Recap my Fortes?

[Redboy]

Is there a general consensus on when/whether to recap Fortes? I've had mine (vintage 1987) for a few months now. They sound fantastic, but of course I wonder if I'm missing anything...

If it is time to recap, does anyone have specific recommendations as to which type and brand of caps to use? Do I replace all caps with original values?

Any and all advice is appreciated.

[cubdog]

I'm sure the experts will chime in but I would think with 87's you are safe for a while. If not, I may be going broke soon.

cubdog

[BECtoo]

Any good polypropylene caps would be an improvement for the Forte crossover. The little blue mylar caps in it originally were not very good from day one. Also, to keep the Forte for a long time, I would suggest getting the heavy components off the plastic input terminal cup. I am seeing a lot more of those things broken all the time. Usually the heavy autotransformer just breaks off the plastic mount and often causes a short in the other wiring connections when it breaks off. A good thing to do is to just mount all the components on a piece of board and attach that board to the cabinet somewhere. Then you can still use the input terminal cup to just feed the new crossover. I like to also use a terminal strip on the new crossover board to clean up the "rats nest" of wires the factory crossover has.

Picture of Forte 1 crossover attached.

Bob Crites

[Redboy]

Thanks for the advice, Bob! I'll definitely do the board mount and use the terminal strips. Do you have a favorite cap for this application? I seem to remember from another post that you don't think much of bypass caps, either... was that right?

[BECtoo]

The Solen or Dayton polypropylene caps from Parts Express would be lots better than the factory caps. You would need 2 1uF and 4 1.5 uF caps. Use a nonpolorized electrolytic for the woofer roll off cap, 47 uF. We are only talking about $15.00 to $20.00 for all those parts shipped.

Bypass caps (what ever that term means) are a complete waste of time and money in crossovers.

Bob Crites

[Redboy]

Use a nonpolorized electrolytic for the woofer roll off cap, 47 uF.

Bob Crites
Bob, I'm taking your advice word for word here. Going with the Solens for the smaller values. There are several 47uF choices at PE:

47uF-100V non-polarized $0.90 ea.
Solen 47uF-400V polyprop $13.09 ea.
Ruby Gold 47uF 500V axial $6.85 ea.
Jantzen 47uF 400V Crosscap $12.01 ea.

The last three don't specify whether they're nonpolarized. Is one better than another, or can I really buy a $0.90 cap for this application? Does the voltage rating come into play here?

[BECtoo]

The non-polorized electrolytic for $.90 is fine for the woofer roll off cap in this crossover. You don't listen to any music through that cap. It just removes some of the highs you don't want to hear out of the woofer. Consider it like a trash can in function. A higher quality cap in that position does you no good.

Bob

[Redboy]

Excellent! I'm okay with saving some change! Thanks again for your help with this.

This is why I love AudioKarma!

Nate

[cubdog]

Bob, is it just the Heritage line or all older Klipsch speakers that suffer from poor cross overs? My recently aquired KG4's sound great but would they benefit from a crossover tweak? Also I am trying to buy some Cornwalls will the crossovers on those also need help and how will I know?

cubdog

[BECtoo]

I usually consider that caps that are at least 20 years old need to be replaced. Some of the Klispch speakers like the Forte, KG-4 and Heresy II could benefit from new caps regardless of age. Just that Klipsch used very cheap caps in them originally. Good news is that all of them can be rebuilt and the just replacing the caps with good polypropylene brings them all back into good shape. As I mentioned earlier, I like to get the components off some of the plastic input terminals and rebuid the crossover on a block of wood.

I haven't tried the build on a separate board trick on a KG-4 yet. It uses a little circuit board, so it is a bit different from some of the input terminal block crossovers.

Here is the KG-4 crossover.

Bob Crites

[Southern]

Redboy,

Have you updated your Forte crossovers?

I was looking at the selection of caps and noticed that the 47uF-100V non-polarized cap is good for 200W on the other hand 200W through a Forte is insane.

I am considering updating mine but I would also like to re-wire my Forte's to bi-amp them with my Dynaco ST-70 for the mid & hi's and my Pioneer SX-1980 for the lows.

[jcmjrt]

I usually consider that caps that are at least 20 years old need to be replaced. Some of the Klispch speakers like the Forte, KG-4 and Heresy II could benefit from new caps regardless of age. Just that Klipsch used very cheap caps in them originally. Good news is that all of them can be rebuilt and the just replacing the caps with good polypropylene brings them all back into good shape.

Just thought I'd chime in with a me too. My understanding is that electrolytics were designed for a good dozen years. I figure that at twenty, they are done and I replace them. Polypros are good economical choices. Bob knows a whole lot more than most of us about the old Klipsch and crossovers and wouldn't steer you wrong.

Southern, if you are seriously considering biamping then you may want to look at an active crossover so you can get the most out of it that you can. A passive crossover may limit the quality of the results...may still be better though than what you have...

[Southern]

Just thought I'd chime in with a me too. My understanding is that electrolytics were designed for a good dozen years. I figure that at twenty, they are done and I replace them. Polypros are good economical choices. Bob knows a whole lot more than most of us about the old Klipsch and crossovers and wouldn't steer you wrong.

Southern, if you are seriously considering biamping then you may want to look at an active crossover so you can get the most out of it that you can. A passive crossover may limit the quality of the results...may still be better though than what you have...

I am considering an active crossover for the low end but I still need the passive crossover for the mid & hi end. Any recommendations for an active crossover?

[Redboy]

Redboy,

Have you updated your Forte crossovers?

I was looking at the selection of caps and noticed that the 47uF-100V non-polarized cap is good for 200W on the other hand 200W through a Forte is insane.

I am considering updating mine but I would also like to re-wire my Forte's to bi-amp them with my Dynaco ST-70 for the mid & hi's and my Pioneer SX-1980 for the lows.
Southern, I haven't gotten around to it yet. I got distracted by all the discussion around boutique caps over there at the Klipsch forum, and am considering buying some better (?) caps for the job. Possibly the Theta caps from PE. Problem is, then I start wondering if that's all I should do :scratch2: . I want to do this once and be done with it. So... caps and resistors?

I'll never have anywhere near 200W going through those speakers. Not with my setup, anyway.

Member doucanoe biamps his speakers via an active crossover, with tubes on top and SS on bass. Very nice sounds coming from that setup :thmbsp: .You might talk to him about his crossover.

[Southern]

Redboy,

I was/am in the same situation, should I spend more $ for the better caps or not. At the moment I am tempted to go with the Solon caps but that might change next week. Since my Forte's sound terrific with the original caps I was in no hurry to upgrade them.

Thanks for the tip on bi-amping.

[Redboy]

Well, I ordered the Theta caps yesterday, should get them on Monday. My Forte's sound pretty great to me too, but the driving force behind this whole hobby for me has been "What else can I hear in my music?" My first vintage purchase opened my ears to how much I was missing before - I want to take that ball and run with it!

I got my Forte's for a song, so the cap refresh seems like a fairly inexpensive upgrade that I'll recover should I ever decide to part with these speakers (seems an unlikely scenario at this point!).

I also ordered the Dayton non-inductive resistors (http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=004-40&CFID=4249008&CFTOKEN=90614456) as replacements to the existing 40 ohm 5 watt ones in there. Anyone have any feedback on these?

[Southern]

Let us know the outcome of your new caps. :music:

I also got my Forte's used at a low price however, it makes it more difficult for me to justify spending 1/4 the purchase price for new crossover components. I also would never considered selling my Forte's.

What did you use for the 1.5uF caps since Theta doesn't offer this value, did you put (2) 3uF in parallel or series (1) 1 uF & (1) .47uF?

I'm leaning towards Auricap since they offer a 1.5uF value and are rated to 400V.

[Redboy]

Let us know the outcome of your new caps. :music:

I also got my Forte's used at a low price however, it makes it more difficult for me to justify spending 1/4 the purchase price for new crossover components. I also would never considered selling my Forte's.

What did you use for the 1.5uF caps since Theta doesn't offer this value, did you put (2) 3uF in parallel or series (1) 1 uF & (1) .47uF?

I'm leaning towards Auricap since they offer a 1.5uF value and are rated to 400V.
I figure the low cost of the speakers allows me to spend more on the upgrade... :yes:

I'll be using the 1uf and .47uf combination. Seems like the Auricaps are a popular choice for this application, so I don't think you'll go wrong there.

[BECtoo]

I figure the low cost of the speakers allows me to spend more on the upgrade... :yes:

I'll be using the 1uf and .47uf combination. Seems like the Auricaps are a popular choice for this application, so I don't think you'll go wrong there.

Did you also notice that those expensive caps are also rated at a 10 percent tolerance? That is a terrible tolerance value.

Bob

[Redboy]

Did you also notice that those expensive caps are also rated at a 10 percent tolerance? That is a terrible tolerance value.
Hmmmmm....

Bob, I probably should have consulted with you first. Are there any "high end" caps that you do like? My impression is that you think it's all a bunch of snake oil. 10 percent does seem pretty lame when you're looking at that kind of cash, especially when PE offers those 1 percent Daytons at a fraction of the price. But are there good sounding caps and bad caps, or are we just looking for something that measures dead on?

Theoretically, my cap values could be off by 10 percent, right? So my 1uf caps could measure between 0.9uf and 1.1uf. And my (1uf + .47uf) combo could measure between 1.32uf and 1.62uf. How much would/could this affect what I hear from my speakers? Do the factory caps that are in there have better tolerances than that? Were they measured and matched once upon assembly?

I don't want to tick anyone off, but there are passionate arguments made by both camps, both for and against these fancy caps. And I understand that I could spend a whole lot more on caps than this! Am I already wasting money?

It would be interesting to hear from anyone else who's actually used the Thetas on this topic, too... Do I send these things back, or are they really the magical creatures they're supposed to be?

[BECtoo]

10 percent tolerance is just inexcusable on the part of a cap manufacturer. Worst case is that you could have 10 percent off in both directions in two channels and that adds up to 20 percent. Yes, I think those caps must be a heavy dose of snake oil. Just what are you being expected to pay the high price for if you get some of the worst specs in the industry? Yellow color?

You know, I doubt if there is more than 25 cents worth of material in any of the caps. So, manufacturing with good quality control must be most of what we pay for. 10 percent tolerance just doesn't say much for quality control. It just says they can be pretty sloppy and still meet their very wide specs.

Now, Yes, I like Sonicaps pretty well. Rated at 5 percent and typically test better than 2 percent.

Bob Crites

[silversport]

...just a vote for whatever Bob puts in his...I have 2 pair of Heresys...bob refreshed the crossovers in both...I thought Heresys sounded great before...he really tightened up the bass and the midrange stepped up a bit...at the very least they sound as if they aren't nearly 28 and 26 years old a pair...WELL worth the price of admission...
Bill

[Redboy]

Yes, I think those caps must be a heavy dose of snake oil. Just what are you being expected to pay the high price for if you get some of the worst specs in the industry? Yellow color?

Now, Yes, I like Sonicaps pretty well. Rated at 5 percent and typically test better than 2 percent.
Well, here I sit eating humble pie! I'm returning those Thetas, as I have no way of testing them. Poo. Will get some Sonicaps and see if white caps are as good as yellow caps... :D

[BECtoo]

Redboy,

Send me an email about Sonicaps.

Bob

[pmsummer]

Bob,

Can't you at least spray those Sonicaps with aluminum paint so they'll look right in Heritage installations?

;)

[SET12]

Well, I ordered the Theta caps yesterday, should get them on Monday. My Forte's sound pretty great to me too, but the driving force behind this whole hobby for me has been "What else can I hear in my music?" My first vintage purchase opened my ears to how much I was missing before - I want to take that ball and run with it!

I got my Forte's for a song, so the cap refresh seems like a fairly inexpensive upgrade that I'll recover should I ever decide to part with these speakers (seems an unlikely scenario at this point!).

I also ordered the Dayton non-inductive resistors (http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=004-40&CFID=4249008&CFTOKEN=90614456) as replacements to the existing 40 ohm 5 watt ones in there. Anyone have any feedback on these?

My Forte outboard crossovers.

http://img237.imageshack.us/img237/7898/stockcrossovervsmodifiedsj1.jpg

SET12

[Redboy]

Looks cool, SET12, but I'm not sure what I'm looking at. I've seen your stuff as I was searching for information on doing my crossovers. What caps have you settled on?

I'm officially going with the Sonicaps now. I'm green enough to all of this that I'm going to go with Bob's recommendations to the word right now.

[SET12]

I am using a matched set of Hovlands and small value MIT matched Polystyrenes as bypasses because the Hovlands were hard sounding. I won't recommend the Hovlands as they took forever to break in but they are sweet now! I guess it depends on how far and how much you want to spend and what the Forte's mean to you my motivation was for experimentation with ease of parts change and BTW I wraped my horns with foam then velcroed the foam in place as well.

I tend to like Film and Foil types for their current capacity and dynamics one cap that I'd like to try is Mundorfs Gold foils and oil but they are very expensive I also have an inkling to try MIT Polystyrene film and foils because these are some of the most dynamic caps that I have ever heard in RIAA networks and I heard that Thiel prefers these in his loudspeakers they would be cheaper to try over the Mundorfs. The Mundorfs cancel internal inductance by actually constructing their caps by two series ones a very expensive way but perhaps very effective soniclly!

I just went to Sonicaps site WoW! Those are expensive and I thought the Mundorf's were! I need some new Caps! By all means keep me inform on your work!

SET12

[Redboy]

I'm going to be using the Gen I Sonicaps, not the high buck Platinums! The six caps I needed came to less than $50 with shipping, so this is a fairly affordable experiment. I stuck with the cheapo caps from PE for the woofers as Bob suggested earlier. I figure the speakers already sound pretty phenomenal to me, and the setup I have is far from TOTL so there's no need for me to go absolutely nuts with this... yet.

I'll be replacing the internal wiring at the same time with the same Canare stranded wire that I use in my system. This is a pretty nice 16 gauge stranded cable, the stuff used by Blue Jeans cable.

[BECtoo]

Redboy,

If you want to take the next step, like SET12 did, that is a good thing to do with the crossovers that are built on the input terminal cups. Here is a picture of one for a Heresy II that I did that way. All parts are re-used from the original except the caps are new. The terminal strip is added also. The input terminal cup is still used to input the signal and a pair of wires is run from it to the terminal strip on the "new" crossover.

Bob Crites.

[SET12]

Nice work Bob!

SET12

[Redboy]

I'm tempted to try the "outboard" rebuild. Is the main advantage simply the ability to swap components more easily? I don't see much in the way of soldered leads in either of your boards... wouldn't that give you better conductivity?

Bob, do you just use those generic aluminum spades that I can buy at Home Depot?

If I'm not going to be rebuilding this on a regular basis, is it better to just solder everything on the existing board if I can make it fit? Maybe I'll try some sort of hybrid, moving the crossover onto a board, and incorporating the terminal strips.

Your thoughts, gents? SET12, I gotta say, that thing is muy cool looking! :thmbsp:

[Audible Nectar]

I got an opportunity to sample Sonicraft caps in a couple (amongst several other) MnIntosh MC-30 rebuilds. One had the whites, the other had all platinums. Now the whites - pretty good, and I could have lived with them......but once I heard the platinum capped version, I had to give my MC-30s the LOVE! These capacitors refined my MC-30s to a level I never thought possible: The background is quieter/"blacker", the music is clearer, and the release of the notes is much more relaxed yet detailed - no constriction or clutter whatsoever. They are VERY "SET" like, yet with testicles :thmbsp: These caps simply elevated the class of performance of these components by more than a step or two, that's for sure!

I never was much to worry about caps. In fact, I have a set of Bob's recapped networks, and they have thier allure. But then I got to sample some AA Jensens, and have heard Auricaps and several other versions - and YUMMEE, is there a lot to sample! For the DIY'er, there's many things to try, and they are worth trying. And them hearing several different MC30 rebuilds with different cap quality levels......and OH YEAH, I'm now a believer in using high grade caps to squeeze the best performance out of your investment - especially if it's a component you wish to keep.

The Sonic Craft whites are definitely good caps. But the platinums are another animal entirely. I was told they are a Sonic Craft version of a "V Cap" (and when you hold a platinum cap in hand you'll go "whoa" - they are heavy)! I don't know that much about caps, but in my amps, they showed their worth. Considering I'm keeping my 30s permanently, I thought them worth it.

Another point when evaluating caps: They DO change in sonics after a while. ESPECIALLY the "high resolution" stuff like Hovlands/Auricaps/Sonicaps and so forth.....so give them some time if you are sampling new ones. My platinums are still "relaxing" after about 300 hours. I'm told that they need 500 hours to be completely burnt in.

I've got another pair of MC30s to recap and am considering the Mundorfs for those.

Bob will think I'm crazy, but that's life when listening through horns. Everything makes a difference. Good caps for rebuilds, good tubes, it all adds to the performance! So feel free to sample! :music:

[BECtoo]

Yes, I would take issue with some of that. The caps when new are perfect in doing what a specified capacitor should do. That is, provide capacitive reactance and nothing else. Now if anything changes in any way, we move away from perfect and toward bad. Must be that we move toward bad since if perfect to start with, bad is the only direction left. I would say that if a cap changes in any way over a few years, that is a bad cap.

The Jensen PIO caps start out life as bad caps. They are so poorly constructed that there is the equivalent of a 1/2 ohm resistor in series with them when new. That will cut the highs back some, but using a poorly performing cap to do that job is certainly the wrong tool to use. A tone control makes a lot more sense.

Auricaps...10 percent tolerance. The cheapest Daytons and Solens are good to 5 percent. What is up with that?

Bob

[Redboy]

Well, while you guys were arguing caps, I got mine today and finished the job :D . I'm really quite pleased with the results! :yes: Pictures show the original crossover, the board with caps removed, and the finished product.

http://audiokarma.org/forums/attachment.php?attachmentid=27679&stc=1&d=1187234521

http://audiokarma.org/forums/attachment.php?attachmentid=57683&stc=1&d=1187234646

http://audiokarma.org/forums/attachment.php?attachmentid=27680&stc=1&d=1187234646

The new caps were a little larger than the originals (except for the woofer cap which was actually smaller) and crowded out the resistors, so I ended up mounting them under the boards. Drilled new holes and scraped down to the trace for new solder points. The resistors were way larger than the originals too, so this ended up being a good way to do it. Each board is then raised on little plastic standoffs. New leads run to the terminal cups.

http://audiokarma.org/forums/attachment.php?attachmentid=27681&stc=1&d=1187234646

So there you have it! I haven't yet reinstalled them, so I'm not 100% sure they actually work yet... but I'm fairly confident they will!

I'll post again once I've had a chance to listen to them and evaluate what I'm hearing.

[Redboy]

Got 'em in, and they work!!! :banana: Sigh of relief... Now to listen.

[Southern]

Got 'em in, and they work!!! :banana: Sigh of relief... Now to listen.

They look great! How do they sound?

Once I decide on the brand of caps I will do my fortes crossover. I plan on doing one at a time so that I can do an AB comparison. Since my fortes are older (crossovers mounted on the back of the round cup) I plan on installing the components on a block of wood so that I have lots of room.

[Redboy]

They sound sweeter than they did before! I was listening for about two hours last night while the solder cooled...

The highs are more detailed, and I get the sense that the soundstage has gotten bigger.

I know it's too early to pass judgment, but so far so good!

[jaymanaa]

Nice job, very clean work. Now you got me looking over my shoulder at my Heresys. :scratch2:

[doucanoe]

Nice Job Nate! I never heard the pre-new cap Fortes but would love to hear them now.

Sounding good with the Eico I bet.

RC

[Redboy]

Nice job, very clean work. Now you got me looking over my shoulder at my Heresys. :scratch2:
Jay, I've been following your crossover project closely... mine is kid's play compared to what you've got shaping up there! Very sweet! :thmbsp:

RC, swing on by anytime! Would love for you to hear this and get your thoughts!

[Yamaha B-2]

Redboy - Where did you come by that Forte' labelled PCB? Would like to recap the x-overs in my brother's Forte II speakers and that PCB would certainly simplify things.

Also, are we talking Forte' or Forte' II in these posts? Are they the same?

Thanks.

[Redboy]

The PCB was original in my Forte's. They're vintage '87, so I think earlier models were different.

Forte' and Forte' II are different models with different crossovers. You should be able to find a schematic on the Klipsch forum, or Klipsch might even provide it for you.

Good luck. BTW, I'm still very happy with the results.

[Yamaha B-2]

Thanks for the info. How would I date my brother's speakers?

[Redboy]

Check the serial numbers, if they're still attached. Mine are serial 87047... The first two digits correlate to the manufacture year, but apparently they changed that somewhere along the line so you may need to check with Klipsch. In fact, you might just want to call them anyway. I was impressed with the quality of their customer service. One more reason to love 'em!

[Yamaha B-2]

Thanks, again.

[silversport]

http://home.earthlink.net/~ivol/klipsch_cornwall/klipsch_date_codes.htm

Not my work but passing it along as it is what EVERYONE else uses!
Hope this helps.
Bill

[damuho]

Let us know the outcome of your new caps. :music:

I also got my Forte's used at a low price however, it makes it more difficult for me to justify spending 1/4 the purchase price for new crossover components. I also would never considered selling my Forte's.

What did you use for the 1.5uF caps since Theta doesn't offer this value, did you put (2) 3uF in parallel or series (1) 1 uF & (1) .47uF?

I'm leaning towards Auricap since they offer a 1.5uF value and are rated to 400V.

I got a pair of KG-5.2's and was interested in getting Al K.'s (alkeng.com) tweeter attenuator but thought I'd do some research first on tweaking the crossovers, so I found this thread...

The above calculations for series and parallel capacitor connections are wrong. Caps in parallel are summed up i.e. 1.0µf in parallel with 0.47µf will make up a 1.47µf cap. Two caps in series will equal the product of the two values divided by their sum i.e. two 3.0µf caps in series total 1.5µf (this would have worked for the example above for your Fortes).

If this has been corrected before and I missed it in the three pages that followed, I apologize. I went through them in a flash.

[Redboy]

I noticed back when it was posted, but I don't think I ever mentioned it. Probably good that you've made note of it, just for reference.

[damuho]

I noticed back when it was posted, but I don't think I ever mentioned it. Probably good that you've made note of it, just for reference.

I see...

That would have been really strange if you used the wrong formulae as your guide and ended up with your Fortes sounding "sweeter".

I think I will go with the crossover cap upgrade first then maybe add the attenuator later.

Thanks.