Newbie needs help

[Never nough]

Thanks for any info anyone may be able to share. I purchased an old Sansui 9090db receiver in pristine condition, Last week I purchased a very mint set of Klipsch KG 4's . This afternoon, while listening to Quadraphenia , the sound became dull sounding, I dont know if its the reciver or the speakers, there still seems to be alot of bass, no midrange, and garbled high end. Where do I start to hunt down the problem??? Yes the windows were rattling. I love these old Klipsch speakers, cant wait to get into a set of La Scalas...........

[Brac]

Start be trying 1 speaker at a time, if it's both speakers look to the Sansui for the issue.

[mustang guy]

What was the source of the music (CD, FM, PHONO)? I'm with Brac. Sounds like it's the supply, not the speakers. I am saying that because it would likely not occur in both at once, but instead a tweeter blown in one, etc.

In any event, check all your connections, and let us know what the source of the music was.

[djk]

The tone control turn-over switches and other controls get intermittent and sound horrible.

[HDBRbuilder]

Thanks for any info anyone may be able to share. I purchased an old Sansui 9090db receiver in pristine condition, Last week I purchased a very mint set of Klipsch KG 4's . This afternoon, while listening to Quadraphenia , the sound became dull sounding, I dont know if its the reciver or the speakers, there still seems to be alot of bass, no midrange, and garbled high end. Where do I start to hunt down the problem??? Yes the windows were rattling. I love these old Klipsch speakers, cant wait to get into a set of La Scalas...........

Does that mean the receiver had been completely gone through? Or does that mean it looked great and worked well when you first got it?

I would put a 95% probability that the problem is the receiver! Those Sansui jobs had tons of "bells and whistles" features, and sold like hotcakes when new. But they also had more than their fair share of issues due to the complexity of the units. As my father used to say, "the more things it has on it, the more things can go wrong...the simpler it is, the easier it is to troubleshoot and repair." The most likely culprit is that brand's lack of "UI"...as in SANS...UI! LOL!

I would bet that the issue is in the preamp section, but you may be able to easily confirm this since that receiver has a pre-out/main-in feature on its back.

If you have an amp (or integrated amp with a Pre-amp-in), you can hook it up using the receiver as the tuner/pre-amp, and tell if the pre-amp of the Sansui is the problem. Conversely, you can hook a separate pre-amp to the Sansui Main-in and tell if the Sansui amp section is the issue.

My preference would be to first turn off and unplug the Sansui, pull the connector yokes for main-in, clean out those RCA inputs, and the yokes and put together again, then give it another try...if that is not the issue, then visually check the amp on the back for chalky stuff around that area. Don;t forget about FUSES...and fuse holders. Ensure that all fuses are the correct ones and are clean and serviceable as are the fuse holders Also, you really need to do a pot cleaning with contact cleaner or gun scrubber for all rotary controls, especially the volume, tone and balance controls. Then use an electrical contact cleaner to clean your push-button and rotary switches, especially your speaker A/B, your loudness/defeat/hi-cut/lo-cut/etc...anything affecting the signal from the preamp to the amp.

Or you can take it in to a pro for a good cleaning and tune-up.

I am a big fan of GOOD old solid state stuff (some of the old H/K receiver models in particular), but I was also around when that stuff was new at the time and saw lots of it being taken back for different issues. I always took notice of how it had been treated by the owner/user when forming my opinions. All Sansui, Kenwood and Pioneer stuff was not made equally dependable...and some of it was crap to begin with...the same can be said for Marantz stuff after Saul was forced out of his own company. Add to that probem the variation even within a model year of the quality control at any one time, for any particular model from any particular brand, and you have major problems waiting to happen.

When the amp "wattage wars" began to take off prior to 1975, there were so many brands and models out it was difficult to tell which were good and which weren't, and to top that off, it seemed they were just throwing some kind of button or knob anyplace they could find room for an additional one on the fronts of the receivers. Bye and large, many of these "bells and whistles" had no practical use whatsoever, except to "look cool" in the display rooms. But, many of the bells and whistles also had the ability to ruin a signal on its way to the amp if they were or became defective or dirty.

So...troubleshoot it the best you can, and if that doesn't find your problem, start to get it all cleaned up...either do it yourself or get it done by a COMPETENT professional. Eventually the problem will rear its ugly head...and you will probably kick yourself for not realizing what it was to begin with!

Welcome to the world of VINTAGE audio!

-Andy

[Never nough]

Thanks Everybody for imput, appreciate it. I had no idea how involved this hobby could truly be. Back to basics, hooked Godzilla to an old pair of advent speakers I had in the basement, the 9090 is fine,. It, I damaged the KG4s, the sound is lacking oomph, a bit muddy. Both of the KG4s sound the same. Do crossover boards fry ???? How do I locate the problem ( blown tweeter, blown board?? ). Again thanks to everybody for help. I think I need bigger Klipsch speakers.

[HDBRbuilder]

bigger speakers will blow just as easily as smaller ones do. The "bigger" ones are only rated at 105 watts continuous power input. The KG4 model was rated at 100 watts continuous....

You don't need a 150 watt amp section to power them, and I would bet that the receiver treble controls were jacked up well above flat when the KG4s blew...weren't they? Throwing high wattage into tweeters destroys them, especially if you have jacked up the top end signal being amplified. All it takes is a few overly-distorted high end power peaks and ZAP!!!!! Dead tweeters! Most people can hear the distortion caused by the amp clipping prior to the tweeters blowing and turn the volume back to where the clipping isn't heard...then drop it a bit more, remembering where that spot is on the vloume control, and not exceeding it under any circumstances. Doing this will save speakers AND the ampliffier section from destruction....both at the time and in the future.

I would suggest following this advice to save destructon of speakers, big or small, in the future.

-Andy

[derrickdj1]

I would bet that the receiver treble controls were jacked up well above flat when the KG4s blew...

An excellent reminder HDBRbuilder for all of us, that modifing settings from the flat position changes the power distribution to the drivers.