Issues with new Pioneer SX-950 + KEF Reference Model 1s

[Luca Signore]

Hey everyone - I'm having some trouble getting my new setup going, and I would love some guidance.

I have a set of KEF Reference Model 1s and a Pioneer SX-950 that I'm trying to hook up using 12 gauge Monoprice wire. The issues I have are two-fold.
1. The KEFs have 4 ports - 2 for HF and 2 for LF. Would it be best to A. just connect to one or the other B. Get a jumper like these https://www.amazon.com/AudioQuest-D...r=1-6&keywords=bi+wire+jumper#customerReviews to connect the two ports, or C. run two runs of cable from the receiver to the speakers? And, if I were to go with C, would I connect one speaker to the A output and one to the B output? Or both to the A?

2. I plugged everything in yesterday and noticed that one channel was much much quieter than the other. When I played with the balance, you could really tell how much weaker the one channel was. When I switched the output to the "Phono 2" input rather than "Phono 1," it sounded better, but still not perfect. Any ideas on how I would go about addressing this?

Also, one last minor issue - some of the knobs (bass, treble, balance) do not line up perfectly with the "clicks" / numbers on the faceplate. For example, when the bass is set to 0, the line actually lines up near the 1. How would I go about fixing this?

Thank you to anyone that can help!

 

[rocknroll1]

I would go with the jumpers. You can use any old copper wire. If had some old tv cable wire with the solid copper in it that work just fine. With you balance problem did you have any jumpers on the speaker terminals? If not that could cause the imbalance. As far as the knobs being off, set them to zero or the click spot and pull your knob off and put it back on in the right position.

 

[satellite65]

Have you switched speakers to make sure it's the receiver that is unbalanced?
Has the 950 had a D-oxit treatment recently? If not, it needs one...

For knob alignment, you can try switching them around.
Some may line up better in different locations.
Many vintage Pioneers have 2-piece knobs which can be separated then reassembled in proper alignment, if they point in between the faceplate lines.

 

[Luca Signore]

Yeah I only had them connected to one input - could this just be issue? I have some leftover 12 gauge wire - should I just strip a bit off each end, screw each end into the matching + to +, - to - input and then hook up the banana plugs to one on each side?

 

[Luca Signore]

Have you switched speakers to make sure it's the receiver that is unbalanced?
Has the 950 had a D-oxit treatment recently? If not, it needs one...

For knob alignment, you can try switching them around.
Some may line up better in different locations.
Many vintage Pioneers have 2-piece knobs which can be separated then reassembled in proper alignment, if they point in between the faceplate lines.

I'm not sure if it has had a treatment recently - previous owner did not know. Would DeOxit D5 be the way to go? Any really good tutorials on how to do this? I've never serviced vintage equipment, but I would definitely like to learn.

 

[Luca Signore]

I would go with the jumpers. You can use any old copper wire. If had some old tv cable wire with the solid copper in it that work just fine. With you balance problem did you have any jumpers on the speaker terminals? If not that could cause the imbalance. As far as the knobs being off, set them to zero or the click spot and pull your knob off and put it back on in the right position.

Yeah I only had them connected to one input - could this just be issue? I have some leftover 12 gauge wire - should I just strip a bit off each end, screw each end into the matching + to +, - to - input and then hook up the banana plugs to one on each side?

 

[rocknroll1]

Yeah I only had them connected to one input - could this just be issue? I have some leftover 12 gauge wire - should I just strip a bit off each end, screw each end into the matching + to +, - to - input and then hook up the banana plugs to one on each side?

Yes that will work but only stripe enough to get it around post. Also just do a search for guid to DeOxit, there is one on this site.

 

[satellite65]

I'm not sure if it has had a treatment recently - previous owner did not know. Would DeOxit D5 be the way to go? Any really good tutorials on how to do this? I've never serviced vintage equipment, but I would definitely like to learn.

D5 for the switches and F5 for the pots.
On an SX-950, quite a bit of disassembly is required to get the D-Oxit where it needs to get, but disassembly is not difficult. No unsoldering required.
All knobs, top/bottom covers, faceplate, then control/switch assemblies need to be separated from the front inner panel by unscrewing them and rotating towards the back.

BTW, welcome to AK, and the search engine is your friend...

 

[Luca Signore]

D5 for the switches and F5 for the pots.
On an SX-950, quite a bit of disassembly is required to get the D-Oxit where it needs to get, but disassembly is not difficult. No unsoldering required.
All knobs, top/bottom covers, faceplate, then control/switch assemblies need to be separated from the front inner panel by unscrewing them and rotating towards the back.

BTW, welcome to AK, and the search engine is your friend...

Awesome - thank you so much. First I'll try hooking everything up properly with the jumper, and then if I'm still having issues, I'll go ahead and tackle the cleaning with the DeoxIT. I'm guessing there should be a guide on here somewhere on how to disassemble what is necessary? This forum seems great so far - I'm really appreciating all the help.

 

[slimecity]

In the meantime - wire both + posts and both - posts of the kefs together, wire them up to another amplifier to ensure that there isnt a problem with them

 

[Luca Signore]

In the meantime - wire both + posts and both - posts of the kefs together, wire them up to another amplifier to ensure that there isnt a problem with them

Ok so I wired both posts and it sounds way better. I'm still getting the issue on the Phono 1 input, but no issue on the Phono 2 input. However, the tone on/off switch seems actually defeat the tone even more when I switch it "on," and the bass/treble knobs don't have much impact on either. Any ideas?

 

[Luca Signore]

Yes that will work but only stripe enough to get it around post. Also just do a search for guid to DeOxit, there is one on this site.

Ok so I connected the speakers with the jumper and it already sounds much better. I'm still having some problem with some of the controls - bass and tone specifically - so I think I'll go ahead and get some DeOxit in there. While I have the case open, I plan on doing at least a visual inspection of the caps to see if there is anything obviously wrong. Is there a way to test the caps for capacitance without desoldering them? All of the videos I've found on YouTube show the cap taken out before testing for capacitance - that seems like a huge PITA. Is this just done for video clarity? Or is it actually necessary to remove the cap to test it?

 

[satellite65]

Ok so I connected the speakers with the jumper and it already sounds much better. I'm still having some problem with some of the controls - bass and tone specifically - so I think I'll go ahead and get some DeOxit in there. While I have the case open, I plan on doing at least a visual inspection of the caps to see if there is anything obviously wrong. Is there a way to test the caps for capacitance without desoldering them? All of the videos I've found on YouTube show the cap taken out before testing for capacitance - that seems like a huge PITA. Is this just done for video clarity? Or is it actually necessary to remove the cap to test it?

Capacitance is rarely the issue with old electrolytics. ESR is what goes bad when they dry up. That causes hum/noise on bypass caps and signal reduction on signal path caps. Anything that old should have all electrolytics replaced or at least measured for ESR.

If phono 1 and 2 sound different, the switches and/or mic jacks need D-oxit. Phono 2 runs thru the mic jacks.

 

[Luca Signore]

Capacitance is rarely the issue with old electrolytics. ESR is what goes bad when they dry up. That causes hum on bypass caps and signal reduction on signal path caps. Anything that old should have all electrolytics replaced or at least measured for ESR.

If phono 1 and 2 sound different, the switches and/or mic jacks need D-oxit. Phono 2 runs thru the mic jacks.

Ok awesome, thank you so much. I'm learning a lot here. How would one go about measuring ESR? And I'm guessing not all capacitors are electrolytic then?

 

[satellite65]

Ok awesome, thank you so much. I'm learning a lot here. How would one go about measuring ESR? And I'm guessing not all capacitors are electrolytic then?

You need an ESR meter. ESR meters can measure ESR in circuit without disconnecting one end of the cap. Electrolytics have a + sign on one end in the schematic. There are $15 component testers on epay that can test caps, resistors, inductors, diodes and transistors. They do measure ESR on capacitors out of circuit, but in circuit they may get confused.