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AR9 Recap or not?


Shacky
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They use the same components as other AR speakers of that era and those capacitors are going bad - so its time. I recapped my 91s with film and my 10Pi and 90s using NPE but added a small film 'bypass' cap on all the series caps. I plan on doing my 9s using film but have NPE on hand if the sound doesn't sound as the speaker was designed to sound.

IIRC, A member here @lARrybody recapped 2 pairs of 9s; one with NPE and one with film. Hopefully he will give you his impressions of each.

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Shacky,  I just love these recap discussions.  I have listened to my AR9s for 5 or 6 years without feeling the need to recap them but lately I've noticed they must be in need.  They are no longer sound "balanced"...one is brassier and the other has muffled bass by comparison.   I've done the math, made the lists, compared brands, considered bypassing, tried to find exact values without paralleling caps, worried about ESR and voicing...and on and on and on.   I've got to admit that price is a consideration for me, I don't want to spend more for capacitors than I spent for the speakers ($400. eBay bargains). Plus, I don't want to keep changing brands and types of caps, adding resistors, taking them apart to tweak things etc.  Besides, I really did like them with the factory NPEs (until recently). 

After a LOT of internet searches for capacitors I think I've found a reasonable solution for MY situation.  I've pulled the trigger on this already so please don't burst my bubble on this unless it's Absolutely necessary.  The HIFI Collective in the UK has in stock a limited supply of exact value Mundorf e-cap 70 NPEs.  includes 4, 6, 8, 24,30, 40, & 80 uf  70vdc smooth as well as other values. I think the Mundorf E-caps have better specs than most other NPEs and hopefully will last a good while. They don't have the 470 or 2500 uf caps but I'll use MDL bundles for these.  I've already received my order today (it only took a week!) but I won't have time to start the project for a while. 

I based my discission on wanting them to sound like original AR9s (rather than revoiced or improved), keeping costs down (the easiest decisions are when you don't get a choice), and not wanting to make crossover tweaking a new hobby.  I sure hope this works to my satisfaction... I'll ley you know how it sounds in a few weeks

Frank

 

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Lance G,

I'm in southern Michigan & purchased from the HiFi Collective because they had what I wanted in stock (Nobody else did!). Shipping was quick and reasonably priced.

I saw you weren't overwhelmed by using Mundorf NPEs. Has your thinking changed?  I hope I not making a mistake using these, but something needs to be done as the sound has gone down-hill. Figured I can always add bypass caps if needed.  I really want to keep them as original as possible. they are very early production with consecutive serial numbers and no replacement drivers (not even warranty replacements).  If this isn't to my liking, then I'll start modifying the crossovers.

Frank

 

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Hi Frank,

Sorry to hear you're not in the UK. I was initially intrigued because I am not sure how many AR9's made it or were assembled over here.

Regarding the Mundorf NPE's and my earlier posting which it appears you have seen ? To be honest at that time I didn't know what I should expect.

The cap's in my speakers when I inspected them were obviously original, and the speakers sounded good, to me, when I first got them used from here in the UK.

I changed the cap's, I think it was two years ago, very largely on the basis that they were obviously pretty old and likely past their best, and I guess I expected to hear a, potentially radical, change/improvement once the new cap's were fitted. With this in mind I perhaps felt a little disappointed when this apparently wasn't the case.

However I do now have peace of mind that the cap's are good for some time to come, and are both in specification and of the type originally fitted. I did test the Mundorf's before fitting, and also tested the old cap's when they came out. I do recall that some of the old cap's had drifted but not to an obscene degree. I am also now more at ease that potential danger of damage to the very hard to find/replace here in the UK drivers, has hopefully been minimised.

Regarding the subjectivity of any listening outcome, I feel sure you will be aware there are a lot of variables. Not least personally to me is my increasing age and no doubt as a result the reduction in my hearing of the higher frequencies.

In closing, HI FI collective were nothing but professional in my dealings with them, and I think it unlikely that you will have made a mistake by using the Mundorf's. I see people dabble with other capacitor types, but I considered that the original amount of research and development warranted the use of OE specification capacitors to retain a sound as near as possible to the original, sound that was so highly regarded at the time the speakers were released.  I hope the above helps, both yourself and shacky.

Lance.

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I recapped my 9's last month. I bought them for a song and figured the caps would need to be replaced due to age. I tested them briefly before recapping, and there was definitely some odd performance issues with the high-range tweeter which went away after the recap.

Ended up using a mix of Dayton and Jantzen film caps on the HF and mid-range circuits. For the woofers I used a Jantzen elecap for the 470uf and a bundle of MDL npe's for the 2500uf. All told I spent about $300 on caps and surrounds. I picked this mix of caps based on my price range and these threads:

These 9's are the only ones I've heard, so I can't comment on how much a different set of caps would change the sound or if these sound as well as designed. I will say that I love the amount of clean, accurate bass these put out. One of my favorite bass test tracks right now is 1st 44 by Aphex Twin. That track sounded great on 3a's but you really bathe in the bass when played on 9's.

 

 

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My experience to a T.  The bass was still great but the mids and highs were muddy and ill defined.  I almost sold my AR9 speakers until I found this website.  It took me a long time to rework them as I had to learn how to refoam drivers, find the right capacitors, then sand and reoil the exterior cabinets.

it is worth while.  I still get a grin every time I fire them up, every single time...

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Beware of what you use as the series 24uF cap on the UMR.   A Solen MKP was a bloody disaster.*  A Jantzen Fast Cap was better but still noisy.  I settled for Mundorf E-Caps with F&F bypass caps.   I'm still happy with the results after 5 years.

I'm not convinced I needed to replace the enormous caps in the woofer section, but I did anyway.

 

*Back in 2007, (Diamonds & Rust) sent me this note on Solen capacitors:  "This led me to purchase Solen capacitors for my 10pi’s and install those.   That experiment was tragic...and there was a harshness that would damn-near run you out of a room.   It wasn’t subtle, it wasn’t even possibly imaginary, and it was so horrible that I just about cried.   Solens aren’t that cheap.   Over the next month or so they began to settle-in (John O’Hanlon explained why this was probably so in a brilliant bit of materials detective work).  They never lost a sort of brittle, sizzle, raspiness, however."

I had forgotten about this email exchange when I recapped my AR9's in 2017 and suffered for it.

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13 hours ago, DavidR said:

John, curious what cap you used in the UMR 40uF notch filter circuit? It could have played a role in the bad SQ.

The 40uF shunt capacitor is a Dayton DMPC 250v 5%.   I don't know if it could have contributed to the problems I experienced.   (As we now know, the Dayton polys are made by............................Solen.)  😲

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9 hours ago, AR surround said:

The 40uF shunt capacitor is a Dayton DMPC 250v 5%.   I don't know if it could have contributed to the problems I experienced.   (As we now know, the Dayton polys are made by............................Solen.😲

Solen or Bennic...?  :huh:

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