Parasound P/LD-2000 preamp mods?

One of the reasons that I bought mine was because I didn't think there was much that could be done to it. A company that I have used on other items says,

(Parasound equipment is usually of good circuit design. Beside normal component failure, the usual problems we see are related to soldering defects, some poor quality parts such as speaker relays, and loose push-on internal connectors. Parasound products generally have good quality parts in the audio path, so service is usually at a repair only level.)

I wonder what others have to say.

The P/LD-2000 does have some impressive circuit design such as dual mono topology, pure class A discrete circuitry, direct coupling, 92,000 uF of capacitance,etc., and pretty high quality parts such as lots of Black Gate capacitors, Nichicon Great Supply capacitors, Vishay resistors, etc., but, I do have to wonder about the silver-plated internal wiring, and the quality of some of the feed-back resistors, diodes, power transformer, bypass caps, etc.
I just wonder where the biggest weaknesses are, and which parts would bring the biggest improvements?

Daltonlanny,
The main sonic signature on the 2000 is derived from the use of the caps Parasound uses to bypass each electrolitic.

Upgrading those caps alone will help the 2000 a lot. Secondly, going through and replacing the metal film resistors with Vishay foil types will add more detail, depth, and drop the noise floor a significant amount.

Third, get rid of the walnut shell sized power transformer, and add an outboard 400-600VA type of your liking, toroid or E core. When you are done, you'll have an amazing sounding piece.

Fourth, replace the stock rectifier with a soft recovery type and replace the stock bypass caps with film and foil.

The sleeper of all time is their little Zpre. Sounds so-so stock, but once gone through, it becomes a true high resolution piece.

John

Thanks for your very detailed reply, John!
Lots of useful information in your post.

Daltonlanny,

you're welcome.

I have modd'ed 1 of the Para. 2000's, two of the 1100's a handful of Zpres, and numerous other manufacturer's pre and power amps.

With the exception of the vishay resistors (available directly from Vishay, but fairly large minimum order quantity), all the parts you'll need may be procured from Digikey.com or Mouser.com parts catalog. The toriodal power transformers are available from several sources on line, such as Plitron, Antek, Talema, and others.

As poster 2002 mentioned, the parasound circuits are done well. Once parts upgrades are done, these units really sing.

I used to think if one would spend enough money one could buy a pre amp or power with these parts already installed. Unfortunately, that is not the case; even with 5 and 6 figure priced gear.

A nice amp is the Parasound HCA-1000A. In its stock form it can be a bit bright, especially with the likes of Paradigm, Thiel, or Infinity spkrs. After the 1000A has been gone through, only then can one hear what this amp really offers for a reasonable price.

Taking the never ending upgrade train to sonic euphoria will never get you there, only with the truly good parts, does one begin to approach what all audiophiles are after.

As mentioned in the earlier post, if the para pre in your system does sound a bit lean or thin, it can be quickly corrected with a change of the bypass caps to a film and foil cap rather than the metalized film types that are so commonly used.

Best of luck in working through your pre.