BTW - Jax2 (and others with similar thought processes), please leave bodily orifices out of the list of options ;-)
7 responses Add your response
Interesting question. I would think, considering that the L-4000's output impedance is low (150 ohms) and is described as being constant with frequency, and considering that the connections are all balanced, it may not make any difference which of those connection methods you use.
However, my instinct would be to have the splitter just ahead of the power amp, with a single run from the preamp to the splitter, and a short run from the splitter to the sub.
That minimizes the amount of cable capacitance that may affect the signal to the power amp by interacting with the preamp's output impedance -- if you had separate runs to the power amp and to the sub, the capacitance of the cable to the sub would add to the capacitance of the cable to the main amp in affecting the signal seen by the main amp (although that effect would be very small, because of the preamp's low output impedance).
Also, having a short connection between power amp and sub keeps their grounds as common with each other as possible, perhaps reducing the likelihood of ground loop issues (although that likelihood is very low in any event, due to the use of balanced connections).
Splitting it near the amp/sub results in the shortest total cable, but it requires one more connection (male to female Neutrik plugs) than two parallel runs originating at a preamp split. The latter approach allows the signal delivery to the amps/subs to follow two seperate wire courses, thus less resistance, but the signal must first get through the splitter, right at the preamp out.
Another option would be to have the Y adaptors made so that one leg is somewhat long (e.g. 10 feet), and can reach from the amp to the sub, whereever the sub is ultimately placed. With this approach, the total length of wire is smaller and the number of Neutrik connections the same as by splitting at the preamp.
This seems a bit anal to worry about, but I'm still quite interested in what would be best.
Splitting it near the amp/sub results in the shortest total cable, but it requires one more connection (male to female Neutrik plugs) than two parallel runs originating at a preamp split. The latter approach allows the signal delivery to the amps/subs to follow two seperate wire courses, thus less resistance, but the signal must first get through the splitter, right at the preamp out.For line level interconnections, capacitance is much more likely to be significant than resistance, although in this case both may very well be insignificant. But as I said in my previous post, if you have two long runs from the preamp, the capacitances of both runs will sum together in interacting with the preamp's output impedance and thereby affecting the signal delivered to the main power amp.
The option you described of having a y-adapter with one leg made long enough to reach from amp to sub sounds good, although my inclination would be to not particularly worry about having an extra connector in the path to the sub, where all that matters is conveying deep bass frequencies accurately.
Thanks Al. I'm having Redco make up a 6" pigtail pair. They also thought the addition of one more connector to the sub would not make a difference, so I decided this would be most flexible.
I'll be doing a bunch of soldering, putting Neutrik connectors on Mogami cable to make the other runs. Any advice on that, besides getting the pin arrangement right (1=ground, 2=positive, 3=inverted). The cable has 4 conductors (2 pairs of like color) and a braid. Each like color pair gets twisted together and goes to one pin. The braid gets gathered up, twisted into one, and to the third pin. Does it help to tin the braid prior to soldering to the pin? Ditto for the other twisted pairs?
Also, do you think there is any significant difference in sound quality between "standard" Neutrik plugs and more expensive models, such as "black", "gold", etc?
Thanks for any advice that can be offerred. Peter
Sounds good. I have no particular knowledge, though, of any subtleties that you might need to be aware of in assembling the cables, or of the different Neutrik's.
I too use Mogami's Neglex Quad cables, btw, in a three-foot length, between my cdp (Bryston BCD-1) and preamp (Classe CP-60). But I purchased them in pre-assembled "Gold Studio" form from B&H Photo Video, with presumably lesser connectors.
Good luck with the project!