# orion 500.4 g5 repair



## 1mouse3 (Oct 31, 2012)

I have orion amps and the last one needed for my 5-way set is a g5 over another g4 500.4, its what I found for now and may get another g4 later. Im not worryed that it dose not match looks of the g4 to much, but it also dose not match the 375 ether. What Im worred about is sound quality between the two 500.4 amps, the g4 has batter parts. The main board is the same as the g4 but the g5 has cost cutting done, the caps do need replace so need to find same as the g4. Also see chip u3 is a unnamed k1a494ap over a texas tl494cn, this is the pwm chip from a search of it. There is no transistor in q26 as well that is in the g4, think this needs added along with missing resitors/diodes next to it. See a resistor that will need resoidered as well, looks discolored. These are the boards, top is the g4 and bottom is the g5. Anything else I should look at changing in this g5 amp? Yes the transformers are not as nicely wound but dont think need to worry about them. Will have to open the g4 back up to find brand caps used, the green ones are more needed but the black ones have heatshrink issues.


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## bnae38 (Oct 3, 2015)

Change the 6 lyrics that are in rough shape and clean all the switches and pots thoroughly with deoxit multiple times.

I would leave the rest of it alone.


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## 1mouse3 (Oct 31, 2012)

bnae38 said:


> Change the 6 lyrics that are in rough shape and clean all the switches and pots thoroughly with deoxit multiple times.
> 
> I would leave the rest of it alone.


K, will do and ignore the differences.


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## 1mouse3 (Oct 31, 2012)

I think best to replace all 11 of the large caps since some are close to failer and thought to get the brand used in the g4. There 7 1000uf 50v 105f ckhm and 4 2200UF 35V 105f jaro capacitor, but those brands are a thing of the past. What would be good brands to use instead for this amp?

Edit: For the cap brands on the g5, do find the United Chemi-Con that was use instead of the jaro. There 35v like the jaro over the 25v that is on the board. As for the others on the g5, there samyoung kme x1 and sms x6 at 50v 1000uf. Those samyoung caps, im am not finding.

United Chemi-Con 2200uf


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## bnae38 (Oct 3, 2015)

Panasonic, nichicon, rubycon, kemet. Buy them from mouser or Digi key, double check your lead spacing and Max heights. 105C for sure.


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## 1mouse3 (Oct 31, 2012)

I mistaken on the green cap in the g4, a search by color gave me the wrong one and the a surge brand. All the black caps where the same as well, so specs are the same betwwen the two.



























The caps are all 16mm diameter, 25mm tall and have a 7.5mm lead spacing. These are the cap I find on mouser under those parameters at 105f. Starting with the 1000uf 50v caps, these panasonic's one are what come up. Which one would of these would be the optimal one, these are 7000 vs 10000 hour life?

667-EEU-FM1H102
667-EEU-FM1H102B
667-EEU-FR1H102
667-EEU-FR1H102B


As for the 2200uf 25v cap, I come up with ones from nichicon. Which one of these would be better, these are 6000 hour life?

647-UPW1E222MHD
647-UPW1E222MHD1TN

edit: Ignore question, 667-EEU-FR1H102 and 647-UPW1E222MHD are the only ones in stock. So those are the ones I will be getting.


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## 1mouse3 (Oct 31, 2012)

I have ordered those caps but was rereading the specs, saw the nichicon has ripple current of 2555 mA. Would that be a issues and that I need to look for a different one, there is this wurth one with a 2.712a ripple current?

710-860160480034


Edit: I found a pdf of the failed 2200uf cap off the g5 amp, it is 1.170a ripple current. So the ones I ordered will not work out and will see on options

kme caps


My though on these two amps, is that the g4 has had a long life with plenty of heat to turn the anodizing purple and the caps are still good. Where as the g5 is still black as night and the caps are done, so my assumption is they might be under spec. So would I be correct in that I would want dobble the ripple current of the caps from can came in the g5?



















Edit: In searching found that surge has a current run of caps and has a 2.555a ripple current, also has low impedance like the nichicon that was found. The cost is good but see low stock, so ordered 12. Unsure if the brand is what it was when orion was using them but specs fit. 

RXW222M1EBK-1625S


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## bnae38 (Oct 3, 2015)

If the caps you ordered have a higher ripple current spec than the old ones, that's a good thing if anything. No issues there..

I wouldn't go crazy honing in on that spec though. None of them will last forever and most of them will last quite a long time.


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## 1mouse3 (Oct 31, 2012)

Yes I might be honing in on the spec of the wrong capacitor and missread data at the same time. I understand that they wont last forever but also dont want to replace them often. The caps on the g4 are at least 20 years old and maybe starting to go dry, so may be a good ideal to replace them at some point. Did some digging on the illinois caps and ones with picks, found that they are mark the 3 letter suffix plus a m on the heat shrink. So that would mean the 1000uf 50v caps on the g4 would be a ckh. These show to do fine at 2000hr ratting and may had gone a bit over kill with the panisonic caps I ordered, they might be too durable and unsure if will effect sound.

Illinois CKH cap datasheet 

So should had ordered ether of these over the panasonic. There both stated for coupling, decoupling, bypass, and filtering and the panasonic dose not say what its good for. For the spes there about the same except dont know the esr for the kemet.

Kemet ESH
Illinois CKH

Knowing the spec of one the caps on the g4, I can find the spce for the others ripple current. I would think ripple current would be the same across the board, so amps at 50v is less than 25v. 

ripple at 120hz
1.01ax50=50.04w=2.02ax25v
ripple at 100khz
1.414ax50v=70.7w=2.828ax25v


Ressson for trying to find this is because the power supply caps on the g5 look like there about to pop from over current. These kme caps are 1,170a at 120hz, this is half the ideal ratting I found above. So the reason for the caps to look like they do is now know.

united KME datasheet


Looking back at it, both these caps are enqual and listed for power supplys. There ripple current is with in margine of the output caps, so there not likely to get blown in short order like the kme.

Nichicon UPW
SURGE RXW datasheet

25V 2200µF 0.22Ω@120Hz 0.44Ω@100kHz [email protected] (8000hr UPW & 7000hr RXW)


As for the 1000uf 50v caps on the g5, two different caps where used. The single one for switching on the power supply was a samyoung kme and the filltering/bypass caps where a samyoung sms. The sms caps have a shrunken heat shrink as if over heated, there 85c caps and the possible reason. Both the samyong kme and the illinois ckh are 105c caps, these show no sigh of overheating.

Samyoung discontinued crossrefference
Samyoung MHA aka SMS datasheet
Samyoung KHA aka KME datasheet


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## bnae38 (Oct 3, 2015)

If you think the caps affect sound, then to you they will, but only to you when you listen. 

Imo they wont.. but don't really want to get into that. 

If you pick proper value and good quality caps, you'll be fine 

At any rate, yes I agree you would probably be best off to shoot them all out since you're in there. Mostly heat and heavy use that causes issues with lytics having issues in my experience, age alone is not so much a factor!


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## 1mouse3 (Oct 31, 2012)

I dont really think they will effect sound quallity, but that could introduce disstortion or cause voltage lag that would effect mossfet switching. Maybe you are right and I am overthinking it, but had a issue in the past with a replacement cap. This was in the power supply of a lcd display and it got a bad buzz/hum, it did not effect operation tho. I use it for about hafe a year before it drove me up a wall and got a replacement lcd. If you say the panasonic will be find, I will go ahead and use them since there above spec.


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## 1mouse3 (Oct 31, 2012)

Just out of curiosity, I looked into what the small caps where on the g4. What I found is there elna, purple is cew 100uf/35v and 47uf/25v. The blue I think is r2b at 10u/50, I would have to look again at it to know for sure. These look to be good brand caps, can these still be had new? Im not finding anything on the cew but the r2b found a pdf.


Elna R2B


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## kiklop32 (Oct 28, 2021)

bnae38 said:


> Panasonic, nichicon, rubycon, kemet. Buy them from mouser or Digi key, double check your lead spacing and Max heights. 105C for sure.


105C is not better


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## 1mouse3 (Oct 31, 2012)

Surge is just a shell of a company, there is no pride to put there name on the cap they sell. The nichicon look better and would rather not put a cap in this amp that screams china quality. Its was worth the gamble and now I know where they stand.


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## 1mouse3 (Oct 31, 2012)

I have been trying to dig for data to ensure me that Im putting the right cap on the output of this amp, not finding what Im looking for. The panisonic FM/FR is esr of .016 at 100khz and the original spec illinois ckh is esr of .166 at 120hz, these two specs are not in the same ballpark. What Im finding is that a coupling/bypass/filltering cap is ment for removing dc from ac and a low esr is needed to do so, other wise can add distortion to the output of the amp. This amp has been speced for those cap to have a esr of .166 at 120hz and the replacement needs to be enqual to or less than that. The datasheet for panisonic caps dont provide that data and its esr rating is past the opperating range of the amp. So how am I to know what the esr of the paniconic caps are when I dont have a means to measure it? I feel it would be best to go with the original spec illinois ckh caps and know I chose right.


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## 1mouse3 (Oct 31, 2012)

They only way to know is to try, so the caps are now changed. Those snap clips put up a fight to get off and need to figer out how to get them back on, need thermal goop/paste first.


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## 1mouse3 (Oct 31, 2012)

I looked at the g4 again and found those purple caps are shoei cw 1uf 50v, 100uf 35v and 47uf 25v. These have a specific purpose like all others on this board, there is some massive r&d done on this board. To even get the g5 close to the same sound quality of the g4, I would need a meter to check voltage loss tangent and esr of caps. What Im finding on these 3 shoei caps is that there good at removing a hum from a power supply. I suppect when they went to the bottom of the barrel for caps it caused a hum and to fix it they removed the q26 transister. So I suppect the g5 is crippled in sound quality and I dont have means to bring it to the state of the g4 currently. As for the elna 10uf 50v caps littering the board, I see a possible substitute but has a trade off. A nichicon fine gold is enqual size and has the same fast bass reponse but could cuts some upper treble. The elna silmic II and nichicon muze are close and dont have a issue with treble, issue with them is there a size bigger. So is probably best to consider this g5 a backup amp and hunt for another g4.


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## 1mouse3 (Oct 31, 2012)

Shoei was bought out by Taiyo Yuden and they developed li-ion caps. So those shoei caps are probably not your run of mill electrolytic capacitor, so a subsitue would be impossible with out knowing what they are made of.

Lithium Ion Capacitors


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## 1mouse3 (Oct 31, 2012)

I cant help but fall further in a rabit hole, this missing transister was bugging me. So on to drolling over the board and trying to come up with a scimatic of the power supply on the amp. In turn I have a bunch of scribble on a papper that is supposed to pass as one. What I have found is that transister is part the circuit for the power led, so I suspect its partially neutered. Reason I could see is to pervent a ground loop or floor noise, between input and output ground. So I suppect they broke it cheaping out and just cut out what made the noise.


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