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

rhale64 · « **Reply #300 on:** 18 Jan 2006, 09:13 am »

Well people I know this thread is kind of dead but I need some help. I bought me some opamps. I am wanting to put them in at AE4 and 5. These are the multichannel opamps. These are for the fronts. I have lost my schematics. I need to know what caps to replace. And what are the values I should use. Bob or Steve please help. I got the OPA 627s. I also have the OPA 637s and need to know if these might work. They need gain over 4 preferably 5 to be stable. This is noise gain. What the heck is this? I would really rather use the 637s if I could.

BobM · « **Reply #301 on:** 18 Jan 2006, 12:39 pm »

Sorry - I don't know what either of these opamps need, power wise, to run them. They might need the same amount of power as the existing op-amps, in which case its a drop in. But if its different you will have to accommodate that by picking up power somewhere else in the circuit and modifying/regulating it to the correct value.

You need to pore over the spec sheets for all of these op-amps and figure it out.

Good luck,
Bob

PS - This is one of the reasons I stayed with the Swenson mod.

rhale64 · « **Reply #302 on:** 18 Jan 2006, 06:28 pm »

Bob thanx for the quick reply. Now that I have your attention which caps should be replaced? The reason I am asking you is I think you are the only one with a manual now that I have lost mine. I am wanting to change the opamps associated with the multichannel outs. I know the caps that are associated with these are AE4-5 which others should be replaced? And should I change the values of any of them? It says in the BB data sheet that the opamps should be bypassed with .47-1uf caps. Does this mean I would change the values on the board to one of these two values? Or would I put these caps on my BrownDog adapter in lieu of the other caps on the board? Thank you

mcspack · « **Reply #303 on:** 31 Jan 2006, 08:45 am »

trying out the jensen cap but I'm not sure how to wire it up correctly, I've read the schematic on Ram's website and the white paper so I have some understanding but when I look at the circuit board and in particular the diode bridge it is a little confsing, there is a large capacitor beteen the pds01 -pds02 diodes and te + on the circuit board where the old two pole cap hooks up originally. I assume I could just take the lead going from this cap and instead of connecting it to the board connnect it to the + imput of the jensen with the + output going to the + circuiit board connect, but which negative lead from the pds03-pds04 do I raise off the board to connect to the - input of the jensen? (curcuit board - going to the jensen - output) or do I raise both up and connect both of them to the negative lead?? maybe someone with the schematic can help or someone who has done this 4 pole cap mod.

thanks in advance,

Mc

compressit · « **Reply #304 on:** 1 Feb 2006, 12:40 am »

I hear you with the RAM diagram for the 4 pole Jensen. When looking at that whole situation past the rectifier diodes there are no clean and clear lifts to isolate the Jensen. There is always capacitance or resistance atached to the circuit traces, not true isolation. I may be way off thinking like this but, well thats me. Here's what I did, kind of un-couth but it worked well for me. Took a dremel tool and cut a complete void through the copper trace just before where the original cap connects. Just light pressure cleanly cuts the copper. Scrape a bare area and solder. Other end of Jensen goes to original cap location. Took all of about 5 mins. Beat the hell out of staring at the RAM diagram for 2 days. Enjoy the 25 min roller coaster ride listening to that Jensen settle in.

compressit · « **Reply #305 on:** 1 Feb 2006, 12:59 am »

I see this conversation is just about dead. How about a quick pick me up? I took a 24ga wire and made a ground loop through the circuit board. Scraped new areas next the existing grounding areas near the mounting screws and soldered the wire to those areas and also tank cap, transformer, ground legs of the 8v 78/7908 regulators, and anything else that made a beep on my meter to ground that was on the perimeter of the board including a few cap legs. I also bypassed the output of both 8V reg. to this new ground loop with a .1 and .01uf ceramic. I got one hell of a response out of this. A lot more overall clarity, and CHEAP. My kind of tweek. Give this a try.

compressit · « **Reply #306 on:** 2 Feb 2006, 12:25 am »

On my last post on the ground loop, I DID NOT include the neg. leg of the the tank cap PER10 as I mentioned.
I did include the neg leg of PICS5/6. This was not mentioned.

mcspack · « **Reply #307 on:** 23 Feb 2006, 08:57 pm »

Hey nice ground mod, I may try it, I did get the jensen working the way I thought, by raising the negative legs of two of the diodes and routing those to the jensens negative input. The jensen does sound amazing but so did the pani that I had broken in already??? still Its more dynamic now. I was wondering if Rhale had finished his opamp output mod I was wondering how he implemented it including parts etc...??

also has anybody tried modding the other samsungs out there 850 941 959??

my next mod for this unit is the clock I have a hagclock that I will buildand put in does anyone know where I can tap into the voltage that I will need??

thanks,

mc

BobM · « **Reply #308 on:** 23 Feb 2006, 10:58 pm »

Interesting topic on Audiogon:
http://forum.audiogon.com/cgi-bin/fr.pl?ddgtl&1140659282&read&3&zzlPmarcian&&

Here's the quoted text of the lead post:

Just read that movie studios want this great little affordable player recalled because you can "back door" the region code. I have one in the bedroom. Plays SACD, DVD Audio, good redbook CD, has DVI out, etc. I think people have been having them modded as well. Better get yours now!

http://www.engadget.com/2006/02/20/samsung-sued-over-dvd-duping-by-discontinued-player/

Pmarcian

watchdoc · « **Reply #309 on:** 5 Mar 2006, 06:13 am »

I own a Samsung HD950 and want to do the Swenson mod for 2 channel SACD listening. I have a CarverPro ZR1000 amp driving Martin Logan SL3 electrostatic speakers. The Carver is a Tripath digital amp with deep power reserves that can drive the difficult loads that Electrostatics present. The Carver has its own volume controls built into the amplifier so I would like to forgo a preamp altogether and keep the signal path as direct as possible. The Carver can accept balanced or unbalanced signals and has an input sensitivity jumper. I would like to do the Swenson mod and add XLR balanced outputs to the back of the 950 so I can connect it directly to my amp. The input impedance is listed as 50k balanced. It doesn't have a listing for unbalanced. From the Carver manual, the sensitivty input options are as follows.

0.316Vrms (common consumer electronics)
0.775Vrms (default "most common" line level calibration)
1.230Vrms (common with pro audio gear with balanced outputs)
2.450Vrms (devices with large voltage swings, ie line level devices)

Please let me know your opinions on this idea.

1. Would balanced outputs be feasible and worthwhile? I have always read that XLR was a cleaner and more noise free connection.

2. Can you add 2 channel output directly from the DAC and still retain the 5.1 output from the stock RCA jacks? I don't want to disable the stock RCA outputs.

3. Considering my equipment, what parts suggestions would you have and where can I buy them? I'm not experienced in this area and I'm hoping you all can help me match the parts to this application.

4. Finally, while the 950 shares most of the same chips as the 4960 (phillips HL7893, Zoran 778, and Burr Brown DSD1608), the board layout is completely different. Does anyone know the best place to do the swenson mod tap without me buying a manual?

david

watchdoc · « **Reply #310 on:** 5 Mar 2006, 05:28 pm »

Responses on audioasylum have led me to believe balanced output may be a large amount of work. If this is the case, I will simply use unbalanced RCA outputs instead. Once again, input from all is welcome.

mcspack · « **Reply #311 on:** 10 Mar 2006, 05:02 am »

watchdog

if you have the oney maybe you should try the exotic class a outputstage offered by LC audio, it has a balanced output option. also I'd be interested in the vinnie mod for that player, are yougoing to try that? If you do maybe you should do a partslist post similar to the one that Bob did for the 841. that would be cool, to do the swenson mod you should be able to figure out where to tap into the circuit based on the location of the opamp chips.

MC

simon wagstaff · « **Reply #312 on:** 13 Apr 2006, 02:41 pm »

I just wanted to mention that I had a friend of mine perform this modification. he stuck wiht the basics, new capacitors and diodes in the power supply and a heavy power cord. Lots of damping material. I bought my unit refurbished from ubid for about 30 bucks. 40 bucks worth of parts and some beer to power him.

I haven't compared it to anything but I have to say for 100 bucks it has to be most cost effective way to deal with my current, and not growing collection of SACDs and DVD-A discs. Highs are very smooth with no harshness, bass is tuneful and tight, vocals couldbe a little more open but it is a joy to listen to.

thanks for all the info!

spangler · « **Reply #313 on:** 8 Aug 2006, 09:15 pm »

Just saw one on audiogone that has a ton of different mods for anyone that doesn't want to do all the work themselves might be an option.

elaubile · « **Reply #314 on:** 1 Sep 2006, 01:37 am »

i recently did a swenson mod for each of the multichannel outputs, but I am getting a hum. Could this be because of a ground loop? Anyone else experience something similar when a swenson mod was done? more importantly, does anyone know how to fix it?

Thanks

tennisdude · « **Reply #315 on:** 30 Sep 2006, 10:44 pm »

hi guys.

i've been trying out some mods, and i have a few questions.

1. I did the "swenson" mod, and although it works there is audible hum, clearly a grounding problem. right now the new RCA jacks' ground are connected only to the - side of where caps AE10 and AE20 were. Where should I connect the ground end of the new RCA jacks? is there a certain good spot on the board?

2. By accident i touched a resistor to another component whilst the unit was on, and that other component exploded. it is marked PVA1 or PVA01, it is one of those two. What is this component (it looks like a ceramic cap, but i'm not sure). Is it easy to replace? does someone have a schematic for the DVD player.

Thanks alot, sorry for all the potentially confusing questions
John

tennisdude · « **Reply #316 on:** 1 Oct 2006, 05:50 am »

its actually PAV1, referring to my previous post. thanks.

tennisdude · « **Reply #317 on:** 1 Oct 2006, 05:53 pm »

it turns out the component PAV1 is fine (its a varistor

). anyway, i'll share my thoughts thus far.

I changed out the power supply caps PCF01 and PCF02 for the auricaps suggested in previous posts.
I also did the swenson mod, using 3uf sonicaps for the DC blocking, .01uf solens to bypass the sonicaps, and silver micas from the + to the - of the RCA jacks.

overall thoughts:
Bass is a bit louder, perhaps punchier
Treble is very crisp and detailed.

Sounds fantastic! Although the player clearly was great before, i think this is an improvement. I'll let you guys know what i think after the caps have had some time to burn in. I have ordered electrolitics to change in for the current power supply electrolitics, and i'll let you know how that goes too.

Later,
John