Here are some updated notes on my Oppo 980 mod.
First a brief overview of my system for context. Sources are a SB3 w/ DIY linear 5v PS, VPI TT/Dynavector Cart for vinyl, and whatever shiny disc spinner I happen to have at the time. Preamp is ARC LS14, mainly for the phono stage as the line stage is good but not great. Amps/speakers are a pair of Quicksilver monos with 6550s driving VMPS RM30s. Stereo subs are a pair of 15” folded cabinet dipoles fed by an Outlaw ICBM xover, a Behringer digital EQ, and a Hypex 200 w stereo amp. Surround provided by a pair of Magnepan MMG-Ws driven by a Hypex 90w stereo amp. All low current gear plugged into my four circuit, eight transformer uber-Felicia. All amps plugged into an Equitech 2Q BPT.
Transport Issue
When I last posted I mentioned that once I reassembled the Oppo after the mod it wouldn’t read SACDs or DVDs. Turns out it was a faulty transport mechanism. With a new transport in place the 980 works just fine. No problems playing SACDs and DVDs. My guess is that the original transport never did read SACDs and DVDs but I didn’t bother to test it before I started my mod. Doh!
Don’t do what I did. Test your player before you start hacking away at it.
Transformers
Bypassing the opamp output stage in the Oppo cost me a lot of gain and I really had to crank up my preamp to deliver enough signal to the power amp. On a lark, I inserted a pair of Lundahl LL1678 moving coil step up transformers between the Oppo and my preamp. The transformers are set for 14 dB of gain. I fully expected the transformers to overload, but they didn’t and it sounded good. Next I disconnected the preamp and ran the Oppo through the transformers directly into my amp and used the Oppo’s RC for volume control. This gave me all the gain I need and it sounded phenomenal! Speed, clarity, dynamics, and dimensionality that the preamp just can’t deliver. I put my ear right up the speaker and hear no noise, and this is with a tube amp in the system. I can’t get over how palpably REAL this sounds. I’ve got to get a few others over to listen to this to make sure I’m not deluding myself. I ended up mounting the transformers in a box with a three way source switch so I can run my Oppo, SB3, and the ARC phono stage through the transformers to my amp.
HDMI
I listen to a lot of multichannel SACD/DVD-A music, so Ted’s comment about using the 980’s HDMI output into an Onkyo processor for M-C hi-rez discs piqued my interest. Kal Rubinson wrote about the same thing in his Music in the Round column just posted on Stereophile.com.
So I borrowed a friend’s Denon AVR2807 receiver to experiment with. The 2807 has HDMI 1.1 so by going Oppo HDMI > Denon preamp out > amp, DVD-A and SACD surround is decoded as PCM in the Denon and sent on to my amps/speakers. I had high hopes for this setup, given what I’ve read about the benefits of Audyssey room correction and a 5.1 hi-rez digital connection.
I went through the Audyssey setup and got everything configured. It did work, but it didn’t sound all that great. Whatever benefits that were gained through the Audyssey DRC and the HDMI connection were lost due to an increase in digital grain and an overall lack of transparency compared to the Oppo analog > transformers > amp setup. This is probably more of an indictment of the Denon receiver’s line output stages than anything else. I’ll certainly try this again if I can get my hands on a high quality HDMI 1.3a processor to see if I can get a better result. For now, analog 5.1 from the Oppo sounds much better than the HDMI approach.
Bybees
A few weeks ago I got a hold of four slipstream bybees to experiment with. Putting one bybee on the +5v pin of the linear PS plug worked really well. It lowered the perceived noise floor even more without dulling the sound. Putting bybees in the analog signal path didn’t work for me. The bybees seamed to soften leading edge transients and added a weird energy to the lower treble. Removing the bybees from the signal path put back the transient snap and recaptured the open, organic character in the top-end.
Overall Listening Impressions
The modded Oppo 980 (mods as described in my first post) sounds really good! As mentioned above, I use the Oppo remote volume control for an ultra-simple and clean DAC > Cap > Transformer > Amp signal path. It sounds better than my SB3 playing back the same tracks. It’s quieter and reveals a whole layer of low level detail and textures that the SB3 misses. The music has a very organic quality to it with little, if any digital etch. The soundstage is very open and dimensional, though not as expansive or rich as the best players I’ve heard. SACD performance is on par with CD, maybe a little better on some discs. Must be the PCM conversion because the very best SACDs are not as delicate and expansive as I remember them sounding on my Sony NS999ES (r.i.p.). SACD and DVD-A multi-channel music really sounds phenomenal on this player. The Oppo fully delivers on this front.
So overall, I’m pretty happy with the results. No, this is not a world class digital player. But it is very musically satisfying given the cost and effort I put into it, and should keep me happy until next digital revolution sweeps over us (in about 3 to 6 months or so).
Russ