B&W 802 D2 Capacitors Worth Upgrading?

@allenf1963 , I think that part of the tubed pre in front of SS amp appeal might be related to heat and maintenance. Meaning that an amp that utilizes output tubes can run pretty hot and also requires occasional bias checks & adjustments and also that the output tubes are probably the tubes that are going to require the most frequent replacement, whereas the smaller tubes most often used in the pre will usually last a lot longer. A lot longer. Thus, a "hypbrid" set up of a tubed pre in front of a SS amp gives one a bit of the vacuum tube flavor without as much maintenance. Also, some might argue (and I might be one who would now also make this argument) that the preamp might have more of an effect on the sonic presentation than the amp.

About 30 years ago, I actually started out the opposite--a ss HT preamp in front of a tube amp. I didn’t think that my system really started to sing & sound delicious until a few years later when I upgraded to a tube preamp (a second hand Cary SLP-90) in front of my tube amp..

As far as other preamps (besides ARC) to consider, most everyone may tell you that whatever they are running with is the way to go. A few years ago I upgraded to a 6SN7 based Cary SLP-05 and it did impart sonic characteristics (more air and imaging resulting in a larger & more defined soundstage) that I truly enjoy, but it may not be everyone’s cup of tea.

I found this post and this 802D2 upgrade journey while asking myself the same question as the OP. The final replacement design is not documented in the writeup. However, they provide diagrams of the OEM crossovers and preform analysis of per-driver characteristics.

@bossybilbo That’s a really nice article and great write up on exactly how that speaker behaves in it’s original form.

This is the kind of perspective I think worth having before trying a complete 1:1 capacitor replacement. Don’t overhaul a crossover design you may not want to keep.

Which then brings me to a philosophical issue. Clearly, the new crossover fixes what many of us would see as deficiencies in the original design, but then I immediately have to ask, if you go through the exercise, are you going to be left with a B&W at all? I mean, if you bought the speaker because you wanted the B&W sound, and a speaker that performed like the reviews glorified, is this in the end the speaker you want? Or should you just sell the speakers and get yourself an excellent speaker kit and cabinets which performs as well as B&W you are going to overhaul?

BTW, there are definitely times when a new crossover fixes important impedance problems such as with several Infinity, some Focal and maybe in the future a Kef. In those cases the original frequency response stays about the same but the impedance is no longer as challenging. Worth doing, without hesitation.

Absolutely @erik_squires. I love these speakers and in a way they have become a part of our home decor as well as the hifi system. As such if there's a way to improve the sound by say "50%" but at a reasonable cost (meaning less than 25% of a new speaker) then it seems worth trying!

I'm a computer engineer by trade - after some careful consideration I've decided that I am going to attempt a DIY active crossover 2/8 setup with some reasonably priced class D amps. This will be closer to my background and allow for quick prototyping iterations. I plan to keep the drivers as is and remove all wiring harnesses and crossovers outright and fabricating my own - this will allow for easy restoration to OEM condition if/when I choose. I don't mean to derail the discussion but I came across that writeup along the way and thought cross posting here would be useful!

@bossybilbo

I love these speakers and in a way they have become a part of our home decor as well as the hifi system.

Welp, it sounds like you love the look but not the sound.  That's fine!! But it won't sound at all the same. It will sound much more neutral and laid back. 

I want to suggest you take future discussions over to DIYaudio where you'll get a lot of input from builders. 

I think you are taking a better approach than a cap replacement.  I'm going to write this up in detail in my blog, but looking at the original driver measurements I immediately thought of a DSP solution as being much easier than a passive crossover.  The mid and tweeter need a lot of EQ and that's why the author has to add so many more parts.

Tips:

• Consider a Hypex 3 channel DSP powered plate amp, perhaps in a custom box.  They have more than enough power. 
• It may be best to measure the speaker on mid-range axis.
• Always fix driver issues before setting high/low pass filters
• If you really want to stick to a 2-way amp per speaker, a hybrid approach using a passive woofer to midrange crossover. The woofer is probably the best behaved of all the drivers so needs least amount of parts.