[Russtafarian]

I just posted this in another thread to response to a question.  I'm posting it here in the Lab to get some ideas flowing regarding Oppo mods. 

So here's what I did to my Oppo 970.  Keep in mind I’m a part-swapper, not an engineer.  I’m open to other ideas that will improve performance, but please don't bash me because I should have done X or didn't do Y.

Power Supply Board:  All electrolytic capacitors replaced with equivalent value Panasonic FMs.  The 22uF 400V filtering cap was replaced with two paralleled Erse 11uF 250V polypropylene caps.  Caution: if there’s a chance the player will ever get plugged into a 220 volt line, the value of this cap should be at least 350V.  The four rectifier diodes were replaced with MUR860 hexfreds.

Main Board:  All electrolytics replaced with equivalent value Panasonic FMs except for the 10uf values, which are Panasonic FCs.  The four DC voltages coming into the main board (+3.3vdc, +5vdc, +9vdc, -9vdc) were each bypassed with Erse 11uF caps.  This step was recommended to me by a friend who designs switching power supplies for a living.

Analog Output:  I removed the four 10uF caps that couple the left and right output from DAC to opamp and opamp to RCA out.  The L & R DAC outputs (taken from where the 10uF caps between DAC and opamp were removed) each go through a Erse 11uF cap to a Lundahl 1527XL transformer.  You have to use the cap otherwise DC from the DAC will saturate the transformer.  Each transformer output is connected to a new RCA jack mounted on the back panel.  I put a 10k resistor and 100pF polystyrene cap between + and - of the RCA jack. The RCA jack negative tab is connected to ground.  The other analog outs (LR, RR, C, LFE) I left alone.

The Panasonic caps and hexfreds were from Digikey.com and cost about $50 total.  The Dale metal film resistors and the polystyrene caps were from mouser.com and only cost a few dollars. The eight Erse 11uf caps were from diycable.com and cost about $50 total.  The two Lundahl transformers were from kandkaudio.com and cost about $75 each.  The transformers alone cost as much as the player but really made a big difference in the sound. 

The only difficulty I ran into in disassembly and reassembly was the small ribbon cable that connects the mainboard to the laser assembly.  After disconnecting and reconnecting this cable five or six times when removing the mainboard, the contacts got mangled and I had to get another cable from Oppo.


Russ

[jqp]

Wow as an Oppo 970HD owner, I am impressed that there is that much you can swap out without being an engineer 

Have you noticed improvements in Video? Analog audio? Digital Audio?

[Russtafarian]

I use it almost exclusively for analog audio.  Going directly into my power amp and using the remote volume control, it sounds very good!

Russ

[jqp]

Meaning CDs mostly, or multi-channel discs?

[Levi]

What about the video.  I would assume it is better?  Worse?

[Russtafarian]

I jumped on the multi-channel bandwagon pretty seriously so I probably have over 300 m-c SACDs and DVD-As.  On all formats, the Oppo is delivering the best digital playback I've heard in my system.  Granted, I've never spent a lot on digital hardware so take that statement for what it's worth.

I don't use it for video all that much so I really can't comment other than to say that I doubt any of the mods hurt the stock video performance of the player.

Russ

[AnthonyP]

I would not use 22uf film caps as your main fliter/storage.
Nothing beat mass capacitance at this location. try fitting at least a 330uf cap at 400v.
install the cap on its side if needed.

Key is to get ripple down to nothing.
once done, you will realize huge gains.

Anthony

[gooberdude]

If you go to AudioAsylum, in the Tweakers section....search Oppo 970 and you'll read some good info.

My favorite is one I adopted to my cheap-o cdp, and that's to place a small magnet directly over the spindle.

the guy who 1st reported it paid $1000 for his modd'd Oppo, then on a whim tried the magnet & was blown away.   It has to do with making the magnets which are already in the spindle work even better, like super magnets.     basically, the soundstage increases bigtime and the smooooothness increases.


You can also place one over the transformer for a slight improvement.

Both these magnet placements are on top the top of the case, not inside the Oppo....

[Russtafarian]

I would not use 22uf film caps as your main fliter/storage.
Nothing beat mass capacitance at this location. try fitting at least a 330uf cap at 400v.
install the cap on its side if needed.

I thought 22uF seemed a bit skimpy for a filtering cap.  I have a BG 200uF/250v "Big Tank" I could drop in instead.  I'll have to try that this weekend.

As for the voltage on the cap, I measured around 170vdc, which I gather is the recified value of the mains voltage (120vac x 1.41).  So I would think a 250v rating would be adequate.  Now if the player got plugged into a 240v line, the voltage on the cap would jump to around 340vdc.  That would certainly require a higher voltage rating for the cap.

Russ

[shep]

Rollo, I have been wanting to try the magnet thing since you brought it up. Lazy...today I realized I had one staring me in the face, on the fridge...one of those flat ones with a dumb saying. It's quite strong. I'm trying it right now. My tweaked-out cdp has a plywood cover that replaced the metal one. I don't know how this is going to work...I'll report back. Should probably put this in the "cheap tweaks" section...

[BobM]

I thought 22uF seemed a bit skimpy for a filtering cap.  I have a BG 200uF/250v "Big Tank" I could drop in instead.  I'll have to try that this weekend.

Russ,

Be careful upping that cap too much, and going from 22uF to 200uF is way too much. The basic rule of thumb is about 20-50% more in a power supply (50-100% for that first big cap, but you'll need to address the diodes if you go to 100%, and 20% for the others); I would say nothing more than 50uF . The problem isn't the cap, but you could easily blow the switching diodes. If you're going to use a larger cap you may want to up the value of the diodes too, getting 2,3, or 5a diodes instead of the 1A ones that are probably in there now. It's also a good chance to put in faster diodes, like Shottly's, which will make more of a difference than the larger cap alone.

Good luck,
Bob

[ctviggen]

And putting bypass caps around the diodes, if they're not there already.  Personally, I think huge power supply caps don't do much other than suck money from your wallet.  I would hazard a guess that there's a limit to the amount of capacitance necessary.  There are long discussions regarding this in my amp books and on the DIY forum (a different forum from here).

[Russtafarian]

After poking around the web looking for other Oppo mod links, I found out that Cary Audio has paid Oppo quite a complement and dressed up the 970 in a nice case for their High End home theater dealers.  The Cary DVD-8 retails for around $1,200.  Same transport, same main board, same remote as the 970 with no upgrades that I can see.  They did put a metal box around the PS board so I can't tell if there were any changes there. 

From what I've seen Cary tube amps and preamps are well engineered, well built, competitively priced and sound wonderful.  I also know that upscale home theater products and sales have been keeping many high end audio companies and nearly all high end audio dealers afloat for the past 15 years.  So I guess Cary's strategy for producing and selling Home Theater gear shouldn't surprise me.

I do know that if I chose the Cary DVD-8 over a $1200 Denon/Sony/Marantz type player because I "trusted" the Cary name, I'd be pretty pissed to find out it had the guts of a $150 player.

Russ

[Russtafarian]

Well the hexfreds I dropped in are rated at 600V 8A so I don't think that will be a limiting factor.  Now you got me thinking about bypassing the diodes...

[BobM]

If you put in Hexfreds, and not Shottky's, I would definitely suggest a snubber on them. Either a bypass cap or a true snubber; a resistor and a cap.

Good luck and let us know how it turns out. I have a 981 that I may get itchy about and mod. However, I'm only using this in a home theater setting and not for critical music listening. So I'm only interested in the video performance upgrade, and perhaps dynamics, over any imaging or soundstaging improvements.

I also plug my whole home theater, including the plasma, into one of Paul's little power conditioners (not a big Felix). Always a worthwhile tweak.

Enjoy,
Bob

[AnthonyP]

I would not use 22uf film caps as your main filter/storage.
Nothing beat mass capacitance at this location. try fitting at least a 330uf cap at 400v.
install the cap on its side if needed.

I thought 22uF seemed a bit skimpy for a filtering cap.  I have a BG 200uF/250v "Big Tank" I could drop in instead.  I'll have to try that this weekend.

As for the voltage on the cap, I measured around 170vdc, which I gather is the rectified value of the mains voltage (120vac x 1.41).  So I would think a 250v rating would be adequate.  Now if the player got plugged into a 240v line, the voltage on the cap would jump to around 340vdc.  That would certainly require a higher voltage rating for the cap.

Russ

The Blackgate tank is a good choice.  Pricey, but if you have it laying around , use it.
Stock diodes are fine, the hexfred you used, are a favorite of mine, and you do not need to use snubbers.
Low current  drawing components like the dvd player, like slow diodes, mass capacitance.
Sometimes using fast diodes can cause more harm than good to a components performance.

Depending on circuit design, if LC and RC filters are used, You must keep the same values in place.
Added performance can be had, using higher voltage caps in this application.

If no filter is used, you can increase the value about 50%+ percent if the values are 100 uf and higher.
Again, using higher voltage rated caps, added performance will be realized.
Keep the same values if the cap value is less than 47uf. Using HQ caps, such as conductive polymer with low ESR is a good pick.
Try to avoid bypassing caps by using a HQ cap as such, as bypassing will increase ESR.
Bypassing is an old trick, used mainly on stock caps to improve HF filtration.
This is  the Upgrade Company "secret". :c)

Use some dampening material, preferably the tacky stuff on the chassis and drive mechanism.
Use some on the underside of the laser head assembly. (hot tip)

Install a ring magnet on the motors end cap. (really hot tip).
Doing the above "shields" the Motor and keep Stray magnetic fields , "in check".
Similar fashion as done to speakers, for example.

Hope his helps, and enjoy the info.

Anthony

[G.Michael]

Russ,

About the Lundahl 1527XL transformers, what connections did you use?  Given that the transformer has two primaries and two secondaries, there are a few options. 

Here's a data sheet so that this will make more sense to everyone (including me!).
http://www.lundahl.se/pdfs/datash/1527_7xl.pdf

[Russtafarian]

For the Luhdahl 1527XL I used the parallel-series connection (1:2) to make up for some of the gain I lost by bypassing the opamp.  Because the DAC is single-ended, pins 2,3,6, and E (shield) are tied to ground.

I'm no trannie expert.  Kevin at K&K recommended the 1527XL because it's a good sounding general purpose line level transformer.  I'm sure there are other options out there that would very work, maybe even for less money.  Any alternate trannie recommendations would be welcome.

Russ 

[G.Michael]

Analog Output:  I removed the four 10uF caps that couple the left and right output from DAC to opamp and opamp to RCA out.  The L & R DAC outputs (taken from where the 10uF caps between DAC and opamp were removed) each go through a Erse 11uF cap to a Lundahl 1527XL transformer.  You have to use the cap otherwise DC from the DAC will saturate the transformer.  Each transformer output is connected to a new RCA jack mounted on the back panel.  I put a 10k resistor and 100pF polystyrene cap between + and - of the RCA jack. The RCA jack negative tab is connected to ground.  The other analog outs (LR, RR, C, LFE) I left alone.

Hi Russ,

From what I'm understanding here...
The stock connection is: DAC -> OpAmp -> RCA jack. 
And the new connection is DAC -> Transformer -> RCA jack, with a coupling cap between DAC and Transformer.

Hence, the OpAmp is no longer used... is that correct?
Thanks, again. 

Gary.

[Early B.]

After poking around the web looking for other Oppo mod links, I found out that Cary Audio has paid Oppo quite a complement and dressed up the 970 in a nice case for their High End home theater dealers.  The Cary DVD-8 retails for around $1,200.  Same transport, same main board, same remote as the 970 with no upgrades that I can see.  They did put a metal box around the PS board so I can't tell if there were any changes there. 

From what I've seen Cary tube amps and preamps are well engineered, well built, competitively priced and sound wonderful.  I also know that upscale home theater products and sales have been keeping many high end audio companies and nearly all high end audio dealers afloat for the past 15 years.  So I guess Cary's strategy for producing and selling Home Theater gear shouldn't surprise me.

I do know that if I chose the Cary DVD-8 over a $1200 Denon/Sony/Marantz type player because I "trusted" the Cary name, I'd be pretty pissed to find out it had the guts of a $150 player.

Russ

This is very interesting. Can you provide links that support the fact that the Cary DVD-8 is essentially a dressed up Oppo 970? 

Thanks.