Hookup powersubwoofer to a tube receiver.

[justpoor]

Hello,

Please show me the best way to hook up my power subwoofer to my tube amp. What I have is an older tube receiver that has output for 2 speakers, an aux input, and a set of tape in/tape out.

I know that I can hook up speaker cables from my receiver to the sub and from the subwoofer connect cables to my two main speakers, but by doing that I am not getting the tube sounds that I want (I think the sound is being driven by the powersub this way instead of the tube receiver.)

I am thinking of using a RCA cable and connect it from the tape out of the receiver to the input of the sub and try it out that way but I am affraid that I may kill the tube receiver as this may not be correct way to hook things up.

Can someone please show me a correct way to hook up my powersub with what I have without purchase additional amp/preamp, etc.....

Thank you in advance.

[Eli Duttman]

Using the speaker level I/Ps on the SW is "correct", as the SS amp in the SW will pick up some of the tube circuitry's sonic signature. The key is avoiding "daisy chaining". Connect your main speakers directly to the receiver; they will play full range. Connect the speaker level I/Ps on the SW to the 2nd set of speaker terminals on the receiver. Set the receiver's speaker selection switch to the "A+B" position. Adjust the SW's controls for best sound.

BTW, you don't need "super duper" speaker cables to connect the SW to the receiver. The 14 AWG OFC "rope lay" Sound King brand zip cord carried by Parts Express is quite satisfactory for this application. Heck, 16 AWG OFC zip cord is probably good enough.

[justpoor]

Thank you Eli. I will give it a try.

[Jeff Yourison]

For Eli,

I've had good luck so far using daisy chaining; it doesn't seem that the ss amp interferes all that much. But suppose I want to avoid daisy chaining, but only have one set of speaker terminals (or OPT with 4 and 8 ohm taps). Using 8 ohm speakers, could one hook the speakers and the sub amp speaker level inputs in parallel to, say, the 4 ohm tap on the OPT? How would one consider the ohm rating of a subwoofer amp input?

--Jeff

[Eli Duttman]

Originally posted by Jeff Yourison
For Eli,

I've had good luck so far using daisy chaining; it doesn't seem that the ss amp interferes all that much. But suppose I want to avoid daisy chaining, but only have one set of speaker terminals (or OPT with 4 and 8 ohm taps). Using 8 ohm speakers, could one hook the speakers and the sub amp speaker level inputs in parallel to, say, the 4 ohm tap on the OPT? How would one consider the ohm rating of a subwoofer amp input?

--Jeff

Jeff,

When you "daisy chain", the SW's crossover sits between the tube amp and the main speakers. Sometimes, as is JP's situation, the sound is degraded.

For you to eliminate the "daisy chain", connect both sets of speaker cables to the 8 Ohm taps on the tube amp. The crossover in the SW presents a "high" impedance to the main amp below its "corner" freq. That's how it keeps a SS main amp from producing power in the deep bass. In the parallel arrangement recommended, the reciprocal rule for impedances applies. If 8 Ohms and 80 Ohms are paralleled, the net impedance is 7.27 Ohms. Notice that the "high" impedance the SW presents does not appreciably alter the load the tube amp "sees".