Modding a DVD-V/A SACD player

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  • schwarcw
    schwarcw Posts: 7,338
    edited October 2007
    Nice work Larry! Any thoughts to "beefing up" the wiring in the power supply and other key wiring?
    Carl

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  • Systems
    Systems Posts: 14,873
    edited October 2007
    schwarcw wrote: »
    Nice work Larry! Any thoughts to "beefing up" the wiring in the power supply and other key wiring?

    Larry?:eek: :confused:
    Other than adding a real power cord to replace the piece of thread they included with the unit, I think I will just wait and see how far these mods get me.Adding the new dedicated supply with sufficient guage wiring should be enough.
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  • hypertone
    hypertone Posts: 150
    edited October 2007
    GV#27 wrote: »
    Great,what model of CDP and what will the 2604 be replacing?You should post some pics.

    It's just a Yamaha CDC-645 I picked up for $20. It came with some JRC 2068 opamps. I started the project, but I didn't have all the parts yet, so I'm still running the old opamps. I removed the mute circuit and soldered in the IC sockets. I tried removing a lpf between the DAC and the opamps, but that was a bad idea and made it noisey, so I've ordered some parts to fix that.

    I found this excellent desoldering tool at work. It works so well the opamps literally just fell out, and were in such good shape that they still were usable in the sockets until the BB amps get here. I highly recommend one of these to anyone who is removing components from a pcb.

    desolder.jpg

    pcb.jpg
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  • Systems
    Systems Posts: 14,873
    edited October 2007
    hypertone wrote: »
    . I tried removing a lpf between the DAC and the opamps, but that was a bad idea and made it noisey, so I've ordered some parts to fix that.
    I don't think its wise to remove the LPF but you may want to upgrade any output coupling capacitors as they are most likely cheap electrolytics.Depending on the DAC used you may even be able to eliminate them entirely as long as DC offset is very low.The 2604 has very low offset so you may even be able to eliminate the output caps entirely.It will depend on the type of DAC the Yammy uses and if it outputs DC.
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  • schwarcw
    schwarcw Posts: 7,338
    edited October 2007
    GV#27 wrote: »
    Larry?:eek: :confused:

    Sorry, too much Polkfest on the brain.:o

    That desoldering tool looks like it's as large as a toilet plunger:eek:
    Carl

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  • hypertone
    hypertone Posts: 150
    edited October 2007
    Lol, yeah it looks huge in the pic for some reason, it's not much larger than a standard soldering iron.

    I just discovered my rail voltage is +/-7V to the opamps. Is this going to pose a problem when I put in the Burr Browns? I've ordered some OPA2134's. Does anyone know if sound quality will suffer from such low rail voltage?
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  • hypertone
    hypertone Posts: 150
    edited October 2007
    GV#27 wrote: »
    I don't think its wise to remove the LPF but you may want to upgrade any output coupling capacitors as they are most likely cheap electrolytics.Depending on the DAC used you may even be able to eliminate them entirely as long as DC offset is very low.The 2604 has very low offset so you may even be able to eliminate the output caps entirely.It will depend on the type of DAC the Yammy uses and if it outputs DC.


    The only coupling caps in the analog signal path are between the LPF and the first opamp. I have some poly caps ordered to go in this spot. I wired the last opamp's outputs directly to the RCA jacks.
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  • Systems
    Systems Posts: 14,873
    edited October 2007
    hypertone wrote: »

    I just discovered my rail voltage is +/-7V to the opamps. Is this going to pose a problem when I put in the Burr Browns? I've ordered some OPA2134's. Does anyone know if sound quality will suffer from such low rail voltage?
    The 2134 will be fine with the +-7 volts.It can operate on as little as +-2.5 volts.
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  • Systems
    Systems Posts: 14,873
    edited October 2007
    hypertone wrote: »
    The only coupling caps in the analog signal path are between the LPF and the first opamp.
    It is most likely there to block DC from the output of the DAC.
    I have some poly caps ordered to go in this spot
    Good plan.
    I wired the last opamp's outputs directly to the RCA jacks.
    I s there a 100 ohm or similar value resistor between the opamps output and the RCA's?It should have one.
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  • hypertone
    hypertone Posts: 150
    edited October 2007
    GV#27 wrote: »
    It is most likely there to block DC from the output of the DAC.

    Good plan. I s there a 100 ohm or similar value resistor between the opamps output and the RCA's?It should have one.

    I don't have a resistor in there. Would the resistor be there to prevent feedback or distortion? I have some 180 ohm metal film resistors I could put in there, it seems to be working fine, but I can throw them in when the rest of my parts arrive.
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  • Systems
    Systems Posts: 14,873
    edited October 2007
    The resistor is there to isolate the opamp from any capacitance in the output interconect cable that may cause instability.

    180 ohms is just fine.
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  • hypertone
    hypertone Posts: 150
    edited October 2007
    I completed the project and it sounds much better. The CD player always seemed to have a really forward and aggressive sound. Now it is much more laid back and the treble is more pleasant. The soundstage seems narrower though. I'm going to experiement with different opamps. Is pure satisfaction with sound even acheivable? :confused::D
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  • polkatese
    polkatese Posts: 6,767
    edited October 2007
    I have an APL-DV-563A mod:

    http://www.aplhifi.com/Pioneer563a.html

    I thought I linked in here the information of what Alex Peychev did to it. It is an obsolete mod since as you know, DV-563A has been OOP for a couple years. Mine is still going strong and hasn't had the urge to replace since then.
    I am sorry, I have no opinion on the matter. I am sure you do. So, don't mind me, I just want to talk audio and pie.
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  • ben62670
    ben62670 Posts: 15,969
    edited October 2007
    GV#27 wrote: »
    I made some progress over the weekend and partially completed the two op amp boards.I still need to install the components that form the low pass filters.I used chip sockets which will allow for easy swapping and comparison of different op amps in the future.
    The blank double sided copper board shown in the pic will be mounted underneath the new boards.This should help shield them from RF produced by the digital circuits on the main board directly below.

    Can't do much more until I recieve my parts order from Digi Key.:(

    I like the fact you are using a socket for the op amps. I dabble in electronics a bit, and was curious... do manufactures (Sony for instance;))use sockets for their op amps, or is that just genius on your part:)
    Thanks Ben
    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 October 2007
    hypertone wrote: »
    Is pure satisfaction with sound even acheivable? :confused::D
    Maybe for a few minutes.:D


    polkatese, the DV 563 with a properly modded analog stage such as you have ,can really be a decent sounding player.;)Im certainly pleased with the first unit I did.(still have some work to do on the second unit).
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  • Systems
    Systems Posts: 14,873
    edited October 2007
    ben62670 wrote: »
    ... do manufactures (Sony for instance;))use sockets for their op amps,
    usually manufactuers do not use sockets because a solder connection is better and more reliable.Also many of the units produced in the last few years use surface mount parts which make it difficult to change IC's unless you have the right soldering equipment.
    is that just genius on your part:)
    He he definately not genius:D just for convience.I used the gold plated machine pin type as they make better contact with the chips leads.
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  • ben62670
    ben62670 Posts: 15,969
    edited October 2007
    GV#27 wrote: »
    usually manufactuers do not use sockets because a solder connection is better and more reliable.Also many of the units produced in the last few years use surface mount parts which make it difficult to change IC's unless you have the right soldering equipment.He he definately not genius:D just for convience.I used the gold plated machine pin type as they make better contact with the chips leads.

    I like the swap ability:)
    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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  • polkatese
    polkatese Posts: 6,767
    edited October 2007
    GV#27 wrote: »
    Maybe for a few minutes.:D


    polkatese, the DV 563 with a properly modded analog stage such as you have ,can really be a decent sounding player.;)Im certainly pleased with the first unit I did.(still have some work to do on the second unit).

    yep. can't complain. It's actually make me appreciated my LSi15 even more since it let me hear micro details..:)
    I am sorry, I have no opinion on the matter. I am sure you do. So, don't mind me, I just want to talk audio and pie.
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  • Systems
    Systems Posts: 14,873
    edited November 2007
    I finally have the second unit up and running.I have so far only tried redbook CD's using the main outputs.The LM 4562 opamp sounds smooth and creamy but in direct comparison to the first unit the sound stage while sounding big and open it's as though it has been moved back several feet.
    Im not sure I like this mid hall perspective:confused:Also the discrete output stage in the first unit has supierior bass extension and drive.So far the differences in SQ are greater than I was expecting.Next up will be comparisons of both 2 ch and multi chan DVD-A and SACDs.
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  • McLoki
    McLoki Posts: 5,231
    edited November 2007
    GV#27 wrote: »
    The LM 4562 opamp sounds smooth and creamy but in direct comparison to the first unit the sound stage while sounding big and open it's as though it has been moved back several feet.
    Im not sure I like this mid hall perspective:confused:

    For those of us not paying attention - what op-amps are you comparing to the 4562? Do you like the 4562 or the other better? I have not modded my DSP board yet in the NAD (its next to go) - still deciding what opamps to go with. (would have to match to the LM4562 in my output stage)

    Michael
    Mains.............Polk LSi15 (Cherry)
    Center............Polk LSiC (Crossover upgraded)
    Surrounds.......Polk LSi7 (Gloss Black - wood sides removed and crossovers upgraded)
    Subwoofers.....SVS 25-31 CS+ and PC+ (both 20hz tune)
    Pre\Pro...........NAD T163 (Modded with LM4562 opamps)
    Amplifier.........Cinepro 3k6 (6-channel, 500wpc@4ohms)
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  • Systems
    Systems Posts: 14,873
    edited November 2007
    McLoki wrote: »
    For those of us not paying attention - what op-amps are you comparing to the 4562?
    As detailed in post #1 the first player has a OPA2604 that has it's output buffered by a discrete high current opamp.The second player has an LM4562 to drive the outputs(so no discrete op amp).For comparison I also plan at some point to replace the LM4562 with a OPA 2134.
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  • hypertone
    hypertone Posts: 150
    edited November 2007
    Take a look at the OPA 2228 as well. I tried both in my phonostage and the 2228 is more open and present. The 2134 sounded a little veiled in comparison. I'm thinking of "rolling" the 2134's in my cd player with 2228 now.
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  • Systems
    Systems Posts: 14,873
    edited March 2008
    Having had lots of time to do comparisons between the two modded players I still have a strong preference for the first unit.While the mods on the second unit certainly improved it sonically ,everytime I put it in my system I was anxious to return to the first unit.The comparison proved in my mine atleast that the analog output stages in digital components have a large effect on SQ.The discrete class A op amp in the first unit beat the highly touted IC op amp in the ares of bass detail and depth,more detailed mids and better dynamics.
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