Good or Bad idea?

megasat16
megasat16 Posts: 3,521
edited December 2009 in DIY, Mods & Tweaks
....to mod the Opamps and DAC in my Proceed PDSD? I am currently upgrading all electrolytic in my PDSD. The PCBs are doubled sided through hole type boards so I have to be more careful with them. But I guess I can upgrade op-amps if there will be a major improvement for sound. Currently, here is what in the PDSD. I don't know if it's even possible for DAC upgrade.

AD823AN X 2 (Opamp)
PCM1702 X 2 (DAC)
SN74HCT00N X 1
BB OPA2134PA X 2 (Opamp)
MAL LF351N
74HCT4051N
2N3904
MC7805CT (NLBR929) X 2
LM2940CT
L7905ACV
LM2990T
Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
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  • Systems
    Systems Posts: 14,873
    edited September 2009
    I assume the AD823's are used for the I/V conversion and 2134's for the low pass filter/ output buffer?As long as they are not SMD types you might try Nationals LM4562's(my current fave) in place of the 2134's.
    Are there any ouput coupling caps?if so they might be worth changing to a premium film type.
    I'd Leave the the 1702's alone.


    Proceed made some very good products.
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  • megasat16
    megasat16 Posts: 3,521
    edited September 2009
    Thanks Fred! I think you nailed in about the OP-AMPs. The plugin card has a small switch (subwoofer on / off) to use it as a subwoofer channel or just regular channel.

    I neither have Schema for it nor do I know anyone who has the Schema for it so I don't know. Proceed does make an excellent gears back then and even with 20Bits DAC, it has one awesome DAC. I put some Peectures for you!
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
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  • Systems
    Systems Posts: 14,873
    edited September 2009
    Nice.It appears they use universal 2 ch DAC modules x 3 to get their 5.1 output.And each ch has it's own duigital volume control(The CS3310's).I don't see any coupling caps so it likely has a servo.Swapping Op-amps should be unproblematic since they are 8 DIP's.Are those BB opamps closest to the output 134's or 2134's?
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  • Systems
    Systems Posts: 14,873
    edited September 2009
    After taking a closer look it appears that the AD823'S do the I/V and LPF functions,the first Burr Brown (middle near big brown film caps) is likely a servo and the Burr Brown's closest to the output are the line driver/output buffers,1/2 of each chip for the single ended(noninverted) output and the other half for the inverted part of the balanced output.Replacing these two with LM4562's might be worthwhile.
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  • megasat16
    megasat16 Posts: 3,521
    edited September 2009
    Thanks Fred! The two OPA2134PA near the outputs are probably the final stage of the preamp. I guess these two can be swapped out with LM4562 as you suggested. Any place I could buy the LM4562 cheap?

    Any likelihood of running into oscillation? Guess I should try first. :)
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
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  • megasat16
    megasat16 Posts: 3,521
    edited September 2009
    GV#27 wrote: »
    Nice.It appears they use universal 2 ch DAC modules x 3 to get their 5.1 output.And each ch has it's own duigital volume control(The CS3310's).I don't see any coupling caps so it likely has a servo.Swapping Op-amps should be unproblematic since they are 8 DIP's.Are those BB opamps closest to the output 134's or 2134's?

    I think there is an EPROM (EEPROM) loaded with proprietary software to be front or rear or center and sub channels use. I looked at all 3 cards and they looks identical in all other aspects.
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
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  • Systems
    Systems Posts: 14,873
    edited September 2009
    Digi key carries the LM4562 approx $6 ea.


    You should have no oscillation issues as it appears there is plenty of local decoupling/bypassing supplied by the red film caps and brown electrolytics next to the chips.If the 2134's are stable so should the 4562's be as they are not super hi speed devices.
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  • megasat16
    megasat16 Posts: 3,521
    edited September 2009
    I just looked at DigiKey but the 8DIP packages are not in stock. I checked with Mouser and the same thing. May be eBay stuff? :D
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
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  • megasat16
    megasat16 Posts: 3,521
    edited September 2009
    While I was searching for the LM4562 and found this. I looked for LME49720 from DigiKey but they don't have 8DIP too. TO99 Metal cans are expensive.

    http://www.diyaudio.com/forums/showthread.php?t=107344
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
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  • megasat16
    megasat16 Posts: 3,521
    edited September 2009
    Finally found 8DIP for LME49720 at Newark.

    What cha think, Fred?

    http://www.newark.com/national-semiconductor/lme49720na-nopb/operational-amplifier-op-amp-ic/dp/46M5435

    Newark also has LM4562NA for $4.10. So, I am going to get quite a few of them since they are harder to find these days. Let me know if you need some, Fred! I'll mail them to you. :)
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
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  • ben62670
    ben62670 Posts: 15,969
    edited September 2009
    OpAmps don't roll as easy as tubes, but I have had some fun:)

    Edit: here are the LM4562's
    http://www.newark.com/national-semiconductor/lm4562na-nopb/operational-amplifier-op-amp-ic/dp/32M1177
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • Systems
    Systems Posts: 14,873
    edited September 2009
    I hope it's not a sign that the 8 pin DIP version will soon become extinct:(
    megasat16 wrote: »
    found 8DIP for LME49720 at Newark.

    What cha think, Fred?
    I have'nt tried it but it is a very close relative of the 4562 so should be good.

    Newark also has LM4562NA for $4.10. Let me know if you need some, Fred! I'll mail them to you. :)
    Thanks muchly James,I actually do need a pair for a project.I can refund you the costs via paypal.
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  • megasat16
    megasat16 Posts: 3,521
    edited September 2009
    ben62670 wrote: »
    OpAmps don't roll as easy as tubes, but I have had some fun:)

    Edit: here are the LM4562's
    http://www.newark.com/national-semiconductor/lm4562na-nopb/operational-amplifier-op-amp-ic/dp/32M1177

    Ben, you and I found LM4562 on Newark about the same time too. :D You just found it a minute earlier than me. Thanks!
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
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  • megasat16
    megasat16 Posts: 3,521
    edited September 2009
    GV#27 wrote: »
    I hpoe it's not a sign that the 8 pin DIP version will soon become extinct:(i F

    I have'nt tried it but it is a very close relative of the 4562 so should be good.

    Thanks muchly James,I actually do need a pair for a project.I can refund you the costs via paypal.

    I think 8 Pins DIP are going to become obsolete soon. I can't find them in MCM, Mouser, DigiKey. They are dropping the cheaper line and only carrying TO-99 versions.

    Are you sure you only need a couple? I guess it's time to stock up on them if you need them. I am thinking to order like 12 or more.

    As for the cost, don't worry about it. We are good. ;) You just need to send me a couple of cold ones from Canada. :D
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
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  • lightman1
    lightman1 Posts: 10,789
    edited September 2009
    What the f*ck are talkin' about, Dan?
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  • megasat16
    megasat16 Posts: 3,521
    edited September 2009
    hehe...Lightman lost the bush he regularly uses. Wassup Russ? ;)
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
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  • Systems
    Systems Posts: 14,873
    edited September 2009
    megasat16 wrote: »
    I think 8 Pins DIP are going to become obsolete soon.
    No doudt,many of the newer chips are only available in SMD packages.:(
    Are you sure you only need a couple?
    Yeah thats all for now their for a preamp for my new puter
    As for the cost, don't worry about it. We are good. ;) You just need to send me a couple of cold ones from Canada. :D
    Wow thanks James,do you prefer Molson's or Labatts?
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  • Systems
    Systems Posts: 14,873
    edited September 2009
    lightman1 wrote: »
    What the f*ck are talkin' about, Dan?
    Hey who let you in here?:eek::D
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  • ben62670
    ben62670 Posts: 15,969
    edited September 2009
    Fred what do you think about the LM's over the OPA's?
    I hope they don't us DIYers with smd's.

    EDit: What do you think about OpAmps in pre's compared to transitors? I see you are a fan of the BOZ and other pass designs.
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • lightman1
    lightman1 Posts: 10,789
    edited September 2009
    megasat16 wrote: »
    hehe...Lightman lost the bush he regularly uses. Wassup Russ? ;)
    No shrub is safe!!!
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  • lightman1
    lightman1 Posts: 10,789
    edited September 2009
    GV#27 wrote: »
    Hey who let you in here?:eek::D
    The door was unlocked. I let myself in.
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  • Systems
    Systems Posts: 14,873
    edited September 2009
    ben62670 wrote: »
    Fred what do you think about the LM's over the OPA's?
    When comparing the 2134 vs 4562 in active crossovers my impression was that the LM part was more "transparent" and less "electronic" sounding for lack of a better description.
    EDit: What do you think about OpAmps in pre's compared to transitors? I see you are a fan of the BOZ and other pass designs.
    IC's will generally have lower noise and distortion but we know that doesn't mean much as far as SQ goes. The BOZ is somewhat noisy (think tubes) but definately more musical than the best IC opamp pre I have(a Jung designed AD744/811 combo) though the opamp design beats it in the bass having a tighter more detailed bottom end.

    However the Jfet/Mosfet discrete opamp I have been using for the last five years or so is still my fave by a comfortable margin vs everything I have built before or since.It wins in the information retrieval dept,being detailed without getting clinical or harsh sounding.Aswell it throws a huge soundstage and has excellent bass extension and drive.Powering it with dual stage discrete regulators and a 100VA toroid likely doesn't hurt either.:D
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  • megasat16
    megasat16 Posts: 3,521
    edited September 2009
    GV#27 wrote: »
    No doudt,many of the newer chips are only available in SMD packages.:(

    Yeah thats all for now their for a preamp for my new puter

    Wow thanks James,do you prefer Molson's or Labatts?

    Save the Molsons for personal visit. :D Just kidding. I am looking forward to the mod. :)
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
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  • lightman1
    lightman1 Posts: 10,789
    edited September 2009
    Who the f*ck is Fred? And the only Molsons I know are the ones that make beer in Canada....Eh?
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  • megasat16
    megasat16 Posts: 3,521
    edited September 2009
    lightman1 wrote: »
    Who the f*ck is Fred?

    Now I am sure you lost your shrub or herb or whatever that is. :D:p
    And the only Molsons I know are the ones that make beer in Canada....Eh?
    Yep, that's the Molsons I want. You got problems with that? :):D
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
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  • lightman1
    lightman1 Posts: 10,789
    edited September 2009
    OH ****! You are one of those Cornadians!
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  • megasat16
    megasat16 Posts: 3,521
    edited September 2009
    No! I Do Not Think So! I am 100% not canukians.
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
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  • Systems
    Systems Posts: 14,873
    edited September 2009
    lightman1 wrote: »
    OH ****! You are one of those Cornadians!
    Just sit there ,be quiet and drink your Pabst Blue ribbon won't ya.
    megasat16 wrote: »
    No! I Do Not Think So! I am 100% not canukians.
    Well I'm a purebread Canuckistani thank you.;)
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  • lightman1
    lightman1 Posts: 10,789
    edited September 2009
    GV#27 wrote: »
    Just sit there ,be quiet and drink your Pabst Blue ribbon won't ya. PBR Sucks.

    Well I'm a purebread Canuckistani thank you.;)
    Well at least you're Canadian with some Greek heritage.
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  • lightman1
    lightman1 Posts: 10,789
    edited September 2009
    Stupid **** Merican. Can't multi kwote.
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