Forte Crossovers Re-Done

[Southern]

I finally re-did my Forte crossovers! Thanks to Redboy's Forte re-capping and Bob Crites advice encouraged me to re-do my Forte crossovers.

After re-thinking how I wanted to re-do my Forte crossovers I decided to go with the Solon caps and Dayton speakerwire, binding posts and non-inductive resisistor.

Originally I wasn't going to replace the 47uf cap with a Solon but since that purchase qualified me for free shipping so I decided to replace them.

Since my future goal is to bi-amp my Forte's with my Dynaco ST-70 and Pioneer SX-1980 I wanted to allow for this when I re-did my Forte crossovers. If I decide later to use active crossovers the subwoofer section of my Forte crossovers can be abandon in place.

I did one speaker at a time so that I can do an A/B comparison with the new crossover vs. the original crossover.

I am very please with the results of the new crossover. The original crossovers made the midrange seem too bright like the sound was occuring 1 foot in front of the speaker compared to the highs and lows. With the new crossovers the midrange sounds like it occurs on the same plane as the highs and lows like they are now "time-aligned".

Interesting to note that the differences were more pronounced with the Dynaco amp then with the Pioneer.

I have attached pictures of my new crossovers. Keep in mind I am use to working on vacuum tube gear and not circuit boards.

 

[Redboy]

Hey Southern, I'm glad to see that you got around to tackling the job. I personally found the actual work to be much easier than the anticipation of it!

I'm still happy with my results - wouldn't it be cool if there were a way to compare the two pairs side by side? To hear the differences between caps... if there were any?

 

[Southern]

I'm still happy with my results - wouldn't it be cool if there were a way to compare the two pairs side by side? To hear the differences between caps... if there were any?

It sounds like your getting the Audio Karma bug. The next step is to put all your crossover components on furniture grade wood and have a dozen or so different caps to try out.

You are always welcome to drag your Forte's down to Chicagoland for a comparison, but I insist that you bring some snow down with you since we got screwed this Christmas without any snow.

I also found the work much easier then anticipated, it helps that the Forte crossover is a very simple design.

 

[Brinkman]

Nice work Southern!

Maybe even I can do it!
I have had my Fortes for a two months now, I bought them off eBay, so I have no history for them. If I go the route you two went, should I have them serviced first, or should I consider a recap/crossover upgrade as good a servicing as is needed?
I may want to both pick your brains a little more, as you both differed in some specifics, and Redboy's prior posts regarding his crossover upgrade experience inspired me to bid on my Fortes in the first place.
Southern, I'd like to note that I am about a week away from completing my ST70 assembly, so if you felt like expanding on your impressions of the Forte/Dynaco combo, I'd be very interested.
Here's some pictures:
http://audiokarma.org/forums/showthread.php?p=1004335#post1004335

Best,
Benjamin

 

[Redboy]

Benjamin, that's a nice thread on the ST70 project. Looks like it's coming along nicely.

Congrats on picking up the Forte's! Klipsch speakers are controversial, and people generally love 'em or hate them, but I've seen very little negative from Forte' owners. I'm not sure about "servicing" your Forte's, or even what you mean by that. Seems to me that if you're getting good sound from all parts, you're well on your way. Just jump in there with the iron, and solder away!

Actually, the toughest part in my mind was deciding which parts to use. There's a mind-boggling array of caps alone, and a matching diversity of opinions to go with them. Then you've got to decide whether you're simply refreshing the old caps, or going whole hog and building a new crossover. Beyond that you could get into mods galore, if you do a little digging on the Klipsch site.

Budget dictated my choices, and I feel that I got sound advice along the way because I'm still happy with the sound. I'm going to spend my money elsewhere in my system for awhile now.

 

[Brinkman]

Thanks for the kind words, Redboy.
To clarify, I assumed that it's good practice to take any used audio component purchase to a specialist who can bench test it and assure you that all's functioning up to spec, and if anything isn't, what's wrong and how much for repair.
That said, I have specialists in my side of town I trust, however, having them bench test my speakers only to tell me the original caps need replacing seems a waste of money. Especially considering that with experienced folks such as yourselves, I could probably do the sweaty work myself. On the other hand, I don't want to modify the x-overs first, only to find that a driver needs replacing.
So you're probably wondering why I'm even got the idea something might be wrong... well, to be honest, I'm paranoid. I can say for sure that these are certainly the most revealing, detailed speakers I've ever heard, but considering my experience, that isn't saying much. Essentially, I feel that the mid-lows are lacking. The bass is rich and authoritative, and the highs are detailed to the point of piercing...
Now, just to clarify, I listen to primarily obscure rock LPs (everything from 60s psych & German progressive to indie rock), so recording quality on the master tapes does vary, but I really feel like the lack of mid-lows is causing me to turn up my amp in a vain attempt to "fill" this spectrum, which results in too much treble. Fatiguingly trebly.
Before I put you in the awkward situation of counseling me, I should let you know that my integrated receiver was a hand-me-down POS SS from the late seventies, and my phono-pre is the Bellari VP129 (nothing to shake a stick at). The receiver has tone controls for bass & treble, and a loudness button that simply drives me up the wall. Every serious listening session has me fiddling with this garbage, trying sound with or without LOUDNESS, then adjusting BASS & TREBLE accordingly. To stir up even more insanity, the phono pre has a GAIN knob, which when turned up make me less reliant on my amp, but also sacrifices bass tighness and detail for an overbearingly shapeless low end.
In a nutshell, I feel forced between too much treble, or too much shapeless bass.

Crossover upgrade time?

Best,
Benjamin

 

[Redboy]

I ran my Forte's with a Pioneer SX-850 for awhile - 60W per channel of SS. Couldn't hack the shrill highs. The only thing I miss from that combination is the bass output - there was definitely more punch than I get with my current tube watts. But the midrange now! Oh, the sweet mids!

Maybe you ought to hold off on the crossovers until your ST70 is up and running. See what you think of the mids then!

On recording quality - that's something I never really thought about until the speakers came into the mix. They're very revealing, and will show any upstream flaw. I listen to some off the wall stuff too, and there are a number of CDs I can't stand to listen to anymore.

 

[Southern]

Nice work Benjamin on your ST70 project.

I have to agree with Redboy's comments. I recommend starting stock and go from there. Based on the age of the Forte's caps, I would recommend a re-capping to start with.

Like Redboy I have listened to my Forte's with my modified solid state Pioneer receiver and my ST70. I prefer the ST70's due to the clarity of the mids and highs, you would never guess a sound like this from 50's vintage tube gear. It makes me wonder why they don't still make them like that (in that price range).

I do prefer the punch that my Pioneer delivers to my Forte's, that is the only thing missing from the Dynaco. Eventually I plan on bi-amping the Pioneer with the Dynaco to have the best of both worlds.

I'm sure you will be pleased with the Dynaco/Forte combo, keep us informed of your progress.

 

[Brinkman]

Redboy,

Amazing! I can babble on and on in my last post and your reply manages to tell me exactly what I wanted to hear. I have a suspicion that tube amplification will give me some syrupy mids (tame that shrillness!). If what you've experienced holds true for me, I'm sure you'll be giving me pointers on how to regain bass punch. I'll keep it in mind; for after I replinth and mate an arm/cartridge combo to my Lenco(s), I begin the hunt for a phono pre and linestage combo. The Bellari won't cut the mustard for long.

By the way, is it always necessary to have a linestage? I currently do not use one... could (should?) I run my phono pre into my integrated's dedicated phono input?

Also, any lingering thoughts in regards to forte crossover options that you may not have considered before your mod project? After the ST70 is up and running, I may make the Fortes a priori.

Best,
Benjamin

 

[Brinkman]

Southern,

Actually, if you go to dynakitparts.com, you'll see they do indeed make reproductions of the ST70s. Not only that, but they are actually price-accurate, adjusting for inflation.

One of my obstacles towards assessing the performance of my Forte/ST70 combo is the fact that there's several aftermarket modification kits for the ST70 (you should really check them out if you haven't already!), many of which are dedicated towards opening up the frequency bandwidth and/or making the amp more neutral. That said, I want to live with my ST70 in stock form before I install the upgrades I've already purchased, however, that makes it difficult to be accurate in my assessment of the varied "versions" of the ST70 if I'm suspect of my Forte's performance.

I guess we'll see. I'll keep you updated.

Best,
Benjamin

 

[Southern]

Benjamin,

Yes I am aware of the Dynaco being available now in reproduction form, I was referring to the time lapse from the 70's up to the present and all of the transistor sound that has taken over during this time.

I am also aware of the various upgrades to the Dynaco but like my Forte's you will like the sound so much that you wouldn't consider any upgrades.

At the moment, I am out of the country (Czech Republic) for business and my Dynaco amp is ill. One side is considerably louder then the other. This happened after I installed binding posts to replace the cheap speaker screws. I haven't had a chance to get into it real deep but it appears that the problem is in the amp itself. I swapped the tubes form left to right and the problem stayed on the same channel. I am considering replacing the original phenolic circuit board with an updated one.

Which upgrades did you go with?

 

[Brinkman]

Czech Republic! I haven't left my city in months. How I envy you!

Anyhow, I have two ST70 upgrades in the wings: the Triode Electronics capacitor board which increases the capacitance & helps the choke (I assume this provides more current for the claimed improvement in bass) and the VTA board by Roy Mottram. This board puts three triodes in the power supply and almost doubles the gain as well as claiming to provide a more transparent, neutral sound with increased dynamics & soundstaging. Kegger, who posts here at AK, has his own tweaks for this board to make it perform superbly for those of us with efficient speakers, as we don't need so much gain.

I am but a pauper, so I'm confident I did more research than was neccessary before settling on these specific mods, as opposed to the handful of others. Your own impressions are welcomed.

Best,
Benjamin

 

[Redboy]

Eventually I plan on bi-amping the Pioneer with the Dynaco to have the best of both worlds.

Benjamin, you may want to do your crossovers along the lines of what Southern did with his (with dual binding posts and a separate woofer board), allowing the future option of putting some SS punch into the bass end. I've heard setups like this that are really nice.

I was also thinking more about the recording quality issue that you brought up, and I think this could be a bigger source of pain than you realize. Try to find a single album in your collection that you're intimately familiar with and you know is recorded well, and use it as a baseline when you're assessing changes in your system. Otherwise, there are just too many variables.

Good luck! That's about all I know.

 

[Brinkman]

...I was also thinking more about the recording quality issue that you brought up, and I think this could be a bigger source of pain than you realize. Try to find a single album in your collection that you're intimately familiar with and you know is recorded well, and use it as a baseline when you're assessing changes in your system. Otherwise, there are just too many variables.

Well, I actually was prescient enough to do this: I've picked At Action Park by Shellac, a trio with two members who are professional engineers. It's always the first record I play to test new components. I bought it new, and it was manufactured on thick vinyl. I should purchase a second for reference-reference....

I won a variac off ebay yesterday, and expect my multimeter to arrive tomorrow. When I got home from work today, my ST70 tubes had arrived(!). Within proper biasing plus tube burn-in time, I'll have a more state-of-the-union post detailing my Forte's performance.

Until then

Best,
Benjamin

 

[jcmusic]

Can I just replace the caps in my Forte' II to improve the sound?


Jay

 

[Southern]

Redboy and myself have replaced the caps in our Forte I's with an improvement in sound. I see no reason why you couldn't do this for your Forte II's.

 

[jcmusic]

Which caps did you replace? What type of caps did you use?

Jay

 

[Southern]

I went with the Solon caps and Redboy used Gen I Sonicaps. I replaced all my caps but it wasn't necessary to replace the woofer cap. The only reason I replace the woofer cap is that my order put me over the threshold for free shipping.

Since Redboy and myself never heard each others recapped forte's, we couldn't comment on Solons vs. the Sonicaps.

 

[Deang]

The capacitor values and part counts in all of those networks are fairly low. With that in mind, why take a least you can spend approach IF there might be a chance that spending a bit more nets an overall smoother more open sound? I'm not as dogmatic about the cap thing as I used to be, but there are definitely differences. Inexpensive metallized polypropylenes don't sound as nice as the thicker filmed types like Sonicap, Auricap, and Kimbers. I mean, using really good stuff in those networks costs less than $75. Not exactly break the bank territory.

 

[Brinkman]

Since I received my Fortes a couple months ago, I've been becoming more and more interested in a recapping and/or a crossover modification. I'm fond of the sound of my ST70/Forte combo now that the ST70's up and running, but I am still looking for improvement.
Can someone try and verbalize the sonic benefits of a recap of the stock crossover circuit?
Furthermore, what improvements can one expect from the typical crossover modification?

Best,
Benjamin