Modding the Toshiba SD4960 DVD/DVD-A/CD/SACD player

Eastwood · « **Reply #140 on:** 30 Aug 2005, 07:51 pm »

Hi all,

I did the mod on the HD841 (Samsung). I did not have a problem with the replacement of the 82 uF 400V cap when using BobM's spec'd 180 uF, 400V cap. Just like BobM said on the 4960, bending the leads and setting it on top of a diode worked just fine. A little snug, but fine. I was also able to fit all 4 soft recovery HexFreds on top of the board.

So far my first listening tests have been very positive. I also modified the multi-channel outputs. I do not really notice any lack of punch with the Swenson mod (of course I have home-grown speakers that use professional drivers...exclusively manufactured for live music). I use a special series crossover, which produces a rather sweet sound out of the horn mids/ horn tweets...a combination that is rather harsh for home use when combined with a parallel crossover. I have never heard speakers such as these sound so warm and live at the same time....anyway enough with the soapbox.

One thing I have noticed (but I was not paying attention to before the mod), that I am unsure if it is normal, is unit heating. The modified HD841 appears to run a little warm (not hot, but warmer than I would expect). Most of the heat appears to be eminating from the power supply area. Maybe the HEXFREDs??? The unit still apears to operate ok though. Have any of you experienced this?

I will try to post a couple dig. pics of my mod. once I get a chance to pull the lid back off.

Thanks again BobM and all you other folks for your geeky tendencies. lol

BobM · « **Reply #141 on:** 30 Aug 2005, 08:32 pm »

Yes, the modded unit ran pretty hot for about the first 100 hours or so, then it seemed to cool down a bit, but was still prettyy hot overall with extended use. It all, or mostly, seems to be coming from the yellow transformer. I took some adhesive backed aluminum tape and made a kind of heat-sink, cutting and bending out some wings on the front and top of this little transformer. You may be able to fashion something similar with aluminum foil.

Be careful if you're putting the unit on Vibrapods or something else soft and squishy. You could melt your V-pod a bit in that front right hand corner.

There was a discussion thread on Audio Asylum about better sound from the 3950/3960 units when they ran hot as opposed to dissipating the heat. personally, these things are so cheap I am a bit worried about them burning out, so I heatsinked mine.

Enjoy,
Bob

Eastwood · « **Reply #142 on:** 30 Aug 2005, 08:55 pm »

Bob,

Thanks for the info. I was thinking about heat sinking what ever was hot. I'll confirm it is the transformer first....wonder if punching air vent slots on the side and top of the cover would give it enough air flow to keep it cooler????

Eastwood.

goldlizsts · « **Reply #143 on:** 30 Aug 2005, 09:25 pm »

Yeap, the 180uf/400V I had to extend the legs (bent a little too so it could sit slightly lower). With only the power supply mod, there is definitely improvement to the sound. Imaging better, resolving better, dynamics better. Before the mod, the sound was just on the dry, or sterile side. It definitely sounds richer now. I'll have to proceed to the other parts to finish the job. Again, I had posted several questions to BobM, which he probably got irritated over. Thanks to you, Bob.

BobM · « **Reply #144 on:** 30 Aug 2005, 09:52 pm »

No problem. Yeah - bad week that week. Kids and wife screaming in my ear that we had to go somewhere when I was trying to write a reply to you. You took the hit, that's all.

Good luck with the rest of the mods and remember to use your imagination with parts placement and such.

Bob

STeveL · « **Reply #145 on:** 20 Sep 2005, 04:47 pm »

Hi all,

Finally found some time to mess with the Samsung.

I have a Superclock 3 that I'm attempting to put into the HD841. I went ahead and removed the clock circuit from the board and soldered in the replacement clock. I seems I've messed up somewhere as the player now powers up, but will not read a disk or even open the drive drawer.

I have the service manual, so here is what I did. Hopefully Bob or someone else with manual and a clue can help out.

Here is what I removed from the clock circuitt. Crystal oscillator ZY1 along with resistors ZR78/75ohm, ZR24/30Kohm, capacitors ZC37/22pf and ZC39/22pf. I could not find ZC38 or ZL10 on the board, so I suspect these do not exist.

I then soldered the positive output from the Superclock to the pad where ZY1 was, this connects to pin 142 of chip ZR36778 the clock input XO. The negative lead from the Superclock I attached to DGND at the - leg of capacitor SAE7.

Any help would be much appreciated, as this is my first clock upgrade and it's not going well so far.

Steve

BobM · « **Reply #146 on:** 20 Sep 2005, 05:17 pm »

Sorry, but one of the reasons I never tried a clock replacement is that it is (clearly) not a simple drop in. It's a fairly advanced mod. I certainly haven't researched it and can't offer any advice at all.

Hopefully someone else can chime in, or you may want to post your question in a separate thread to catch the eye of other experts.

Good luck,
Bob

STeveL · « **Reply #147 on:** 20 Sep 2005, 05:53 pm »

Hi Bob,

Thanks for the quick reply.

I'll continue to poke around with it. Going to borrow a scope from work and see if I'm getting a clock signal at the appropriate locations on the board.

Perhaps I'll post over on Audio Asylum also. I know it's been done, just need to find who is willing to share the steps.

Steve

simon wagstaff · « **Reply #148 on:** 8 Oct 2005, 11:40 am »

Greetings,

I have been reading this thread many times and am anxious to get a player and mod it. I have a friend who will take care of the dirty work. What with software evaporating for hi def music I fiigure this is the best way to get good sound from SACD and DVD-A without spending more money than 50 discs justifys. Now for the stupid questions:

1) Looks like there is an article that describes the mod process in detail. However, the link is dead. Is there an active link for this article or could somebody e-mail iit to me?
2) What is the Swenson mod and where do you find information on it? Is it worthwhile to do this or to just upgrade the op amps or is that a REALLY stupid question?
3) since I wil be buying one of these units and they are both cheap is there any advantage to the Toshiba vs. the Samsung? I guess the case is larger on the Samsung making things easier. Now there is the Samsung 941 which I can get cheap as well. Worth going with this player to mod or stick with the Taoshiba? BTW, don't care a whit about the video performance.

thanks for all your (anticipated) help!

I get out of the way now.

goldlizsts · « **Reply #149 on:** 8 Oct 2005, 12:43 pm »

Simon, by now I think you may have found out already, the Samsung is supposed to be a bit more good-looking? It looks a little more solid. Its remote is beefier. Otherwise, internally they're supposed to be identical. This thing has gotten so cheap that it's at least worth taking it apart and play with. $60 or so can even get you one. The more expensive investment is your time and effort.

I had the Samsung modded (the whole 9 yards of it, the caps, the clock, even new RCAs and Coaxial RCA), and am now using it. So far, the one aspect I have to praise is the increased transparency. The sound otherwise is dry to my ear; something some people call as sweetness is missing. May be over time, as it breaks in more (it's seen only about 20 hours of play time thus far), it may turn out to be more musical to my ear. I am also playing with different hardware with it too, like power cable and amp switching. For example, I initially had a Harm Tech AC 3 in there. When I switched to an Acoustic Zen Tsunami cable, the sound actually got better. So, this Hi-End thing has no end to the frustration; be warned, if you haven't realized already.

sjmikeb · « **Reply #150 on:** 11 Oct 2005, 05:17 pm »

Simon,

So are you talking about Bob's IEEE article? Anyway, this thread has all the info, so you don't need it.

The Swenson mod is taking the output direct from the DAC chip via a coupling capacitor (see one of Bob's initial posts) to new RCA connectors added to the back of the unit.

Changing the opamps looks non-trivial, and I'm an engineer. Of course, my soldering skills are not as good as the techs I work with. Besides, the Swenson mod is a big step-up IMHO.

BTW, I am using Nichicon UPW lytics instead of the Panasonics. In general, I prefer them. They have lower impedance and higher ripple specs. However, the substitution will not be as straightforward as with Bob's recipe. Not all the values are available in the voltages Bob specifies.

I have not completed the mods, just the Swenson mods, and a few cap swaps with parts I had on hand. The parts on order.

So far, I don't forsee any problems fitting any of the parts, but once again, I am not using the same parts as Bob.

Regards,
Mike

sjmikeb · « **Reply #151 on:** 13 Oct 2005, 02:34 am »

Hi Bob,

Just wanted to thank you for doing the pioneering work on this and documenting it in this thread. I was looking for an inexpensive player for a second system.

When I got the Samsung and initially played it, I was a bit skeptical. I did the Swenson mod with some Solens, and bypassed with some Orange Drops I had on hand. I made a few other PS cap swaps with stuff I hand on hand. Basically, I wanted to determine whether I wanted to continue the investment in time.

Well, I am listening now with the player hooked up to my main system. I can't believe how good it sounds, especially considering the dollars invested. Needless to say, I have some better output caps (Aurics) on the way, as well as Hexfreds and more lytics.

Thanks,
Mike

BobM · « **Reply #152 on:** 13 Oct 2005, 12:20 pm »

Yes Mike, it is a surprisingly good sounding player - for the money. And it can be made much better with the mods. Is it a giant killer? Not necessarily so, but I believe it does compete in the $1000 range, or better perhaps.

Then again, if you do your own mods theres the surprise of your friends and the pride of ownership thing going on too, which is always an enjoyable experience in my book.

Glad your having fun.

Bob

sjmikeb · « **Reply #153 on:** 15 Oct 2005, 02:33 am »

Bob,

I wasn't expecting a "giant" killer, but I certainly hear the potential. If indeed when I finish, if it competes with $1000 players than certainly my goals for this project have been exceeded.

Absoultely, on the whole DIY thing. That's why I have built alot of my own equipment, and modded other stock equipment in my system

I will post a report a report when done, and the player has sufficient burn-in time.

Thanks again,
Mike

rhale64 · « **Reply #154 on:** 16 Oct 2005, 03:20 pm »

I have all the parts in except the Swenson mod Sonicaps. I even have the RCAs put in. I am going a different route though on the diode bridge. I have bought a 25.00 dollar bridge from RAM. It has surface mount diodes on it instead of TO220 style. I have all the diodes removed. Here is where I need help. I need to figure out where to solder the wire for each of four legs. I cannot read a schematic to save my life. What i need to know is where on pds01-04 looking at it from the front of the board would I solder for AC positive and neg. Then where for DC+ and DC-. I think I might have it figured out. But I do not want to fry my board because of one mistake. I am going crazy waiting to hook this thing up. I have waited for 2 months for my caps and it is driveing me crazy. So anybody that has the schematic that can read it please HELP ME.

BobM · « **Reply #155 on:** 17 Oct 2005, 12:26 pm »

Sorry - I don't know anything about the surface mount diode bridge. If I'm guessing correctly it's probably just a stand-off little board with 4 diodes on in, and perhaps some additional snubbers. Should be fine.

But in order to mount it correctly you will need to follow the traces. I'm sure you can get some assistance from RAM, but basically you'll need to orient it the same way the current diodes are oriented and connect it at (probably) 4 points to the main board. Can't tell you much else without seeing it and figuring it out myself. You can certainly dio this yourself with a little effort.

If you look closely at each of the diodes you will notice they have a line at one end. Remember, a diode is just a one way valve - goes in one way and out the other and prevents anything from coming back against the current flow direction. If you line up the diodes on the board to the diodes on the RAM card you should be able to orient it correctly. Definitely double and triple check yourself before firing it up.

Good luck,
Bob

GHM · « **Reply #156 on:** 17 Oct 2005, 03:40 pm »

Not sure if this can help you or not. here's some pics I took of a modified Ram 3960 a while back. You can down load the pics and use your computer software to zoom in. The pics are very detailed.

Occam · « **Reply #157 on:** 17 Oct 2005, 04:13 pm »

Rhale -

I would hope that RAM could help you..... otherwise, tell us what is written on the packages and we'll talk you through it. Are they the same as that elegant package shown in GHM's picture?

sjmikeb · « **Reply #158 on:** 17 Oct 2005, 05:40 pm »

I dunno, but 25.00 for a rectifier bridge seems awful expensive. Then, I checked out the RAM website, and now it features a $50.00 "Exotic Diode" Bridge. Seems like quite a markup, less than $10 (probably less than 5) for parts, and maybe another 10 minutes for assembly.

Why would someone want these, rather than just installing some Hexfreds or some other ultra-fast/ultra-soft recovery devices. Seems like the installation is more difficult and not as clean.

Maybe I should start building these on the side

BobM · « **Reply #159 on:** 17 Oct 2005, 05:58 pm »

Well, it may be worth it if it inclkudes that 4 pole Jensen cap too. Those things go for about $40-50 all by themselves. Then again, a few Cree Shottky's hot glued to a piece of wood does sound like a rather large markup. For those #'s it should come with tech support and an installation manual with pictures to boot.

You may find more info on installing this on Ram's own forum.

Enjoy,
Bob