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5 Dollar AV-710 Capacitor Mod [Phase 1]

Discussion in 'Electronics & Electrics' started by decayed.cell, Aug 1, 2006.

  1. decayed.cell

    decayed.cell Member

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    5 Dollar AV-710 Capacitor Mod [Phase 1 80%]

    Credits
    Credits fly out to thedoctor, who's idea is the basis of this mod - I only take credit for changing it slightly and choosing easy to source components (for us Ozzies).

    Preamble Notes
    This mod is separated into what I call Phases - its just easier for me to see what the difference is when changing caps. Phase 0 is my original mod, used for testing. I'm starting all over again at Phase 1. All components can be bought at Jaycar, although the equivalent at Dick Smith is also suitable. Is this mod cheap? Very yes. The complete mod, from Phases 1 to 3 will cost you less than 5 bucks.

    Introduction
    After reading around articles on Head-Fi.org and here on modding an AV-710. This is a fairly cheap ($) soundcard but good sounding card for stereo (due to the Wolfson W8728 DAC). It can be purchased from SecretNet for only $40.20 AUD including postage :D. Stephonovich has a great review of the card over at Head-Fi.org

    It doesn't support EAX and stuff like that so its not really a gaming card, and to achieve 7.1 it uses a VIA 1616T for 6 channels plus the Wolfson DAC for the remaining two channels (which makes for some crappy surround sound). However, it also has Optical-Out and is capable of doing Bit-Perfect Output - meaning that your audio will come out completely unchanged - something that only cards in the $100+ range usually offer.

    Back to the mod. What I am basically doing here is replacing some capacitors on the AV-710 to achieve better sonics.

    Phase 0 (Test Phase)
    Replace Output Decoupling Capacitors
    Capacitors Used: 2x Jaycar 22uF 63V Electrolytics (RE6080)
    Estimated Time: Approx. 5 minutes

    The mod itself is fairly simple - replace the current caps are circled in red
    [​IMG]

    Why do we replace the caps? The DAC goes straight to the analog outputs and these caps are directly in line with it - which means the your audio will be passing through them.

    As explained on Afrotech, the current output decoupling capacitors are cutting off all frequencies from about 54Hz down if you are running without an amp. Humans can hear from approximately 15 to 20000 Hz, thus this means that around a 39Hz range of frequencies is being thrown away - there goes all our bass sounds.

    By plugging in headphones or speakers we are creating a simple High Pass RC Filter. There is a simple mathematical formula used to calculate the cut-off frequency and it is

    frequency = 1 / (2*Pi*R*C), where R is your resistance in Ohms, C is capacitance in Farads, and Pi is, well Pi. Afromods explains that if we plug in headphones (or even speakers) there is going to be resistance. I will use 300Ohms for the sake of this. The AV-710 has 10uF 16V decoupling caps as stock, thus we get a cut-off frequency of 1 / (2*Pi*300*0.00001) = ~53Hz.

    However, if we replace the caps with higher values, for example 22uF as I am using here, we get 1 / (2*Pi*300*0.000022) = ~24Hz. 24Hz is not bad, in theory there should be less signal loss.

    Pictures
    [​IMG]

    [​IMG]
    As you can see, the replacement caps dwarf the stock ones thus I had a bit of problem soldering them on flat side by side heh :thumbup: so one of them is sitting on top of the other.

    The whole process doesn't take very long provided you have a nice soldering iron :D and particularly skilled hands.

    Results
    Definitely more bass
    Sound is a bit warmer, instruments like the piano and guitar are more well-defined

    You could argue that I'm under a placebo effect... but I've done a RightMark Audio Analyser test to verify the results.

    Method: Hook up Wolfson DAC analog out to VT1616 line-in via El Cheapo analog cable from AeroCool GateWatch

    Results in white and on the left of the table are after the mod, and likewise the results in green and on the right of the table are before the mod.

    [​IMG]

    The results speak for themselves :thumbup: - There is improved frequency response, less noise, a greater dynamic range, less THD, less IMD less stereo crosstalk etc, etc.

    Not bad for 50 cents worth of caps and a few minutes of soldering :D

    The Mod
    Components List
    -2x Low ESR 470uF 16V (RE6314) 2x 0.59 = $1.18
    -5x Low ESR 100uF 25V (RE6322) 5x 0.22 = $1.10
    -1x Low ESR 220uF 25V (RE6336) 1x 0.78 = $0.78
    -6x Greencap 0.47uF 100V (RG5165) 6x 0.25 = $1.50

    Total Cost: 1.18 + 1.10 + 0.78 + 1.50 = $4.56 :shock:

    Phase 1
    [​IMG]
    -Replace output caps (marked in red) with 2x Low ESR 100uF 25V (RE6322)
    -Replace DAC power caps (marked in yellow) with 2x Low ESR 470uF 16V (RE6314) and 1x Low ESR 100uF 25V (RE6322)
    -Replace cap at CE11 with 1x Low ESR 220uF 25V (RE6336)
    -Replace caps at CE13 and CE15 with 2x Low ESR 100uF 25V (RE6322)

    Phase 2
    [​IMG]
    -Replace cap at CE12 with 1x Greencap 0.47uF 100V (RG5165)
    -Parallel solder 1x Greencap 0.47uF 100V (RG5165) with cap at CE15
    -Parallel solder DAC power caps (marked in green) with 3x Greencap 0.47uF 100V (RG5165)

    Phase 3
    [​IMG]
    -Bootstrap Q2 regulator to Q1 regulator by removing third leg of Q2 regulator from the board then wiring it to the grounding of Q1 regulator - please view these pictures for reference:
    http://img149.imageshack.us/my.php?image=allpics071sw5.jpg
    http://img149.imageshack.us/my.php?image=allpics059bv0.jpg
     
    Last edited: May 2, 2008
  2. Shadow27

    Shadow27 Member

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    Wow, awesome work :thumbup:

    Very tempting to do to mine. Looking forward to the other caps being replaced too.
     
  3. Goth

    Goth Grumpy Member

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    If the capacitors are physically too big, use ones with lower voltage ratings.
     
  4. OP
    OP
    decayed.cell

    decayed.cell Member

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    Well theres not much of a choice at Jaycar hehe - I think I'll be putting in the Low ESR ones instead with a higher uF and lower volt rating, it'll save a couple of milimetres but it doesn't really matter because I can always solder them so they sit on the back of the card :thumbup:
     
  5. lil^mac

    lil^mac Member

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    Excellent work decayed.cell!!!!

    I have been sus'in out this sound card for a while as I really want some quality sound to my headphones ( Beyerdynamic DT770-80ohm and PA2v2 amp). I currently have the X-Mystique 7.1 sound card and I am not a fan of the Cmedia chip and whatever DAC is on that card. Thanks to your AV-710 Mod write up, it looks like I'll burn some money now just for testing purposes till I get a chance to purchase parts for a DIY USB External DAC ( the Alien DAC over at head-fi). Im no audiophile but I am starting to get into the scene.
     
  6. GooSE

    GooSE New Member

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    Yeah, the 16V electrolytics from Jaycar would be suitable. The diameter is 5mm.
     
  7. lil^mac

    lil^mac Member

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    btw, its AV-710, not AV-170 as per title
    ;)

    Although Im sure people who know about the great sound card would know its a typo.
     
  8. OP
    OP
    decayed.cell

    decayed.cell Member

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    CRAP. LOL. Just noticed... thanks... I'm currently looking through Jaycar's Low ESR cap catalogue for suitable replacements for the Wolfson DAC power caps and decoupling caps (again)
     
  9. PooJou

    PooJou Member

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    hah Excellent mod! - You want to do mine? I'm local as well haha :D :thumbup:
     
  10. OP
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    decayed.cell

    decayed.cell Member

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    I would, but I use the equipment at school and to be honest, my friend helps me out with the soldering - he's teaching me how to do it pro xD... I do the picking up the replacement stuff
     
  11. brodsta

    brodsta Member

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    Farads is actually used to measure capacitance, not current. So I'm guessing that C in this case stands for capacitance, as I is the unit usually assigned to current, Cs usually used for capacitance or charge. (AFAIK!! :Paranoid: ). That aside :p hehe

    This is a really good value mod. Is the sound coming out of the card good quality? I gather with it having Bit-Perfect that the optical out is pretty good? Might grab one of these and give it a shot. ;)
     
    Last edited: Aug 2, 2006
  12. OP
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    decayed.cell

    decayed.cell Member

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    Of course the sound coming out is good... its a Wolfson DAC :D
    Capacitance... yeah crap... I is for current - goddamn forgotten last year's electronics lessons at school. C should be input capacitance in this case. :Paranoid:

    The optical out is probably (afaik) equal to a lot of midrange ($100+) cards as I stated earlier - it comes out completely unmodified, unlike some cards which do some processing, leaving the signal altered when it comes out of Toslink.

    Yeah this is a good value mod, excellent value I say. I'll be posting more of it when I get some time and hold of some new caps from Jaycar. At the moment, after Phase 3 it should only cost $6.60~ :thumbup: :D

    Reviews of the AV-710 lets see... Stephonovich has done a nice job on Head-Fi.org . A common complaint is that its a bit harsh on the cymbals, and overall the sound is good without an amp, but this mod will get you more bass :D
     
  13. OP
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    decayed.cell

    decayed.cell Member

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    Okies got some new caps hopefully doing Phase 1 tomorrow :D
     
  14. Goth

    Goth Grumpy Member

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    Have you considered using Tantalum caps instead of the larger Aluminium electrolytics?
     
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    decayed.cell

    decayed.cell Member

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    Tantalums tend to thin the sound... electrolytics give a fuller sound ;). I've got Polyesters bypassing them so that should take care of the impedance
     
  16. PooJou

    PooJou Member

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    Are you sure you won't do the mod for me? I'm happy to pay a fee :) - my speakers are complaining about the quality :upset:
     
  17. OP
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    decayed.cell

    decayed.cell Member

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    Lemme get my own done first lol... I have a feeling that the output caps I ordered are a bit too big (goddamn Jaycar website must have had the wrong dimensions)
     
  18. orF

    orF Member

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    Try upgrading the crystals and see what difference it makes.
    Something from here maybe: http://www.hy-q.com.au/
     
  19. Goth

    Goth Grumpy Member

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    Would replacing the crystals really make much of a difference? You can't change the frequencies, if that's what you're thinking.
     
  20. orF

    orF Member

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    Higher quality crystals with more accurate timing should make a difference.
     

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