The Tosh SD-3950 family — a Generational Development?

lorne

Sonic Lizard
NOTE: I have posted a rather long and completely fresh point of view in regards to a range of Toshiba DVD players. Please see Post 51 in this thread. I have attempted to outline a number of points about the development, marketing and technical variations in these mass-market, but nevertheless interesting appliances. This post (immediately below) remains unedited despite what I now consider inaccurate due to more information and research. Lorne, Sendai, November 2, 2008.

Bear with me because I am not rambling. I hope that we can gather information and facts about the family of budget Toshiba DVD machines as STOCK units. So much has been done in the mods field that enthusiasts are beginning to ask about the genuine lineage.

I believe that the Toshiba family of cheap DVD players featuring a celebrated, attractive audio capacity is the result of an orchestrated, generational development by the manufacturers. Might we be on the edge of something interesting and special here? After all, this is a spin-off to audio from the AV craze that has hitherto subtracted interest in two-channel audio so dramatically?

Toshiba’s current low-end DVD model in Japan is the SD-270J (see below). A net search on this model will yield results numbering in the thousands. Mine had to be back-ordered as they had run out of stock. The Toshiba family of cheap DVD machines has definitely struck a chord in terms of price and function around the planet. I believe the story gets more interesting.

We have two related Toshiba DVD players in the house. They are Japanese domestic models made in Thailand. I bought the first one a year ago so my wife could watch DVDs in the family room. It's an SD-260J which appears to be the equivalent of the 3960. The chassis is plastic like the 3960 and has the same internal metal shield.

My first impressions were decidedly underwhelming. Bright, bold brassy ... ummm interesting, but I remained unconvinced and persisted with the old Sony 222ES on the same system. But Mrs Wife went with the Tosh, and a year later I tossed a CD in it ... and ... I was a new acolyte at the Toshiba shrine. Only my very worked-over NAD-502 in Lorne’s audiomania room could come up to it. And then I killed it in an accident with DC. (I will spare the embarrassing details.)

I had other (vintage) units to replace the NAD, but recently I bought a Toshiba SD-270J (the current model here) for the audiomania room. Could it be the equivalent of the European 3970? In turn could the 3970 be the equivalent of the 3980? I think so. Vinnie Rossi of Tosh mod fame has cited the 3980 as his favourite. It has an all-metal case, but more than that it is just different from the earlier models in some interesting ways. I am guessing at some of this because I have seen no pictures of the 3980’s boards.

On the surface of things, it would seem that the Toshiba boardroom lizards have been reading discussions on all the various audio forums. They have embraced a number of updates we might have asked for, albeit at a price. Duh ... we ARE talking about a $60-$70/7,000 Yen machine.

The latest SD-2XXJ/39XX rests in an all-metal chassis, except for the usual plastic bezel. The PSU PCB is now larger. Perhaps it is borrowed from a more upscale model as a lot of real estate is unfilled yet silk screened for additional or alternate components. The little transformers appear similar, but many, if not ALL the electrolytic cap values have been increased — so entirely that I am wondering if the Vinnie mods to the cap contingent are really necessary in terms of mere capacitance. One is left with ESR and more arcane matters to consider. The caps in the 270J are the standard Rubicon YK series except for the big 200V cap, which is a WA at 82uF. A polyester 22uF X2 rated cap sits on the AC lines as a filter. Much of the ribbon connecter has been replaced by a harness of 300 Volt, 1001 AWG 24 wires. What I take to be the controller chip has a separate black wire threaded around to the far side of the other board. The AC cable is still 0.75mm square, but it is housed in a more robust VCTFK insulation case. (It is annoyingly unmarked as to polarity.) The PSU is simply a new board.

Similarly the 270J/3980(?) AV board is new with 8-10 more caps (all Rubicon YK) than the 3950. The display is mounted on it as well. The big processor is a Zoran — perhaps someone can shed light on this one. The BB-1751, which I take to be the DAC in the 3950, is now a BB-1753. The op-amp is an 8 DIP JRC 4580. Someone might like to comment on whether that is an improvement. I have noted some mixed opinions around the net.

SOUND: this time I did NOT have to wait for a favourable impression. As soon as I popped a disk in it I knew I had a winner. Response from the remote was improved over the 260J, and the disks were loading into process/read much faster. The emotional magic of the earlier emanation was still evident — the very ingredient that got the rage started in the first place. The 270J may be less congested, and the sound stage appears larger in every dimension. I won’t say much more on that score, because I have had both machines on the mania-room system, and I like them both. And, the day is still young. Still, I have to be thinking that the younger unit is better.

Anyway, to tie this up and hopefully kick off some info-sharing on the STOCK Toshiba models, I’ll say this. Seldom do I get the idea that in the electronics world — in particular audio — the boardroom lizards are listening and actually making good on the feedback. But in this case they seem to have been tuned in. Here is a machine family that if anything has been enriched and developed in successive generations without losing its original charm and effectiveness. Successful families often just decline.

Sure, it is not all perfection. No one would expect that. But I am enjoying disks again — enjoying them more than ever before. Considering my current predilection for smoking anything with chip tech in it, I may leave this unit unmodded except for mechanical stuff like dampening etc. Electronically speaking, it’s good enough as is — something not always said about the original grandparent, the 3950. And I’ll be looking out for the next Tosh emanation, which I hope will remain cheaper than a single 300B tube. Keep it up Toshiba!

Over to you guys in Audio karma. Hopefully we can pool enough info to be of use in mod projects down the road. Lorne
 
if ya have a 3960 that suddenly developed dysfunctional sonics, does anyone know where to send it?
 
shrinkboy: I think that Toshiba considers it a disposable item if it should develop problems. Apparently this is the reason why a comprehensive service manual is unavailable AFAIK. On another site, a member paid for the manual only to find that it directed service techs to replace the unit outright. So I guess if it is off warranty, you are on your own. IMHO, if the trouble is on the AV board (ie due to a defective chip or surface mount component) it's effectively toasted.
 
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well, today I finished my initial (and probably ony) mods to my spanking new Toshiba 3950. Because of the low cost of the unit and uncertain longevity I decided to go with the 'less is more' approach (a la Swensen).

Instead of removing the DAC output coupling capacitors (C910 & C912) and tapping in wires that ran outside the unit to large (physically) .47 uF caps that were attached to 'hanging RCA jacks, I decided to make internal mods that were not so homely.

First I removed C910 & C912 to disconnect the DAC from the final digital filter and OpAmp (as did Swenson). Instead of removing the circuit board (as Swenson did) I decided to make the entire mod above the board. The main reason is that the flat strap wiring harnesses are built so flimsily that I decided that taking them apart may cause permanent problems.

I removed the capacitor by grasping with flat nosed pliers and twisting them in a constant circular motion until they snapped off. The first one I tried to snip with dikes but the left over lead was a little short. By experimentation I found the twisting left enough lead to work with.

I used the same removal method to take outC918 and C20 to disconnect the OpAmp from the RCA jacks.

There are two small yellow caps next to the RCA jacks that go between the RCA jacks and ground. Another DIY post claimed by others the removal further enhance the output signal of the Swenson mod, so I performed the twisting removal of those. Starting to be fun by now!

In the (6) capacitor removal, what was left was their leads flat against the circuit board and touching each other at the center. I used a small flat blade screwdriver to pluck the remainig wire away from the board for tinning.

The inner leads of the two small yellow capacitors connect to the signal lead of the RCA jacks so I decided to take advantage of them for my added capacitor connections.

The remaining proceedure is simply to tin the capacitors, and the upright short ckt bd leads and attatch new coupling capacitors.

I ordered .68 Uf poly German made ERO's and the man on Ebay sent a couple of extra samples of ERO .47Uf caps. The .47's were somewhat smaller than the .68's so I decided to use them (they are the size Swnson used anyway). Even tho I had previously figured the .68's were more suited to my Technics SU8600's preamp in, I think the size difference justified using the .47's.

I installed the new ERO's to the short leads left from C910 & C912 and the RCA jack side of the leads left from removal od the small yellow caps.

Because the ckt bd leads were so short (about 3/16") I could not make a mechanical connection prior to soldering and had to rely on a good solder job. This is difficult with two hands and help would be advised to make sure there is no movement while the solder sets.

That's it! Initial sound trials were very satisfying. I have no good reference to what the stock 3950's great sound was like, but It seemed to me that there was a noticeable improvement. I am a opera fanatic so I put on some standards like Rene Fleming and others that I had been listening to for years and I do love what the little unit does for the.....especially when they hit their highs.

sorry for the long wind and no pic's. Every time I try to upload a pic I use way two many bits of info and get rejected. Chuck
 
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Good on ya Chuck! I have wondered about the Swenson mod for the 270/3980(?) but I haven't heard of anyone doing it yet. Recent failures have me shy of being a pioneer. Has anyone compared the sound of a stock 3980 with a swenson modded 39XX?
 
I now have two 3950s modified by Larry Moore. The first one I got a year ago, and it's great.

The second one I got last month, and it's BETTER. He has some new tricks, and he really used them.
 
Strangely enough, I broke out my modded 3960 today. It only has about 20 hours on it since the mod, and the guys in the know seem to recommend at least 100. One other thing I noticed is that this thing sounds a LOT better when it is warm. I found a post by Swenson later on saying the same thing. The first few minutes of listening are uninspiring, to say the least. Once warmed up, the veiling in the mids just lifts off and it starts sounding pretty darn amazing. Was about to sell it, but now I am having serious second thoughts. Gonna give it a good burn in and see how she sounds.
Erik
 
Just went by the local BB and saw the 3990. All metal case and same specs on the audio DAC. Nice looking update, wonder how it compares to "grandpa".

I haven't done any electronic mods to my 3960...only dampening. Added some heavy vinyl tile to the inside of the case top and the case and alot of rope caulk to the transport and case edges. This improved the sound quality noticeably. I might just have to break down and do the Swenson mods....sigh. Thanks for the play by play AK 47!
 
Crotalus wrote:
Just went by the local BB and saw the 3990 ....
Jeez — a 3990! That must make the 3950 "Great Grandpa". How did you find the specs on the DAC? Can you post them? I can't even find a pic of one yet.
 
Bigerik wrote:
One other thing I noticed is that this thing sounds a LOT better when it is warm. I found a post by Swenson later on saying the same thing.
And I guess you know that ‘Standby’ won’t do it. It's gotta play. Well at least my tube pre-amp is in synch :D

I wonder what the heatsink mods do in relation to this? You can see this mod written up and illustrated in a step-by-step account posted by Raul Saavedra over at Hi-Fi and Portable Audio — http://www5.head-fi.org/forums/showthread.phps=fe199c5354d645a9c9d98a25e913e0ac&t=70377&page=1&pp=25 Sr. Saavedra has done a comprehensive job on his 3950. Perhaps the stock machine is running too hot for its own health. This may be an indication that it's not intended to last forever. Burn it up and toss it when the chips fail. :bigok: except if you modded it like crazy. :scratch2: If we apply heat sinks to the chips, just how will they affect the ambient, optimum operating temp. of the chip? Some users say they can too hot to touch.
 
There are "sd-k750"s in costco that look to be of the same family, they also have the 24bit dac. Anyone know how those sound? Will they take the same modifications?
 
lorne said:
Bigerik wrote: And I guess you know that ‘Standby’ won’t do it. It's gotta play. Well at least my tube pre-amp is in synch :D

I wonder what the heatsink mods do in relation to this? You can see this mod written up and illustrated in a step-by-step account posted by Raul Saavedra over at Hi-Fi and Portable Audio — http://www5.head-fi.org/forums/showthread.phps=fe199c5354d645a9c9d98a25e913e0ac&t=70377&page=1&pp=25 Sr. Saavedra has done a comprehensive job on his 3950. Perhaps the stock machine is running too hot for its own health. This may be an indication that it's not intended to last forever. Burn it up and toss it when the chips fail. :bigok: except if you modded it like crazy. :scratch2: If we apply heat sinks to the chips, just how will they affect the ambient, optimum operating temp. of the chip? Some users say they can too hot to touch.

Got a dead link there. Will have to go hunting for it.
Yeah, weird catch 22, isn't it? It doesn't sound good until it is hot, but running too hot will eat it up. Go figure.
Wonder how long these guys are lasting anyway? AA seems to be the centre of the universe for these things. Maybe I should throw a post overthere too.
E
 
>>shrinkboy: I think that Toshiba considers it a disposable item if it should develop problems. Apparently this is the reason why a comprehensive service manual is unavailable AFAIK. On another site, a member paid for the manual only to find that it directed service techs to replace the unit outright. So I guess if it is off warranty, you are on your own. IMHO, if the trouble is on the AV board (ie due to a defective chip or surface mount component) it's effectively toasted.<<

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got that, lorne. i was just thinking through my fingers as i read that i'd like to find an address for toshiba and take a shot at sending mine back to see if they'd gimme a replacement, but then i thought, by the time i've paid shipping, i'm at least half way towards paying my initial outlay on the thing. i just hate tossing a basically intact unit in the bin!!
 
Keep the Sled

OK, here are some ideas — I know from experience. I have been too embarrassed up to now, but I'll confess: I smoked my first 270J/3980(?) :sigh:

I was removing the PSU board and flipping a three terminal wire retainer thinking that the single black wire involved was attached to the retainer dingus. Boing! Off popped the retainer, and out flipped the wire. :eek: I couldn't remember what pin it was on, and for once I had neither taken pics or done drawings. I probed about with the continuity tester and made a guess based on the fact that it appeared to feed voltage to a certain chip on the AV board. Two pins were putting out about 5.5 Volts. The middle one was puting out an ambient range in millivolts. I estimated that the chip was wanting macho voltage — WRONG! :nono: After that the transport did nothing but open continuously and refused to upload data indicating that I fried the suspected chip.

Here is where my suggestion starts: I saved the murdered unit and found a new one. Now the old one now is empty of all the guts and completely lined with bitumen dampening tape. I will add some copper shielding next, after which I will transfer all the new guts into the older chassis. Using the smoked unit, I have experimented with how to take the entire insides out of the chassis without disconnecting a single wire or tape. It's a simple switch, and barely no downtime from playing music involved. I think that even I can do it without a disaster.:yes:


And I'll save the transport in case the pickup in the new one dies. I can also stuff the the old PSU with some cool caps and transfer that later too — now that I know which is the correct pin etc. :D:

My DIY blunders are getting expensive, but at least I am rescuing some stuff. You never know, if I keep blowing things up I might start a used parts business — or incurr a divorce, which ever comes first! Just a few thoughts ... don't dump just yet. Maybe you can use something.
 
AK 47 said:
crotalus.....did you get a price on the xx90?

BB was running a sale on them for $59.....they were all gone but the display. :thumbsdn:

Lorne, sorry to mislead you, I just meant the DAC was the 192/24bit at least. Not sure of specific specs.
 
WARNING!! one of the dudes on the DIY forum located a 3950 service manual on CD. Bought it for 50 clams (lots of members were willing to buy the schematics to ease the burden).

He finally got it and it was (4) pages that said "If it is under warranty, Toshiba will replace the unit.....otherwise, toss it, it is unrepairable....!!)

$50 would have bought a replacement unit.....!!! :tears:
 
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this is short for what I did: removed C910/C912 to disconnect DAC from output.

Removed C918/C920 to disconnect the op amp from the RCA jacks'

Removed the two small yellow caps that shunt the RCA jacks to ground.

Installed .47Uf caps between C910/C912 input stub leads to the stub leads left by the yellow caps.
 
Crotalus wrote:
Lorne, sorry to mislead you, I just meant the DAC was the 192/24 bit at least. Not sure of specific specs
Quite all right ... and in fact what you say is interesting. As every owner knows, the entire family (AFAIK) comes with "192 kHz 24 bit Audio DAC" clearly silk screened on the bezel. Toshiba literature on the net tags the audio performance as 'high resolution'. I can't say if this is unique among cheap offerings on the DVD planet, but the fact that Toshiba touts this as a selling point specifically spells out how audioholics benefit from a spin off. We red book people are not getting the full milage out of the chip, but the gains in terms of the price are significant. And my main point is: the situation is not accidental. In my travels around the budget shelves, I did not find other companies directing attention to the audio section. Of course, this in itself does not mean other makers are slacking off in the audio department.

If the industry percieves that Toshiba is at an advantage here, perhaps a contest will emerge among makers of budget machines to supply the best audio available given the price niche. If that comes to be the case, how long do you think it will it be before we see LM833 op-amps appear in the output stages of DVD gear? — an inexpensive component, but one that is a much better choice than what we are hearing today.
 
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