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Thread: 250TI Jubilee spikes

  1. #46
    CLASS A
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    Originally posted by Earl K
    [B]Hi CLASS A



    AudioCap is a trade name for a line of audiophile caps that are manufactured by RELIABLE CAPACITORS . Their UK representative is "Audio Com" who can be emailed at [email protected] . Get them to quote some prices to you , including their delivery times . If it seems the caps having to be shipped out from California then consider checking out Parts Connexion who sell Reliables' other 2 lines' of caps. These other 2 lines are "MultiCap" and "RelCap" . Parts Connexion is a Canadain eTailer ( Toronto based ) .

    I'd be very wary of just replacing the bypass caps and expecting instantly positive results. For Instance; The reason I asked if the existing bypass caps were MKT or MKP ( or MKC ) is: If MKT was used , they would be present to blunt the edge or round out the typical "edgy" signature of the electrolytic. The necessity to include MKT would imply to me something about the sonic signature of the Elna(s). MKT , unfortunately doesn't offer great depth or resolution - just a "masked rounded" quality. MKT is Metallized Mylar ( MKP is metallized polypropylene & MKC is metallized polycarbonate ) . If MKP types are present , they would suggest that the DC-biased Elna(s) are not as edgy as most typical electrolytics. That would signal (me) that they might be able to be left intact with just higher quality Film & Foil bypasses shouldering the resolution burden. MKC has qualities that combine attributes from both MKT & MKP .

    Base Caps - replacement

    Space limitations could dictate that you might have to replace your electrolytics with "Metallized Polypropylene" caps . Smaller physical size was the driving force behind the development of all types of "metallized caps". Eliminating the separate foil layer ( by vapour depositing ) metal directly onto one or both surfaces of the plastic dielectric creates a "metallized" dielectric capacitor . Smaller size is the only "real" benefit for this type of cap. All the current cap makers are trying to construct MPP types that sound as good as a plain old "Film & Foil" types .

    - Giskard has already recommended Solen - "Metallized" ( the second post of this thread) and then went on to later mention that the 250ti(s) developer ( from JBL ) has used Solens in his Charge Coupled Networks. Giskard has also stated that what is released to the public isn't necessarily what those who know better will use them themselves. Does more really need to be said on this ? I'd add, that you should stick with the smallest Solens available - the 250 volt variety . Also, I don't believe "Axion" MPP(s) will be much different with these transducers. I'd buy whatever type is most available to you.

    <> Earl K

    ps I wouldn't let all the recent "yellow-flags" over replacing your NP electrolytics deter you from pursuing better resolution.
    Earl K
    thanks for that, I have just had another look inside the network and found that the big blue capacitors have ELYTONE and are 100V np and the small ones have MPR .01K 250V CMC . with this information, would you still reecomend changing only the bypass capacitors and of what make and value. How many bypass capacitors are there within my network?.
    Many thanks.

    PS: where can I get my hands on the network diagram.

  2. #47
    Administrator Robh3606's Avatar
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    Hello Class A

    I run an active set-up with a charge couple compensation on my horn compression driver combo. Very simple with my part count. I use Mylar and polpropylene bypass caps. Sounds to me like you have a bypassed Charge Couple network in place. If it were me I would leave well enough alone unless I could get a schematic to see what the deal is. You have to remember to run a charge coupled network you have to double the required capacitance and then add another cap so they are in series with a resistor going to that 9 volt battery. As you can imagine it is a very expensive way to do a network with high quality parts. Do you have a small 2 way set-up you can experiment on?? That would be a lot easier than trying to tackle a tweeked TOL 4 way design.


    Rob
    Last edited by Robh3606; 09-30-2004 at 07:13 AM.

  3. #48
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    Lightbulb

    Hmmm,

    Went looking for the 250ti schematic and found this. The 250ti schematic is back there in the jungle somewhere - I saw it a couple of days ago . I'll post a link to it when I find it.

    Giskard did up the following schematic a while back. It'll closely represent some portions of your network. It's obviously missing all the bypass caps plus it shows the "buss-strap type padding" that ( apparently ) your network lacks. But it's a great start. The main thing is that it gives you the idea of the size of the cap values you need. NOTE: since your (050 ? ) tweeter is different than the 044ti found in the 250ti - keep a lookout to see if the new tweeter warranted any network changes - inspect your existing caps to find out their values .


    The numbers and lettering on the bypass caps mean little to me . I would start by replacing the caps in the UHF and HF section first . Leave the existing bypass caps in place. I'd focus on getting rid of the electrolytics first. If you can afford to do more then replace the Midrange caps followed by caps in the parralleled shunt circuits.
    Attached Images Attached Images  
    Last edited by Earl K; 09-30-2004 at 02:33 PM.

  4. #49
    CLASS A
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    Originally posted by Earl K
    Hmmm,

    Went looking for the 250ti schematic and found this. The 250ti schematic is back there in the jungle somewhere - I saw it a couple of days ago . I'll post a link to it when I find it.

    Giskard did up the following schematic a while back. It'll closely represent some portions of your network. It's obviously missing all the bypass caps plus it shows the "buss-strap type padding" that ( apparently ) your network lacks. But it's a great start. The main thing is that it gives you the idea of the size of the cap values you need. NOTE: since your (050 ? ) tweeter is different than the 044ti found in the 250ti - keep a lookout to see if the new tweeter warranted any network changes - inspect your existing caps to find out their values .


    The numbers and lettering on the bypass caps mean little to me . I would start by replacing the caps in the UHF and HF section first . Leave the existing bypass caps in place. I'd focus on getting rid of the electrolytics first. If you can afford to do more then replace the Midrange caps followed by caps in the parralleled shunt circuits.
    Thanks again Earl.....what brand of capacitors would you recomend in place of the electrolytic concidering I will fall into space problems if I go for the big ones. I have found two 250 network diagrams within the forum awhile ago, but I dont think they are the correct ones for the jubilee. Please have a look and give advice. Thanks
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  5. #50
    CLASS A
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    The second one.....
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  6. #51
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    Well, Just lost a fairly lengthy post into the ether . Oh well.

    What caps? - Start with 250v Solens . They are decent, inexpensive metallized-polypropylenes. Hopefully they'll fit .

    Have you taken measurements of the available space ?

    I just looked at Solens' 2003 Cdn price list . Doing all 3 legs ( series caps ) will cost around $130.00 Cdn ( no tax , no shipping included ) .

    Have you established a budget for this ?

    <> Earl K

  7. #52
    CLASS A
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    Earl
    Thanks again, I have decided to go with the solen capacitors. Would you recommend using the solens for the bypassing too. I think I would keep the values of the bypass capacitors to the original value of 0.1 uf. This way, I m going to get the same kind of sound as original and hopfully much better in all areas.
    Cheers

  8. #53
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    Hi

    I'd leave the existing bypass caps in for at least a month after putting the Solens in. If I figured there was something to be gained with new bypass caps - I would buy just what Giskard suggested at the beginning of this thread; Film & Foil Polypropylene "AudioCap" (s). If they aren't available then other makes will do the job - but that need is weeks away .

    Giskard has mentioned this before and I'll reiterate it here. It takes some time for DC biased caps to "breakin" or get fully formed from the DC voltage. What one hears on day 1 of installation is quite different than what is heard a week later and then to a lesser extent 2 weeks later. I'm always suprised 10 days into the process at the sonic differences. I wait 3 weeks into a cap change to determine if I like the results. I routinely changein different cap combinations ( on a monthly basis - for the fun of it ) .

    <> Earl K

  9. #54
    CLASS A
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    Originally posted by Earl K
    Hi

    I'd leave the existing bypass caps in for at least a month after putting the Solens in. If I figured there was something to be gained with new bypass caps - I would buy just what Giskard suggested at the beginning of this thread; Film & Foil Polypropylene "AudioCap" (s). If they aren't available then other makes will do the job - but that need is weeks away .

    Giskard has mentioned this before and I'll reiterate it here. It takes some time for DC biased caps to "breakin" or get fully formed from the DC voltage. What one hears on day 1 of installation is quite different than what is heard a week later and then to a lesser extent 2 weeks later. I'm always suprised 10 days into the process at the sonic differences. I wait 3 weeks into a cap change to determine if I like the results. I routinely changein different cap combinations ( on a monthly basis - for the fun of it ) .
    Hi
    Thanks Earl, I will take your advice to leave the bypass capacitors in for a monthe after changing the solens. How would I know if I need to change the bypass capacitors after the solens are in for a month?.
    Cheers

    <> Earl K

  10. #55
    CLASS A
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    Earl

    At what point after installing the solens do you know if changing the bypass capacitors are of benefit to the sound?. Are all of the bypass capacitors are of value 0.1uf?.
    Cheers

  11. #56
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    Question Original Bypass Caps

    Hi CLASS A

    I'd suggest you keep a small journal of your impressions of the sound of your speakers - when listening to some of your favourite music.

    (A) Start with the way things sound like now.
    (B) Then what your immediate impressions are after putting in the Solens
    (C) Your impressions 1 week after installing the Solens
    (D) Your impressions 2 weeks after putting in the Solens
    (E) Your impressions 3 weeks after installing Solens
    (F) 3 - 4 weeks after (Solen) installation remove the Bypass caps in the UHF & HF portions of the circuit & record your listening impressions . This should give you & others (like me) some clues as to just what nuances your existing bypass caps contribute to the overall sound. Then we can revisit this subject once you have some of your own impressions.

    BTW ; I think you said your existing bypass cap values are .01 uf - so stick with those values if you ever change them out .

    <. Earl K

  12. #57
    CLASS A
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    Earl
    Thanks a million for all your advice. I will let you know how I get on with the change of capacitors. I have e mailed JBL requesting for the network diagram, its a shot in the dark but had to try.
    Cheers

  13. #58
    250Ti only
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    250Ti only

    I too am looking to upgrade the over 20 year old caps in my 250Ti's.
    Cost for the "best" caps is not an issue for me. I want to go for the gold , I'm not getting any younger and listening to music is my 'BIG" hobby.
    I bought my 250Ti's new--(upgading from my previous "QUAD" electostatics), and I figure I already have more than my moneys worth in listening pleasure.
    Particularly since the upgrades I have done have just made them sweeter, more detailed, more dynamic and seemingly more powerful!!
    I drive them with 200 watt Spectral amps through MIT Reference cables. And a lot of MIT's very best in AC conditioning-which alone has made a staggering improvement !!
    If you haven't heard your 250's with absolutely top class AC conditioning- take heart- your speaker can sound TWICE as good as you've ever heard it without doing anything else!!The sound is "stunning" now according to all who hear them-but, I know they can still be improved-- since there must have been ""huge"" improvements in caps in the last 20 years.
    I don't care if I have to buy Solen or Mundorff or ???--just please someone say what is the best BEST they have heard or can think of or let me know if I can just order identical value replacements from a manufacturer.
    What would a 250Ti lover want to upgrade them with?

  14. #59
    CLASS A
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    250ti only

    I have not had the chance to upgrade the capacitors in my 250ti jubilee's. One look into my cross over scares me in tackling the job since the lack of room. However, you have alot of room in your 250ti cross over board, I would change all to solens with the same values as factory for big improvements.
    What upgrades did you proform on your 250's.
    Cheers

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