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stridsvognen
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| Posted: Mon May 14, 2012 9:07 am Post subject: |
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| kabuby77 wrote: | | You can find a right cap for every application you need, but there isnt a cap right for all. |
Don't look like there is many pointing out the same cap for this VIM application.. LOL
whats funny is no one seems to mention how it effects the image. I Don't know whats the best cap for this.. I might know if i test all the possible options. Who did that.? I just know that those Nippon Chemicon looks better than the original tants.
Based on my image.
My point is that no one knows if they are the best for the application, unless they tested those against others.
Until then ill say its pure religion, based on to much talk and to little action. 
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mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
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| Posted: Mon May 14, 2012 10:54 am Post subject: |
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There is no magic cap... And as I said before, almost any of the newer caps will do well to upgrade the caps on the VIM. Either tent or electrolytic should do fine, because you'll only be able to get but so much performance improvement when changing out caps only. And again, it does not have to be a high hour VIM before those tants should be replaced. For some reason they would test good, but replacements would produce a better image.
And this is where draganm's mods would make sense to do to any VIM. And that was the case with stridsvognen low hour Marquee, when after changing out the tants with non-boutique caps, he saw a substantial improvement in the image.
Since you can only achieve but so much with caps alone, let's also look at inductors. And when going after higher bandwidth performance, there's a lot more to look at. To start, you would need to tighten up the DC rails (see my shot below), and that would require adding Series Inductors on the DC rails to start, because the only way to get tighter lines, you'll need a tighter DC supply:
Super 02 VIM
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Also, and back to the Internal Generator issue. I've mentioned that I chose to leave U106 active and only deal with switching out the OSD. Therefore the RGB Internal will remain always in the circuit, because I'll be using the same method I've used to hard filter it (see below).
VIM showing beads series soldered on the connector from the Internal Generator on the CLM
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kabuby77
Joined: 28 Mar 2011
Posts: 147
Location: Italy
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| Posted: Mon May 14, 2012 11:36 am Post subject: |
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Have you got a simple schematic for it? are you adding a pi filter to power supply chain?
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mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
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| Posted: Mon May 14, 2012 12:01 pm Post subject: |
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| kabuby77 wrote: | | Have you got a simple schematic for it? are you adding a pi filter to power supply chain? |
Yes, I've added a simple PI circuit, but I don't have a diagram for the changes. Maybe someone who knows how to pull this off the diagram can post it here showing the Inductor in series both rails as they come from the SMPS.
here's demo on a PI circuit in a power supply showing what happens with the inductor added:
http://www.youtube.com/watch?v=WzwaHO6WPCk
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kabuby77
Joined: 28 Mar 2011
Posts: 147
Location: Italy
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| Posted: Mon May 14, 2012 12:51 pm Post subject: |
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I asked because I don't know this board, I've enough work with mine  .
For power supply lines I agree for the tantalum
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mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
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| Posted: Mon May 14, 2012 12:59 pm Post subject: |
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| kabuby77 wrote: | | For power supply lines I agree for the tantalum |
Are you saying you agree for the tants on the DC rails, or for the decoupling?
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kabuby77
Joined: 28 Mar 2011
Posts: 147
Location: Italy
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| Posted: Mon May 14, 2012 1:13 pm Post subject: |
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I experienced tantalum in power lines with good results, while in signal chain usually I use thin film type (even because they are no polarized).
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Mon May 14, 2012 1:28 pm Post subject: |
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| kabuby77 wrote: | | I experienced tantalum in power lines with good results, while in signal chain usually I use thin film type (even because they are no polarized). |
Yep.
Mike, for the Fat caps on the Vim Power rails try to find same value but longer and thinner, fat caps usually have a higher ESR than the same value of the longer thinner size.
Athanasios
_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
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Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
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mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
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| Posted: Mon May 14, 2012 1:37 pm Post subject: |
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| kabuby77 wrote: | | I experienced tantalum in power lines with good results, while in signal chain usually I use thin film type (even because they are no polarized). |
talk to me about decoupling caps or the caps used directly at the chips DC supply. Do you only use one film cap there?
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mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
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| Posted: Mon May 14, 2012 1:54 pm Post subject: |
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| Nashou66 wrote: |
Mike, for the Fat caps on the Vim Power rails try to find same value but longer and thinner, fat caps usually have a higher ESR than the same value of the longer thinner size.
Athanasios |
That was the case style I used. I don't like retrofitting long caps on these boards.
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kabuby77
Joined: 28 Mar 2011
Posts: 147
Location: Italy
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| Posted: Mon May 14, 2012 2:07 pm Post subject: |
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| mp20748 wrote: | | kabuby77 wrote: | | I experienced tantalum in power lines with good results, while in signal chain usually I use thin film type (even because they are no polarized). |
talk to me about decoupling caps or the caps used directly at the chips DC supply. Do you only use one film cap there? |
There I use double, the smaller is better if smd type.
First is big: electrolytic (es tantalum) , the second with smaller capacitance is film type (low esl) decrease the impedance at high frequencies
http://www.ti.com/lit/an/scaa082/scaa082.pdf Figure 11
Last edited by kabuby77 on Mon May 14, 2012 2:13 pm; edited 1 time in total
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Mon May 14, 2012 2:11 pm Post subject: |
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| mp20748 wrote: | | kabuby77 wrote: | | I experienced tantalum in power lines with good results, while in signal chain usually I use thin film type (even because they are no polarized). |
talk to me about decoupling caps or the caps used directly at the chips DC supply. Do you only use one film cap there? |
I like putting a 22uf or higher OsCon across the +/- power rails of the chips, especially on any chips that transmit data. The newer style CMM really needed help and only OsCons helped. Other caps of similar values didn't work, even though the specs were very close regarding ESR, the oscons were lower but not by much. Which is why I wonder about trying wet tantalums on the HVPS. Sometimes it seems similar specs but different cap design may bring different results and the only way to know for sure is to try. But here we go again, does anyone want to spend a few hundred dollars on expensive wet tants?
Jeh Hong Lea and his Taiwan friends use wets all over the place on the power rails and said they had awesome results, similar to Chris Stevens findings, this is why i am curious about them.
nashou
_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
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mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
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| Posted: Mon May 14, 2012 2:14 pm Post subject: |
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Looks like a good read. It definitely addresses the problems with taming parasitic oscillation and methods to use for best high frequency performance.
When if upgrading SMD ceramic or poly's, try going triple stack (one on top the other). And use various values like; 0.1uf, 0.01uf, 0.001uf).
I've been using this combination, to also at times ad a tant in parallel to the mix.
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gjaky
Joined: 05 Jun 2010
Posts: 2802
Location: Budapest, Hungary
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| Posted: Mon May 14, 2012 2:29 pm Post subject: |
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Fortunately I have sold my marquee and with the NEC I don't have to mess with caps for high quality picture -haha
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
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| Posted: Mon May 14, 2012 3:27 pm Post subject: |
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| gjaky wrote: | | Fortunately I have sold my marquee and with the NEC I don't have to mess with caps for high quality picture -haha |
warning, these posts could get you banned for life!
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
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mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
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| Posted: Mon May 14, 2012 10:33 pm Post subject: |
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| kabuby77 wrote: | There I use double, the smaller is better if smd type.
First is big: electrolytic (es tantalum) , the second with smaller capacitance is film type (low esl) decrease the impedance at high frequencieshttp://www.ti.com/lit/an/scaa082/scaa082.pdf Figure 11 |
I took a shot of a section of one of my neck boards. In the shot you should see what I mean by stacking the SMD caps. I'm only doing doubles on three different 1206 SMD's. On these same locations, using leaded capacitors is not a good idea.
There are also three feritte inductors soldered in that same location. Also noticed the amount of solder I used on the two double stacked caps (C10,C11) right at the screw-through output transistor (MRF549). The heavy up soldering was necessary to pull those caps in with the output transistors and prevent oscillation.
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mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
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| Posted: Tue May 15, 2012 11:45 am Post subject: |
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I had also mentioned earlier that I was only using two of the four switches in the SD5401's. Two are used for the clamping switch, and the other two are used to switch the video from INTERNAL (Pattern Generator on the CLM) to EXTERNAL video input (RGBHV connectors - Moome Card).
I'm no longer using the INTERNAL/EXTERNAL switching in the SD5401's. I do that using a retro mini board (see below) that's attached right over the three AD835 contrast amps.
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The OSD is inserted directly into this mother board as well.
I'll be posting this and other shots in my DIY section next month.
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mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
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| Posted: Tue May 15, 2012 11:56 am Post subject: |
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my decoupling tants
33uf 16vdc Tant
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kabuby77
Joined: 28 Mar 2011
Posts: 147
Location: Italy
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| Posted: Wed May 16, 2012 7:45 am Post subject: |
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Very interesting work, now I need to download the VNB diagram to follow your upgrades
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