Hot Rod Crossovers

[airboss]

Greetings:
Has anyone tried substituting high dollar high performance capacitors (value for value)in Altec crossovers? What do you think. In my case we're talking about the 604-8K crossovers.

Dan
Fairbanks, -4F sunshine

[jmarkwart]

Hi Dan,
I experimented over the years with replacing the caps and wire found in stock Altec passive crossovers, and feel it can be beneficial to change them for home stereo listening. The older crossovers particularly benefited, as some of the old capacitors tended to drift in value and get leaky after 30 or 40 years of being continually exercised by AC waveforms. Replacing the older type wire made an audible difference also, depending on the type that was substituted. I finally settled on Sidereal or Kimber for caps, and long crystal CCC copper wire from Vampire for wiring because of their transparency and quietness on Altec compression drivers.
Jeff
Pearland, +70F

[Steve Burger]

+70F, I am jealous, we tried to work on my barn(where my large format stuff/theater is going in) and it started snowing. Jim D is also collaborating with Jerry Hubbard on some crossover designs and improvements.

[Charles Chance]

In the past, I opened one of my N500-G crossovers to discover that it was *****d with tar. Was this a common practice at Altec? This would make component replacement most difficult.

[Charles Chance]

The asterisks above replaced f_i_l_l_e_. Have I discovered a new bad word? Somebody tell me what it means so that I may use it correctly.

[Steve Burger]

I have also noticed that sometimes the censoring software seems to make some wierd mistakes!

[jmarkwart]

Charles,
I've rebuilt a number of the older xover types (N500, N800, N1500, N1550, etc) and found them all potted with that black tar-like goo. The newer frame mounted crossovers are not potted like the old timers. The old types were just stuffed into a can. The goo usually came out as a chunk as I separated it from the crossover can or waxed cardboard liner. Messy stuff that stuck to everything. After rebuilding the xover I would use either hot glue or RTV to make the components re-adhere to each other and the container.
Jeff

[RClark]

airboss--------the large altec crossovers like the N-500-C and E types used caps that seem to last forever and were really overkill for their application--------when tested on a HP bridge they seem to be as good as new-----in the many samples i have measured i have never found a bad one-----that doesn't mean bad ones don't exist---the smaller networks occasionally seem to have some variations with age------ the "black caps with red ends" (for lack of a better description) sometimes show some tolerance drifting--------perhaps if they have been used at high power levels for extended time periods??????--------as for someone claiming to hear the difference in old vs new wire i will not even address that technovoodoo.............RC

[RonSSS]

I messed with caps in the crossovers for my 904-8A duplexes. These are the Dual Shelving control types, most likely the same as the ones used in the later 604 series drivers.
Anyway, there are 5 caps in each crossover. I chose Zen caps from North Creek Audio. Rebuilt the crossovers, moved the 3 inductors away from each other, used good wire etc etc.
When I listened, I didn't like the result. Too harsh.
So after all that work, I put the Altec caps back in.
Jeff M warned me........but I didn't want to fork out $200+ dollars for even fancier caps.
Ron