Active crossover components

[chrish]

G'Day everyone. I am building 4 of BrianGT's gainclone amps to combine with an active crossover. I am building the premium kits, and the crossover is Rod Elliot's http://sound.westhost.com/project09.htm

My concern is that I do not want to build the premium amp to run through a less than premium crossover, so my question is what resistors/capacitors do you recommend for this network? Was thinking Caddock or Ricken for the resistors, as in the amp, but the capacitor choice for the filter section has me scratching my head. Links to where to purchase would be helpful too. Thanks for your help.

Oh, BTW, very happy with the results so far with Brians amps, much better than my inverted point to point with standard components effort!

Chris

[officeboy]

Well you could pay $3-7 each for the rikens or caddocks.
If it was me i would get some of the Vishay/Dale 1/8W 1% Metal Film (RN55D from mouser.com $0.16 each)
or the 1/4W. But the resistors are the easy part.

I ordered some Xicon 2% Radial Polyester Film Capacitors to use in my crossover but I haven’t put it together yet so I can't tell you how it sounds.

[tiroth]

I think the dale's a good option as well. I like Wima for crossovers, their FKP series is nice and not too pricy, and is available in good tolerances. Many of the "premium" caps are sold as 10% or so.

Some people hate Wima, YMMV.

[moving_electron]

Originally posted by chrish
G'Day everyone. I am building 4 of BrianGT's gainclone amps to combine with an active crossover. I am building the premium kits, and the crossover is Rod Elliot's http://sound.westhost.com/project09.htm

My concern is that I do not want to build the premium amp to run through a less than premium crossover, so my question is what resistors/capacitors do you recommend for this network?
Chris

I built one of the crossovers with polypropylene caps in the input and high pass filter sections. These are larger than polyester so did not fit reasonable on the circuit board. The circuit board is sized to fit box type MKT or similar sized capacitors. Most any other capacitor types other that electolytic will be larger. There are a bunch of caps in a 24 dB active crossover as you know.

One consideration for the crossover is that you want the caps matched as close as possible. One way is to buy a bunch and sort. This can get you values that are very close to each other. I would propose that if you go with higher price parts and don't get many extras your matches may not be as good and the overall results will be poorer than well matched caps that you sorted from say 100 polyester caps.

Going off board was not really that hard though. I believe I ended up attaching wires to the underside of the board and bringing them to some perfboard on either side of the PCB. It ended up being pretty easy to keep them neat and orderly.

I ended up using non-sheilded wire but if I do it again it would be interesting to consider using sheilded. I put the crossover into a grounded sheilded box anyway so perhaps this would have been overkill. But without a grounded metal enclosure I would worry about added noise etc of going off board.

The particular crossover was a gift to someone so it was fun to splurge on the components. And it looked pretty cool. It might be fun to put them in your personal crossover as well. I am sure there is someone who will insist there is an absolute must-have high end part to use, but I really do not detect a difference between this and the same crossover with polyester caps.

But then maybe my system is not premier enough, my ears not golden enough, wrong power cord etc, but then that is another thread

Given the chance of introducing problems and noise by going off board with longer signal paths, and the lack of improvement I experienced by going to polypropylene, I will tend to build with on-board polyester caps going forward I should think.

[chrish]

Thanks for the replies. Have been away with work for a few days, so sorry for the late reply to your help. Yes, when I added up the number of resistors required the Caddock or Ricken option becomes VERY expensive. Have taken the advice re the Vishay/Dale resistors. As for the caps, have found these Panasonic P-Series polypropylene 2% tolerance at digikey for $1.36 each (0.27uF) (10+) http://rocky.digikey.com/WebLib/Pana...ies%20bulk.pdf
Am happy to mount off the board, so size not such a big deal. Are these an appropriate component for crossovers? Once again guys, thanks for your assistance,

Chris