Are these 0.125W resistors ok for 4PM?

I’m ordering some missing parts for my 4PM at Farnell and noticed they only sell some of them in minimum quantities of 50. I only need 1 :slight_smile:

Would the 0.125W versions be ok for the 49.9 and 82k and 1M? For example 9343580?

Btw I noticed a small typo in the BOM. The reichelt listing for 33.0K should be 33.0KXBK-ND instead of 33.2KXBK-ND

Yes.

Btw I noticed a small typo in the BOM. The reichelt listing for 33.0K should be 33.0KXBK-ND instead of 33.2KXBK-ND
No, I think this is correct. The 33.2k value implies that those resistors have a 1% tolerance, while a 33k value would yield a 5% tolerance. This difference does matter in the 4PM filter, as well as the 220pF capacitors have to be styroflex with a 1% tolerance.

All the precision thats saved in the Polivoks gets used in the 4PM :wink:

@MicMicMan There are 30k and 30,2k resistors listed in the BOM, both with the same Reichelt product id.

There are 30k and 30,2k resistors listed in the BOM, both with the same Reichelt product id.
Yes, this is to specify that the 33k resistors don’t need to be very tight on tolerance, while the 33.2k need to be tight. The best solution is simply to pick 33.2k resistors all the way, so you’re guaranted that you don’t do any mistake.
I’ve asked about the same question some months ago :slight_smile:

I get it now! :slight_smile:

Actually the 33.2k comes from the original Xpander filter design-Tom Oberheim must have wanted the ratios of the various poles going into the mixer to be as close to ideal as possible, hence using the E96 series of resistors (33.2k) rather than the more familiar E12/E24 series (33k)-in this case not much of a difference if using 1% parts in either series.