MechEngVic

From what I've read over the years, in generic statement form: 8ohm tap has less bass but wider soundstage, better HF extension. 4ohm tap has better bass, narrower soundstage, rolled off highs. Of course the speaker plays a part. In my experience, with Klipsch speakers: 4ohm tap improvement in bass outweighs any narrowing in soundstage. I have noticed very little if any narrowing of soundstage, but what sounds like a bringing forward of the midrange frequencies. Final thought: The 4ohm winding should in theory be the one with the least distortion.

I have loved my Dynaco ST-70 Series II since I bought it new in 1993. It has since been rebuilt, with improvements made to component quality and wiring traces on the not-the-greatest PC board (Thanks Jeff!). It has always impressed me with its sound quality. For years I ran it with a solid state Adcom preamp. Then I bought a 200$ Chinese tube preamp based on the Marantz 7 and was blown away! I have since upgraded the preamp with high quality capacitors and NOS Mullard 12AX7 tubes for an extra 200$. This pre was the best improvement in SQ-per-dollar I have made. I know many think that old tube circuits like the ST-70 and Marantz 7 are outdated and have been improved upon, but I've listened to amps and pre's costing several times more and have yet to hear an equivalent increase in SQ.

Anybody else having trouble un-zipping these files?

https://critesspeakers.com/prices-other_stuff.html

They look like the Crite's titanium daiphragm replacement for some Klipsch drivers. https://critesspeakers.com/klipsch_tweeters.html

They're not replacements, I just wanted to show you the coil leads.

You can test the resistance of a driver using a multimeter, testing the impedance is more complicated. A driver will have between about 3-10 ohms depending on the impedance rating of the driver. If it reads short or open, then the voice coil is bad. It's also possible a voice coil lead on the driver has been damaged, it'll show open. They can be fixed but it's tricky.

I paid 400$ for mine and don't feel I paid too much. Mine were made in the later period of production, so I didn't have issues with the front or rear face coming loose. The earlier ones had a melamine coating on both sides of the front and rear faces that didn't allow the glue to grab well. The later produced ones only have the melamine coating on the outside. Check for loose front and rear faces in addition to the regular stuff.

"Burlington" by Martin Sexton, the album is good, but this song, REFERENCE QUALITY. "Into the Mystic" by Van Morrison, remastered. BIG SOUNDSTAGE, EXPRESSIVE HIGHS, WARM HORNS.

Klipsch tended to run their horns a bit hot in the past; it sounds like current offerings are way more balanced. Simple resistor mods in your Forte crossover can make a substantial difference, bringing the woofer and mid horn into strong cohesion, making lower midrange stronger, taming horn "hotness", making tweeter stand out and sparkle more, both widening the soundstage and bringing the midrange forward.

It might be your ears, try facing away from the speakers and see if it switches. Happened to me.

At lower volumes, we hear less bass coming from sound sources (Robinson–Dadson/Fletcher–Munson curves). This could be the reason you're not liking your lower volume listening. Also, depending on the age of the receiver, you may need capacitors replaced or other maintenance. And lastly, you may consider a different amp, I've owned two different Yamaha Natural Sound amps and they didn't sound good with Klipsch speakers for my tastes.

Do you have the crossover schematic for the R26F's? Does anybody have it? A solution to tame those horns may be possibly small, simple changes to the crossover.

It's a good source of solid copper, cheaper than most connectors made for wire. I also cut them in small pieces and use them as crimp sleeves.

https://tubes-store.com/article_info.php?articles_id=4 Here are K75-24's serving coupler cap duty. And KGB-MN's in a crossover upgrade for a pair of KLF-10's The best bang for your buck in capacitors, even with the shipping from eastern Europe.

About the 5:30 mark he starts talking about the size of a driver, crossover frequencies, and off axis roll-offs. Certainly worth digesting. I added 3.3uf to the 8uf second order capacitor low pass in my klf10's. They normally cross at 2300hz. It flattened a downward slope of 2db between 1-2khz in the frequency response, and made the phase response slope a little less shallow, moving the crossover phase shift up by maybe 100hz, and smoothing out the impedance peak there also. It worked well with the changes I made to the horn. In my case, it gave me a pleasant filling of upper bass/lower midrange. Us horn lovers tend to want the horns to do as much of the work as possible, but we forget just how much information is already coming from the woofers. Measure, measure, measure.

You're probably gonna receive them and want them in position before you find the optimum stand. Do you have some furniture sitting around that you can put them on top of for now? Maybe a pair of nightstands or a pair of low bookshelves. Sitting at your desk your ear height is gonna be about 40 inches give or take. The sixes tweeter center will be around 13" so you'll want something about 27" tall. Just my guestimate.

From what I remember, both the Chorus and the Chorus II had the k-48-E. Have you measured their resistance?

Now where's that stack of pallets I left laying around...?

IMHO, focus on bracing the widest dimension. In the case of my KLF-10's, the widest dimension is the 16" depth, the face/back are only 12" wide. They came with two stout braces spanning the 16" sides from the factory so I was satisfied. The forte's widest dimension is the face and back. Plus the big holes in both make those two faces prime candidates for some front-to-back bracing. Something that works well that I have seen few guy use is 1.5" or 2" wood dowel. Cut four of them super tight fitting, use a bottle jack to create a tiny bit of separation between the front and back faces, glue the dowel ends and stuff them in around the woofer and radiator, putting glue on the cabinets in spots where the dowels will rest. Make sure you hold them in place (you may need more hands), then release the bottle jack. No need for clamps or weights and you'll be able to use them as foundations for your house.

They look great!

First thing I would do is listen to the offending song passage through headphones or a different speaker. Maybe you never noticed it before, but your cornwalls may be resolving so well, you're hearing distortion in a recording. Now that you've heard it, you'll probably be able it pick it up through a different source if you listen carefully. If you can't hear it then you can proceed to tear apart your speakers...

If you have a jumper connecting the two sets of terminals together, then you can connect to either.

I read a guy on another forum installed a pair of CL-80's on a Dynaco ST-70 power transformer's primary. I believe he installed one on each hot leg of the primary, but I'm not sure. Is this a viable application of these NTC thermistors? Jeffery mentioned using them but bypassing them once warmed up. Not that I am considering this as a fix, nor am I really interested in changing the basic circuitry of this amp, but I have read that a solid state power supply can beat up the tube side of the amp.

not enough to matter.