Having asymmetric leakage current is like having some characteristic of a diode. It seems to make sense to avoid getting into that kind of operating mode. Some tests show that unbiased polarized caps do not operate linearly. However, I have not yet seen how critical the magnitude of bias effects linearity. Having tried a different value for C9 using an bipolarized cap has convinced me it is worth investigation. I have the original value bipolarized caps coming soon, so it would be interesting to see what is discovered. Since bipolarized caps do not have bias across them they will still be nonlinear, so the bypass cap should solve this.
How do leakage currents compare for polarised electrolytics, non polarised/bi-polar electrolytics, film caps?
How do asymmetric leakage currents differ from the above when signal currents are passing and the signal voltage across the plates is necessarily very low, say <100mVpk?
What if the plate voltage difference were less than 10mVpk?
How do asymmetric leakage currents differ from the above when signal currents are passing and the signal voltage across the plates is necessarily very low, say <100mVpk?
What if the plate voltage difference were less than 10mVpk?
This is an interesting issue. I don't think anyone had tried to quantify it. I think it would be like if you put a diode across signal and ground, at how small a signal will this diode not influence the signal. Which also brings an interesting question as to whether the signal clamping diodes used in the FE have a sonic effect or not. Has anyone tried removing them for comparison?
Yes, I did.
I was expecting them to be pretty transparent but it's not so.
Actually it seems to sound better (fuller) with diodes in place... 😱
I guess it could be related to the added parasitic capacitance.
Note that I'm talking about a pretty tiny difference.
Back to something simple - I just got my first stick of Chipquick alloy for SMD removal. Dario, are you using a small vacuum/air system with it or just pushing it away?
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What do you mean? In which phase?
If you'referring to parts to be removed I simply push them.
I use vacuum to clean pads after removal.
That's the answer I was looking for. There was a streak of the alloy/solder that smeared on the board and I wondered if holding down the part with tweezers while using a small tip vac/air nozzle was a cleaner process. I was considering modifying this tool, but it may be overkill. I'll have to practice some more.
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I have one of those and it never seemed to work. I think the problem of mine was the rated wattage was not enough.
I think the problem is the tip design - walls at the business end are not thick enough to transfer a lot of heat. I'll let you know if I come up with a better one.
I received the FE RC PCBs, everything looks fine.
I lost some pads on my beta boards and with Dario's help, I am able to start over. The BOM I will order is dependant on what I can salvage/desolder from my beta boards.
I lost some pads on my beta boards and with Dario's help, I am able to start over. The BOM I will order is dependant on what I can salvage/desolder from my beta boards.
would they happpen to be mcap 220uf? i was looking into those until i went for bg nx hi q. would still love to hear a comparison between the two.
No, I always start from cheap caps to justify concept. In this case CapXon had an agent near where I am located.
Not really sure how they rate, I just decided to try them because the agent is close by and provides adequate support. I ordered the 220uF 6.3V NP type, since these are really cheap, I have offered to provide a free pair to anyone on the FE beta program or have purchased first lot of boards after the beta build. The offer ends Aug 20th when my order is scheduled for shipment. Those interested can PM me.
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gentlemen may i direct your attention to my mini group buy?
http://www.diyaudio.com/forums/swap...ystyrene-caps-150-220-1000pf.html#post3127030
i don't know how they would compare to ero caps but my guess is that they would make a warmer alternative 😉 they certainly improved upon the wima caps they replaced on my myref. treble smoothed out, and the tone was more vivid.
it will take about 3 weeks for me to receive the parts after the payment is made.
http://www.diyaudio.com/forums/swap...ystyrene-caps-150-220-1000pf.html#post3127030
i don't know how they would compare to ero caps but my guess is that they would make a warmer alternative 😉 they certainly improved upon the wima caps they replaced on my myref. treble smoothed out, and the tone was more vivid.
it will take about 3 weeks for me to receive the parts after the payment is made.
Did you discover any other standout alternatives for the V1.2/V1.3 boards? I still have a pair of each - though the TP red boards are still completely stock builds.
On another subject - I have six LM3886 chips (used and removed) that I would like to test before soldering into anything. Could one of you "Hot Shot" PCB Gurus 😀 come up with a minimalist board or circuit (using Andrew's socket idea) for this purpose. I thought about getting a BrianGT or XY board but if something even simpler is possible, that's even better. I have looked at this thread but am really not after good sound - just confirmation of the chip being operational.
On another subject - I have six LM3886 chips (used and removed) that I would like to test before soldering into anything. Could one of you "Hot Shot" PCB Gurus 😀 come up with a minimalist board or circuit (using Andrew's socket idea) for this purpose. I thought about getting a BrianGT or XY board but if something even simpler is possible, that's even better. I have looked at this thread but am really not after good sound - just confirmation of the chip being operational.
I found here in Romania a small local dealer who's having some BlackGate Standard type on stock. The price is also good (~5EU/pc only 330uf/16V type) worth to buy some of them for C9 or for some bypassing maybe in some other projects ?
does he have any 100uf/(35v or greater) in stock? i'd like to put something better than blackgate f in c6,11
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