 1% polyester cap which is needed for the VCO. Can this be replaced with 1nF 1% silvered mica? I would imagine so.

TIP145 darlington. Umm...replace it with TIP147?

That is all for now. More (stupid) questions will certainly follow. smile
ringstone
catatemycaps wrote:
Hi, a new poster here.
I'm very happy to be here on this great forum.

Just recently I started planning on a small basic system and while browsing the parts list I encountered a few components that seem quite elusive.

BC 549, 550 and 560 are not carried in stock by very many dealers. I tried to find replacements for those, but I seem to get mixed results from different sources.

1nF 1% polyester cap which is needed for the VCO. Can this be replaced with 1nF 1% silvered mica? I would imagine so.

TIP145 darlington. Umm...replace it with TIP147?

That is all for now. More (stupid) questions will certainly follow. smile


BC549, BC550, BC560 are all common parts, should be no problems obtaining these. A quick search on Farnell and Mouser indicated they have 1000s of these in stock. You are checking for variants too? Sometimes only A, B or C are available. Cheapest source is Tayda (3c each) but they have no BC560.

1nF polyester cap - pretty much available everywhere. I wouldn't personally use silver mica unless specifically indicated for that application. It's not styrene you're after?

TIP145 is a little more problematic but I note that Farnell have some in stock, and also indicate TIP147 as a suitable replacement (cheaper).

Cheers
Blair
catatemycaps
Thank you, ringstone.

Ok, so I can safely use BC550C where BC550 is required. I noticed that there are differences in some values such as higher hFE.

Yes, you are absolutely right. It is 1nF 1% polystyrene. Sorry about that.
Polyester caps are common but this is the one I have not been able to find.

Ok. TIP147 it is then (Farnell is a wholesaler in Finland and resellers don't seem to carry TIP145 in their stock - special order, I guess).
ringstone
catatemycaps wrote:
Thank you, ringstone.

Ok, so I can safely use BC550C where BC550 is required. I noticed that there are differences in some values such as higher hFE.


Would depend on the circuit. I've just noticed that often the variants will be quoted as a suitable replacement for the original part, and I've often received them (and used them successfully) when ordering that part. For example ordering BC547 will usually get you either BC547A or BC547B and I've never had a problem substituting them.

Personally I would try and source the closest variant according to the datasheets. But if the C variant specs overlap that of the original part you could order extras and test for those that fall within the original part's spec.

catatemycaps wrote:

Yes, you are absolutely right. It is 1nF 1% polystyrene. Sorry about that.
Polyester caps are common but this is the one I have not been able to find.


Should be available from Mouser, they have a wide range of styrenes at reasonable prices. Failing that, or if you don't want to put in a full Mouser order (their postage can be expensive), I can recommend a guy in France who sells high quality parts through Ebay (under the name "mightycroket") He should have plenty of these in stock (Philips Styroflex in the modern case style).

I can't comment on the silver mica caps, never used them as they are expensive and nothing I've ever built has specified their use. Certainly not a VCO. I am aware they do have high stability which is usually the property that polystyrene caps are used for, but I don't know if there might be any other properties that might make the silver mica unsuitable for use in this application.

catatemycaps wrote:

Ok. TIP147 it is then (Farnell is a wholesaler in Finland and resellers don't seem to carry TIP145 in their stock - special order, I guess).


Hope that works out ok then.

Cheers
Blair
Synthbuilder
catatemycaps wrote:
so I can safely use BC550C where BC550 is required.


Yep. Unless the parts lists actually states the grade you can assume that all grades work.

And TIP147 will work too - it's a higher voltage version of the TIP145. I must add that to the Builder's Guide if the lower version of the part is now proving harder to get.

If you can order from Farnell, don't forget there's a list of the most common parts I use with Farnell parts numbers in the Parts Guide on the site.

Tony
catatemycaps
I was a bit worried that differences in BCxxx variants would cause some unexpected behavior.

Thank you both very much for your help.
thebot
Synthbuilder wrote:

If you can order from Farnell, don't forget there's a list of the most common parts I use with Farnell parts numbers in the Parts Guide on the site.


This is a fantastic resource by the way. Even if you can't use Farnell / Rapid in your area you can use their sites as a reference to get either specs or part numbers. I find it a real help, especially for Rapid as their search function isn't the best.
mumblinstevedubya
Greetings all

I am having difficulty sourcing some 4u7, 35V electrolytic capacitors for my VCOs
Is there any alternatives that I can use
I am in the UK

Thanks

Steve
magman
Hi Steve,

You can use a higher voltage rating if you wish, as long as it's not too big physically. I quite often use 63V rated parts in place of 35V in my projects, these are easily available from places like Rapid, Farnell and ESR.

Hope this helps

Magman
mumblinstevedubya
Thanks Magman
mumblinstevedubya
Evening all

Has anyone got a Farnell or Rapid part number for 8-way jumper lead (ribbon cable)

I cant seem to find any part numbers in any documentation.

Thanks

Steve
Synthbuilder
mumblinstevedubya wrote:
Has anyone got a Farnell or Rapid part number for 8-way jumper lead (ribbon cable)


I've started using this stuff from Farnell.

Rapid used to do some nice plastic coated interconnects but have since discontinued it.

The Farnell stuff looks fragile but is surprisingly tough, very flexible and easy to cut down into various widths.

Tony
mumblinstevedubya
Thanks again Tony

How long is that? as I cant work it out from that link.
Cant be two inches surely?

Steve
Synthbuilder
mumblinstevedubya wrote:
Cant be two inches surely?


Yep, 2" long. Just right for fitting between the main PCB and pot board.

Tony
Dr. Sketch-n-Etch
Polystyrene caps are all but obsolete. Some folks (including Ian Fritz) feel that C0G ceramics are just as good (if not even better) than polystyrene; they have perfect temperature specs. I use C0G caps in my VCOs (and they are used in the Intellijel Dixies as well). They work just fine, they're cheap as chips and available everywhere.

I prefer 1% silvered mica caps for filter cores, and polypropylene film caps for S&H circuits. A recent study showed that polypropylene caps had less leakage than any other cap. You could probably safely use these for VCOs as well.
trimix
I'm in a bind - I placed a huge order with Mouser based on the parts lists for the VC/ADSR module.
A BC560PNP Small Signal is spec'd, but the part # for Mouser comes up obsolete, and no stock is available.
I don't know enough about electronics to seek a substitute (more of a "part x into slot x" kinda level)
Can anyone suggest an alternative?

UPDATE: I found what I needed at Mammoth Electronics - thanks!
Synthbuilder
trimix wrote:
Can anyone suggest an alternative?


BC560 ( Mouser Part No: 512-BC560CTA) is currently out of stock from Mouser although more are due in January. But you can use the BC559C instead:

Mouser Part No: 512-BC559CTA
Manufacturer Part No: BC559CTA

The BC559C can be used in place of the BC560C in any location in an Oakley project.

Tony
trimix
I'm parting up for the VCA/ADSR Upgrade, but there is no handy spreadsheet listing the part #'s for this build. So according to the Oakley parts list I will need a small 3 pin 0.1" normalisation jumper (yes I know I can do without, but I don't wanna)

I can't find them on Mouser site - don't even know the correct term for these.
Does anyone have a Mouser part# or an alternate supply?
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