Distorted Bass Zenith Y960

[FairhopeJon]

Just purchased a Zenith Y960 in good working condition. This is my second solid state console I’ve recently purchased. My first was a 1965 Voice of Music with record, am/fm and R2R. I love the Zenith purely because of the mid century modern styling and analog display, however, the VOM sounds much better. Nice clean lows and pretty decent mids and highs. My goal is to keep the Zenith and either use the parts from the VOM or simply sell it as I don’t have room for both.

The Zenith console has two 15” woofers and two horn speakers. I can adjust the balance and get pretty nice highs but there is a muffled, distorted bass sound that I can’t get rid of. I used DeoxIT on all of the connections, as most of them had a yellowish oxidation. Not sure what to do next. After a bit of research, I’m thinking it might have bad capacitors (although I’m not even certain what those are). If so, does it make any sense to try and swap the solid state amps or just replace the capacitors?

Or am I way off? I know very little about this, so patience is appreciated.

I’ve attached some pictures of the Zenith. Can also upload pics of the VOM if that helps.

Thanks in Advance!

John B

 

[century tek]

FYI, the speakers in that thing are 12 inch.

Both channels would be a power supply issue but I dare say anymore since you say you know little about electronics.

Since that has a separate amp and tuner, trouble could be in either or both.

 

[FairhopeJon]

@century tek, thanks for the response. Learned something new already, I thought they were 15’s . Is there a way to test whether it’s the amp or the tuner? Maybe using external speakers?

 

[century tek]

You have to be able to know which wires coming from the tuner are the outputs. These will be the inputs to the amplifier.

If you have a phone with any music on it, you can plug it straight into the amp and listen to see if you still hear the bass discrepancy.

If you own another amplifier, you can plug the tuner into it and listen to see if you still hear the bass discrepancy.

Without test equipment, this is just a kinda quick and dirty way to rule out either amp or tuner.

 

[KentTeffeteller]

@century tek, thanks for the response. Learned something new already, I thought they were 15’s . Is there a way to test whether it’s the amp or the tuner? Maybe using external speakers?

You know this has less than 10 watts/channel in terms of amplifier power. It needs super efficient speakers. You also know it needs a full servicing, those old electrolytic capacitors need replacing, in both chassis. It needs to go to a service technician who knows what he or she is doing. And they're not cheap.

 

[Skywatcher]

You know this has less than 10 watts/channel in terms of amplifier power. It needs super efficient speakers. You also know it needs a full servicing, those old electrolytic capacitors need replacing, in both chassis. It needs to go to a service technician who knows what he or she is doing. And they're not cheap.

This I agree with 110%. I just had an old Zenith console in here, and fresh electrolytics brought it back to it's former glory. And for "only" about 10 watts, she still reaches out and tickles your eardrums. The tuners have excellent selectivity too and sound so warm and wonderful. Zenith built these to last. The main "cans" for the power supply filtering absolutely affects the lower frequencies.

 

[FairhopeJon]

You know this has less than 10 watts/channel in terms of amplifier power. It needs super efficient speakers. You also know it needs a full servicing, those old electrolytic capacitors need replacing, in both chassis. It needs to go to a service technician who knows what he or she is doing. And they're not cheap.

I’ve got a local guy that works on these older consoles and can get it running right again. He can’t get to it until early December though and I was hoping to have it ready for Thanksgiving. Thanks for the response!

 

[FairhopeJon]

This I agree with 110%. I just had an old Zenith console in here, and fresh electrolytics brought it back to it's former glory. And for "only" about 10 watts, she still reaches out and tickles your eardrums. The tuners have excellent selectivity too and sound so warm and wonderful. Zenith built these to last. The main "cans" for the power supply filtering absolutely affects the lower frequencies.[/QUOT

You have to be able to know which wires coming from the tuner are the outputs. These will be the inputs to the amplifier.

If you have a phone with any music on it, you can plug it straight into the amp and listen to see if you still hear the bass discrepancy.

If you own another amplifier, you can plug the tuner into it and listen to see if you still hear the bass discrepancy.

Without test equipment, this is just a kinda quick and dirty way to rule out either amp or tuner.

That makes sense. Going to try and troubleshoot it this way. Thank you for the help!

 

[Skywatcher]

I’ve got a local guy that works on these older consoles and can get it running right again. He can’t get to it until early December though and I was hoping to have it ready for Thanksgiving. Thanks for the response!

Where are you located? There might be someone from AK here who is close by, and willing to help out. We're mostly hobbyists and don't care much for demanding "arms and legs" for our help.

 

[FairhopeJon]

Where are you located? There might be someone from AK here who is close by, and willing to help out. We're mostly hobbyists and don't care much for demanding "arms and legs" for our help.

I live in Fairhope, AL. You?

 

[Skywatcher]

I live in Fairhope, AL. You?

Pa. It would be a looooooonnnng road trip.

 

[chazglenn3]

I own a Zenith YT960. The difference is that mine has a built in reel to reel tape deck. I can assure you that it has 15" woofers. It also has two 3.5" midrange speakers mounted in front of each woofer in addition to the two horns. I also don't know where the 10 watts per channel number is coming from. There is certainly more power than that being generated. It's not the 320 watts from the marketing literature but it's more than 10 watts. I'm sure once you have it serviced you will be blown away by its performance. Mine certainly rocks! It has to be at least 30 watts RMS. Just to double check, did you Dexoit the speaker switches at the rear of the turntable compartment?

 

[century tek]

I also had that console. Still have the guts and speakers. They are 12 inch unless you can show me otherwise.

I can show you mine if need be. Not sure Zenith ever used a 15inch.

EDIT: Mine is a different tuner preamp but the amp is the same. This is what mine came out of.

 

[chazglenn3]

Maybe you had the earlier version of the Y960. They made what I think was the MM2690 in 1964 and 1965 that was in the same cabinet mostly, but had a tube tuner and solid state amplifier. They did have 12" woofers. The X960 in 1967, Y960 in 1968 and Z960 in 1969 all had solid state tuners and amplifiers along with 15" woofers. I'll try to get a photo next week. I'm out of town.

 

[orthophonic]

The Sibelius was earlier and did have 12" woofers, from 1966 on, the 960 series had 15" woofers in sealed
enclosures. The power output is 27 watts per channel rms, I had McIntosh labs check one some years ago.

The bass on these is very clean and tight, but if in a very small square room, it can become boomy.

I suspect the amplifier power supply electrolytic need replacing.

I noticed you have all the tone controls maxed and the extended bass control engaged, it will never sound
good like that.

 

[century tek]

That is just too cool! Learn something new everyday!

I have seen hundreds of Zenith consoles in my time but just never any with the 15's.

 

[Skywatcher]

I also had that console. Still have the guts and speakers. They are 12 inch unless you can show me otherwise.

I can show you mine if need be. Not sure Zenith ever used a 15inch.

EDIT: Mine is a different tuner preamp but the amp is the same. This is what mine came out of.
View attachment 2027462

This was the same console my Brother and I just got done with. Yes, 12" woofers, horn, and a tweeter. Adding a little damping material in the speaker cavities helped smooth out the lower frequencies.

 

[regore]

If the bass is distorted or muffled there is something wrong.
I'd pull both woofers first and check for cone rub or debris.
The speaker mounting nuts also may have become loose due to wood shrinkage.
If that doesn't help get out the test equipment.

 

[orthophonic]

Again, the 12" woofers were in an earlier version, the 960 series starting in 1966 has 15" woofers in a sealed
enclosure. The Y960 is a 1968 model.

 

[chazglenn3]

And sounds every bit as good as my Magnavox Concert Grand.