Sound dropouts on h...
 

Sound dropouts on hifi amp - how to get it fixed?

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I've got a Teac A-H300Mk2 I bought on eBay sometime pre-covid.  They stopped making them in 2008 so it can't be more than about 17 years old.   I don't think I've treated it well - it runs hot, and it was on a shelf that probably meant it didn't have enough ventilation (only about 15mm above it to the next shelf).  I've moved it to a different shelf so it's got more space to breathe, and taken the top off and blown out all the built up dust. 

However, it periodically cuts out momentarily.  It's irregular and not at even intervals but has been getting more frequent. When I had the top off the capacitors didn't look swollen or leaking or any other obvious faults.  

Any thoughts from anyone on what the problem could be or how (or if) it's worth getting fixed?   I don't like throwing stuff away but given you can buy these on eBay for around £100 I'm wondering if just buying another might be easier.   


 
Posted : 11/12/2025 11:02 am
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Posted by: b33k34

I don't like throwing stuff away but given you can buy these on eBay for around £100 I'm wondering if just buying another might be easier.

I'd do that - then list yours as spares or repair.

If it were some mega valuable vintage amp that would be a different matter.


 
Posted : 11/12/2025 11:07 am
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A quick online search suggests that the common cause of this fault is a dodgy output protection relay. 
Not sure how much it would cost to fix, as the relay used is out of production according to Mouser Electronics.

edit

but still available at Fixpart:

IMG_7980.jpeg

 


 
Posted : 11/12/2025 12:31 pm
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Posted by: temudgin

A quick online search suggests that the common cause of this fault is a dodgy output protection relay. 
Not sure how much it would cost to fix, as the relay used is out of production according to Mouser Electronics.

edit

but still available at Fixpart:

Thanks - can you point me at the source of that info before I go ordering parts?  I'd have thought if it was a (physical) relay I'd have heard it clicking in and out.  There is a relay activates when you power up the amp that you can hear clicking, and I'm not hearing that sound when it's cutting out in use. 

 

 


 
Posted : 11/12/2025 4:41 pm
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ha.  I think I might have found the issue - I've got a the amp running to terminals on a wall plate.  And a high level subwoofer connected to those wall terminals as well - one of the sub channel cables was floating around - I wonder if that's been shorting the amp and causing the protection circuit to cut in.  

 


 
Posted : 11/12/2025 4:59 pm
temudgin reacted
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Great that you found the solution and it didn’t cost a penny!

 


 
Posted : 11/12/2025 9:43 pm
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Does seem ok so far - wouldn't have found it without this thread.  Searching for reference to that output relay found a thread where someone mentioned stray strands on speaker cables, which is effectively what I've got.  


 
Posted : 12/12/2025 10:11 am
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that didn't fix it.  I"ve bought another one and going to list this for spares/repair


 
Posted : 31/12/2025 7:06 pm