I am rebuilding a Marantz 2270 and I am currently working on the amplifier driver boards. There is an input coupling cap (C751) which is a 1 uF polyester film I believe.
I am wanting to put something on the nicer side in that position. I have some fairly nice polycarbonate caps and have read that they are highly regarded. Any negatives to going to this 2 uF cap? I also have some nice 1.7 uF polypropylene. I also have some nicer ones that are a little bit bigger, like 3.3. Though I’m leaning towards the polycarbonate. How big would you potentially go in this position?
Dan
I am wanting to put something on the nicer side in that position. I have some fairly nice polycarbonate caps and have read that they are highly regarded. Any negatives to going to this 2 uF cap? I also have some nice 1.7 uF polypropylene. I also have some nicer ones that are a little bit bigger, like 3.3. Though I’m leaning towards the polycarbonate. How big would you potentially go in this position?
Dan
I would try to keep the cap physically small. Large body film caps can be a bad idea. If you have good 1uf cap in a small body format that might be the thing to try first. Otherwise, at some point if you want more capacitance and you want to keep it physically small, sometimes an electrolytic maybe bypassed with a .01uf Wima MKP2 can end up sounding better. Depends on the electrolytic you choose. It can also take some time for the sound of an electrolytic to fully settle out. Maybe a week or 2 or3 of continuous power-on time. Depends on the cap an how picky you are about the sound.
When you make it very large, the offset voltage at the output will settle slowly after power-up, but that should not be an issue yet when you don't go above 5 uF or so
No need for over 1uF there. Just use the best quality cap you have near that value.
But it should fit the board properly.
But it should fit the board properly.
Hilarious. Plenty of suitable and available electrolytics for this spot and in this amp. Caps that would fit perfectly and sound decent without looking ludicrous and creating all sorts of problems. Wanna go crazy, get BG-N 4.7/50
So you’re thinking that electrolytic would be better here? As for bipolar I think my only real options would be Nichicon UES, I could go 1, 2.2, 3.3, or 4.7. By reading im guessing no need for going larger. Ehh, not going to go with the Black Gate lol.
So looking at my stash, here is what I have. Nothing too much larger than the original film.
The top cap is the original. Right under it is what I was asking about, a 2 uF TRW polycarbonate. Under that is a 1 uF ASC TEK 122 (can’t find info, but thinking it’s polypropylene). Under that the tiny one is a 1 uF 50v Electrocube polycarbonate, I’ve read these are very nice. And then under that are the UES of course.
I have these others, but they are getting larger and the Wima have shorter legs so in order to get them to fit I’d have to solder leads to extend them.
Top is the original, under that is a 1 uF Wima MKP 4, under it is a 2.2 uF Wima MKC 4 (polycarbonate), under it is a 1.8 uF MKP 10, and lastly a 1.82 uF electrocube. If people like the idea of these films more I have tons of each of them so I’m good using them, but I think one of the axials would be a better fit.
Thank you.
Dan
I'd try the Electrocube first, and if no joy, the UES. But with each, run the circuit for a few hours of casual listening before deciding.
I'd use either a low leakage electrolytic, or a Kemet 1uF 63V film cap. Small footprint.
Do you mean a polarized? I have Nichicon UKL. Any reason for the Kemet? Just because it’s smaller? I have much smaller Wima polypropylene, just curious why specifically the Kemet.
Alrighty, have them fitted. I’d imagine they’ll work fine considering that I’m going from 1 uF film to 1 uF film.
Dan
What makes you think these are polyprops? I find it very unlikely but at least it is something easy to test.
Because when I ordered them from Mouser I made sure that they were. The bigger one is 100%, I confirmed with the part number, it’s possible the smaller of the two it PET, but I’m pretty confident that it is polypropylene.
Dan
Personally a fan of Cornel Dubellier (pardon the spelling) but also Elna has some audio electrolytic silk caps that Nelson Pass was a fan of. Cheap, small.
I had to wake up a little and have my coffee to realize which cap you were talking about. I was thinking of something else at first. I'm old, I get confused easily. 😛
If it's the gray flat mylar, I change those out with whatever axial polypro I have on hand. If it has the red cylindrical one, I think I just leave those alone. I don't think you really gain anything by upping the size of that cap. It's a high pass that is already deep in the infrasonic.
I like the Kemet as a replacement for small e'lytics, as they are small, have long leads, and are reasonably priced. AFAIK, all of the small WIMA and Kemet film caps are PET. The polypros are bigger.
@eriksquires Elna Silmic have been gone for a while now.
No worries, I get it lol. I’ve posted things before I’ve had my 1st cup of coffee of the day and later realize I didn’t say what I wanted to say. I always replace those flat gray film caps in the Marantz, from what I understand, those are kind of known to go faulty. This is one of the round red capacitors, I have thousands of parts and figured I might as well put some a little nicer in.
I do keep a handful of Wima PET on hand as they will fit in areas where polypropylene won’t, so it’s nice to have them on hand. But polypropylene do come relatively small, for instance…
This capacitor is 100% polypropylene. Obviously the MKP 4 or 10 is going to be larger and probably considered better quality, but if I can get polypropylene in a small enough package I grabbed them over PET every time.
I was sad to hear about Elna. I still have quite a large collection of Silmic II, but don’t use them too often, saving them for special projects.
Dan
Actually, a Audyn 1uF axial polypro will fit just about perfectly in place of the original. I was gonna suggest Jantzen, but they are OOS until May.
https://www.parts-express.com/Audyn-Cap-Q4-1.0uF-400V-MKP-Foil-Capacitor-027-108?quantity=1
https://www.parts-express.com/Audyn-Cap-Q4-1.0uF-400V-MKP-Foil-Capacitor-027-108?quantity=1
Excellent. The larger being polypropylene because I still have them in the order bag, but I have many in bins, how can you tell which series they are? Is it because of the silver markings?
Thank you,
Dan