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Message |
    
Ca346
Advanced Member
Username: Ca346
Post Number: 737
Registered: 8-2003
| | Posted on Friday, April 30, 2004 - 3:36 pm: | 
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NOTE: I WOULD HAVE POSTED THIS IN TECH SECTION, BUT NO POSTING CURRENTLY ALLOWED?
I have been doing some research on replacement power transistors for my two amps. One is a GALAXY 350 with two 2SC2979's and the other is a COPPER KL-500 with four SD1446's. I was looking for a single replacement for the GALAXY 350. (No problem with the KL-500) But what I am finding is the suggestion that they be replaced in pairs or QUADS.
Can I replace a single transistor or should I replace both (pair) even though they both don't need replacement? |
Tech808
Moderator
Username: Tech808
Post Number: 2263
Registered: 8-2002
| | Posted on Friday, April 30, 2004 - 3:59 pm: |
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Jim,
Not sure what the problem could be.
I just posted two TEST Messages there 1 in Ask the Tech ~ Modification's and 1 in General Tech Question's, and everything is working ok.
Let us know if you continue to have problem's.
Lon
Tech808 |
Tech808
Moderator
Username: Tech808
Post Number: 2264
Registered: 8-2002
| | Posted on Friday, April 30, 2004 - 4:07 pm: |
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For you question,
I am not sure if there is a Standard rule but When I personally replace one, I alway's replace in Pairs or Quads to avoid any possible future problem's.
Maybe Tech8541 or Tech237 has had more experience and can offer you help.
Lon
Tech808 |
Ca346
Advanced Member
Username: Ca346
Post Number: 738
Registered: 8-2003
| | Posted on Friday, April 30, 2004 - 6:02 pm: |
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Well do transistors lose their power after time for any reason? I can see if there was too much input it could cause burn out, but does time just eventually wear them down also? |
Ca346
Advanced Member
Username: Ca346
Post Number: 740
Registered: 8-2003
| | Posted on Friday, April 30, 2004 - 6:09 pm: |
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Sorry Lon:
I was trying to post in the first title section under the tech section. I needed to click into the next section.
I reposted in the tech section. |
Tech8541
Moderator
Username: Tech8541
Post Number: 178
Registered: 12-2003
| | Posted on Saturday, May 01, 2004 - 12:08 am: |
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always try to replace the complete set (pair, quad, etc) as a 'matched set'. rf parts is the only place that i know of to get these 'matched sets'. matched sets help to guarantee that each trans is pulling its own share. non-matched sets can cause a serious unbalance where one trans is doing more than the other, which will lead to premature failure.
lets say that you have a 4 'pill' amp and one trans goes bad. it is best to replace all 4 with a matched set, but if you can't replace all 4, then replace the 2 'pills' that share 1 transformer. there is a combining system that will aid in balancing the output of each transformer. before this combining system there is nothing to balance the 2 transistors sharing that 1 transformer, so you need to use a 'matched pair'. |
Ca346
Advanced Member
Username: Ca346
Post Number: 741
Registered: 8-2003
| | Posted on Saturday, May 01, 2004 - 11:22 am: |
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So it sounds like if you don't replace the pair (or Quad), you probably will end up replacing them anyway. Okay. Thanks. |
