USSA-5 Build with Review

fab

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Please?
It would be some kind of urgent if someone could answer my question, is there is any sonic advantage to use the United Chemicon 4700uF 35V (EGVD350ELL472MMP1H) for C5, C6 VS another type?
I need to order other items also like Nichicon FG 220uF for the other project etc. While I was waiting all last week to ask this question, Mouser sold out the mention capacitors found out today morning.
Now I went over to Di-Gi Key they have some limited quantity on the stock, I afraid if I wait a week or so they will run out from stock also, after other option min order 500PC.
So I feel like sitting on needles until I get answered so I can place mine order.
Wery likely Fab can answer this question or someone who made an A/B comparison of other types of capacitors at the mentioned place.
Thank you!
Hi Gaborbela
I believe some builders used different caps for that position (psu filtering on the pcb). I sure have nothing to say against putting an even better or equivalent cap but I can not recommend something less efficient....The effect on the sound of one suboptimal part on the overall circuit is difficult to predict. the sound impact also depends on many other factors such as the rest of your sound system to be able to notice something.... Check for ESR and capacitance value of the alternate cap if it is in the same range as the one in the BOM.

Fab
 
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Hi Gaborbela,
I tried to find the capacitors you were thinking of using without luck. Mind you, I only looked for maybe 10 minutes (I hate Digikey's new part selector). So I can only speak in general terms.

If the capacitors you are thinking of are not polymer types like the ones fab has specified, they will not behave the same way. Also, running with half the capacitance isn't going to help you either. I would say from experience that there will probably be a performance difference between the two parts and that you should probably use the ones that were specified.

If it weren't for the low stock situation I would say, try the ones you have, then compare with the proper capacitors later on when you could afford them. I would have to recommend the ones that fab has specified.

-Chris
 
The cap is in stock at both Mouser and Digikey.

Chris, you can just cut and paste the part number (EGVD350ELL472MMP1H) into the search bar of either website and it will come up for you.

EDIT: I just checked and that is not the same part number as specified in the BOM EGPD350ELL472MK30H

EDIT 2: Gaborbela just search Mouser or Digikey for EGPD350ELL472MM30H, there are plenty in stock at both.
 
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The Nichicon FG is for audio also, I purchased those from Korea.
I am not a big fan of the UCC on NCC capacitors (the cheapper type, this looks like something special) but when that is recommended by Fab it is a reason. They are very pricey to me at my circumstances. When I will finish the amp and may have some dissatisfactory I will end up needing to dismantle the amp to replace those caps due to the type of PCB design. I think better to follow fab's instruction.
 
I can't recommmend the FG-types... Well they are in golden color. That's all. The technical specifications are settled in the midfield - rather high ESR and higher failure rate compared to some other (Pana FR/FC, UCC G** and also Nichicon UKA) eg. There's a difference between those and the ones recommended by fab. The golden toys are just botiqueparts...
 
OK guys, thank you! I will order the type was recommended with the same order at least I save on the shipping if I order it now and not later. I have to order some other parts now.
Soundwise the FG some places they are very good, actually to me better they are than the Panasonic FC. I did use those previously. That is why I purchased for this project also but.....
 

fab

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OK guys, thank you! I will order the type was recommended with the same order at least I save on the shipping if I order it now and not later. I have to order some other parts now.
Soundwise the FG some places they are very good, actually to me better they are than the Panasonic FC. I did use those previously. That is why I purchased for this project also but.....
Hi Gaborbela
Yes FG caps can probably be good in line level circuits but not for high amount of current such as filtering of output stage of power amplifier.
Fab
 

fab

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Important note for builders

It has been mentioned somewhere (either this thread or others) that pcb v0.4 has a different identification for PGND and GND from earlier pcb versions. The USSA-5 manual was based on earlier versions.
The following section 8.14
“Connect V+ and V- and PGND (the one close to V-) to power supply (from 15Vdc to 30Vdc).” Should read “...GND or PGND (the one close to V-)” otherwise return is floating instead of a good reference to ground. The simple way is to connect both Gnd ( PGND and GND) if you are not sure.

Fab
 
I'm selling a USSA 5 kit from a friend that is getting out of the hobby. It is a kit from the first GB that was done on the French forum quebecdiyaudio.

It has all parts plus the PCB (first PCBs were red, the same ones I'm using in my build). All Mosfets are also in the package.

Only shipping to north America. Shipping to Europe, the proforma invoice needs to have all individual parts written down and I don't have the patience.

Price is USD$195 + shipping

Thanks
Do
 

fab

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Hi Fab,

I am out of 47R resistors for the initial RV2B but do have 51R here. Is this going to cause any problem down the track when doing the measurements for the final RV1b, RV2b resistors?

Cheers,

Anthony
Hi Anthony
No problem at all to use 51R since RV2B will be in parallel with RV2A after final resistance determination for equalization of current in driver stage. Just remember to do the maths using 51 instead of 47 ohms for the resistor calculation.
Good luck
Fab