Active crossover advice

[Duck-Twacy]

Thanks for that info. Is it based on some Treshold product from 1988. Wow, how about progress

Funny to see so many different opinions om crossovers...

Does sombody have any experience with the tubed crossover form Tube-cad. Will the use of tubes give better results then with opamps?

[Peter Daniel]

Originally posted by Duck-Twacy
product from 1988. Wow, how about progress

There is not much progress when it comes to crossovers, unless you go digital.

If you look at the latest design from Pass Labs it's not that different, except for more settings

[Duck-Twacy]

Okay, not much progress in this field. However I'm really looking for the of the shelf kits here, most of which are using opamps.

But can sombody enlighten me wether using opamps in de Xover is okay or not when you really want to get a good hifi system. For example I'm planning to "modify" my CD player with the LCaudio discrete zapfilter. Now if I use opamps in the Xover, isn't that a litle bit silly. Or is that a very different thing???

So will I be "spoiling" my Aleph5 if I feed it with an opamp based crossover, or is that silly???

[Peter Daniel]

You might use just a series cap at Aleph's input which will act as a first order filter and use active, third order filter on low pass amp. That's what I'm doing in order to get the best sound quality.

[Duck-Twacy]

Hello Peter, That would mean a first order (6 dB/octave) filter for the high pass I guess. For me that would probably do, because 1 of the options for the mid/high section is using a high end 2 way monitor system (I'm thinking of Von Schwiekert VR1, which is 89 dB/watt).

But how about adjusting the signal levels. Wil a simple potmeter (or some resistors) in the high/mid section do to get things "even"??

(My low (< 130 Hz) section will be a pair of 85.5 dB/watt 12" Lambda units in a sealed box)?

[Peter Daniel]

I prefer not to adjust anything in a high/mid section. I use an active buffer stage for the subwoofer 3rd order filter (from Threshold) and I make sure that it has enough gain to match the level of mids and highs. I use a pot before that active filter and this is how I adjust the levels.

My crossover is around 120Hz, so the capacitor required in my Aleph X (actually 2 of them for both positive and negative inputs) are 0.22u. I use Jensen copper foil in parallel with 0.022 silver foil cap. Crossovers don't get much better than that.

[Duck-Twacy]

Originally posted by Peter Daniel
I prefer not to adjust anything in a high/mid section. I use an active buffer stage for the subwoofer 3rd order filter (from Threshold) and I make sure that it has enough gain to match the level of mids and highs. I use a pot before that active filter and this is how I adjust the levels.

My crossover is around 120Hz, so the capacitor required in my Aleph X (actually 2 of them for both positive and negative inputs) are 0.22u. I use Jensen copper foil in parallel with 0.022 silver foil cap. Crossovers don't get much better than that.

The Reveille of Welborne labs would be an example of that I guess.
http://www.welbornelabs.com/rev4.htm

Anybody any comment on that crossover. How is the active part (for a 18 dB lowpass around 130-150 Hz)??

Don't know if its available for 230 VAC though. Also a bit expensive.

(sry for kicking this ancient topic)