Audioengine A5+ Speaker Upgrades - Page 4

Quote:

Originally Posted by cssarrow 

1cm is kind of small eh? enough for a polymer cap. 

I'll most likely use a wire, as it seems to be the easiest way, but i'll have to see one i have the capacitors in hand.

 

To you and your friend, was the sound improvements that large? (After the polymer/ceramic bypass)

The sound improvement was big to my ears.  I didn't have 2 sets to do A/B comparisons, but they definitely sounded better to 3 pairs of ears I had auditioning them on top of mine.

I'll post a picture sometime on how I managed to rig the 2 back to back caps onto a surface mount.

Here is how I did my back to back Silmic II's soldered to a surface mount spot of the polymers at the input, demonstrated on an old dead video card:

And you want to ideally NOT use wires to lengthen the legs of the caps, because it introduces an extra un-shielded pathway for hum to be picked up from the large toroid right next to it, as well as other external sources and internal sources.  Keep the signal path short, as short as possible.  Anyways, this is what I did, replicated.

You can also lay the capacitors on its side, so instead of standing up like that, turn them 90 degrees to lie on the board, the legs absolutely won't touch anything then.  I think that's how 1 of 2 sets of my Silmics were mounted to avoid the surface mounted parts. 

I guess Elna changed the packaging on the Silmics, they used to be brownish like in the picture (those are Silmic II's).
 

The A5+'s are a sweet upgrade.  The A5's were notorious for overheating under loud use or hot weathers.  The heatsink was internal, and didn't ventilate well.

So.. you're "upgrading" the OS-CON capacitors for two ELNA Silmic II in series. 

And in another thread. Someone "upgraded" ELNA Silmic II for OS-CON.

It seems to me that all you're doing here is making the signal go trough 2 capacitors instead of a single one. Since OS-CON and ELNA Silmic II are debated to be the best capacitors on the market, we can conclude they are almost the same quality. That said, your "upgrade" is really a downgrade, since you're really doubling the distortion introduced by those capacitors.

Objectively, there is no way this can improve the sound. But then you're claiming that changing a couple inches of wires has a more significant influence on sound than damping in the speaker cabinet. So I'm just gonna conclude you're not being objective, and will leave you to your placebos.

But just as a final piece of advice: please don't go bypass components that you have no idea why they are there. A couple of pages back, someone tried to "correct" me by saying to bypass the capacitors. I was talking about the power decoupling capacitors, but this person spoke about the coupling capacitors. Let's just say bypassing one or the other won't give you the same end result.

Quote:

Originally Posted by qusp 

there is no way you have improved performance if those silmic are decoupling caps (well actually at this size they become reservoir caps), you do know that putting the 2 caps in series like that reduces the capacitance, rather than increasing it right? it only increases the voltage rating, which i'm guessing is not what you were trying to do? you will have created a 'cap' that is more inductive, higher impedance and most likely resonant.

SMD is the superior format for decoupling, hell these days its pretty much superior for everything, yes even audio.

edit: sorry I just read back, I see you know its lowered the capacitance value. it has also increased the impedance, which is now seen in series, so youve doubled the impedance of the silmics, which are already higher than the caps you are replacing.

silmics can be used well in some applications, mostly for if you have to use an electro in the signal path, which is why you would connect 2 together to make a bipolar cap to handle the AC signal, for DC it serves no purpose IMO (well unless degrading the specs is the purpose?).

it is done because there are not all that many high quality bipolar electros made anymore for audio (probably because most stuff is moving towards being DC coupled these days) and if a bipolar cap is needed for AC signal duties, most will use a film cap.

AC (alternating current) switches polarity twice each 'swing' so a polar cap can distort on the alternate phase, so if for AC signal and film cant be used, this trick was sometimes used to make a nice quality non-polar cap. This has no bearing whatsoever on decoupling DC power supplies.... for power supply reservoirs and decoupling, the SMD polymers you replaced are the better choice.

wow you are replacing ceramic HF decoupling caps with them too? just a little bit of info, even a small 0402 size ceramic capacitor placed directly across pins with via in pad pattern for the PCB (lowest possible inductance and impedance) is only good up to 10MHz.

the silmics are literally pointless for bypassing HF signals, the ceramics were orders of magnitude better for the job and even those were probably too large. For really effective digital HF decoupling, only even smaller SMD parts than 0402 (0201, like a spec of sand), as well as planar capacitance designed into the PCB power and ground planes is effective.

for getting rid of/attenuating such noise, a combination CRCLC is required. Something like the Murata EMIFIL products

it is clear, funnily enough, that audioengine have a better idea about how audio hardware and basic electronics functions than your friend. who woulda thunk that?

I don't think you have read the whole thread...   The Silmics II's are in a signal coupling situation, the ceramics that were surface mount were used for signal coupling (in my mod, as indicated by the pictures with circles around the caps), and the back to back config effectively forms a bipolar cap, getting rid of some distortion, i.e.,:

"If used as AC coupling capacitors (i.e. as high-pass filter) they do generate appreciable distortion at low frequencies. As a rough guidline I’d expect them to start with serious distortion (above 0.001 % at +20 dBu) at about 10x the cutoff-frequency. Or the other way round: choose the cutoff-frequency no higher than 2 Hz. At the same time this figure will mostly avoid time domain waveform distortion due to low-frequency phase shift. DC bias will increase distortion even more. Bipolar electrolytic capacitors (both as “true” bipolar capacitor or implemented with two polar ones back-to-back) show greatly reduced distortion and are recommended if space and cost allows their use. Obviously if used e.g. as smoothing or bypass capacitor in power supplies this distortion characteristic is far less problematic."

From the analog guru Samuel Groner, whose contributions to objective studies on a LARGE variety of opamps still enlightens us to this day.  Although this is fairly well known and textbook material. 

While I'm sure AudioEngine has a good assortment of knowledgeable engineers on staff, the product is a compromise between the engineering team, the cost-cutting admin-bean-counters, and the OEMs who actually manufacture the product.  ALL OF THESE PEOPLE gets a say on what the product should be designed like.  So many examples of corner-cutting resulting in substandard equipment that was engineered well are out there.  In fact, Centrance in their development blogs for the DacPort even said that the OEM making the DacPort wanted to substitute (among other things), a JRC opamp for the OPA1612 in their design to save a buck or two on a several hundred dollar product.  It took a lot of insistence from Centrance to get the OEM to stick to the plans by the engineers.  Pioneer's excellent Andrew Jones designed speakers is another example, where the engineers had to physically go down to the factory there they were made to MAKE SURE the speakers turned out they way they designed it, and wasn't tinkered with along the way. 

Quote:

Originally Posted by KimLaroux 

So.. you're "upgrading" the OS-CON capacitors for two ELNA Silmic II in series. 

 

And in another thread. Someone "upgraded" ELNA Silmic II for OS-CON.

 

It seems to me that all you're doing here is making the signal go trough 2 capacitors instead of a single one. Since OS-CON and ELNA Silmic II are debated to be the best capacitors on the market, we can conclude they are almost the same quality. That said, your "upgrade" is really a downgrade, since you're really doubling the distortion introduced by those capacitors.

 

Objectively, there is no way this can improve the sound. But then you're claiming that changing a couple inches of wires has a more significant influence on sound than damping in the speaker cabinet. So I'm just gonna conclude you're not being objective, and will leave you to your placebos.

 

But just as a final piece of advice: please don't go bypass components that you have no idea why they are there. A couple of pages back, someone tried to "correct" me by saying to bypass the capacitors. I was talking about the power decoupling capacitors, but this person spoke about the coupling capacitors. Let's just say bypassing one or the other won't give you the same end result.

First of all, the polymers were not OSCONs.  OSCON is one of Sanyo's brands if memory serves me correctly.  They are marked by Sanyo's markings.  These are who knows what make type of polymers.  Secondly, polymers are way better than electrolytics (typical electrolytics) at HIGH frequency, as in MHZ to GHZ range (and piss-poor at audible frequencies, particularly the bass region).  You see them in digital circuits all the time, motherboards, GPUs, etc.  However, polymers are terrible at coupling audio signals.  The fact that these were surface mount gives it away, the reason why you surface mount tank capacitors is mainly to reduce lead inductance at very high frequencies, typical of digital circuits.  This is the inappropriate choice here, since the frequency spectrum we're interested in coupling is far, far lower, where there are TONS of good coupling choices in terms of capacitors that way outshine polymers.  In this region, electrolyte distortion is the main consideration, where Silmics, Black Gates, etc are all optimized for.

For the 2 caps back to back, the reason is that the single caps are polarized, and one "pole" of that capacitor is responsible for a lot of distortion temporally (the cathode and anode are not equal in how much distortion they create, because fundamentally, the cathode and anode in a polar cap are different).  When you couple two of those capacitors together back to back, you form an effective bipolar capacitor with symmetric distortion products which minimizes the total distortion (if the capacitors are similar, which they are in this case).  But don't take just my word on it, ask Walter Jung and Samuel Groner, people we all should respect:

http://www.reliablecapacitors.com/pickcap.htm

http://www.sg-acoustics.ch/analogue_audio/parts/index.html

Lastly, the objectivity in my mods comes from the fact that AudioEngine chose to use inappropriate coupling capacitors.  Again, don't take my word on it, look at the links above and read up on ceramic capacitor distortion for yourself.

I have already investigated the circuit where I commented, all the positions I have adviced to shunt (or bypass with a wire) are signal coupling situations.  This is KNOWN to objectively improve the sound by eliminating capacitive distortions all-together if there is no DC on the lines, which I have also made sure of.  I never made mentions to shunt power supply bypass capacitors, I assumed the OP meant the same ceramics I talked about in my pictures, THEN LATER ON, the OP uploaded the pictures pointing out where he installed the MKPs and FKPs and I immediately replied on it.

Cheers mate! 

What type of SMDs are you referring to that are coming out these days ?  I'm going to evaluate some PPS caps against MKPs or PPs (non-metalized polypropylene) for signal coupling when possible in the future.  I have only used PPS film caps for compensation and filters, and seen them once (assuming they are PPS) in a Pedja Rogic built Aya II dac for the resistor-ladder DAC chip.  Or are you referring to some other technologies ?  I have once heard that niobium oxide caps are supposed to be great with the pros of tantalums, but none of the drawbacks, but then haven't heard anything on them since. 

Quote:

Originally Posted by qusp 

Handy Ray, I was commenting on the photos posted recently, since they were posted several times and people were talking about following recommendations and buying bunches of Elnas, I made the fairly reasonable deduction people would be replacing the 'crappy ceramics and SMD polymers' as is the current mode.

oscon has become the generic name for polymers it seems, I dont use it and I agree with you, terrible signal coupling caps and DC leakage is an issue, but myself I try first to build DC coupled, then film if I have to, I wouldnt use an electrolytic ever. I build from scratch mostly these days or with designs ive chosen, so I dont have to put up with bad decisions (of course I sometimes make them)

as a side note, there are some very good and very linear thin film SMD caps starting to appear, these will be a good alternative to film caps. ive used them for compensation and clock supply decoupling with very good results, but only available in small values as yet.

my apologies for the misunderstanding re the lineage of the photos, the photos were posted, a blog mentioned, conversations mentioned and odd decisions illustrated, so I replied to them. I wasnt aware the odd ones were cssarrow's.

cssarrow:

replacing them would be more than a waste of money for most people, replacing them in the way you describe is destructive, it doesnt just do no good, it does evil. Replacing caps because you dont like the colour and posting it on your blog? wow

I wasnt aware I had to read the entire thread when replying to a specific post asking for opinion..... out of due diligence I read back a couple of pages and edited my post.