Suggestions on a new /used amp for Focal speakers.

Tubes which leads you to Primaluna most likely at this price point. I have owned some of their stuff and it is very nice. 

If you look at the first graph, you’ll see the 826W’s are 2.5ohm around 100hz this is the power region, and on top of that it has around - 60 degree phase angle as well down there.
This is a load that needs an amp that can deliver current.

If you want good tight powerful bass, I would suggest a >100w solid state amp that is not Mosfet output but BJT (bi-polar).

http://cdn.stereophile.com/images/archivesart/1110Focfig1.jpg

Cheers George

if they are like the profiles, the low impedance is fake.  look for two large electrolyruc caps in the crossover, each attached to a number of resistors.  remove smaller one.  replace tweeter caps with mundorf mkp.  issues solved for around $18 a speaker.

erik

The Profiles are a old/deleted Focal series, the Chorus 826W is a totally different speaker and current.
The test bench graph (above) was measured by Stereophile, I think they are trustworthy in how they measure, as they’ve been testing since 1962 and constantly upgrade their test equipment to the latest/best gear.

Cheers George

@georgelofi

Sorry, was drunk flaming again. :)

No, stereophile’s charts are reasonably reliable. However, the deep impedance drop in the Profile series and the Sopra is too much alike so it makes me suspicious of more French Fraudulence.

I thoroughly analyzed the Profile 918 crossover and the speaker drivers in a way no reviewer would have dared....hahahah...and found that the impedance dip was deliberate and unnecessary. It makes the speakers seem more discerning, more exclusive. "Oh my god, my speakers can really tell the difference between a $10,000 amp and a $500 amp! I’ll take them!"

For a thorough explanation of what I"m talking about, please see the woofer section in this blog posting.

http://pqltd.blogspot.com/2016/01/focal-profile-918-ultimate-upgrade-guide.html

There is a pair of C/R circuits in the woofer section that caused this. For about $35 in parts, the impedance could be brought up to around 4 ohms and exactly matched the original response. However, a smaller tweak was to remove one of the two C/R circuits causing the impedance droop.

I have not analyzed these, but the circuit is easy to spot. Look for large electrolytic caps, around 120uF or more, with 4 or more power resistors to ground in the woofer section. If you see it, you’ll know what the problem is.

Best,


Erik

By the way, the tweeter cap mods are independent of the woofer section, if any. Focal uses SCR/Axon/Solen tweeter caps and I have repeatedly found the Mundorf MKP (around $7) each a much better match for their tweeters, and a much better cap overall. Warmer, with much better microdynamics/low volume details.

Also, the Mundorf MKP’s are a reasonably good physical fit on the crossover board. :) A little solder and hot glue and you’ll be done.

Erik

As luck would have it, another DIYer has posted the schematics for the 826 V (not W) here:

http://www.diyaudio.com/forums/multi-way/269257-focal-chorus-826v-crossover-advice-needed.html

Here the crossover avoids necessary components instead of adding more. There are a couple of bypass components (C4/L4) which need small value resistors to keep them from becoming a dead short to ground.


Best,

Erik

Great advice on the crossovers! Thanks to all.
What happened to the answer to the question about the amplifier upgrade?
Thanks.Fred.

Hafler 9303 or 9505 used for $500-$1,000 range (depending on condition) - incredible sounding SS amp with GOBS of power and control and smooth highs.  I have listened to $5k - $10k amplifiers that didn't sound this good.

Also just tried a McCormack DNA-0.5 (Deluxe Rev B) which was also excellent sounding amp.

Steer clear of anything McIntosh... horribly overpriced for how they sound.

Don't drop $3,000 on a single amplifier... not necessary.

I love my warmish sounding Pre5 and Multi5 audio refinement / YBA gear. I'm considering selling and extra Pre5 and Multi3 AR I have on hand.