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My completed Toshiba 3950 Mods...

Posted by Vinnie R. (M) on March 7, 2004 at 11:43:03

All,

Below are the mods that I have finished on my Toshiba 3950. My review of the resulting sound follows the list. I hope that others will find this information useful and informative. Feel free to contact me for any details that I missed:

TOSHIBA 3950 MODS

POWER SUPPLY PCB MODS

-->Replace the stock 68uF 200V electrolytic cap with a Panasonic FC
150uF 250V type for better filtering and lower ESR
-->Add a Panasonic X2-rated 0.47uF Noise Filter cap in parallel across C801 and one across C802 for better mains filtering
-->Replace C822 and 824 (10V, 680uF) with Panasonic FC 16V, 1000uF caps
-->Replace C827 (16V, 470uF) with Panasonic FC 16V, 680uF
-->Replace C825 (10V, 120uF) with Panasonic FC 16V, 220uF
-->Replace C821 (16V, 120uF) with Panasonic FC 16V, 470uF

AUDIO PCB MODS

-->Replace C621, C514, C533, C506, C702, C631, C709, C707, C710,
C705, C902, and C910 (all 16V, 100uF) with
Panasonic FC 16V,120uF
-->Replace C918 and C920 with Black Gate NX-HiQ
Non-Polarized 6.3V, 47uF caps
-->Replace dual-opamp IC with Burr Brown OPA2604
-->Add L and R Cardas RCA jacks for stereo output, wired with twisted CAT5e copper wire

*** All soldering done with Kester 60/40 solder

*** All parts obtained from www.digikey.com, except for the Cardas
RCA jacks (www.diycable.com) and the dampening sheets (Home Depot self adhesive vinyl floor tile does the trick nicely!)

TRANSPORT AND DAMPENING

-->Loosen the three screws that hold down the transport (rubber spacer coupled) so they are just snug enough to hold the transport down, but not as tight as they are stock. This allows the rubber spacers to dampen vibrations better (which they are designed to do).
-->Add dampening sheets to the inside of the top cover, under each PCB, on the rear panel, and on the transport. Knock on the top of this player and there is no metallic ringing anymore. It's more solid, less resonant.
-->Added those small, clear radio shack rubber feet where the stock feet were. I love these things, so cheap but they are effective.

***Overall, this is not really that much tweaking, it's mainly part substitutions. Replacing the opamp may be tricky for those who are new to soldering surface mount devices. If this is you, be sure to practice on junk boards that have surface mount parts before you attempt to do this. If you are not careful, you can easily rip up some pads and make a mess. I use solder wick, tweezers, and a 25W iron.

THE SOUND :)

I am happy to report that I am extremely pleased with how enjoyable and musical this unit sounds now!

The bass is very tight, fast, and clean. Compared to the stock bass, there is more of it (just the right amount IMHO) and the quality of it has improved a lot.

The highs are now very liquid, detailed, and a pleasure to listen to. There is absolutely NO LISTENER FAtiGUE to report here folks, I'm talking about beautiful treble that is very similar to the
ack!dack's. It is not rolled off in any way, and it is a joy to listen to! Much improved over the stock treble (changing to the black gates and removing that crappy JRC dual-opamp and putting in the Burr Brown OPA2604 really did the trick!) As mentioned before by Jon Risch, the OPA2604 is a perfect balance between the tube and solid state sound. I agree 100% on this one.

Soundstaging and depth reproduction are superb to me as well. The whole soundstage is push back a bit more than stock (which is what I wanted BTW), and the overall sound is quite 3D. The congestion during complex passages that I noticed with the stock unit is all gone. I think the combination of using lower ESR caps, and using the Black gates and Burr Brown Opamp fixed this problem the most.

As you can tell by now, I am just floored by the sound this weekend. I never thought I'd get so lucky in tweaking this player. I am totally satisfied, and right now have no desire to tweak any further, look any further, etc. I just want to listen and enjoy the music, which I've been doing the last 4 hours. I'm just tearing through my CDs!

I took a few pictures of this tweaked unit that I can send to anyone who is interested. Just email me. They are taken at 2Mb resolution I think, so they are a little big.

I bought another 3950 that I didn't open yet just to have in case I need another transport, but this one seems to be doing fine. Did I mention that it is whisper quiet and does a great job in reading scratched discs? I noticed that it spins faster than a typical player, and must be doing some decent buffering of the data. Last night it read a rented Blockbuster DVD that was in bad condition just fine! I haven't heard this unit skip once yet. The video quality using the S-Video jack to my 27" Sony Wega is brilliant!

Dollar for dollar, this player simply RULES!

-Vinnie

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