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Crossover A Klipschorn cap replacement help


Aoran994

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1 hour ago, Deang said:

These measurements directly influence the voltage curves and transfer function. This much I learned directly from Roy, which is why he asked me to use Tecate, and to have Universal Transformer bring back the T2A, T4A autoformers and various coils. I even had to request a certain steel type for the laminations, as these also effect the voltages.

 

Well, I'm out. I no longer have the emotional bandwidth for this.

 

 

I respect your decision to opt out, so can someone please define for me "transfer function" as it relates to Klipsch components?  I always assumed it was the voltage curves across the driver attached to a crossover when doing a frequency sweep.  I've been using REW and a Focusrite Scarlett Solo.  However, when I Google "transfer function", I get complex mathematical equations.

 

Are voltage curves and transfer functions the same thing?

 

Thanks, Mike 

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9 hours ago, Travis In Austin said:

@Deang and @captainbeefheart So we (what am I saying, you guys) talked about some of the technical measurements of three brands of caps:

 

1. Dayton

2. Tecate

3. Sonicap

 

I'm not even up to speed on if they were identical inner materials or different. But they had a different ESR/DF (slightly). 

 

Will they sound different to someone with average hearing they they go onto the board and are hooked up?. Not better, worse, just different. The average Joe, not Deano's golden ears. 

 

I have no golden ears and I am an average Joe in that sense.

My BC Type AA had Sonicaps polypropylenes installed. I replaced them with Polyester types (later in another thread I described my impressions for the better when using the very right capacitance values). I will not bore anyone with the thread linked below, but the difference between the Sonicaps and the Mylar types are night and day in my view and described in detail below in the link. Not only in the way the treble is performed but in an important change to the positive how the bass is stronger and the timing is much more musical. In the end it is a sound out of one piece. We are not talking subtle nuances.

 

 

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1 hour ago, mboxler said:

Are voltage curves and transfer functions the same thing?

 

In this case, a voltage transfer function, so yes.

 

"The transfer function of a filter is the voltage amplitude at the output as a function of the frequency of a constant amplitude sine wave applied to the input."

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12 hours ago, Travis In Austin said:

I'm not even up to speed on if they were identical inner materials or different. But they had a different ESR/DF (slightly). 

 

Will they sound different to someone with average hearing they they go onto the board and are hooked up?. Not better, worse, just different. The average Joe, not Deano's golden ears. 

 

I wouldn't call the difference in ESR/DF between the two caps as "slightly" different.

 

A DF of .5% with the Tecate is far higher than .0125% 

 

At 1kHz that was .47 ohms for Tecate and .01 ohms for Sonicaps. It may look slightly different to you but in the world of capacitor selection that's very different.

 

I feel your average audio enthusiast will fairly easily be able to hear the difference between the two.

 

As mentioned several times the Tecate is a Mylar cap and Sonicap is Polypropylene, I posted graphs of the DF characteristics for these types and Mylar is very similar to paper, high DF that varies drastically depending upon temperature.

 

I am only trying to show why people shouldn't be using Sonicaps in their vintage Klipsch heritage speakers unless they want modify them by being brighter because that will be the result. Dean has mentioned some Polypropylene caps like the Daytons that aren't as bright as Sonicaps and I found in the Datasheet that they do not have the quality factor that the Sonicaps do, or the DF is much higher by a magnitude of almost 10x at .1%, the Sonicaps were very low at .0125%. This matched pretty perfectly with how Dean heard them.

 

I am in no way putting down what Klipsch does. I said many times that I have no idea why Klipsch stuck with Mylar for so long and still do, but I did say the clearly have a reason to do so. Some of us heard Roy mention that they keep the same transfer function, and so that's what we have to go on and that's what we have been discussing. The ESR can alter the transfer function and since DF is a ration between ESR and Xc it's more appropriate to discuss DF and not ESR. The reason is ESR is a resistance at a specific frequency and specific capacitance. So if we just throw out random ESR values we would need to include frequency and value of capacitance. Dissipation factor clearly tells us what we need to know with just that single value in %. The higher the number in % the more lossy the cap is from the consequent higher ESR, and of course the lower the number is in % the closer the capacitor is to becoming a theoretical perfect capacitor with lower ESR.

 

My point is that other non sanctioned vendor claims people should use the highest quality capacitor with the lowest DF possible. Dean and I are saying that's a bad move because it effects the transfer function, to match the original performance and transfer function you need a cap that behaves like the original ones, like Tecate.

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3 hours ago, captainbeefheart said:

 

I wouldn't call the difference in ESR/DF between the two caps as "slightly" different.

 

A DF of .5% with the Tecate is far higher than .0125% 

 

At 1kHz that was .47 ohms for Tecate and .01 ohms for Sonicaps. It may look slightly different to you but in the world of capacitor selection that's very different.

 

I feel your average audio enthusiast will fairly easily be able to hear the difference between the two.

 

 

 

Silly question but for someone who already has polypropylene caps, can you run a parallel 0.5 ohm resistor on the existing caps?  I found this at Partsexpress but am curious about something that might be less expensive from Digikey or a similar source:

 

https://www.parts-express.com/Jantzen-0.51-Ohm-10-Watt-Audio-Grade-Superes-Resistor-255-941?quantity=1

 

 

 

 

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18 minutes ago, tigerwoodKhorns said:

 

 

Silly question but for someone who already has polypropylene caps, can you run a parallel 0.5 ohm resistor on the existing caps?  I found this at Partsexpress but am curious about something that might be less expensive from Digikey or a similar source:

 

https://www.parts-express.com/Jantzen-0.51-Ohm-10-Watt-Audio-Grade-Superes-Resistor-255-941?quantity=1

 

 

 

 

 

Are you trying to add resistance to the capacitor to simulate ESR?  If yes, then the resistor would need to be in series, not parallel.  Unfortunately,  ESR changes with frequency.  I have a 2uf polyester cap that measures .31Ω ESR at 1000hz but .06Ω ESR at 10000hz.

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15 minutes ago, mboxler said:

 

Are you trying to add resistance to the capacitor to simulate ESR?  If yes, then the resistor would need to be in series, not parallel.  Unfortunately,  ESR changes with frequency.  I have a 2uf polyester cap that measures .31Ω ESR at 1000hz but .06Ω ESR at 10000hz.

I know that it changes with frequency, but if a speaker were too bright, this might be an easy solution, although the mylar caps appears to be inexpensive. 

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9 hours ago, Deang said:

 

That was kind of the point of the discussion. It was in the earlier posts - comparing numbers from the data sheets and measurements for the different dielectrics. Sonicap and Dayton are polypropylene. Tecate are Mylar. Klipsch has been using Mylar since the early 70's. We are trying to show the OP, and anyone following along, how the different dielectric material impacts ESR, DF, etc. These measurements directly influence the voltage curves and transfer function. This much I learned directly from Roy, which is why he asked me to use Tecate, and to have Universal Transformer bring back the T2A, T4A autoformers and various coils. I even had to request a certain steel type for the laminations, as these also effect the voltages.

 

Yes, it's audible, as Jim from JEM discovered, along with many others, who mostly just quietly fix things because they don't want to be caught in the middle of this quagmire. 

 

Klipsch doesn't make their engineering processes public, so we are often left to speculate. It's not a slam on Klipsch, just the reality of it. No one was being critical, so I don't understand the heavy hand.

 

Well, I'm out. I no longer have the emotional bandwidth for this.

Great thread, (as others have  also pointed out )you guys sure are knowledgeable . Curious about the universal autoformer crites 3636 can it be used as an accurate substitute for the T4A ? Your  post makes me question  its use . I was under the impression that T4A was no longer available .

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1 hour ago, tigerwoodKhorns said:

 

 

Silly question but for someone who already has polypropylene caps, can you run a parallel 0.5 ohm resistor on the existing caps?  I found this at Partsexpress but am curious about something that might be less expensive from Digikey or a similar source:

 

https://www.parts-express.com/Jantzen-0.51-Ohm-10-Watt-Audio-Grade-Superes-Resistor-255-941?quantity=1

 

 

 

 

 

I think you are trying to add resistance to the capacitor to emulate increased  ESR correct? If so it would need to be in series and not parallel.

 

It won't work how you want it to work because ESR is frequency dependent. Which is why when discussing this topic we refer to DF instead of ESR as it would get confusing and annoying to keep having to reference the ESR value to what frequency it was measured at and what the capacitance value is.

 

 

 

 

 

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5 minutes ago, Tom05 said:

Curious about the universal autoformer crites 3636 can it be used as an accurate substitute for the T4A ? Your  post makes me question  its use . I was under the impression that T4A was no longer available .

 

The 3636 has slightly different primary inductance, I believe it's higher. This slightly alters the transfer function on the low frequency side.

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30 minutes ago, captainbeefheart said:

 

The 3636 has slightly different primary inductance, I believe it's higher. This slightly alters the transfer function on the low frequency side.

Thanks for the reply, I believe that the T4A is no longer available, which would leave me with the 3636 option. “Slightly altered transfer function “ what does this mean in practical  terms, (a different crossover point to woofer? ) Kinda guessing here.

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24 minutes ago, Tom05 said:

Great thread, (as others have  also pointed out )you guys sure are knowledgeable . Curious about the universal autoformer crites 3636 can it be used as an accurate substitute for the T4A ? Your  post makes me question  its use . I was under the impression that T4A was no longer available .

 

You can get pretty darn close.  The inductance between taps 0 - 3 on the 3636 is roughly 20mh.  The inductance between taps 0 - 3 on the T4A is 7.3mh.  On it's own, a 11.5mh inductor across tape 0 - 3 of the 3636 will bring it's inductance down to the T4A level.  If you are using it for an AK-3 crossover, the 5mh inductor across taps 0 - 3 of the T4A gets you 3mh of inductance.  If you place a 3.5mh inductor across taps 0 - 3 of the 3636, you end up with the same value.  Is this for an AK-3 crossover?

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8 minutes ago, mboxler said:

 

You can get pretty darn close.  The inductance between taps 0 - 3 on the 3636 is roughly 20mh.  The inductance between taps 0 - 3 on the T4A is 7.3mh.  On it's own, a 11.5mh inductor across tape 0 - 3 of the 3636 will bring it's inductance down to the T4A level.  If you are using it for an AK-3 crossover, the 5mh inductor across taps 0 - 3 of the T4A gets you 3mh of inductance.  If you place a 3.5mh inductor across taps 0 - 3 of the 3636, you end up with the same value.  Is this for an AK-3 crossover?

Yes , I’ve got a set of AK2’s that I’d eventually like to convert to AK3 . I bought the 3636 a few years back  , never got around to doing the conversion . I see the 5mh across tap 3 what does that value need to be?

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