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Opamps improve CD Player's Sound

I also try and stick with the dip style. But for surface mount components I usually use an adapter from here http://cimarrontechnology.com/index.asp?PageAction=VIEWCATS&Category=1

I usually remove the opamp and solder in a socket (dip or so8) that way I can "roll" the opampas without all that nasty soldering lol. Here are some smt soldering tips
http://www.seattlerobotics.org/encoder/200006/oven_art.htm
http://www.kevinro.com/newdocs/learningcenter/surface.htm


Make sure you use low melting point solder for best results. Seems obvious enough but that tip took me quite a few ruined devices to figure out.
 
Oh, man, thanks for that link for the adapters! I looked all over the net for a DIP to SIP adapter for this purpose and couldn't find one! :tresbon:
Andyman, the best way to remove a SMT component is with a special heat gun:
Weller or Ungar 6966. You hold the gun about 1/2 inch from the component and heat it up. When the solder begins to melt you remove the component with tweezers. These guns are about $150 new, but you can buy them cheap on E-Bay. There are also expensive reflow systems you could buy but the gun is the cheapest way to go without damaging the board.
 
SicMan said:
Here's one of those air stations. We have a more elaborate one at work but this is pretty good for a DIY'er, take a little getting used to .

http://cgi.ebay.com/Sale-Rework-Sys...QQihZ010QQcategoryZ100184QQrdZ1QQcmdZViewItem

John
Click to expand...
Wow, that is a great price. Have you used this model? I see some SMD work in my future and was looking at Hakko and others. I didn't want to put out $500, though. For $100, it's a no brainer, as the trouble of replacing a vintage board is going to be a lot more. Would that connector on the box fit any of the mainstraem hoses and nozzles that are available? Since that is a 24v. system could you replace the soldering iron with a ceramic type? Forgive my newbness on the questions as I'm just getting into rework and there are a lot of choices.
Thanks,
Lance
 
opamp & dx-702

This is a question for dr*audio.

Warren - I have the opportunity to purchase an Onkyo DX-702 for $10,-. After reading your post, I would like to replace the opamp. You mentioned that you were planning to experiment with different ones to find the "best sounding" ones. Before I start shopping on ebay, what's your recommendation?

Thanks.

Cheers
 
Andyman said:
So, how do you guys do this?
Click to expand...

It's easy if you live close to Warren a.k.a. dr*audio, because for a modest fee he'll swap the opamps for you! :yes:

I have only just discovered this thread, but have enjoyed my DR*AUDIO MODIFIED ONKYO DX-702 for a couple of months now. I also had the pleasure of a direct comparison listening. First between my original DX-702 and Warren's modified one - wow what a difference, mine stinks :tears: Then between the two modified DX-702 - wohoo, now mine sounds just as great at his :banana:

It's hard to describe the difference other than to say the mod CDP is warmer and a lot more rounded. This is a mod you certainly won't regret doing!

Greetings

Frank
 
which would you recommend for the DENON DCD-1500?



DSCF0453.jpg
 
whoaru99 said:
I think you can hold off on the CD player picture in (nearly) every post. :yes:
Click to expand...

sorry, i just use it as a visual aid... there are new members joining all the time, so i figure there is always at least a few people out there who have never seen this magnificent player, and might be curious. i see it as my personal duty as one of the few AK evangelists of this CDP to educate and inform...:music:
 
Since this post is here:

Generally speaking, would the OPAMPS of a DVD player use the same replacement's as those mentioned here?

I'm assuming I'd have to check the voltages to verify it's compatibility. One day I'm going to break down and mod this old KLH DVD player...
 
Most likely, yes.

However, I think it's a stonger chance that a DVD player would be SMT.

I've looked at playing around with one of mine, but I'm poorly equipped for a successful SMT opamp replacement.
 
whoaru99 said:
Most likely, yes.

However, I think it's a stonger chance that a DVD player would be SMT.

I've looked at playing around with one of mine, but I'm poorly equipped for a successful SMT opamp replacement.
Click to expand...

Good point. I've an older KLH DVD221 that does ok - provided its a brand-new-store-bought-disc. I need to open it up and check, but I'm pretty sure I can replace the transport w/ a standard IDE drive - that should fix the disc compatibility issues. After that, I figure I can try out whatever in it.
 
The problem with the National LM833 is that it's bog slow. The typical slew rate is only 7 Volts per microsecond -- even slower than the NE5532, which clocks in at 9 V/us typical. Philips used the 833 and the 5532 in their multi-bit CD players of the '80s and early '90s, and several firms (including Musical Concepts and Audio by Van Alstine) made a profitable business out of replacing them with faster op amps and upgrading the linear power supplies. The usual result was reduced harshness and a better-defined soundstage.

The last time I upgraded a CD player, I used Analog Devices AD827 duals (300 V/us slew) to replace the 5532s or 833s. With a bit of power supply improvement, these op amps transformed the player from so-so to excellent.
 
Well, I am certainly open to other opamps besides the 833. Slew rate isn't everything, though, and since the output of the CD player most likely isn't going to swing more than 1V, having a 7V per microsecond slew rate should be more than adequate. I'll have to order some AD827 for my next mod and listen for what the difference may be. That's the idea of installing 8 pin dip sockets when possible, so you can easily change out the opamps and listen for differences.
Also, you need to be aware that if you install a very fast opamp with a 300V per microsecond rise time, you must make sure the circuit is unconditionally stable and won't oscillate with the capacitive load presented by different cables. (According to the AD827 datasheet it is, but it's a good idea to do some testing.)
Also the LM833 has much lower noise than the AD827; 4,5nV/Hz vs. 15nV/Hz for the AD827. That will make a difference once you amplify the output enough to drive speakers to realistic levels.
The LM833N has a distortion spec of 0.002%. The AD827 data sheet does not give a rating for distortion, which usually means it isn't anything they want to brag about. You can't design circuits relying on only one performance parameter, you must balance all the ones that affect the desired performance of the device.
 
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