Using a subwoofer with only LFE inputs with a receiver lacking sub out....

[lattiboy]

Hello all,

I've got a MK V75 mkii subwoofer I absolutely love, but I recently replaced my Denon X3600H with a small tube amp lacking subwoofer out. I need a way to incorporate the sub into my system and am unclear on the best way to do this. Source is a Chromecast audio going into a Tubemagic DAC, outputting to the tube amp.

Back of my sub looks like this:

 

[RVT1K]

The sub has speaker-level inputs, its the ones labeled "FROM AMPLIFIER"

All you need to do is run another set of cables from amp to the sub.

 

[lattiboy]

The sub has speaker-level inputs, its the ones labeled "FROM AMPLIFIER"

All you need to do is run another set of cables from amp to the sub.

To clarify, I’ll be running two sets of speaker cables out of the tube amp? 1 set to the speakers and 1 set to the sub out of the same terminals? And that won’t cause impedance issues?

 

[JoeESP9]

Nope. The impedance of the subwoofer is too high to effect anything.

 

[RVT1K]

To clarify, I’ll be running two sets of speaker cables out of the tube amp? 1 set to the speakers and 1 set to the sub out of the same terminals? And that won’t cause impedance issues?

You are right about the cables but there is no need to worry about the impedance.
Those connectors are not going to the driver in the cabinet, they are going to the inputs of the amp. And, as mentioned above, it is too high to cause a problem.

 

[Jason Lafler]

Use the speaker level inputs. Won't harm a thing.

 

[whoaru99]

There is one caution. Not all tube amps use the "common" terminal for the common ground point. For example, some (perhaps many) Audio Research amps have what is labeled common/0 ohms terminal, but it's actually the 4 ohm terminals that are ground. So, in cases like that, connecting speaker level input of the sub you'd connect the sub's black terminals to the 4 ohm terminals on the amp, rather than to the common/0 ohms amp terminals.

 

[Jason Lafler]

There is one caution. Not all tube amps use the "common" terminal for the common ground point. For example, some (perhaps many) Audio Research amps have what is labeled common/0 ohms terminal, but it's actually the 4 ohm terminals that are ground. So, in cases like that, connecting speaker level input of the sub you'd connect the sub's black terminals to the 4 ohm terminals on the amp, rather than to the common/0 ohms amp terminals.

My mistake. Totally missed the tube part.