How to Connect My Sub to My Preamp

[Hello man]

Hi guys,

I just scored a Polk 8 inch 100W RMS sub for $12 at goodwill yesterday. However my receiver and amp are old Technics pro line gear. The preamp is a SU-9070, and the amp an SE-9060. Being old, they have no designated sub out. There are two possible ways that I can see to run the sub, but I need your expertise on this one.

I have the sub plugged into the "EXT Unit" output. Only problem is it stays at the same volume even when the volume is turned down on the preamp. Any ideas?

Here is the service manual. Second page shows the back input/output ports. SU-9070 PREAMP MANUAL

 

[rexter]

Yes but line level inputs will give you volume control whereas rca won't.

This is true. I just leave my preamp/sub at one volume and turn down the input.

Your sub only has two input; line level in and LFE.

If you don't want to spend money then don't use your Technics power amplifier and use the sub amplifier instead. Connect the preamp to the sub then your speakers to the sub amp.

or you need to get yourself some kind of audio distribution unit. one example is link below. install it between amps. like the other person mention about a splitter cable, but this way is better in distributing power signal between the two power amp.

http/www.amazon.ca/Ultra-Compact-4-Channel-Stereo-Headphone-Amplifier/dp/B000KIPT30/ref=pd_sim_MI_3?ie=UTF8&refRID=02AJ5MZ3BA8SNQFAFWFX

the other option is buy an amplifier/receiver with LFE output.

 

[Hello man]

Yes but line level inputs will give you volume control whereas rca won't.

This is true. I just leave my preamp/sub at one volume and turn down the input.

Your sub only has two input; line level in and LFE.

If you don't want to spend money then don't use your Technics power amplifier and use the sub amplifier instead. Connect the preamp to the sub then your speakers to the sub amp.

or you need to get yourself some kind of audio distribution unit. one example is link below. install it between amps. like the other person mention about a splitter cable, but this way is better in distributing power signal between the two power amp.

http/www.amazon.ca/Ultra-Compact-4-Channel-Stereo-Headphone-Amplifier/dp/B000KIPT30/ref=pd_sim_MI_3?ie=UTF8&refRID=02AJ5MZ3BA8SNQFAFWFX

the other option is buy an amplifier/receiver with LFE output.

Too much money to get a comparable unit. Just the preamp is still about $600-800 used in pretty beat up quality. The amp is about the same and the tuner it probably $400 along with the parametric equalizer which cost a bunch. I don't have a grand and a half laying around.

 

[madmatt30]

You don't need to do any of that ,I'd just buy 2 runs of speaker cable (& as cheap quality as you like as all you need is the low frequency signal) long enough to reach the secondary amp to the sub & just wiree it in parallel from the left/right speaker outs - job done ,volume control from Pre or main amp in tandem with your main speakers.

 

[Hello man]

You don't need to do any of that ,I'd just buy 2 runs of speaker cable (& as cheap quality as you like as all you need is the low frequency signal) long enough to reach the secondary amp to the sub & just wiree it in parallel from the left/right speaker outs - job done ,volume control from Pre or main amp in tandem with your main speakers.

Gotcha. I'll give it a try. I have some good cable laying around. My preamp is pretty cool and designed to drive two of the power amps together for 140W per channel if need be. I managed to get volume control by using the second RCA out.