Amp matching for Klipsch Forte III

I'm considering a pair of Klipsch Forte III, and I was wondering what amplifiers folks are using with them. I would be using a Pass Labs XA-25. I'm currently running the XA-25 with Zu Audio Soul Supremes. I listen to mostly 50s, 60s, 70s rock (rockabilly, 60's garage/psych, punk, power pop), funk, soul, instrumental and vocal jazz (esp. female vocal), classic and alt country. Thanks for your comments.
I heard them paired with a McIntosh integrated and the sound was excellent.  I suspect the mellow sound of the Mac tamed some brightness that some find

I owned those, just about anything will drive them, just need something with laid back highs, old school tubes come to mind.
As the upper mids and tweeter can take your head of with a bright amp that has a lean/tight bass as well.

The Pass Pass Labs XA-25 could be OK not too open in the highs.

Used Quicksilver amps would be nice

All will love passive preamps, even the Pass at 50kohms, unless your source has a volume control, then use it.

Cheers George
I have the Forte III as well and run them with a Parasound amp. Parasound tends to be on the warm side and pairs quite nicely with the Forte's. Enjoy these speakers they are loads of fun!!
In my second system I run my Cary SLI-80HS through a pair of Forte III's.  The synergy is fantastic.  Not the last word in detail or nuance but a really fun enjoyable listen.  Forte III's like tubes.

If you don’t go with a 300b, 2A3, 45 amp, check with members over on the Klipsch forum. Several over there successfully running Quicksilver Mid Mono amps. A buddy is running them with basic EL34 tubes in his QS Mid Monos, sounds great, lovely midrange.  I’m also a former Cary, Inspire, Parasound, QS amp owner saying this about the lower gain QS mid monos specifically for your speakers. Sweet with Forte III.

"Power is 40 watts at 50% triode operation with the standard EL34s or KT88s, 45 watts with KT120s and 50 watts with KT150s."

I own a pair of the Forte III's and I'm willing to bet they will sound good with just about any amp. Your Pass Labs XA-25 will be fine.
I have used the following amps with great success: Plinius SA REference, Luxman 590 AXII, Allnic T-1500, Conrad Johnson Classic Sixty SE, Class D Audio SDS-470C, Marantz 2215, 2252, 2270.
I have the klipsch Quartets the little brother of the Forte and drive it with a 6 watt Grommes PHI-26
Thank you all for your comments and tips. I like seeing the adjective "fun" in several of them. That's what I'm looking for. My current "fun" speakers are a nice vintage pair of JBL L112s, but as I have been experimenting with some different gear over the last few months, I no longer have an amp that will give them the power that they like. This is why my eye was wandering to the Forte IIIs. The XA-25 has good warmth, and I have a Primaluna EVO 300 preamp that I can use if I need some more.
...The XA-25 has good warmth, and I have a Primaluna EVO 300 preamp that I can use if I need some more.

A few friends did fairly extensive paring of the Pass XA-25 amp with various tube preamplifiers, and found the combo to work really well in many cases. Hey, your PL EVO preamp with select 12AU7 input tubes to fine tune with the Forte IIIs could work out nicely as an option to consider.  I’d try that first! :)

I'm running my Heresy III with a pair of Quicksilver Mid Mono amps with KT77 and it is an awesome combo

I heard the Forte III with the new 10 w Luxman integrated and it was also a great combo.

The new mid monos have bias adj for each tube instead of global bias for the pair.   Also can run the big KT tubes

I dont think you can find a better pair of mono amps for the money, they are that good

When I had Forte IIIs I was using a Line Magnetic 518i and this was a very good match. 18 watts lit those speakers right up.


agree w decooney

if u have a primaluna running factory supplied chinese modern made tubes it would be a good idea to swap out to old stock tubes and hear the difference in tonality and soundstaging
Guess i/we should have not assumed you had not already tried others.  What tubes are you using in your current PL EVO 300 preamp now...

Are they the original stock ones or - ?
I'm using a Sophia Electric Baby with my Forte III's, I find it to be an excellent pairing. 
08-29-2020 1:33pm
Thanks decooney, the tubes are stock.

If you decide to pair your PL EVO 300 preamp with the Pass XA-25, doing some checking, the current model from uncle Kevy has six 12AU7 tube across the front. The center two are the input tubes, just start with those.  

There is some history with upscale replacing these two center inputs with CIFT 12AU7 for some customers on upgrade requests. They are just okay to me, not the best, all circuit dependent of course. You can just start with those two center ones first for the most impactful change. Depending on what changes you are looking for, brighter/detailed, softer/more laid back, etc.

Upscale has a fairly sporadic stock of U7s, running lower each year. Still some good stuff out there, depending on who you source good tubes from - any of the top5 dealers in the USA. Fwiw, I’ve tried over 20 different/brand variations of vintage U7s (on different amps/preamps) and most of the new issue stuff too. Lots of options for you to choose from and they all do sound different from one u7 to the next. Try that Evo 300 with the XA-25 for sure!

Thanks, I ordered a pair of the Brimars to try. I've enjoyed it with the stock tubes. Will probably get the Forte IIIs in the next couple of weeks. 
Great choice on the speakers. Like said before they are "Fun" !! Enjoy! Let us know your thoughts once you get some time with them. 

Nice. Those Brimar u7s are pretty nice.
I’ve tried them and compared them in a few different amps and compared to some of my best early 60s Mullard Blackburn factory ones. If they are true NOS or have not been used in a while, need to give them at least 24-40hrs to burn off the coating and settle in some. It will change a few times until at least 40hrs, which should help settle some of the edge with bad recordings and make the XA-25 sound even more musical. My good friend ran the Pass XA-25 with a super nice 6SN7 tube preamp last year, felt it was as good as some of his upper end tube mono blocks excluding some layering and 3D soundstage kinda stuff. Some nice interconnects between the EVO 300 preamp and the XA-25 can help too.
An update...I've had the Forte IIIs for about three weeks now, driving them with a Pass Labs XP-12 preamp and XA-25 power amp. So far, I love some things about them, but don't love the presentation as a whole. With this set up, the Fortes are very dynamic and clear sounding with simple to moderately complex music. Acoustic and pedal steel guitars sound especially nice. Just listened to a couple albums by Neko Case and by the Avett Brothers, all sound very good. Also simple live albums like Curtis Mayfield's Curtis/Live! sound amazing. I do notice a slight midrange horn coloration on a lot of vocals, a slight resonance like one might hear if one is speaking into a tin can. It's slight, but it starts to bug me after a while. Highs are smooth and sweet. Bass has good tone but is less powerful than I expected, a bit blunted, although some of that could be my room acoustics. Overall the tonal balance is a bit leaner than I like. My biggest complaint is that when the music gets more complex, it sounds smeared and congested to me, especially from bass to mids. It's not music I consider very demanding, stuff like indie rock, 70's power pop/pop rock. Maybe this is a reflection of deficiencies in the XA-25, I don't know, since the Forte III is often recommended as a good rock speaker. The Fortes in this setup definitely reveal bad recordings to be nothing but bad. If it's dull or grainy or compressed, you hear it. I'll continue listening for a few weeks more, but I'm not sure at this point that the Fortes will stay. Not sure about the Pass gear either. Maybe I need to try different amplification with the Fortes. I also haven't used the tube preamp yet. Thanks to all who commented earlier.
Post removed 
Klipsch " Heritage " speakers are fun, and I am glad folks besides myself, think so. I have spoken here and elsewhere, about damping the mid horns ( the greatest improvement ), the tweeter horns, the woofer and passive woofer frames, and the cabinets, all to clean up those nasties, that ALL stock Klipsch, have. Louder volumes, the more this is noticeable. Many YT videos on what and how to do it. Dynamat is the go to product for this, but there are many other products that can be used. Peel and Seal roofing repair tape can be used and does a great job. Enjoy, be well and stay safe. MrD.
Klipsch Forte IIIs were my first high-end speaker and I played with low-wattage SET amps mostly.  They were so much fun and so revealing!  It seemed I could drive the Forte IIIs with the wattage generated by a lit match!  I noticed pretty quickly, though, that there was a harshness to them with poorer or more processed recordings (although with some many variables in a system, who really knows the cause).  Bob Crites, by email, suggested I try a fabric-based midrange dome (rather than titanium).  I never did that, though (scared of ruining the speaker).  I wish I had read more about the damping treatments that have been recommended here.  

I don't use the Forte IIIs as my main speakers anymore because I discovered the joys of single-driver (plus subwoofer) speakers for imaging precision, something the Forte IIIs were not as good at (lack of time coherence??).  My Omega Alnico driver has nicer midrange than the Forte IIIs as well, although dynamics are not comparable.

BTW, I also use Pass XA30.8 power amp w/ tube preamp.  Great combo!

Try getting them spread as far apart as practical. Then fire each speaker at your opposite shoulder. This should have the axis crossing very slightly in front of your listening position. This worked for me when I had the Forte IIIs and works very well now with the Cornwall IV.


have run with rogue 180/belles 350/prima luna all with good results..look at gr research the make an upgrade kit that brings these to a new level and may adress some of the issues
i think it is common knowledge that super efficient horn loaded speakers mate well with very pure sounding low powered amps, generally tube but also solid state ones

i went that route some time ago, and still have some lovely lovely SE tube amps by Cary and Gordon Rankin/Wavelength, but I gave up on such speakers due to their colorations and 'shoutiness'... of course, this is a tradeoff to get the efficiency and the 'effortless' way these speakers portray dynamics in the music... for me, the trade wasn't worth it, i went back to more 'normal' speakers that delivered a more controlled, neutral and natural tone
Heresy IIIs with 2 REL subs, a Dennis Had Firebottle HO Single ended amp ("high output" depending on power tubes...12 to 17 watts pc maybe), Schiit Freya preamp...magic. Never shouty, can play loud as the clap of doom, astonishing imaging and coherent detail, and makes me wonder if I should try the Heresy IVs.