| jean-paul |
| quote: | | 2) Do I need to decouple digital ICs with Os-Con and ceramic capacitor in parallel? |
Forget about using a ceramic cap in parallel when using OSCON. Try to place the OSCON as close to the pins as possible with short tracks.
I don't know what to answer on the first point, I use MRS 25 for everything. |
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| Bricolo |
| quote: | Originally posted by jean-paul
Forget about using a ceramic cap in parallel when using OSCON. |
Why? Because it's not necessary, or because it will ring?
And will 0.1uF film caps be OK? |
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| Oli |
| quote: | | Why? Because it's not necessary, or because it will ring? |
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| jean-paul |
As you refer to the document of Guido Tent I advise you to read it again for reference. The man knows his stuff and he also knows to explain it well. Way better than I can, I just try and test.
I like the comment of Peter Daniel on OSCON although I use them in digital circuits often. In analog I will never use them again as they are responsible for a metallic sound there as experienced by me several times. Decouple an opamp with them and you'll know ;) OSCON has a break in period too but less than BG. |
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| Oli |
Let me quote:
"When selecting an electrolytic, the series inductance must be taken into account, and properly compared with the total inductance of the supply loop the cap is in. That inductance of the (for a DIL28) package for example) is about 12nH. the ESL of the capacitor shall be relatively small compared to this value; it does not make sense to look for 2nH as the loop itself dominates!"
- i.e. the effect of a ceramic capacitor will be insignificant. |
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| Oli |
"Modern electrolytics are far better RF performers. Their construction is such that the series inductance is very low (both films are terminated at the same side). They have very low impedance over up to 4 decades in frequency; Enough to say goodbye to the additional ceramic capacitor. It saves money and space as well and eliminates the risk of yet another resonance."
i.e. Os-Cons are good (enough) for the RF we are dealing with. Using a ceramic capacitor in parallel is asking for trouble. |
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| jean-paul |
| Could not have said it better ;) BTW why ask if you know the answer ? |
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| Oli |
I had read Guido's words of knowledge, but I lacked confidence in applying what they were telling me. Indeed, Sanyo give PDF examples on their website where OsCons alone are used as decoupling devices.
So why do so many people believe in using ceramics and low impedance electrolytics in parallel? Are they simply wrong?
My asynchronous reclocker operates at 66Mhz. Are 0.1uF ceramic capacitors alone a better choice? |
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| jean-paul |
| If you don't believe an analog designer with a good reputation I doubt that you'll believe me ( I wouldn't ) as a DIYer so I won't comment anymore on the subject. |
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| jewilson |
I have used the OSCON because of Radial design and they have great ESR, also I can get them in one day. I normally use Sprague 550D low ESR tantalums which are great but cost 6 time as much as the OSCONs. I have not tried out the BG's, their are harder to get and they cost more.
Also, I have found if you running fast logic it still best to decouple with .1 or .01 on ever chip and the size depend on the ringing.
The last time I checked carbon film had a better tempco than carbon comps and I hate carbon comp's. |
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| Oli |
I find reassurance in the experience of others.
I already intend to implement Guido's ground plane, IC interfacing and inductive supply decoupling. I respect his authority!
From your experience what decoupling is best for Op-Amps. |
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| Oli |
Thanks Jim,
I had a feeling that even an OsCon electrolytic would only go so far....
On my fast logic I will stick to ceramics on each chip. This is exactly the broad opinion I seek.
P.S. I read that carbon film resistors can become capacitive |
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| jean-paul |
| quote: | | P.S. I read that carbon film resistors can become capacitive |
What about caps that become resistive ;) |
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| Oli |
and inductors that become.....
Now we're just being silly!
(You're point is taken)
Sooooo what do you use for op-amps? BGs? |
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| jewilson |
Oli,
That depends on the application. There are lot of AD and Burr Brown part that are very good. |
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| Oli |
Sorry I was not being clear.
What single 'capacitor' is best to decouple op-amps?
Quite a number of people believe the OsCon to sound harsh in this application. |
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| jean-paul |
| BG, Pana FC etc. |
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| Oli |
Panasonic FC- Easy to get from RS
Black gates- any special type?
Which are best? |
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| Peter Daniel |
In my experience, with the DAC, BG N type sounded the best. BG NX Hi Q are fine too, but they don't provide the resolution that N type gives you. Low voltage NX seem to be veiled and rather laid back in comparison. But they are good choice in a bright system.
I'm still using a triple bypass configuration, with 0.01 and 0.1u X7R caps (0612 type) stacked on each other and soldered directly to the pins of IC. I don't think big value cap is necessay and the electolytics are 33/16 BG N. It sounds good and I'm not tempted to look for any other bypass configuration yet. Those tripltes are influenced by the article by Pete Goudreau.
http://groups.google.com/groups?sel...u&output=gplain |
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| Oli |
Thanks for all the hints guys.
Going to do some thinking and tinkering... |
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| Guido Tent |
| quote: | Originally posted by Oli
I have been doing some reading and thinking...
1) Regarding resistors in the digital signal line: Are 'low inductance' resistors needed?
We are already imposing slew rate limitations due to the resistor acting together with the input capacitance of the IC. Is the inductance significant?
2) Do I need to decouple digital ICs with Os-Con and ceramic capacitor in parallel?
Will the inductance of the tracks dominate such that the ceramic will be ineffective in practice and that the Os-Con will do 99% as good a job? I believe Guido Tent makes such a claim in his publication on 'decoupling digital ICs'.
Comments? |
1: No need for low inductance, I prefer small carbon resistors
2: See comment of JP
cheers |
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| Petter |
| quote: | Originally posted by Peter Daniel
I'm still using a triple bypass configuration, with 0.01 and 0.1u X7R caps (0612 type) stacked on each other and soldered directly to the pins of IC. |
Peter,
please share a picture or two of this implementation - it sounds really really cool!
It is so typical of you to go right for the legs and stack as well :)
Petter |
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| jean-paul |
| Don't you guys read threads at all ? The picture is here in a similar thread. |
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| jean-paul |
| quote: | Originally posted by Peter Daniel
In my experience, with the DAC, BG N type sounded the best. BG NX Hi Q are fine too, but they don't provide the resolution that N type gives you. Low voltage NX seem to be veiled and rather laid back in comparison. But they are good choice in a bright system.
I'm still using a triple bypass configuration, with 0.01 and 0.1u X7R caps (0612 type) stacked on each other and soldered directly to the pins of the IC. I don't think a big value cap is necessary and the electrolytics are 33/16 BG N. It sounds good and I'm not tempted to look for any other bypass configuration yet. Those triplets are influenced by the article by Pete Goudreau.
http://groups.google.com/groups?sel...u&output=gplain |
Just curious, did you use BG only as well ( without the triple bypass) ? Bypassing BG did not bring much here, it became worse when bypassed with ceramic caps....
In fact I stopped bypassing some time ago as I like one good cap better when implemented well. I am talking soundwise this time, not technically/measurements. I even rediscovered using plain BCcomponents electrolytics and I like them.
Electrolytics have made great progress in the last years and although my prejudice against them is hard to get rid off I am starting to judge them right. How difficult it can be to readjust to something one got used to. In the eighties I bypassed every cap I saw and now I am using just one....
Same thing with BG N series. Put 4.7 uF MKT in my preamp to discover ( again ! ) that BG N was better despite being an electrolytic. |
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| Peter Daniel |
To tell the truth, I didn't check BG only, without ceramic bypass. I tried BG with 0.01U first and then added 0.1U and addidng additional cap brought improvement. I still have to try the BG by itself only.
It is also my experience that the single caps sound the best. But here, we deal with digital circuits, so it's harder predict what works and what not. Trying the parts in a circuit is the best way, IMO, to find the best choice. |
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| jean-paul |
| quote: | | To tell the truth, I didn't check BG only, without ceramic bypass. |
Sorry Peter but then your findings have devaluated. An opinion can only be formed when both situations have been evaluated. After that the conclusion can be published and advice can be given.
Do you agree ? |
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| Peter Daniel |
We would have to ask millwood about it.;)
I never mentioned if ceramic work or not. I only stated that BG worked the best, and I don't think that ceramics have much to do with that.. |
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| jean-paul |
How can you say that when you parallel BG with ceramics ?!?!? I am pretty sure BG is even better without the ceramics. Did you test film caps only as well and how did they compare to the BG's with ceramics bypass ?
| quote: | | In my experience, with the DAC, BG N type sounded the best. |
How about film caps ?
BTW ceramics do work, but the question is how they add to the sound quality ;) |
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| Peter Daniel |
| quote: | Originally posted by jean-paul
How can you say that when you parallel BG with ceramics ?!?!? I am pretty sure BG is even better without the ceramics.
BTW ceramics do work, but the question is how they add to the sound quality ;) |
Because I compared all the other electrolytics with ceramic as well. Ceramics were always in a circuit. If BG sounds better without ceramics, it's even beter (and BGs are probably more sensitive to paralelling than other caps).
So how they sound with ceramics and how without? What type of ceramics did you use? It's not easy to remove those small SMD caps, so I better be sure my efforts will pay off;)
I tried some ERO MKP, but I didn't like them (comparing to BG N) |
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| jean-paul |
Leave them where they are as chances are big that you'll damage things that worked and sounded real fine before. For what, 5 % better sound ? ;)
I just wanted to point out that assuming matters because of empirical and somewhat incomplete ( not meant as negative as it might sound ) tests can be flaky. On the other hand: testing everything can't be done when one wants a life beneath the hobby.
make the best of it,
regards,
Jean-Paul |
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| Oli |
This thread appears to have developed quite a bit since I have been away.
The following trend seems to be emerging:
Os-Cons for digital :cool:
Black Gates for analogue :cool:
No further decoupling required :cool: (I might try some for 66Mhz)
Q. What values for Os-Con and BG?
(I have seen 33uF so far..)
Some people regard BGs as 'snake oil'. I am more open-minded and want to know the 'sound' they offer versus lesser capacitors? e.g. are they more transparent? warmer?
Anyone? |
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| Peter Daniel |
If you put them in a circuit and won't here any difference, then they will be a snake oil. But when I listen to them, the difference is bobvious, it's more like veils and colorations are moved away and you are left alone with music only;). But seriously, regarding BG N, they are more direct and detailed, and I wouldn't say warm but rather neutral. Itried as low as 4.7 for bypass and it worked fine, even on TDA1543 DAC. I'm using now 100u and the sound became more liquid.
In my experience BG were also better in digital circuits (DAC, receiver, input buffer). I subjectively perceive OsCons sound as "adding a sort of sparkling grain to the sound, like someone was sprinkling fine metallic powder into the soundstage";)
I don't like them in digital circuits either. But it's very easy to test out. Just install some sockets and start inserting different caps, while listening to the sound. It will give you more info than you could gather from a 100 members here;) |
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| jcarr |
Peter:
Isn't your quote a comment that I originally wrote to describe how silver-mica caps sounded to me when these were used in modified Spectrals and various Connoisseurs?
http://www.diyaudio.com/forums/show...2664#post262664
Personally, I haven't noticed any major sonic problems when bypassing either digital or analog ICs with Sanyo's OS caps, with or without local film and/or ceramic bypasses added. In fact, recently I've been listening to them in various IC-based amplifier prototypes. I've also been experimenting with other OS-like semisolid-electrolytic caps (different chemistry and construction from Sanyo) which I think I like better, but this doesn't mean I felt that either the SP or SG series of OS caps were in any way bad or unusable. Subjectively the sound with the OS caps was pretty natural - I wouldn't say "lush", but certainly open, detailed, smooth and with zero perceived harshness.
Due to individual differences in schematic design and physical implementation (including pcb and harness design), my observations are that disparities in preference are quite understandable. And of course, personal taste is likewise a major issue.
BTW, to reiterate my overall perspective, I still stand by what I wrote in this post from the same thread.
http://www.diyaudio.com/forums/show...1741#post261741
hth, jonathan carr |
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| Terry Demol |
| quote: | Originally posted by Peter Daniel
Because I compared all the other electrolytics with ceramic as well. Ceramics were always in a circuit. If BG sounds better without ceramics, it's even beter (and BGs are probably more sensitive to paralelling than other caps).
So how they sound with ceramics and how without? What type of ceramics did you use? It's not easy to remove those small SMD caps, so I better be sure my efforts will pay off;)
I tried some ERO MKP, but I didn't like them (comparing to BG N) |
I would start by using a low Z "ground plane", or is that hiding
underneath the PCB????.
Terry |
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| setmenu |
Hi all
Apologies for being the naive newb barging into this fertile thread:D
I am just about to embark on assembling my first 8412/1543 based nos dac.
This is intended for portable use so battery power ,optical input,
ldo regs are being implemented.
My question is regarding ground planes.
I am considering a v reg for each part of the circuit bar the op-amps.[2 for the 8412,1 for the 1543 and 1 for the ToRX176]
As I am going to be using point to point wiring at this stage , I am able to attach my tiny regs[reg113] and decoupling caps directly to the pins of the chips.
Areas where multiple pins need grounding I had intended to
use shaped pieces of copper shim to create small ground planes.
As the components will be as close too each other as practical for
reasons of producing a compact unit, I wondered whether
trying to achieve large surface area planes was really essential?
Cheers
Setmenu:angel: :xeye: |
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| jewilson |
The beef I have with using Black Gate caps is I have never found any engineering specifications on these caps. They might be good as the OSCON styles but where are their data sheets. Anyone have a URL for them.
As for BG for coupling, I have a hard time buying that because of my experiences with normal electrolytic types. |
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| Peter Daniel |
Yes, it is. That's why I used quatation marks and a smile;). While it may be not exactly the describtion of the sound of OsCons (to me), this is what first comes to mind. And I really like that expression. The OsCons I was using have no grade marked on them, just the value and are sourced from Chinese seller.
It is hard for me to believe that all of them sound that way, as I noticed that others use those caps and are quite content. To me, their sound is dull and boring. |
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| ALW |
| quote: | | The beef I have with using Black Gate caps is I have never found any engineering specifications on these caps. |
Me too!
I did try some recently though as I needed a 10u for the input of a bipolar phono stage, and didn't have space for films. In my defence I didn't pay for the BG's, they were kindly donated to me ;)
They sounded absolutely ***** for about 3 weeks.
Now they sound fantastic, quite astonishingly so bearing in mind I really wanted to hate them. I also wonder what would happen if I turned the phono stage off for any period of time?
Anyway, I now view them as a tool in the armoury, for times when I have to use a 'lytic. I've never tried them in decoupling apps though (I'm not going to either...).
Andy. |
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| Peter Daniel |
| quote: | Originally posted by setmenu
Hi all
Apologies for being the naive newb barging into this fertile thread:D
I am just about to embark on assembling my first 8412/1543 based nos dac.
This is intended for portable use so battery power ,optical input,
ldo regs are being implemented.
My question is regarding ground planes.
I am considering a v reg for each part of the circuit bar the op-amps.[2 for the 8412,1 for the 1543 and 1 for the ToRX176]
As I am going to be using point to point wiring at this stage , I am able to attach my tiny regs[reg113] and decoupling caps directly to the pins of the chips.
Areas where multiple pins need grounding I had intended to
use shaped pieces of copper shim to create small ground planes.
As the components will be as close too each other as practical for
reasons of producing a compact unit, I wondered whether
trying to achieve large surface area planes was really essential?
|
While large ground planes may be beneficial, I don't think they are issential. Here's my protoype DAC borad (TDA1543) done p2p, without any ground planes, just thick wires for ground bars, and the performance is splendid. I will build the same cuircuit using a proper PCB and I'll be able to compare performance, but I doubt it will be any improvement.
The other side is one big ground plane, but it has only one point connection with main ground, so it acts as shield only between components and p2p wires, nothing else is connected to that plain. |
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| setmenu |
Hi Peter
Thank you for your reply.
The p2p method using only wire will sure make life easier at this
stage.
I am at present fiddling around with some very,very tiny SOT packaged regs, trying to find a way of best mounting them on the bottom of the bypass caps...
Oscons in fact..
The differing opinions in 'best approach' tend to make my electronics newb head spin:xeye:
It is all fascinating none the less:D
Have have enough parts to build several dacs so this looks like
a nice project to become another one of my select obsessive
compulsive disorders:devilr:
Cheers
Setmenu |
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| Christer |
Just curious, while people often take care to specify the exact
type of Black Gate, Rubycon and whatever, I think I have never
seen anybody saying which type of OS-CON they refer to. There
are several types. The ones I know of are those available here
which are the SA/SC type and the special audio model SG. In
addition there are two SMD versions, SM and SV. All of these
are Sanyo, by the way. |
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| Peter Daniel |
| That is true regarding OsCons. The ones I was using is probably the lowest grade. Yet I noticed that other people use similar type (in pictures) so before coming to any particular conclusion all available options. But the ones I tried are definitely no good (to me;) |
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| Peter Daniel |
| quote: | Originally posted by setmenu
.
I am at present fiddling around with some very,very tiny SOT packaged regs, trying to find a way of best mounting them on the bottom of the bypass caps...
Oscons in fact..
The differing opinions in 'best approach' tend to make my electronics newb head spin:xeye:
It is all fascinating none the less:D
|
At certain point, I got also confused with so many parts choices and decided to check everything myself. That's why I built this prototype, where by using special sockets, I can easily swap caps and resistors as well regulators for sonic evaluation. It was quite a revealing experience.
Please not that non polarised BG caps are still directional, and they definitely sound different depending on their orientation in a circuit.;) |
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| fmak |
Please not that non polarised BG caps are still directional, and they definitely sound different depending on their orientation in a circuit.;) [/B][/QUOTE]---------------------------------------------------------------------
Which direction sounds best to you. I usually use the long lead for signal input.
And how does the direction of your ouptput resistors affect your conclusion?
:angel: |
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| jewilson |
My experience is it better to have a large ground plane for analog and Digital. It just make the design easer to implement and reduced digital switching noise and increase the analog performance. Also, it's help if the power traces or low impedance too.
This can be accomplished on a prototype with p2p wiring. 3M makes a copper foil tape with can be attached to the bottom or top side of the board. Of course you can place a piece of Mylar between bottom and the foil if you have p2p connections their. The copper tape is also helpfull when resolving emi problems.
So does any one know if Black Gate has a Web site, I have never seen one. |
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| Peter Daniel |
| quote: | Originally posted by fmak
Which direction sounds best to you. I usually use the long lead for signal input.
And how does the direction of your ouptput resistors affect your conclusion?
:angel: |
Short lead is marked with non polar print on a sleeve. I prefer short lead on the input (long lead to the output). As to the bypass positioning, I prefer short lead on a pos supply, long lead to the ground.
The short lead marks the start of the foil and this is in line with my other observations regarding caps orientation. Usually, the outer foil should be directed towards the output or connected to the ground.
As to the resistors orientation, it seems like there is a slight variation in different orientation, but so far I didn't pursue it more extensively. It is too inconsistent and time consuming that I let it go for now;) |
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| jewilson |
| Directionality is also true for some film caps, TRW use to mark horizontal to the end of the cap the end. That end would go to lowest end impedance part of the circuit, acting as a shield. You can check to see if the BG can is connected to one of the leaded, if so do the same. |
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| Christer |
Actually, a linkt to the Black Gate webside was once posted in
a thread discussing these caps. I cannot remember if there were
any actual datasheets, but there was at least some more or less
credible description of how they work.
Unfortunately, I cannot remember the URL and I couldn't come
up with any good search terms to find the thread, but by saying
that I remember there is such a thread, perhaps it can trigger
somebody elses memory to remember even which thread it was.
The thread might have been called something like "Black Gates,
myth or reality" or something similar. Anybody remember it?
It might have been Per-Anders starting it, or at least I know he
was involved. |
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| Pedja |
http://www.blackgate.jp/english.htm
A bulk of Jelmax Technical Reports can be downloaded from PartsConnexion’s site:
http://www.partsconnexion.com/resources.php
BG was even kind enough to send me some missing Reports that I was interested for… But there is always something left unsaid. At the other hand these caps sounds extremely good, used either like PS or signal carrying caps.
Pedja |
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| jcarr |
Peter:
>The OsCons I was using have no grade marked on them, just the value and are sourced from Chinese seller.<
The SP grade has "SP" marked on the side, integrated into the whitish negative polarity band. I believe that the SG was likewise marked on the side, but I don't have any open samples at hand (I'd have to search), and can't confirm the SG markings with 100% certainty (the lettering and polarity band will be gold on the SGs).
These two are the only grades of Sanyo OS caps that use decent-quality copper in the leads, and according to Sanyo, the chemistry has also been tweaked somewhat for audio use (compared to the other Sanyo OS caps). Also according to Sanyo, they should be powered up for a pretty long time (weeks) after they have been subjected to the heat of a soldering iron.
The technical explanation given to me for the above was that the OS electrolyte should remain tar-like in texture for best operation, but partially turns gasseous under the heat of soldering. It takes time (with power applied) for the gases to be re-absorbed into the tar.
BTW, years ago I was far more focused on componentry than I am now. Today - I believe largely due to my improved skills in the areas of schematic, pcb and harness design - I find that I can use a much wider range of componentry and still get good sonic results. It is surprising what a clever schematic and matching board layout can do to correct a variety of sonic problems that you may have initially thought were caused by other factors (such as component choice).
I also agree with the Jim Wilson about the desireability of designer-dependent features like a ground plane (and don't use it only for shielding!), low-impedance power traces, and more. Or perhaps I should say "potential desireability", as an ineptly designed ground plane can cause more damage than good. Once again, a ground plane is a tool, and the results depend as much on the person using the tool as the tool itself.
hth, jonathan carr |
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| Christer |
Thanks Jonathan,
that was interesting. For once we get a technical reason
from a manufacturer for burning in a component. There are
probably other such cases , but they seem to be rare. |
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| Peter Daniel |
| quote: | Originally posted by jcarr
BTW, years ago I was far more focused on componentry than I am now. Today - I believe largely due to my improved skills in the areas of schematic, pcb and harness design - I find that I can use a much wider range of componentry and still get good sonic results. |
I noticed that. When looking through your older posts on AA, I perceive a similar attention to componentry (that I have now) , but your recent comments here, show less regard in that matter.
Yet to me, at this point, it still seems not comprehendable how in more complicated and advanced circuit, componentry plays a lesser role. To be clear, I don't play with complicated circuits. Most of my current boards contain only few components, and I can't avoid not having to pay attention to my choices if first rate performance is desired. Could it be that with more complicated designs, the amount of components and what's going on a PCB simply masks the effect of a single part and although such circuits prevail in certain aspects of sonic retrival, yet, they don't posses delicacy and intimacy that most simple circuits produce? |
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| ALW |
You should try some of the SP series OSCon's, in my view.
Sonically these are very different from the standard parts. They are also, in my experience, better than the earlier SG parts, which I was less keen on.
I'm with Jonathan here, the SP series' sound is almost the complete antithesis of the comments you have made about Oscons.
Andy. |
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| jcarr |
Peter:
>your recent comments here, show less regard in that matter.<
No, I am still attuned to what components can do to the sound, but now I am also aware that other issues can play a much bigger role. And as I mentioned in my previous post, I observe that sometimes we may be blaming component choice for sonic issues that may have more to do with schematic or board design. What I spend a lot of effort now is to analyze what sort of operating environment a given active or passive component needs to provide acceptable performance, and then figure out how to create that environment. And as a personal challenge, I find this approach more satisfying than component tasting.
Now _if_ I should ever feel that my present, more design-oriented approach is beginning to peak out and major steps forward in terms of sonics become harder and harder, at that time I _may_ once again focus more acutely on component choice. OTOH, I could simply resolve to work and study harder on improving my design abilities. Only time will tell.
>Yet to me, at this point, it seems still not comprehendable how in more complicated and advanced circuits, componentry plays a lesser role.<
If you can provide the componentry with an operating environment where their flaws are less likely to be evident, their sonic impact will be mitigated as well. Should circumstances force you to recite the Ten Commandments convincingly while running the 100 meter dash in under 12 seconds, you'd need to be a decent athlete as well as a practiced orator. But if you could ask someone else to recite the Ten Commandments while you did the running (or vice versa), the total task wouldn't even be a challenge worth mentioning.
>Most my current boards contain only few components, and I can't avoid not having to pay attention to my choices, if first rate performance is desired.<
With circuitry of few components, the functions required of each component tend to be complex (and often ill-defined), and so each component needs to have a multitude of characteristics that are all very good. With more complex circuits, you can break the desired functions into smaller, better defined tasks, and you can then begin to use components that only need a few characteristics that are outstanding (and frequently obvious).
>Could it be that with more complicated designs, the amount of component and what's going on a PCB simply masks the effect of a single part and although such circuits prevail in certain aspects of sonic retrival, yet they don't posses delicacy and intimacy that most simple circuits produce?<
Depending on the audio system (including RF conditions, acoustics, and setup) and personal preference, of course anything is possible. But according to reports from professional reviewers, audio dealers and private audiophiles (as well as what I hear with my own ears), the latest Connoisseur 4-2 and 5 clearly outperform all of the older models when it comes to sonics as well as measured performance. The new designs have lower noise, faster overload recovery, better low-level detail, more complex timbres, more natural tonal balance, better soundstaging, greater intellectual and emotional involvement and so on. In fact, it would be very difficult for me to think of any sonic aspect of a older design like the 3.0 or 2.0 which I prefer over the 4-2 and 5. Circuitry-wise, the new designs are considerably more complex than the old ones, so the "simple is best" philosophy has not held up to at least _my_ personal scrutiny.
But again, you're not me. And the point should not to defend your own subjective choices and personal aesthetics (which you really don't need to justify to anyone but yourself), but to make great-sounding audio designs in the best manner that you can.
If your guiding star doesn't lead you naturally in the direction of complexity, complexity shouldn't be the path that you take. In the end, you should go with whatever approach is most rewarding for you.
regards, jonathan carr |
|
|
| Peter Daniel |
| quote: | Originally posted by jcarr
so the "simple is best" philosophy has not held up to at least _my_ personal scrutiny.
.... but to make great-sounding audio designs in the best manner that you can.
If your guiding star doesn't lead you naturally in the direction of complexity, complexity shouldn't be the path that you take. In the end, you should go with whatever approach is most rewarding for you.
|
Well said Jonathan, and of all people here, you are one of the few that can provide the most insight and inspiration when it comes to truly high end design.
Well, I will be doing all I can and as always, I will follow my intuition and personal 'feel'.
And I already, on few occasions, learned that the simplest is not always the best. But it can be pretty damn good.;) |
|
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| Peter Daniel |
| quote: | Originally posted by ALW
You should try some of the SP series OSCon's, in my view.
Sonically these are very different from the standard parts. |
The ones I tried were SA and SC series from this source: http://hk.geocities.com/wkchenghk2000/orderformEng.htm |
|
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| Terry Demol |
| quote: | Originally posted by Peter Daniel
While large ground planes may be beneficial, I don't think they are issential. Here's my protoype DAC borad (TDA1543) done p2p, without any ground planes, just thick wires for ground bars, and the performance is splendid. I will build the same cuircuit using a proper PCB and I'll be able to compare performance, but I doubt it will be any improvement.
The other side is one big ground plane, but it has only one point connection with main ground, so it acts as shield only between components and p2p wires, nothing else is connected to that plain. |
| quote: | Originally posted by jewilson
My experience is it better to have a large ground plane for analog and Digital. It just make the design easer to implement and reduced digital switching noise and increase the analog performance. Also, it's help if the power traces or low impedance too.
This can be accomplished on a prototype with p2p wiring. 3M makes a copper foil tape with can be attached to the bottom or top side of the board. Of course you can place a piece of Mylar between bottom and the foil if you have p2p connections their. The copper tape is also helpfull when resolving emi problems.
So does any one know if Black Gate has a Web site, I have never seen one. |
WRT ground planes, totally agree. I think it's funny seeing
people evaluating various dig bypass caps such as ceramic
and low esr electros when they don't go directly or almost directly
to a ground plane.
Maybe that's why we have so many differing views on sound
of various bypass configurations.
WRT proto boards, also agree, I usually use a single sided
solid copper covered pcb and xmas tree off that. All the decouple
caps can get a good lo z gnd even though its still P-P wired.
WRT Blck Gate caps, some info.
http://www.blackgate.jp/ebg3.htm
http://www.octave-electronics.com/P...p/bg_tech.shtml
I have to admit that most of this sounds like marketing
bullsh!t. However as ALW also found, these puppies definately
have a very transparent and clean sound unlike most other
electros.
Some (KYW) find them too mechanical and unmusical, this is
also a common thing. I have one friend who will not use Black
Gates, period.
In the end it's all subjective... choose your poison :)
I really like Jensen 4 pole electro's, seem to have
a good balance of transparency and playing "music", but have
only tried large HV ones for tube amps.
cheers,
Terry |
|
|
| Christer |
Jonathan,
If you don't mind, may I ask you two brief follow ups? Was that
tech. explanation on burn in after soldering specific to the audio
grade OS-CONs or all models? Is your experience that it matters
to use the audio grade versions also for digital decoupling, for
analogue decoupling or just for coupling and similar?
Another reflection, probably not very relevant in practice but
nevertheless interesting. The design philosophy you describe
of making an overall more complex design to get "modules"
with more well-defined behaviour/environment for components,
has some similarities with good software engineering where
we tend to break things down (hierarchially or otherwise) into
well-defined modules that make it easier both to design,
debug and understand the program, even if the overall complexity
becomes much greater. |
|
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| Peter Daniel |
| quote: | Originally posted by Terry Demol
I think it's funny seeing
people evaluating various dig bypass caps such as ceramic
and low esr electros when they don't go directly or almost directly
to a ground plane.
Maybe that's why we have so many differing views on sound
of various bypass configurations.
|
And I still think it's funny to see people talking about something they didn't try.
On my board the ground plane is a piece of 14 ga wire, 1" long, directly at the chip. All connections are done there. You think you can get better with your fancy ground plane?
Receiver chip has a similar "ground plane" and both planes are connected with wide PCB track.
It may be funny, but I don't think you can teach me much about ground planes. This is what I call optimum decoupling. Can you do better?
http://www.diyaudio.com/forums/show...2733&highlight= |
|
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| Terry Demol |
| quote: | Originally posted by Peter Daniel
And I still think it's funny to see people talking about something they didn't try. |
Settle down Peter, you are being a little defensive here. ;)
I HAVE tried many grounding schemes, built and modded many
DAC's with less than optimum grounding schemes.
Just changing the grounding can often make as much or more
difference than changing the components (caps) themselves.
What I am saying is get the grounding scheme right and
THEN make careful judgement of the various bypass caps and
arrangements. Otherwise the results can be skewed, especially
when dealing with very low impedance caps. An improper
ground can easily nullify any advantage that a ceramic cap might
have had.
FWIW, I pretty much agree with Guido T's approach, 1 GP,
uninterrupted as much as possible and keep HF current loops
short.
Cheers,
Terry |
|
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| Peter Daniel |
As far as I understood, I was the only one in this thread talking about different bypass caps and doing p2p wiring;)
I'm not a grounding expert, but my impression is that doing it in a simple way is one way to avoid possible complications.
I also had a board from another member, and actually cutting and separating one plain into two subplanes brought some improvement.
Also, comparing the caps in the same setup (without regards if ground plane is optimal or not) should be considered as valuable information regardless The difference was there and this difference will be in a different circuit as well. We don't even know if the ground plane wasn't optimal, in many cases it's hit and miss anyway.
Going back to ceramic caps, do you find them beneficial when paralleled with electrolytics? I never did my own testing as I rather trusted the comments of Pete Goudreau (talking about the triplets). |
|
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| till |
| Terry, i don´t understand - how do you make a proto board with a groundplane? do you have a picture? |
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| Peter Daniel |
| Groundplane supports all the parts that need ground (they are soldered to copper side), all the other connections are wired in a free space. |
|
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| till |
| without holes? same as soldering to a solid piece of copper? |
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| Christer |
Till,
I suppose both Terry and Peter are referring to a board with a
groundplane but with predrilled holes. Terry seems to refer to
a board with copper only on the ground plane side, if I understand
him correctly. Otherwise there are boards to buy which have a
ground plane on one side an soldering islands on the other.
Roth Elektronik manufactures such boards, for instance, and
sell them as boards for HF design. |
|
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| Bricolo |
Since you mentionned Roth electronic, do you need to register in order to be able to see theyr product catalog?
That s*x... |
|
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| Christer |
| quote: | Originally posted by Bricolo
Since you mentionned Roth electronic, do you need to register in order to be able to see theyr product catalog?
That s*x... |
I have no idea. I didn't find it at their website but in a component
catalogue from a local retailer (Elfa). There are probably more
models and also other manufacturers.
Here's the datasheet for the Roth board, beware though, it is
very expensive.
http://www.elfa.se/pdf/48/04832333.pdf |
|
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| till |
Reichelt:
guess why the number starts with RE ? (Roth Elek.)
3,902 to 15,20 isn´t really cheap. |
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| Bricolo |
The one Till showed is the RE-201, double or single sided. If double, the component side is a ground plane
There are also 2 variants, epoxy and "hartpapier", epoxy is twice the price... Is it really better?
Roth also has another interesting board, the RE-200. It seems to be the same bubt without the part on the left to place a connector.
It's cheaper, too |
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| Oli |
Been doing some reading from the 'parts connection' website.
I have also been reading a lot of threads from diyAudio.
My overall understanding of the decoupling capacitor situation has shifted:
1) Everyone who has actually tried Black Gate N capacitors for supply decoupling agrees they are a good thing- better than OsCon. (Does anyone disagree?)
2) The parts connection data sheets contain poor English, with weak explanations. This has given many individuals the impression that Black Gates are 'snake oil'.
I do wish to give them a try, since so many people have had positive experiences. I have read a little about super 'E' configuation. I have read the other threads on this site, but I would appreciate clarification. My understanding is...
1) Buy 2 x BG-N capacitors
2) Connect them in parallel or series, but with opposite leads connected.
3) Keep them physically close together.
I believe Peter Daniel suggested 100uF, so I might use 2 x 50uF in parallel.
Has anyone had recent experience with the super 'E' connection.
Does it not ditract from the ideal of the single bypass capacitor already advocated in this thread.
i.e. will 2 parallel capacitors resonate? |
|
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| Peter Daniel |
I tried super-e configuration and didn't like it, single capacitor sounded better to me in coupling application. Paralleling causes loss of resolution and veiling. People with bright speakers like it though;)
You might try OsCons, as it seems that the better grades are quite good, just don't buy the cheapest ones available from China.
In my opinion 33u/16V BG N should be large enough value for most decoupling applications. I use 100u directly at the DAC, it works better than smaller values. |
|
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| Guido Tent |
| quote: | Originally posted by Bricolo
The one Till showed is the RE-201, double or single sided. If double, the component side is a ground plane
There are also 2 variants, epoxy and "hartpapier", epoxy is twice the price... Is it really better?
Roth also has another interesting board, the RE-200. It seems to be the same bubt without the part on the left to place a connector.
It's cheaper, too |
Hi
Epoxy is more robust, hardpaper sounds better. If you build once - never changes I'd go for hardpaper
regards |
|
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| Oli |
I am using AD1865N-K and OPA627 opamps- I prefer this combination.
I am using 74VHC74 in my reclocker.
The whole unit uses loads of NiMhd cells!
Perhaps I should use 22uF for digital decoupling, but save 100uF for the DAC and the I-V converters. does sound reasonable?
Interesting to note that you prefered a single capacitor. My 'decoupling' application is different.
A single bypass would save me money;) |
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| jcarr |
Dear Christer:
>Was that tech. explanation on burn in after soldering specific to the audio grade OS-CONs or all models?<
The way that the message was conveyed suggested that the gaseous vaporation and gradual reabsorption process applied to Sanyo's OS electrolytes as a family, and would not be affected by minor alterations in chemistry (as may exist between the audio and non-audio versions). Note that Marcon also developed a competing line of OS caps which was subsequently acquired by Nippon Chemicon (United Chemicon). I don't know how the gaseous vaporation and gradual reabsorption process applies to Nippon Chemicon's OS caps, but I have observed that these caps also need a fairly substantial operating period after installation before the sound stabilizes.
>Is your experience that it matters to use the audio grade versions also for digital decoupling, for analogue decoupling or just for coupling and similar?<
I find that the SC and SA grades do not sound as nice as the SP grade, for either digital or analog PS decoupling. But due to a rather highish leakage factor, I wouldn't suggest using any OS cap for signal coupling, nor would I use them for high-impedance applications like S/H circuits, DC servos or whatnot.
>Another reflection, probably not very relevant in practice but nevertheless interesting.<
On the contrary, I think that your reflection is _very_ relevant in practice, as it dictates the development philosophy itself, which in turn sets the tone for the development environment and list/hierarchy of technical priorities to attend to. When the philosophy or mental approach underlying product development is different, it would be quite surprising if the resulting designs turned out to be similar.
>The design philosophy of making an overall more complex design to get "modules" with more well-defined behaviour/environment for components, has some similarities with good software engineering where we tend to break things down into well-defined modules that make it easier both to design, debug and understand the program, even if the overall complexity becomes much greater.<
I now try to spend a lot of time before a design project, listing up the (perceived) problems, setting the goals, and defining the project boundaries/limits. Next I will write out an overall circuit flowchart which usually does not contain any circuits or circuit fragments at all, but rather consists of boxes with the desired functions noted in the form of formulae, labels and comments. Once I am satisfied with the general electrical flowchart, I will then design individual circuit blocks to correspond to the labelled boxes in the flowchart. By this stage, the circuitry more or less designs itself. Or to put it more practically, by this stage I have a very good idea what the schematic needs to look like and be. During the flowchart and circuitry design stages, I also will envision what sort of physical structures will best suit the schematic choices, decide whether the physical structures under consideration are feasible, and if so, what the best way of building them will be. In fact, I usually keep re-drawing the schematic to most accurately reflect the current state of physical construction (pcb layout et al), and if I don't like what I see, I will redo the schematic, the physical structures, or both.
Once the prototypes have been built and production commences, I will conduct regular post-mortems regarding the ease of production and QC, and devise revisions if so required. Those post-mortems are also put to good use when I am designing the next project.
I nearly always find that the more time that I spend thinking about and planning a project before doing the actual design work, the less time I need to spend trouble-shooting and debugging it later. Mind you, I am not deliberately searching for greater complexity per se, but I do find that inserting an extra layer of mental abstraction subsequently makes it much easier to comprehend what I should be trying to accomplish, and also to keep the project under control so that it doesn't unwittingly metamorph into something that I wasn't originally looking for. The downside of my preferred approach is that you may not have much concrete to show or play until fairly late in the development cycle, and so if you are designing a commercial product, it helps to have an understanding CEO! And I know other designers - perhaps more hands-on in approach - who prefer to get a prototype functioning as quickly as possible, and wil revise and debug this until they are happy. So whatever works for you is the right approach, I'd say.
Nonetheless, it is a great feeling when a complex circuit that you have never prototyped nor built before works perfectly the first time out, and surpasses your best previous efforts into the bargain!
regards. jonathan carr |
|
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| fmak |
[QUOTE]Originally posted by Peter Daniel
[B]I tried super-e configuration and didn't like it, single capacitor sounded better to me in coupling application. Paralleling causes loss of resolution and veiling. People with bright speakers like it though;)
--------------------------------------------------------------------------
The super E connection takes a long time to settle. I didn't like it at first but after several weeks, it sounds better than a single. |
|
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| Peter Daniel |
That's what people say.
Does that mean that super-E config takes longer (than a single cap0 to break in and sound better? What change for better it actually makes ? |
|
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| Terry Demol |
| quote: | Originally posted by Peter Daniel
Groundplane supports all the parts that need ground (they are soldered to copper side), all the other connections are wired in a free space. |
Exactly.
I have also used strip board and glued copper foil (from an
alphacore inductor) to the back. This was much less successful.
I'd really love one of those prototype PCB drill/router
machines but just haven't got funds for it.
Cheers,
Terry |
|
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| Oli |
fmak,
What was your application? Coupling signals or Decoupling power lines? |
|
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| Christer |
Dear Jonathan,
Thanks for the elaborate responses about the OS-CONs.
It is very interesting to read the detailed description of your
design philosphy. If one replaces a few techincal terms here
and there it could just as well be a text-book description on
how to do a software project. I wish more programmers had
your understanding of system design. There wouldn't be as
much crappy software around then.
| quote: | Originally posted by jcarr
I nearly always find that the more time that I spend thinking about and planning a project before doing the actual design work, the less time I need to spend trouble-shooting and debugging it later.
|
Yes, that is what is usually known as the 90/10 rule in software
engineering. Either you spend 10% of the time designing the
program and 90% debugging it, or you spend 90% of the time
designing it and 10% of the time debugging it. Almost always
the second approach results in the 100%s
amounting to a much shorter total development time.
| quote: |
Mind you, I am not deliberately searching for greater complexity per se, but I do find that inserting an extra layer of mental abstraction subsequently makes it much easier to comprehend what I should be trying to accomplish, and also to keep the project under control so that it doesn't unwittingly metamorph into something that I wasn't originally looking for.
|
Same thing as in software. Although the program may get more
complex in the sense of getting bigger, at least if measured in
source code, it will get much less complex in the sense that it
has a much clearer structure, making it easier to understand,
debug, maintain and modify. I would suppose this design
philospophy is also common for any type of sufficiently
large-scale engineering projects. You always gets to a limit
where it becomes necessary to control the system complexity,
but few probably apply it for smaller-scale projects like amplifiers.
(Here I mean an amplifier is small-scale compared to say the
control system of jet fighter, or a power plant.)
| quote: |
The downside of my preferred approach is that you may not have much concrete to show or play until fairly late in the development cycle, and so if you are designing a commercial product, it helps to have an understanding CEO!
|
Yes, that is often experienced by programmers tought to do
programming "the right" way, especially if the bosses are not
competent programmers themselves as is, or at least used to
be, common. I have friends who started working in industry
and already the second day the boss asked them "Why haven't
you started coding yet?!!!" Of course my friends were already
deep down into understanding the problem specification and
the overall design of the program. The coding phase would
mostly be routine craftmanship for them once the overall design
was clear and the important technical decisions taken.
| quote: |
And I know other designers - perhaps more hands-on in approach - who prefer to get a prototype functioning as quickly as possible, and wil revise and debug this until they are happy. So whatever works for you is the right approach, I'd say.
|
I would think that audio equipment are usually still of such
small size that the major challenge is in the details and it is
usually possible to have sufficient control over the whole
system without moving up to a more abstract layer. For
software, you very quickly get into a complexity where things
get into a mess if you don't do it.
There was an interesting observation made once (over 20 years
ago now, I think) at the university where I studied. There were
two similar masters programmes, roughly an EE oriented one
and a more CS oriented one. Both did the first course in digital
design in the second year. However, while the CS programme
had the first programming courses already during the first year,
the EE programme didn't have any programming courses until
the third year. Although no statistic study was done, it was
observed that the CS students performed much better in the
digital design course. This was assumed to be because
the programming courses had forced them into approaching
design on a more abstract level, leading to a better ability to
split up the system into functional blocks etc. |
|
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| fmak |
| quote: | Originally posted by Peter Daniel
That's what people say.
Does that mean that super-E config takes longer (than a single cap0 to break in and sound better? What change for better it actually makes ? |
-----------------------------------------------------------------------------
My own take from cap changes is that better caps can reveal problems in other areas such as longer warm up times, opamp sonic problems, and longer settling times. I'd give everything a month beforev a verdict.
The super E seems to reveal more at the top and bottom than a single BGN. The reason why I think this is liked more than FK is that it is a 'mellower' cap and less revealing. |
|
|
| fmak |
| quote: | Originally posted by Oli
fmak,
What was your application? Coupling signals or Decoupling power lines? |
----------------------------------------------------------------------
Coupling; BGNs are too expensive and too big. I prefer OSCON SG or SP for digital; FK for IMPORTANT decoupling positions (expensive), Elena Stagets for eveuyday and Rubycon ZAs, ZLs (magnetic leads) for low esr.
Most of the time decoupling analogue PS doesn't seem too critical, provided there is no groun, oscillation or regulator noise problem. |
|
|
| setmenu |
Hi All
Forgive my ignorance [yet again:whazzat: ], I have a couple of further questions.
Regarding decoupling caps on the 8412 etc.
The data sheet shows .1uf yet i often see some quite large[single] values used in its place.:xeye:?
Another question regarding ldo reg cap values.[I suppose
this is related in that the cap value effects both devices]
I have been investigating regs [especially those that are BIGGER than a grain of rice:mad: :bawling:] , for example Burr Brown Reg 103.
The data sheet states:
"None of the versions require an output capacitor for regulator
stability. The REG103 will accept any output capacitor
type less than 1µF. For capacitance values larger than 1µF,
the effective ESR should be greater than 0.1Ω. This minimum
ESR value includes parasitics such as printed circuit
board traces, solder joints, and sockets. A minimum 0.1µF
low ESR capacitor connected to the input supply voltage is
recommended."
Mmm ..how does one go about using such a device if the device it is supplying requires or benefits from a higher value[low esr type] cap?
Cheers
Setmenu:clown: |
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|
| jewilson |
| quote: | | Mmm ..how does one go about using such a device if the device it is supplying requires or benefits from a higher value[low esr type] cap? |
I don't understand what your trying to say!
Check out the attachment |
|
|
| setmenu |
Hi jewilson
I can't even explain what I don't know correctly:xeye: :bawling:
I think I meant to say something like:
If I wished to use the mentioned regulator ,that I would be
unable to use it to supply my devices if I intend to use a bypass
cap that has a low esr with a value over 1uf, or instability could result.
Types such as OSCONs, Black Gates etc.?
Is the above the correct interpretation of below?
"None of the versions require an output capacitor for regulator
stability. The REG103 will accept any output capacitor
type less than 1µF. For capacitance values larger than 1µF,
the effective ESR should be greater than 0.1Ω. This minimum
ESR value includes parasitics such as printed circuit
board traces, solder joints, and sockets. A minimum 0.1µF
low ESR capacitor connected to the input supply voltage is
recommended."
The reason for all this is my wish to be able to run the thing from as small a battery pack as possible, hence the ldo reg investigations.
I suppose I could just up the cell count [probably will need to anyway] and shove some standard 3 pin in there...
UGH.. I just hate being so ignorant..I feel a real duck out of water here:(
Just dunno what I am talking about...sigh..
Perhaps I should stop vandalizing this very interesting thread with my posts eh?:nod:
Cheers
Setmenu |
|
|
| jewilson |
First, your choice of regulators should not be biased on a minimum acceptable cap for that regulator or ESR value. The one specification should be that the regulator will remain stable with a minimum 100uf or more. If the regulators cannot handle that then do not use it. For example, look at the specification of a LM317 and LM337 they are decent regulators, even a 78XX or 79 series regulators or ok when used with low ESR caps.
You should be looking for a regulator with good performance specification. Most regulators require a minimum size cap to function, however, that does not mean you should use the minimum size. In fact, you will not get good filtering using the minimum size.
If you wanting to building to be battery powered thing, you should be looking at a "low drop out regulator" they are the most efficient. Most low drop out regulators are not high of performance, however with good filtering they will get close. When using a LDO Regulators you really need goof out filter caps, because their noise performance and ripple is worst. Check out Linear Technology they makes a bunch LDO regulators.
:) |
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|
| setmenu |
You are correct of course.
I was working my self into a right old frenzy at the weekend:o
I have since done some more reading and investigation.
I have ordered some ADP3301 regs to try.
these are low dropout , low noise and can tolerate a wide range of caps/esr.
Cheers
Setmenu |
|
|
| Guido Tent |
| quote: | Originally posted by setmenu
You are correct of course.
I was working my self into a right old frenzy at the weekend:o
I have since done some more reading and investigation.
I have ordered some ADP3301 regs to try.
these are low dropout , low noise and can tolerate a wide range of caps/esr.
Cheers
Setmenu |
At best these are above 100nV/SqrrtHz, which is about the same as an LM317, not realy low....
cheers |
|
|
| Guido Tent |
| quote: | Originally posted by jewilson
You should be looking for a regulator with good performance specification. Most regulators require a minimum size cap to function, however, that does not mean you should use the minimum size. In fact, you will not get good filtering using the minimum size. |
What is good ?
A little bit more specific would help these guys......... |
|
|
| setmenu |
I have little idea of what noise figs mean.
I just try to find products that use the same definitions and go for the lowest figure:xeye:
The ADP 3301 quotes:
OUTPUT NOISE VNOISE f = 10 Hz–100 kHz
@ 5 V OUTPUT CNR = 0 100 uV rms
CNR = 10 nF, CL = 10 uF 30 uV rms
They say it is low noise, so I believe them??
Setmenu:clown: |
|
|
| jewilson |
| quote: | | A little bit more specific would help these guys......... |
Guido,
That all depend on his application. It not so important to have ultra low noise regs for a digital application. ;) |
|
|
| Terry Demol |
| quote: | Originally posted by setmenu
I have little idea of what noise figs mean.
I just try to find products that use the same definitions and go for the lowest figure:xeye:
The ADP 3301 quotes:
OUTPUT NOISE VNOISE f = 10 Hz–100 kHz
@ 5 V OUTPUT CNR = 0 100 uV rms
CNR = 10 nF, CL = 10 uF 30 uV rms
They say it is low noise, so I believe them??
Setmenu:clown: |
Also worth a look are LT1963 regs.
These have following attributes:
Low drop out
Very low noise (14uV rms 10Hz~100kHz)
Fast transient response
Stability with wide range of OP capacitors
Refer data sheet for more details.
Cheers,
Terry |
|
|
| setmenu |
Hi Terry
I had spotted the 1963 in my searches.
The reason I got into such a fret over the reg 103 is the fact I could just simply order it from RS:D
All the others seem to be thin on the ground in the UK
I get sooo sick of hunting for components:dead:
The nice folk at Analog Devices UK are sending some samples
of the 3301 [could not find it anywhere else as usual].
I have yet to speak the Linear Technoloy...As I cannot find
this one by other means either:rolleyes:
As for noise, I cannot recollect reading of an off the shelf reg
that anyone here jumped up an down about, [I probably missed that one!] preferences generally being shown for discreet types.
Soo..what kind of noise figure would be considered good then?
Assuming I understand the answer of course:xeye: .
Cheers
Setmenu |
|
|
| thadude2 |
Hey,
Have you guys checked out the TPS791xx series from TI, the specs look pretty impressive. |
|
|
| Oli |
Fmak,
Interesting that you use OsCons.
I still am thinking OsCon SP series for decoupling digital.
BGNs for decoupling my op-amps in my DAC.
Does this sound reasonable? |
|
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| jewilson |
The fact is, many of these regulators will work fine if the correct filtering is used, even a PI filter helps and ferrite beads will not hurt either.
For the digital stuff except for the receiver, noise is not that big of deal unless it ends up on your analog power and ground. That another discussion.
;) |
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| fmak |
| quote: | Originally posted by Oli
Fmak,
Interesting that you use OsCons.
I still am thinking OsCon SP series for decoupling digital.
BGNs for decoupling my op-amps in my DAC.
Does this sound reasonable? |
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Yes, but include BG-FK if you are rich and Elna, Rubycon if not for anannlog stage.
Just try, measure if you can and listen. |
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| Guido Tent |
| quote: | Originally posted by jewilson
Guido,
That all depend on his application. It not so important to have ultra low noise regs for a digital application. ;) |
Low noise is important in digital, as some aspects of digital are not so digital. Domains where low noise is a must are at least the clock, analogue PLL supplies and DAC supplies.
Low means low, 5nV/Sqrrt Hz at least up to 100kHz
cheers |
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