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Just a couple watts ya reckon

avionic said:
Minor setback :scratch2: Seems channel B has developed a slight very low level hiss..Isolated problem to the output module..Noisy transistor :scratch2: this is going to be fun. NOT.. Its one or more of these..
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ouch! well, hopefully it's not because those new outputs were fakes. i know it's unlikely since the amp already stood up to a couple clipping tests, but i always worried a little about that. are those 2SC2238B's available?
 
Not the output assembly...:no:Before I started swapping out transistors.I reverefied the situation with the "quiet" channel "A" assembly - still noisy..I'm thinking main filter caps for channel " B " possibly.Which presents another problem - I need 2 X 39,000uf@63v and 4 X 18,000uf@100v - screw term.- no larger than 50mm X 130mm. All I've been able to come up with are " snap-ins ". Anyone have any idea's..I mean I can make snap-ins work, but....look kinda tacky:yes:
 
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John
The UCC 36DA183F100CC2A is a little to large case style CC is 2.5" dia.
Manufacturer: United Chemi-Con (UCC)

Product Category: Aluminum Electrolytic Capacitors - Screw Terminal

RoHS: Details

Capacitance: 18000 uF

Tolerance: - 10 % to 50 %

Voltage Rating: 100 Volts

Operating Temperature Range: - 40 C to + 95 C

Series: 36DA

Diameter: 63.5 mm (2.5 in)

Length: 105 mm (4.125 in)

Lead Spacing: 28.6 mm (1.125 in)

Product: Aluminum Electrolytic Capacitors
 
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Yes there is a fat one but this one

U36D100LG183M51x117HP - is ok

Must be the wee small hours over there - best sleep on it ?
 
sheeattt... is it possible to try swapping filter caps and see if the problem follows, dave? if this really is it, it's too bad we didn't know before the UCC discount site shut down...
 
Yes I will verify..Thats a lot of money for caps.:yes:
 

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I could use new PS caps for my PC5002M. I'd go in on an order if it helps get a better price.
 
there is also the Vishay 101/102 PHR-ST series. we'd have to downgrade to 15000uF and 33000uF, but i doubt that would be noticeable. i don't know the price, but they are at least available from Marsh Electronics.
 
Mark B said:
I could use new PS caps for my PC5002M. I'd go in on an order if it helps get a better price.
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I´ll let you know what kind of a real PITA it is to R&R these puppys.Almost have to split the amp in half.:yes:
 
This might be Key...A little copper corrosion around one of the 39,000uf caps on the "noisy" amps power supply.The only discoloration on any of the copper buss bars...for either channel.From the bottom side it doesn't look like it vented though.
 

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i just ordered the replacement caps from Newark.com. had to downsize ~16% in total capacitance. not ideal, but really all we could do here. considering how overbuilt the amp was in the first place (~100,000-uF/channel), it's unlikely this will be noticeable in my particular setup. because of the size constraints, it was basically impossible to find the spec'd capacitance available in small enough quantities. i went with 18K7986 and 95F4477 and it cost $300 all told.

this better be all you need, Mr. PC5002M!
 
Finally.They arrived after a 9 week back order..My DL now has the capacity to handle 1200 watt @ 4 ohm.
Configured in the photo for 2-channel @ 8 ohm @ 600 watt.

Also recieved a big box full of Chemicon's
 

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