2 questions re. caps for use in Marantz CD63

[SimontY]

Hi chaps,

I have two fairly straightforward questions for you passive component experts, or anyone really

Background
I have a rather modified CD63ki, and yesterday I went searching for more guidance on modifying it, after mostly exhausting Thorstens tweaks on TNT-audio TNT-Audio, and reclocking.

Looking on Audioasylum I quickly realised the name Bobwire was synonymous with CDP tweaking. Eventually I found what I was looking for: Bobwire's article/post. This is an excellent guide, and obviously some of it overlaps with Thorstens mods, but from it I have a couple of questions:

Questions I have
1 - It is suggested to use a tantalum capacitor in one place:
"CAPACITOR ON THE RF AMP PCB:
C106 REPLACED BY DIPPED TANTALUM CAP."
Why use a tantalum, I've often read they are crap for audio? Would it be sensible to use a ~.5uf film cap or a good electrolytic instead? Or is tantalum just well-suited to this application? If so, what size is appropriate - 1uf, 10uf??

2 - He says to use 16v/1000uf caps all over the place, which seems nice. Can someone suggest a suitable reasonable quality cap, which is available in the UK? I wanted to use Nichocon MUSE FS, as they are meant to be good, and the price is bearable. However, they are about 1.2cm diameter, which seems too large for many places. Something 1cm d. would be better...

Would Rubycon ZL be appropriate/decent? These are well-priced, a good size, and have these 'features':
"--40% Lower impedance than conventional low impedance electrolytics
--High ripple and low impedance offers component reduction or miniaturisation opportunities"

These caps are mainly to go around the chips, opamps, and hdam buffer.

Any advice appreciated, thanks! (sorry for the longish post, I'm crap at brevity)

ps--anyone replace traces with coax, as seems popular? It looks like a nightmare task...

[SimontY]

Please give me some clues, some of you must be able to answer my questions easily!

[wintermute]

Hmmm, don't know that I can help, I'm just getting together a list of replacement caps, was using all Panasonic FC series, but found that don't have a 47uf.

I just found rubycon ZA series, which is even lower impeadance than the ZL at 60% lower than normal low impeadance, although the suggested application is high speed digital and SMPS.

Don't know whether it makes any difference for audio......

Tony.

[SimontY]

hi wintermute,

Thanks for the reply, I was beginning to think noone would say anything!

I've often heard Panasonic FC caps are good sounding and cheap. I can get those, so I think plenty of 1200uf 16v are in order. I'm thinking of using WIMA 0.1uf metalised polyester to bypass them with.

Would it sound extra good to bypass critical ones with an additional film and foil 0.01uf polypropylene WIMA? I'm crap at soldering, and 3 caps together is obviously tough work, but if it will give an excellent result...

Another spot can probably take a 16v/3300uf (C806). Crap thing is, next to this (C805) Bobwire recommends a 35v/4700uf!!! Now, what kind of cap will fit into a 1cm diameter space, and is anything more than 1000uf?!?!?

BTW, Wintermute - do you have the same/similar player? If so, what else have you done to improve it?

[wintermute]

Hi SimontY

I'm probably as much a newbie on caps as you are ... I chose Panasonic FC's because they are readily available and quite a few people here seem to like them, thought it would be a safe bet. I'm ordering new ones for my 16 year old amp, which is starting to develop some problems. I think you are on the right track with the bypassing idea, from what I've read seems to be the way to go. Are you going to solder them on the reverse side of the board?

I did a search on Rubicon caps and a few people mentioned the ZA's and seemed to like them. The other interesting thing mentioned was that Rubycon make the black gate caps.

I'm going out on a limb and replacing my bypass caps (as well as a couple of greencaps which I'm not sure of the function of) in my amp with Revox Rifa, Metallised Polyphenylene Sulphide (PPS) caps (currently they are all greencaps). Couldn't find much info on them (other than spec sheets which look good, to my inexperienced eyes) but thought I'd give it a go. I don't know that I'm going to be qualified to say whether they make a difference or not

I just replaced all the ceramics with NPO ceramics, and I can't honestly say whether it made a difference, too much time between when I disconnected everything, and hooked it back up! (My speakers probably aren't detailed enough to pick up subtle amp differences anyway). It's the electros, though that I'm hoping will make a difference (if for no other reason than their age). Have yet to run an rmaa test on it to see if there is any measurable difference, in distortion.

I've got a Marantz DV18 MK II, haven't touched it..... Only just out of warranty about a month ago. I think I have more severe probs with my amp and speakers, so have been trying to concentrate on them, but I guess eventually I'll get to the DV18

Have you got a decent soldering iron or soldering station? I had a cheap 25W iron for years, and eventually splurged and bought a Hakko 936 soldering station. Man did that make a difference! Highly recommend a good rig!!! The adjustable temperature is great, it's really useful when soldering "Heavy" stuff that normal soldering irons simply cool down on. You can do it quickly without overheating anything. I've only got the standard tip, but the difference is like chalk and cheese.

Tony.

[SimontY]

Bits originally posted by wintermute

...I think you are on the right track with the bypassing idea, from what I've read seems to be the way to go. Are you going to solder them on the reverse side of the board?...

...The other interesting thing mentioned was that Rubycon make the black gate caps...

...I just replaced all the ceramics with NPO ceramics, and I can't honestly say whether it made a difference...

...I've got a Marantz DV18 MK II, haven't touched it...

...Have you got a decent soldering iron or soldering station?
Tony.

My bypass caps will be going on the reverse side yes. I've got quite a few there already from previous changes, and things have only ever got better...

I noticed that Rubycon make BG, and that sort of piqued my interest But the Panasonic ones are 'miniature' so I'm gonna get those I think.

What are NPO ceramics? Actually, I just searched(!) and they are 'more stable'. So I guess they're just superior types.

Just did a search for your DV18, looks like a good player. But I bet it could be better

Actually, I haven't got a good soldering iron, mine is a diabolical cheap piece of crap, with a tip that bends and bluntens just from being left on! I have pulled out solder-tags and had solder running to the wrong places, and all sorts of nightmares, when using this iron. My problem with getting a good one is partly not knowing what exactly I need, and the fact that soldering stations cost a lot of money

Any advice in this area would be appreciated, because I will have more difficult jobs in the future. For example, changing my op-amps was a pretty tough task for me! Couldn't do anything more fiddly than that...

Cheers

[wintermute]

Hi SimontY,

Yeah from what I can gather normal ceramics tend to be a source of distortion, but NPO types are apparently superior, in that respect, as well as in temperature related performance.

I think changing op-amps (especially if they are bigger than 8 pins) is a challenge for anyone, unless you have some serious desoldering gear! I use desolder braid, but it is slow and a bit hit and miss.

I only have the one tip for my iron, pic attached. I find this type of tip good for general soldering, although I could probably do with a chisle point tip for heavy duty soldering (such as power supply wiring). Note that my tip looks worse than it is, because I didn't clean it after use the last time.

If you don't want to fork out for a soldering station I would suggest getting a reasonably high power (say 50W) iron with a variable temperature control (this bit is important especially with a high wattage iron, or when soldering stuff like op-amps). Get one with a choice of tips available not the screw in type but the slot in ones with a sheath that tightens down over them.

I did have an iron like I just described for a while before the hakko (after the two or three cheap and nasty ones) but when it blew up I bought the hakko, and it really is a major improvement over even the decent iron I had before it.

here are some user reviews of my Iron. They are certainly cheaper overseas than here in Aus. I paid $200Aus for mine!

http://www.eham.net/reviews/detail/2871

Tony.

[SimontY]

Thanks for the advice wintermute!

I need to search around for a good value station. The only place I've properly looked is Farnell, they have loads, but the cheapest is about £70, which is quite a lot for me. Thats 165 of your magic Aussie beans

You've got me convinced that its something I need though now, because I have much more soldering to do on my CDP, and I want to build a gainclone soon. I also want to put fancy diodes in my current amp, which I can't afford to break!

Thanks

[wintermute]

Yeah when you look at how much we spend on components (whether individual parts or a DVD player etc), the cost of a good soldering station starts to look pretty cheap Especially when you consider how long a good one should last, and how much benefit you should get from it.

It always amazes me how much easier things get when I get the right tool for the job, I always think, why didn't I do that sooner!

Tony.

[Zombie]

I recommend matching the 10k and 27k resistors at the diff.amps after the DAC within 0,1% or better. Makes a great difference in sound quality...
Cheers
Tom