[anubisgrau]

has anyone tried similar with 981?

[jkeny]

Tried what anubisgrau?
Blowing up a SMPS?

[anubisgrau]

Tried what anubisgrau?
Blowing up a SMPS?

 

modding oppo 981

i've just got one - not too happy with the stock CD redbook transport sound through altmann DAC with UPCI reclocker employed. excellent resolution and detail, not much fatigue, but not very involving and convincing it's anything but a reproduction. not very musical. would be curious what is there to be done with it.

[anubisgrau]

Does anyone know what opamps 981 uses in analogue stages?

[G.Michael]

modding oppo 981

i've just got one - not too happy with the stock CD redbook transport sound through altmann DAC with UPCI reclocker employed. excellent resolution and detail, not much fatigue, but not very involving and convincing it's anything but a reproduction. not very musical. would be curious what is there to be done with it.

I had a modded 981 that I bought on A'gon, and that was also posted on AudioCircle.  Power supply, caps, and the stereo-channel omp amps had been upgraded.  The seller was a very talented modder, so I assume he took the unit about as far it could be taken for a reasonable cost.  I was impressed with the video, but not with the audio.  Not with CD or SACD.  I agree with your description, "not very musical."  I did like the mechanical quality of the transport--very quiet mechanism.  I sold the unit on AudioCircle, to a buyer who wanted it primarily for video, so he was happy with it. 

I do have a 970 that was modded by a buddy of mine.  He replaced almost every cap, but not the op amps.  I use it for video, and am pleased with it for video. 

[Papajin]

Out of curiousity, has anyone looked at the 983 yet?

[Russtafarian]

I have an update on my 980 mod odyssey (modyssey?).  As soon as I can snap some photos, I'll post the details.

Russ

[ted_b]

I have an update on my 980 mod odyssey (modyssey?).  As soon as I can snap some photos, I'll post the details.

Russ

Modyssey...I like it.   Great name for a new modding company (sorry Dan).   

I look forward to your update.   I think the 980 has potential beyond its stock form, but no clue as to modding.   

[Russtafarian]

Well this project has been on the shelf for a few months, due primarily to Little League season.  Memorial day weekend was the first baseball–free weekend since late February and gave me some time to get the 980 going again.

Here’s what I’ve ended up with.  The best part is, it works and it sounds very good.  I’m not having any of the erratic functionality problems I reported earlier.

 


Yes, those are two outboard power supplies sitting on the player.  One is a dedicated unregulated PS for the DAC and the other box houses the players SMPS.
 


On the back you can see the 9 pin computer-thingy connector in place of the IEC jack.  This is where the outboard SMPS connects to the 980.  Next to that you can see the DC connector for the DAC.



Removing the SMPS from the player gave me room to mount a LT1086 5V regulator near the DAC.  Yes, that’s a Jensen 4 pole cap on the output of the regulator.  If you look closely at where the original 7805 regulator was, you’ll see a red thingy between the blue +5V line from the LT1086 and 5V board connection.  That’s a slipstream Bybee finished in Ferrari red heat shrink.  Stacked on top of that is a 0.1uF polypropylene bypass cap.  To the left you can see the connections from the SMPS box cable to the player's power and control lines.  Soldering the cable to those connectors removed from the SMPS board was a bear, but it made for easy connections inside the 980.



Inside the SMPS box is the 980's SMPS board and a 3A Coilcraft Felicia on the AC input.  I used shielded CAT5 cable from the SMPS box to the 980.  The 8 conductors + ground was just enough for all the SMPS power and control lines.  I hoped getting the SMPS out of the player and shielded in it's own box would make a big difference.  It did make a difference, but it was pretty minor.  Putting the Felicia on the input of the SMPS made a bigger difference.
 


For the power supply that feeds the LT 1086 regulator I’m using a 6V SLA battery with a Panasonic FM 6800uF cap across it.  I’m not married to the battery approach; it was just the easiest solution to wire up at the time.  I’m also going to try an unregulated Linear PS and compare it to the battery to see which one sounds the best. 

The down side to this approach is if the player is turned on but there’s no power to the DAC, the player outputs some loud ugly pulses that are not pleasant to listen to.  With the battery supply, I have to keep the player turned off when not in use.  The battery then has to be turned on before the player is turned on, otherwise YIKES! The NOISE!  So turn on/turn off sequence is important.  An “always on” linear PS would avoid this hassle. Of course, if the battery sounds way better, it maybe worth the hassle.

More comments to follow.

Russ

[JoshK]

Nice job Russ.  Looks like a heck of a lot of work.

One thought to the ugly noise on turn situation...I've thought about this solution to another problem but could be used here....
Think about driving a NC relay with the 6V battery power to mute the outputs, i.e. shorting the outputs.  When the 6V battery power is present, the relay will be open and out of the circuit and the outputs will not be shorted.  This will avoid nasty sound coming out of the outputs when powered on incorrectly. 

P.S.  I am not up to speed on relay offerings, but I think I've only seen 12V and 5V relays in the low volt space.  This wouldn't be a problem though, just use a 5V relay and a voltage divider using resistors.  Look up the needed current to drive the relay and determine the resistor values from that.

[Russtafarian]

Just to make things clear, my Oppo 980 modyssey has turned into an overly worked, ongoing DIY experiment.  I didn’t intend for it to get this elaborate.  It just turned out that way. 

Mounting the SMPS in a separate box was an experiment to see if shielding and isolating the SMPS from the rest of the player would make a big difference.  It did make a difference, but the amount of effort I put into it was not worth the result.  And at this point, it’s not worth the hassle of putting it back the way it was.  Like I said, putting the 3A Coilcraft Felicia conditioner on the AC input of the SMPS made a bigger difference in performance.

What I can vouch for is that putting a separate regulated power supply on the DAC transforms this player into a music-making machine.  The sonic descriptions I posted earlier in the thread still hold true. 

Next up is a linear DC supply that will work in tandem with the battery supply so that when the battery is charging, the DAC is still powered (so as not to fart when the player is on) and still sounds good.  Stay tuned…

Russ

[Russtafarian]

Last night I had a few hours to listen and compare the latest iteration (see above) 980 to my modified 970.  Here are the tracks I used for comparison:


Reference Recordings 30th Anniversary Sampler, Track 4: Liszt: Prelude on B-A-C-H, Felix Hell, Organist


The Fratellies, Costello Music, Track 8: Creeping up the Back Stairs


Stacy Kent, Breakfast on the Morning Tram, Track 1: The Ice Hotel


The Floristan Trio, Dvorak Piano Trio 1, Track 1: Movement 1

Dynamics:  Leading edge transients on the 980 were more apt to startle me rather than bludgeon me like they did on the 970.  When an instrument or passage got loud it leapt out and took over the acoustic space and when it got soft it receded back into its place.  This could really be heard on the Liszt pipe organ piece.  When just higher register pipes were played, the sound receded way back into the acoustic space, like I turned down the volume.  Yet a moment later a full-organ crescendo energized and shook the entire room. 

Moving from Bach to rock (couldn’t resist that one), the opening drum thwacks from Creeping Up the Back Stairs by The Fratellis jumped into the room and grabbed my attention. Rhythm guitar stayed recessed and bathed in cheesy guitar amp spring reverb until the “wall of sound” guitars took over the song.  Imagine that, dynamics in a rock recording.

Noise Floor: The player is dead quiet.  The only noise present comes from the gain stages in front of it.  Low level detail that I hadn’t heard before emerged from a black background and added texture and nuance to the music.   A few bars after the piano opening of Stacy Kent’s The Ice Hotel, the acoustic bass came in and doubled the piano.  Instead of just filling out the piano with lower octave weight, on the 980 I could now hear the upper registers of the bass tracking along with piano note for note.

Space:  Moving from the 970 to the 980 was like opening the windows and flooding the room with fresh air.  Whereas the 970 sounded pleasantly round and rolled off like a decent moving magnet cartridge, the 980 opened up the soundstage like a light and airy MC cart.  The stage significantly increased in height, width, and depth.

Highs: Again, light, airy and extended.  Violin, cello, and piano harmonics from The Floristan Trio just floated off the instruments and hung in the room as they played.  Brushed cymbals on The Ice Hotel rang out with an airy shhhhhhhh rather than the gritty, spitty spray-can-like tssssss that I often hear from digitized cymbals. 

Midrange: Smooth and open.  On Stacy Kent’s voice the slight grain and roughness I heard on the 970 was replaced with a silky naturalness on the 980.  There was an organic bloom in the mid bass that fleshed out the acoustic bass and vocal on The Ice Hotel and the cello and piano on the Dvorak piece.

Bass:  Deeper and better defined on the 980.  On low pipe organ notes, the 980 seemed to be pushing more energy through the subs and energizing the room with more deep bass.  Acoustic bass on The Ice Hotel was full bodied and deep without getting blurred or muddy.

OK, so I think I’ve used every audio cliché in the book.  But I hope you get the idea that with a few mods, the 980 can be transformed into a quite a music maker.

Russ

[jrebman]

Russ,

I'm just a little confused about actually what's in the player now.  Do you still have the transformer coupled outputs?  Do you think you could re-summarize everything that is in the player as it now exists?

Thanks,

Jim

[Jon L]

Dang, Russ, great job! 

I hate working on digital components in small spaces, as I just spent a couple of days making some repairs and doing minor mods to a DAC.