What's the problem do I have blown Output Transistors

[TapeMaster]

Hi it's been awhile since I had my Kenwood KR-4070 hooked up. Last time I used it I ran it with an old pair of Scott SP-4000 Speakers 150 watt 12" Woofers The crossovers and Voicecoils were working fine. None of the connections were loose. But when cranked at high volume the right channels cuts out. If there is NOT a problem with it I'm going to give it to my neighbor that is why I need your guy's help on identifying the problem. I don't have the speakers any more. My dad checked all the fuses they are good.

 

[TLS Guy]

Hi it's been awhile since I had my Kenwood KR-4070 hooked up. Last time I used it I ran it with an old pair of Scott SP-4000 Speakers 150 watt 12" Woofers The crossovers and Voicecoils were working fine. None of the connections were loose. But when cranked at high volume the right channels cuts out. If there is NOT a problem with it I'm going to give it to my neighbor that is why I need your guy's help on identifying the problem. I don't have the speakers any more. My dad checked all the fuses they are good.

You were probably over driving the amp. If there were blown transistors you would have no sound on that channel.

 

[TapeMaster]

Is it okay or no? I thought it may be been over driven at one time kicked the protection circuit breaker on my speakers. What is an IC Amp Chip?

 

[TLS Guy]

Is it okay or no? I thought it may be been over driven at one time kicked the protection circuit breaker on my speakers. What is an IC Amp Chip?

An IC amp chip set is an integrated circuit power amplifier. The resistors, caps, and diodes are all etched into one device. They are totally miserable. They are in low end gear only.

If your Kenwood has it, that is probably why it shuts down. Thermal protection cuts in very easily and they blow as soon as you turn your back on them I suspect the specs of your unit are way optimistic.

I think you can use your units, but if it is an IC power stage, then you use it very gently and don't push it.

 

[jeannot]

Hi it's been awhile since I had my Kenwood KR-4070 hooked up. Last time I used it I ran it with an old pair of Scott SP-4000 Speakers 150 watt 12" Woofers The crossovers and Voicecoils were working fine. None of the connections were loose. But when cranked at high volume the right channels cuts out. If there is NOT a problem with it I'm going to give it to my neighbor that is why I need your guy's help on identifying the problem. I don't have the speakers any more. My dad checked all the fuses they are good.

If I remember well, the 4070 had a DC amplifier. Not sure. If there is DC at the input, the protection may only kick in after so much volume. Have you checked if your woofers move more forward as you raise the volume?

 

[TapeMaster]

The 4070 does NOT have Thermal Protection or any circuit breaker just two main Power Supply Fuses both are in good condition.

 

[TLS Guy]

The 4070 does NOT have Thermal Protection or any circuit breaker just two main Power Supply Fuses both are in good condition.

Well, it must have some protection or would just blow and not shut down.

 

[TapeMaster]

That is what it does IT BLOWS AND DOESN'T SHUTDOWN.

 

[TLS Guy]

That is what it does IT BLOWS AND DOESN'T SHUTDOWN.

If it is fuses that blow, that unit is now a boat anchor.