Missing tube integrated for Klipsch Forte III?


2 weeks ago i acquired and set up the forte iii's in my 25x35 basement (8ft ceilings).  i paired it with a gorgeous yamaha as-2100 - man that amp is beautiful and solidly built.    granted, both the forte's and that amp aren't really broken in yet BUT (i hate) i am missing that low end bass presence that i hear so much about from tube people.   they all talk about "bass slam."   it's not that the yamaha doesnt deliver, but i'm just not feeling it as a slam.   i understand the primaluna evo 300 uses EL34 tubes and are supposed to be highly musical, dynamic, and able to slam.   reading all those reviews leaves me tempted to try to tube route.   thoughts?   looking for real low end at low volumes with great detailed resolution up top (but not too bright).   i do love the build quality and aesthetics of the yamaha - would be hard to see that go on a trade.   
mjb87062017
That's a pretty large room.  How are the room treatments (particularly absorption) especially behind the Forte III's?  I would expect the Yamaha to deliver more bass slam than a EL34-based tube amp. You may want to consider adding a sub - not that it will deliver more bass slam, but it will fill out the low end and help provide bigger soundstaging. Keep in mind the Forte III’s only go down 38hz. I have a pair of Forte III’s that I run with a tube integrated and I use a sub as well. Really nice depth/width of soundstage with the sub and overall more saturated dynamics. I wouldn’t say it has a ton of "slam" though. I’d stick with SS amplification if that’s what you’re after.
Wow your talking apples, and  oranges here. 

The room is big.. Is there room treatment?
50-150 hours on the breakin. 

The speaker needs to be pretty close on the back side 2-12" MAX

They are not know for, tow in, to much. Kind of a straight forward speaker.
The back wall distance is pretty important, though. Closer is better.

El 34s are not know for BASS slam, in any of the circles I run in.
Mid bass, mids, and highs..

If you're the kind of person that like, more... MORE,  M O R E... I'd be going the other direction, away from the valves. The Yamaha is 150-60 watts @ 4 ohms

The little valve amp, is 25-35 WPC with EL34s.

6L6s,6550,KT88,90 would all have better lower ends, but probably not as good in the mid bass, mids, and highs, of the EL34s KT77

A valve top end and SS bottom end, would be very nice.  It would also cost 2-4 times the amount.

For the dollar SS is gonna deliver more, a lot more, BASS.

Folks are gonna chime in about bass boxes (subs), WAIT.. let it break in,
Klipsch is no slouch when it comes to bass. Really.. Place the boxes..

Happy listening

Regards

It’s a large room. Also Sounds like you are at house concrete foundation level. If so the bass will be more heard and less felt.

if you want more slam the solution would be to add a powered subwoofer  or subs  
Forte III is not a low end machine. Mapman made a very good suggestion to add subs.

tuberist
516 posts
05-17-2020 12:57pm
Forte III is not a low end machine. Mapman made a very good suggestion to add subs.

tuberist, I'll tell you, their not bad.. really.. They may not, LOL,
SLAM, whatever that means, go deep enough? Maybe?
But they measure pretty well, the bass is not bloated, nor is it lacking. Compared to most, in that range, 802 and a few other,
They can reach right down there, with pretty good authority.

If you want, Boom Boom, in the room room... different, question..

OP was asking about Valve, Amps, and EL34s for god sakes.. hee hee
Got to get the guy on the same page first..BASS and EL34 don't really go together with the word SLAM!

But they play pretty good down to 40 hz or so.
Very Klipsch. like.. It's a horn...
But OP,  knew that going in, right?.
Klipsch is horn loaded. and, a loudspeaker,
in every conceivable way. Get them close to the back wall
really.. I've actually tinkered with this speaker,
nephew has a pair. Don't pull them out from the wall.
Won't image well, but that is the factory preferred way
2-12"

Regards


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With my Heresy IV speakers I am using Tung-Sol 7581a tubes in my Primaluna Dialogue Premium. Find they have almost the minds of the El34 but stronger low end with the extra watts. Used KT88s,  EL34s, and KT120s previous but the 7581a is the keeper for me.

Not likely a fix for the lack of bass though. Subs or a different speaker.
Considering the big listening space of OP, I also recommend adding subwooffer.

If he want to use tube amp, then I recommend used Rogue Cronus Magnum II with kt120 tube which has lot of power and good extension to the top.

Thomas
I think that the triode (6550, KT88s, etc) amps are going to be better top to bottom if you want a more linear/accurate tube presentation. If want a warmer and thicker presentation then the pentode (EL34 EL84) amps will be better.

I far prefer the triode amps but I like a more neutral presentation and would tend to alter the presentation with tubes or cables as needed. I think it is easier to make a neutral amp warm than to make a warm amp neutral. 

The Fortes never struck me as a very subtle speaker so some of the more sublime and nuanced amps might find these qualities lost on the Klipsch. I think that there is a good synergy between Klipsch and tubes. I cant stand S.S. on Klipsch speakers, but have not heard them driven by really high end S.S.

I believe that the Fortes have a rear firing woofer. If this is the case, I cant imagine putting them close to a wall would be a good idea.



I own the Klipsch Forte III's along with several other speakers and class A solid-state amps and tube amps. I totally agree with those that say you should add one or two powered subwoofers.
The bass is good without the subwoofers but I don't think you will hear what you desire without subwoofers.
O.K. so its a passive radiator. Do you think that putting a speaker with a passive radiator against a wall is a good idea?
great comments, thanks to all.  i'd appreciate recommendations for a sub that pairs well with the fortes.   primary is 2channel music with some limited HT.   thanks 
Back in the late 80's I had Forte's.  I was new the hobby and didn't have the knowledge to dial them in and sold them quickly.  Years later I used a Jolida JD-1000a integrated amp in a 2nd system with Spica TC-50's and felt the Jolida would have been an outstanding match with the Forte's.  The JD-1000a of later models may be worth a little research.
How much bass do you want?  What size room?  How much space do you have?  Have you done any room treatments?  I'd suggest searching some of the existing threads on subwoofer usage.
audition_audio 
As you wrote, the el34 is a Pentode tube. The 6550 and KT88 ( also the  KT 90) aren't true triode tubes but are classified as power beam tetode/pentode. It is true that all of these types of tubes can be 'wired' to triode function. Many amplifiers offer a switch for choosing Ultralinear or triode operation. 
True triode power tubes are for example, 45, 2A3, 300b,PX25, 845, 211 etc.
Charles 
58hz is where the Heresy IIIs drop out, although "lower mid bass" until that point is amazingly good. I have a couple of Stereophile test CDs that show these facts to be true...and 2 REL subs adjusted to around 58hz to take the baton, so to speak.