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

rhale64 · « **Reply #160 on:** 17 Oct 2005, 10:10 pm »

Know it doesnt look anything like that. It is a big x. Each of the legs has four super fast surface mount rectifiers . It I believe is the murs 160 diodes shown on their site. Each tab of the hexfred is bent around some audio consulting pure solid silver wire. So it has a total of 16 diodes on it. I got some more solid silver audio consulting wire to hook it up. The price is pretty high, but I figured I would give it a shot. I will take a pic as soon as I get my other parts to do the Swenson mod. But right now it is working. YEEEESSSS. This is the first thing I have done like this. I want to thank everyone for all the info. Expecially you Bob. I have used BlackGates in all the critical areas. SAE1,3 AE7,8,9,22 Also the Big power supply cap is a Blackgate. Right now it is grainy as crap. But that is signature BlackGate supposedly. I guess they need time to break in. I still have that crappy opamp also. I am sure those two are the reasons. I still have to put my cones on it, along with another power cable. But right now it is burning in and sounding better every 15 mins or so. I will keep you guys posted. Again thank you for all the help.

rhale64 · « **Reply #161 on:** 17 Oct 2005, 10:44 pm »

Well everytime I walk into the room it gets tons better. I would say from when I first turned it on the sound has gotten on a scale of 1 to 10 it was a 3 before, now it is about a 7. Man those caps sure do sound bad when first installed. It is not me getting used to it neither. I havent stayed in the room with it for any longer than thirty seconds. It is getting a lot less grainy. I will keep you guys updated.

rhale64 · « **Reply #162 on:** 17 Oct 2005, 11:28 pm »

Quote from: sjmikeb

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

To answer your questions. This thing doesn't look that easy to make. All those tabs on 16 diodes times two have to be bent around this thin silver wire. Trust me I cant believe how easy it is to bend this thing. It comes in a perfect x. Each one of those bent legs has to then be soldered. I bet if you were very proficient it would still take about an 1/2 hour to make one, at the least.
And to answer the other question why would somebody want one? Well Kyle wasnt even trying to sell one to me. We were discussing what I was doing. He said that they found that surface mount with this Audio consulting wire sounded better than the TO-220 style. He said they think it has something to do with the long cheap legs on the others that does this. That is the only thing they can figure out. I can tell you one thing. This thing is sounding amazeing. To each his or her own guess. I figured it wasnt that expensive. And I like to be different.

rhale64 · « **Reply #163 on:** 17 Oct 2005, 11:34 pm »

GHM by the way very nice pics. Do you happen to have anymore pics you would share with the crowd. I am particularly interested in the way they do there bypassing of the opamp. I am considering this or the Swenson. I haven't decided yet.

sjmikeb · « **Reply #164 on:** 17 Oct 2005, 11:51 pm »

A bridge rectifier consists of 4 diodes, so it is not clear to me what you have. I can imagine 8 components if snubbers are added, but you shouldn't really neeed those with ultra-fast/soft devices. I would be interested in pictures.

FYI, I think all the cap changes are more responsible for the difference you are hearing than PS rectifier changes. But anyway, I don't want to rain on your parade.

If you like what you are hearing, cool.

BobM · « **Reply #165 on:** 18 Oct 2005, 12:20 am »

I agree - a rectifier bridge is only 4 diodes. With Shottky's you don't usually need snubbers. With Hexfreds they are a good idea though. Then there's the big 4 pole Jensen cap smoothing tweak the RAM likes a lot. Empiracle Audio uses this also in their CD player tweaks. I put one into my EA modded Sony 7700 transport and it definitely made a nice improvement (subtle, but still noticeable).

As for the Black Gates. Boy oh boy have you got a wait in front of you. They do sound smoother at about 20 hours, and sound "almost good" at 40 hrs. Somewhat more open at 100. Then nothing until you hit about 200 when they just open up like you won't believe. The imaging and soundstaging and detail and extension will most certainly make you laugh out loud.

Just keep those disks spinning for 2 weeks - but take breaks every day to let things cool down a bit before you begin again.

Enjoy the experience - it's half the fun,
Bob

rhale64 · « **Reply #166 on:** 18 Oct 2005, 12:52 am »

Bob the pic will be coming soon. But I wrapped it in heat shrink. So you will not really be able to see what it looks like. I will tell you this though. Every part on the bridge looked exactly the same. And there was 16 of them. Dont worry you didnt rain on my parade. And I didnt go with the Jenson 4 pole. I was going too but I had allready ordered my BlackGate. I really didnt think that was the main reason why this thing is sounding good. I believe it is the combo of caps. Along with the rest. I really dont know which way to go with the rest though. I think the Swenson would be the easiest. But Ram does something similar but very different if you can use similar and very different in the same sentence.

But anyway they take and bypass at ae4 and 5.

GHM · « **Reply #167 on:** 18 Oct 2005, 01:57 am »

Here's another one for you.

sjmikeb · « **Reply #168 on:** 20 Oct 2005, 07:29 pm »

Bob,

So why do you feel you need snubbers for HexFreds and not Shottky's, both are ultra-fast/ultra-soft devices. I have not heard that recommendation before.

Regards,
Mike

BobM · « **Reply #169 on:** 20 Oct 2005, 08:53 pm »

Shottky's are a bit more than ultra fast. They basically have no "rebound" or bounce back (forgive me, I don't know the technical term for it). With hexfreds you find they are very fast, but they can have this recoil or rebound effect. Hence the snubbers to absorb this and smooth it out.

Please, please take this explanation with a huge grain of salt. This is my interpretation of the effect. One of our resident engineers can probably explain this far better than I. But basically Shottky's are cleaner working as a diode bridge than hexfreds (every part for its intended use).

Enjoy,
Bob

sjmikeb · « **Reply #170 on:** 20 Oct 2005, 09:01 pm »

Hi Bob,

I am engineer. What you are talking about is soft or ultra-soft recovery. So, once again both Shottkys and HexFreds are ultra-fast and ultra-soft.

Have you snubbed HexFreds or Shottkys, for that matter and detected any sonic difference.

Regards,
Mike

rhale64 · « **Reply #171 on:** 20 Oct 2005, 10:43 pm »

I do not have any electrical engineering knowledge. But I do have knowledge about the sound. And I can tell you even without the Swenson mod, I am amazed at the difference. I can finally listen to cd's without cringing. I have hated digital since it began. But this is very tolerable. I think with some more burn in time and the Swenson I will be fully satisfied with my audio for the first time. Well allmost, I think I may start on my Sherwood Newcastle preamp next. It is made very good but it has the same exact caps in it that this cd player had. And it is a modular design. It shouldnt be hard to figure out what caps to replace.

sjmikeb · « **Reply #172 on:** 20 Oct 2005, 11:37 pm »

Hmm,

I think my question may have been misunderstood. I too modded my player: Swenson mods (biggest improvement IMHO) now with Aurics, HexFreds, cap swaps. I went with a smaller PS input cap (120 uF) as I was afraid of over-taxing the design, and similar values (Bob's recipe) for the other caps with Nichicons rather than Panasonics. Heck, I might even spring for a few small value BGs now, since I am more than pleased with the results.

I am a bit skeptical about the AC line filter caps, the value seems rather large. I will probably go with about .200 uF total with AC line rated caps.

I was asking a very specific question: Does Bob have experience with snubbing HexFreds and what were the sonic results. Traditional engineering wisdom says this as not necessary with ultra-fast/ultra-soft recovery devices. Both HexFreds and Shottkys are examples of such devices.

As I remember, you stated that your bridge did not have snubbers, only the diodes. I have not tried this myself, but I may, especially if someone has realized positive results.

Regards,
Mike

Occam · « **Reply #173 on:** 21 Oct 2005, 01:25 am »

Quote from: sjmikeb

Hmm,...
I am a bit skeptical about the AC line filter caps, the value seems rather large. I will probably go with about .200 uF total with AC line rated caps. ...

Why would you be skeptical? With my Toshiba 3960 playing, I measure 18va and 10 watts, giving 15var. So if my intent is to passively power factor correct, at my nominal line voltage of 124VAC, I'd need about 2.6uf. I'd certainly never use a non X2 rated cap directly accross the line for fear of it failing shorted and bursting into flames, but behind the components fuse, my concern is adequate AC rating. I prefer lower cost alternatives to Auricaps, other than the .01uf value, for accross the line duties, and use descending values to stagger the (self)resonances. IMO, it sounds substantially better too.
FWIW

sjmikeb · « **Reply #174 on:** 21 Oct 2005, 01:53 am »

If your intent is to attenuate the AC, then I agree. I have read some other justifications which didn't make sense. I don't have the same problem with line voltage, and in fact, all my audio equipment is powered via isolation transformers, so it's not likely I will realize much improvement. But I have the caps on hand, what the heck.

Regards,
Mike

Occam · « **Reply #175 on:** 21 Oct 2005, 02:18 am »

This has nothing to do with attenuating my line voltage. The Toshiba/Samsung has a self regulating switching supply that runs efficiently over a wide variance of voltages. I simply stated the line voltage to allow you to back into the same calculations, your being an engineer and all. Nor does it have anything to do specifically with being 'green' with regards to the grid. It was simply to illustrate that a .94uf 'accross the line' is certainly not going to do any harm, quite the contrary. In addition, an accross the line cap is a quite useful adjunct to an isolation transformer (which is worsening your PF) as it turns differential noise into common mode noise. Let me ask you a question -
Why are you skeptical, given its going to increase your power factor and attenuate differential line noise?

sjmikeb · « **Reply #176 on:** 21 Oct 2005, 02:36 am »

I didn't give your post the proper consideration.

Thanks,
Mike

BobM · « **Reply #177 on:** 21 Oct 2005, 12:09 pm »

Quote from: sjmikeb

Have you snubbed HexFreds or Shottkys, for that matter and detected any sonic difference.

No, like you I have gone on the premise that snubbers are generally unnecessary with Shottky's. I have always used this type and never tried Hexfreds for a rectifier bridge. I was only passing on the wisdom of others who have tried Hexfreds and suggested snubbers when using them. Hell, it's not expensive to give them a shot. Try it and report back. Perhaps they will help, but most likely they won't hurt.

As for the Auricap tweak ... These are across the line, but behind the fuse, so no worries about X rated caps and such. They do help, but you might want to check out the "Felicia Balanced Power Conditioner" thread also. They've used a variety of different and less expensive caps in this type of configuration with great results. I'll probably try those (I think it was the Jupiter caps from partsconnexion they liked so much) next time.

Enjoy,
Bob
Bob

Occam · « **Reply #178 on:** 21 Oct 2005, 02:12 pm »

Hi Bob,

I'm far too cheap to use those Jupiters. What Tianguis and I have settled on are paralleled .47 and .1uf Jantzen caps (for non specific accross the line use) from PartsExpress, $1.50 for the pair in single quanties-
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=197#capacitors
A STRONG caveat - These are rated 400vdc, with unknown ac specs. By 'equivalence', the 400vdc Solen, SCR, Mundorf, Audyn metallized polypropelene axial caps are all rated 250VAC. Given that none of these are X2 rated caps, I strongly agree that these caps MUST be behind fuse(s) specific to the component in which they are mounted. I keep remeasuring these caps over time to check of any degradation, and to date, have found none.
For incremental improvement we have found an additional paralleled .01 Auricap [The smallest Jantzen is .1uf] offers accross the spectrum subjective improvements, including bass. Go figure. The whole idea that different, nominally equivalent caps can have radically different subjective effects has me quite befuddled. I find my descent into tweakdom quite embarassing.

FWIW,
Paul

BobM · « **Reply #179 on:** 21 Oct 2005, 02:36 pm »

Paul,

I knew the ones you liked began with a "J"

Bob