Sho~Bud Christmas Tree Amp
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- Larry Moore
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Sho~Bud Christmas Tree Amp
I have a old Christmas Tree Amp that has a M-31 JBL 8 ohm speaker in it.
How can I find out if it would hurt if replaced it with a D-130 JBL 4 ohm speaker
Larry
How can I find out if it would hurt if replaced it with a D-130 JBL 4 ohm speaker
Larry
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I don't know if the Xmas tree amp would like a 4 ohm speaker, usually solid state amps have a safe minimum load. Sometimes that's 8 ohms. If the factory put in 8 ohm speakers, it's likely that is the minimum speaker impedance the amp can safely tolerate without overheating and damaging the output transistors. That's my guess anyway..Jerry
- Rex Wiseman
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- Roger Dillingham
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Sho-Bud Christmas Tree Amp
I agree with Jerry! For what it's worth, I had always held the view that the tube amps were generally more forgiving to an impedance mismatch due to the massive power output transformers that are present; whereas, the solid state amps don't have that same luxury of large transformers in the output stage. An impedance mismatch of lower impedance than what the transistors were designed to safely run at could result in them frying themselves if pushed too hard! A higher impedance value than what the amp was originally designed to see would probably not damage the amp at all, but would just limit the available wattage output; i.e. 200 watt rating @ 4 ohms would probably drop to arount 120 watts or so into a 8 ohm load. I'm certainly not an amp technician, but before I would do this of going into a lower impedance speaker under the assumption that everything would be OK, I would check with an amp guru like Ken Fox or someone of his caliber. Hope this helps! Good luck, Roger.
- Bill A. Moore
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Schematic
Does anyone have a schematic for this amp? If I had a schematic I could answer Larry's question. If this amp uses the old germaniun output transistors, I would almost bet it was designed for 8 ohm speakers. Back when this amp was built 4 ohm speakers were not very common.
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- Larry Moore
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