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  #1  
Old 10th December 2016, 04:06 PM
Lyndon Johnson Lyndon Johnson is offline
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Default Output transformer for K5881 *SORTED*

I built my K5881 mk1 amp shortly after it first appeared in Hi Fi World (1994?) and it has given faithful service since then, sounding better with every upgrade. However, the left channel has now gone low volume and poor quality. Voltages are 50% down at most check points and zero volts at one of the OPT HT terminals. Exchanging the left and right OPT's moves the problem to the right channel so I am certain the fault lies with the left channel output transformer.
My question is - how can I obtain a new one?
Failing that, is it feasible to get the faulty one repaired and can anyone recommend a suitable repairer?
Thanks
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  #2  
Old 10th December 2016, 04:29 PM
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Greg. Greg. is offline
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Default Re: Output transformer for K5881

Transformers for the WAD K5881 were made by SP Wound.

http://www.woundcomponents.co.uk

They still supply transformers for the original WAD 300B PP and there is every possibility they can wind you a replacement Tx for your amp. I have found them very helpful in the past so give them a call.
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  #3  
Old 10th December 2016, 05:16 PM
Lyndon Johnson Lyndon Johnson is offline
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Default Re: Output transformer for K5881

Greg
Thanks a lot. I will contact them and let you know how I get on.
Lyndon
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  #4  
Old 10th December 2016, 07:07 PM
Richard Richard is offline
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Default Re: Output transformer for K5881

Hi Lyndon, yes as Greg says.
If you have no joy though you could use one (or more ideally a pair) of easily obtained OPTXs designed for Mullard 5-20 amps.
Yours are specified as 6K primary 8R secondary. 5-20 spec was almost always 6k6 8R. They usually come with taps on the primary so you'd just leave them disconnected.
If you go this route measure the physical size of your TX core stack and mounting holes. This will make replacement easier and give you a good guide to buying a similar quality replacement from a decent supplier like Sowter, Danbury, Lundall, Hammond, etc
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  #5  
Old 10th December 2016, 09:46 PM
davebms davebms is offline
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Default Re: Output transformer for K5881

hello all DANBERY,, are closing down, what's left are in the
for sale section on audio talk. I don't think there are any
for your amp but worth a look ?

dave
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  #6  
Old 13th December 2016, 07:57 AM
Lyndon Johnson Lyndon Johnson is offline
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Default Re: Output transformer for K5881

Greg/all
Just to confirm that SP Wound are fixing me up with a replacement for 135 delivered. Like you say, an excellent service.
Thanks for your help
Lyndon.
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  #7  
Old 13th December 2016, 12:40 PM
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Greg. Greg. is offline
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Default Re: Output transformer for K5881

Excellent news although I note what the price of copper now has done to the overall cost.
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  #8  
Old 13th December 2016, 02:45 PM
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pre65 pre65 is offline
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Default Re: Output transformer for K5881

Personally, I might have gone for a matched pair, and kept the good one as a spare.

Often two can be cheaper than two singles.
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Everything in this post is my honest opinion based on what i thought I knew at that very moment in time.
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  #9  
Old 1st February 2017, 09:24 PM
Lyndon Johnson Lyndon Johnson is offline
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Default Re: Output transformer for K5881 *SORTED*

I took your advice and got a pair- they just arrived today! So hopefully soon I will have both channels.
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  #10  
Old 3rd February 2017, 12:17 AM
John Caswell John Caswell is offline
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Default Re: Output transformer for K5881 *SORTED*

"Help with repair post" moved to WAD problems

John
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