x0xb0x BOM v1.9 attached (last updated March 6 2009)

[katarakt]

Are these 1% resistors exactly as good as the 5% ones? because the 5% are in the official parts list.

[eil]

1% resistors are better than 5% because they have a tighter tolerance. (If you're not familiar with the term "tolerance" in reference to resistors, Google is your friend.)

I've found that when buying resistors from Mouser, 5% (carbon film) and 1% (metal film) resistors are often the same price, so you can basically get lower tolerance for free when buying in small quantities. That's why they are 1% on the BOM but and 5% on the parts list. (Although in quantities of 10 or more, carbon resistors are cheaper by a full cent.)

Of course, this might not always be the case since Mouser does have a tendency to change their prices and suppliers. I suspect that metal film resistors cost more than carbon film to make, but the narrow price difference probably results from economy of mass production.

[katarakt]

ok thanks

[roland]

Trying to put my order together on Mouser - have imported the 1.6 bom but the 895-FT232BM - USB Interface ICs USB TO SERIAL UART is listed as Obsolete, and they suggest Similar Product 895-FT232BL...

Anyone know if this alternative is ok

[niksun]

I posted a new BOM (v1.8) here.

[katarakt]

Excellent, now we've the updated sticky thread keep them updated.

Niksun, have you put the mcmaster part specs (in mm) which i've send you via pm in the upcoming (if ther'll be one) v2.0 version? Would be nice if so, but it's up to you. The information is helpful for the european guys to easy find the mcmaster parts in their country. You can put them in a special optional information in your excel sheet.

Oh, and i've looked for part.nr. for some sockets with gold connection because not all part. nr. in the bom have the gold connections which i prefer...i'll pm them to you if you want

[niksun]

PM me the gold parts and I'll also add those in the next version (this weekend maybe). I'll also add the metric parts; that's a good idea! Thanks.

[ACrIkeD]

I need the Datasheets of all the hard parts so I can find replacements or alternative option.

The only rare item is BA662A - but as I see it with a little modification of BA6110FS would make this all even easyer.

[ACrIkeD]

Are these 1% resistors exactly as good as the 5% ones? because the 5% are in the official parts list.

The % of the resistor refers to variation given to ohm values.

100ohm resistor with 5% can actually be between 95ohms to 105 ohms. Generally, this doesn't make huge difference, however in notes and tones they do.
The R1R2 ladder has been made with matched pairs with 1% metal film resistors, that should be exact. There you should not use 5% things or you have hard time
to measure correct pairs.

The original TB-303 used 0.1% precission resistors with selected pairs to get the exact values to the R they wanted. This means to have exact notes.

To get this problem sorted way easyer is to use precission Trimmers. But Well, thats too raw school to be done xD.

Metal film resistors are typically 1% meaning their measure variates in 1000ohms... it is 1990 to 1010 ohms.

(1/R1) + (1/R2) = 1/Z [Z is total R] You most likely want to get the Z exactly to the R value needed.

[adafruit]

the power supply and r2r ladder resistors should be 1% or better but from what i remember the tb303 had 5% for everything else. other than the VCO tuning, its a cheap machine

the FT232BM has been replaced with FT232BL which is identical except for being leadfree

[niksun]

Latest x0xb0x BOM (last updated April 25, 2009) is v2.0. Instead of always updating the filename to match the version, I figure I'd keep the name the same so that re-downloading it at any time would ensure obtaining the latest version:

Latest x0xb0x BOM!

I'd like to know if someone's used some type of connector (perhaps Molex) to hook the IO board to the main board. Adding that to the BOM would be very nice! Please either reply in this thread or PM me. Thanks!

[mr aize]

hi there. I've been makin a self sourced x0xb0x and i'm havin a few problems going through and finding all the parts. Just wondering if one of them's been missed off the bom. its the 4066 analogue switch. Has it been replaced with something else? http://www.digikey.com/scripts/DkSearch ... -2061-5-ND Thanks.

[mr aize]

never mind. i've found it. There's a hell of a lot of parts here an i'm confusing myself....

[katarakt]

Niksun, i think substuler uses these cable-connectors as i know. I've orderd one first to check it out and i think these are cheap and excellent for x0xing so my next x0xes will be soldered with these connectors.
After my first x0x i hate these stock cables because they are very short, it's not fun working with such cables!

Here's a pic again from the excellent cable-connector. I'm sure mouser have these cables but i don't know the english name for it, so i'm not able to find them in the mouser catalog. If anyone find them in mouser, please let us all know!

PS25 3G BR.jpg (11.27 KiB) Viewed 4052 times

[dnigrin]

Subatomic glue has info on which molex connectors he used on his mods page:

http://www.subatomicglue.com/x0xl0g/mod ... guide.html

Dan