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MikeM
05-26-2003, 02:03 PM
Has anybody cloned the 4435 network with newer high perfomance parts? The inductors I would think are the most important to get exact as well as everything else

Robh3606
05-26-2003, 02:30 PM
I have the parts ready to go. I would definately purchase the .04mh from JBL. They are a very small light gage air core on a nylon form. The 30 ohm pots are available too. I haven't been able to get those networks together yet!!

Rob:)

Ian Mackenzie
05-27-2003, 03:40 AM
The thing to sort out is the final adjustement of the pads for flat response.

JBL did this of course with 0 db markers on the front level controls.

This would normally require a analyser to measure the response of the complete speaker.

JBL state the 4435 network will give about 4 db extra level around 2 khertz.

I agree with this having measured it, so back of the 8 ohm 30 watt pad about that much. The other pad , the 30 ohms should be adjusted to about 4.5 ohms for a flat HF response.

The 0.04 mh coli should be within 5% as should the capacitors. Try using a good metalised polypropolyne and bypass with 0.01 uf or a nice film and foil like a Hovland. ]

Ian

MikeM
05-27-2003, 06:21 AM
Thanks for the info What did the pots run at jbl? $$?

4313B
05-27-2003, 07:02 AM
Use this schematic, use this price list

http://www.jblproservice.com/pdf/Studio%20Monitor%20Series/4435LR.pdf

http://www.jblproservice.com/pdf/Misc.%20Parts%20List/02MISCPPL.pdf

61014-0R04 0.04mH $11.19

N15-61390 30 ohm 25 W Rheo $26.48

You might want to pay attention to the DCR's on the coils as it is fairly important, especially on the bass drivers, and especially in this particular system.

MikeM
05-27-2003, 07:27 AM
Originally posted by Giskard
Use this schematic, use this price list

http://www.jblproservice.com/pdf/Studio%20Monitor%20Series/4435LR.pdf

http://www.jblproservice.com/pdf/Misc.%20Parts%20List/02MISCPPL.pdf

61014-0R04 0.04mH $11.19

N15-61390 30 ohm 25 W Rheo $26.48

You might want to pay attention to the DCR's on the coils as it is fairly important, especially on the bass drivers, and especially in this particular system.
THANKS

4313B
05-27-2003, 07:45 AM
This past week I built a pair of charge coupled networks using Dayton metallized polypropylene capacitors for mains and no bypass capacitors.

Without the batteries installed the sound was (true to form) up-front, in-your-face, two dimensional and quite bright. Not as bad as Solen Fast Caps but still not good enough for my taste. On the plus side, they did sound quite clear and boundless on the top end and the transient character was right on.

After installing the batteries the depth actually did improve a bit and the brightness was somewhat decreased. Most obvious though was the drop in distortion. These things got very clear.

Overall the sound quality of the unbypassed, non-charge coupled metallized polypropylene's wasn't as good as the stock metallized mylar bypassed with polystyrene and polypropylene. (Duh! We've only known that for over twenty years now) Charge coupled, the metallized polypropylene's were slightly better than stock, with lower distortion, better top end, and exceptional attack, but not as much depth and warmth. I would say warmth is what was lacking most though.

Needless to say, I will be installing some good film and foil bypass caps this week. Hopefully the Daytons won't respond negatively like Solen's do when bypassed. I would have liked to have used straight film and foil mains but the price is simply too rediculous to contemplate, especially when charge coupling.

4313B
05-27-2003, 10:30 AM
Niklas has kinda gotten me to thinking... :)

I had 4430's and replaced the 2235H's with 2234H's back in the 80's to gain efficiency. After swapping the 3134 for the 3135 and giving the system a listen I decided the 2234H was woefully inadequate in the VLF when used in singles and returned to the original stock 4430 configuration.

However, since the 4430's sound so much cleaner when bi-amped to subs I've been thinking about perhaps revisiting that old configuration. This time I would put the 2234H in a 2.0 cubic foot sealed volume to maximize it's already excellent transient response capability. Then I would be free to biamp this smaller 2.0 cubic foot configuration with whatever sub system I had on hand. A 2.0 cubic foot "4430/4435" hybrid would be much easier to move around or mount in a wall than a 5.0 cubic foot 4430. I would completely bypass the need for any inductors in the VLF. And I would gain the 3 dB sensitivity by using the 3135/2234H as well....

Earl K
11-10-2004, 08:29 AM
Hmmmm,

Glad this thread is archived and still available .

Based on Giskards observations about the Dayton MPPs, I think I'll have to buy some to try out in my cap-building matrix.

Over the last 2 weeks , I've been using motor-run ( MPP in Oil Mallory made ) caps as a base cap to build upon. I had tried this with quite mixed results about 14 months ago. These motor-runs have a ton of lower-midrange and essentially little else. As such they are a decent foundation to build upwards ( sonically ). Without heavy bypassing and a lot of paralleled companion caps they are quite dull, slow and maybe even somewhat distorted sounding. I have ambivalent thoughts towards this distortion comment. ie; I'm not very sure about it. Anyway, a 50/50 split using a dry-film MPP married to the wet film MPP creates a cap hybrid that is quite nice. This split is a little "cooler" than some may like, but altering the ratios is easy enough to rebalance the harmonic spectrum. A bigger weighting towards the "oil" side creates a warmer cap - though somewhat at the "nuanced" expense of clarity or sharp focus.

I use a .47uf Solen cap to add "brilliance" or upper presence into this mix. Again, the dominating characteristic tendencie of a Solen cap makes this .47uf value all that is needed ( or desired to my ears ).

Large value "Bypassing" rounds out the above mixture. Surplus Polyproylene Film & Foil and surplus Polystyrene caps create the Bypasses. Their values are about equal to each other at .18uf for each type. Since I don't use tweeters I am always trying to ram through/exaggerate as much UHF as I can. These larger value bypass caps do help out in that area.

The overall value of the "built" cap is about 34uf. I am DC biasing ( Charge Coupled ). I actually need to get up into the 40uf area to keep these caps from effecting my crossover values . These caps are being used in a DC blocking positon and as a Phase Correction to my existing HF Bypass caps. The HF Bypass caps are mated/paralleled with a 8 to 10 ohm resistor .


Overall, It's fairly easy to create a balanced sound with these ratios that can easily be construed as "detailed, clear, warm (enough), and even luxurious ". Unfortunately, I can't reference these results to Jensens or Mundorfs or Audio Note Silvers since I just can't afford any of those caps.

Now unfortunately for the budget minded ( & why else would anyone fool around with this ), Solens just won't play nice with this meccano approach to cap building - hence my interest in the Daytons . ( The existing dry-film MPPs being used are emblazoned with a RC logo - so maybe they are from Reliable Capacitor ,, I mention that just for any perceived sonic reference point someone may try to create ).

Anyone tryout Daytons' Film & Foil bypass caps ?

regards <> Earl K

4313B
11-10-2004, 09:02 AM
I tried the Dayton film & foil bypass caps with the Dayton MPP's and that was ok. I thought the Dayton MPP's bypassed with the AudioCaps were considerably better.

I had two pairs of 4406's and used them for numerous tests. I think the 4406's running charge-coupled Daytons bypassed with charge coupled AudioCaps are astounding. The biggest concern going in was using such a "minimal" system for testing. Rest assured, it ended up being a great system to use. I can't say enough good about the silly little 4406 at this point. They gave my stock pair of 18Ti's a bare bottom spanking. My 4430's sounded quite boring next to them and the 4430's were running ElectroCap metallized mylars bypassed with ElectroCap metallized polypropylenes and polystyrenes, which sounded better than the stock 4430's. I'll get around to putting the 4430's back together someday but they will definitely get new filters (Actually, I'll probably just go back to bi-amping them with the passive highpass portion biased and the active highpass portion converted to line-level passive).

I might be charge coupling one of my pairs of 240Ti's in the near future. I would most likely use the Dayton main / AudioCap bypass combination.

Earl K
11-10-2004, 09:11 AM
Giskard , thanks for your insight on that . :)

Earl K

EDIT

Actually, I quite liked the comment about $100.00 20uf caps.
I wouldn't , and just won't pay that much for essentially, DC blocking caps. Since I already biamp my horns and I'm quite committed to Charge-Coupled caps that "itch" would end up costing @ $1,600.00 if using Mundorfs' Silver & Oil ( 16, 10uf caps x 101.50 ). The economics behind my matrixing/search will be fairly obvious .


I'll get around to putting the 4430's back together someday but they will definitely get new filters (Actually, I'll probably just go back to bi-amping them with the passive highpass portion biased and the active highpass portion converted to line-level passive).

COMMENT

I'd be interested to hear of your impressions if & when you rebuild the 4430 thingies . Especially if you tuck an inductor in behind the 7.5 ohm conjugate instead of using the 20uf DC blocking cap. My last guess at it's value would be in the .5 to .6mh range. ( My AC impedance meter has been broken for a while or else I would probably do a "mockup" of this .) I guess that 2uf cap needs to become a bit smaller - like maybe 1.8uf .

Guido
11-10-2004, 12:35 PM
(Actually, I'll probably just go back to bi-amping them with the passive highpass portion biased and the active highpass portion converted to line-level passive).
Giskard, with what active filter and how exactly can this be done? If I understand correctly you'll not use the passive HF EQ but EQ it active?