Complete N3134 from parts list above fits neatly on 7" X 7" board, LP top, HP bottom. We're backordered on one inductor which goes at lower left. Won't get to hear them for 30 days, alas.
The requisite four input terminals will enter from the rear in the space along the left edge. Switch shaft extends out the rear panel as well. It's located where the action is to keep the leads short:
Done. About 8 Hrs. apiece, incuding "figurin'" time.:
Zilch:
looks very nice..... so, how does it sound? Also, do you have a stock crossover to compare this to ( if I missed that part excuse me)
He does, both in 4430s and extras that he bought. Which brings me to my question. Why did you build these? "( if I missed that part excuse me)" to.Originally Posted by JBLnsince1959
Widget
Well, suffice it to say the "Magic" is there.
I haven't tuned L2 (P.E. Jantzen 1.8 mH vs. factory 1.6 mH) or L102 (2.7 mH vs factory 2.6 mH) yet, but they sound very much like factory originals.
Bottom line: if you want 4430 using 2344A, 2425/6/7, and 2235, you gotta build them crossovers, or at least those portions of them you intend to use.
I do have factory stock units I want to compare with them, before and after retuning, and the simple N200T3's I built at Giskard's suggestion, a more easily constructed "Suh-weet" substitute. We'll see over in the "Quick & Dirty 4430's" thread how they all measure up.
1) I'd have to reconfigure my factory crossovers to split them to play in the "Biwire" mode, which I use most often. That's all of the components in both the LF and HF sections, each running on separate amps, not an available option on the original crossovers. The six-pole switch I found permitted me to add it.
2) By the time I'd have also replaced the inductors with air cores, replaced the mylar caps with metalized polypropylenes, and upgraded the bypass caps to Thetas, all that would have been left was the el-cheapo resistors to change. It made NO sense to rework the factory ones. I could make better boards than the one-sided phenolic ones they used originally anyways.
3) I repeatedly found myself advising others doing DIY 4430's on the forum to build the crossovers, but had never done it myself. It's easy to say, but what are the contemporary parts and sources? HOW to assemble them? Will they sound as good? Will the 4430 "Signature Sound" be there? What do we use for the HF rheostat? Only one way to find out -- build 'em.
4) All the info is here, now, except the coil tuning, which I'll add after I do it. I can advise with confidence on this matter now....
OK, so you built these to allow you to "upgrade" the components and facilitate bi-wire. I guess I would have wanted to replace one part at a time to see where and if any real improvements occurred. Should be an interesting comparison none the less.
Bi-wiring? You buy into that huh? I'm not convinced... what's that state's motto? Show me?
Widget
Well, it's not biwire in the conventional sense, although that's possible in this configuration as well. I'm running HF and LF on separate amps.
That's biamp, actually, but in the standard 4430 context, using the "ext" option, external crossovers and EQ are also required.
I think we can agree that "biwire" in this sense is a worthwhile option.
BTW, did you run tests on that 6260 I drug over there yet?
[That's my standard LF amp. Another nice one just came up on eBay last night. Don't need any more here, fortunately, or I'd be biddin'....]
There are three parts worth using in the stock 4430 or 4435 network and they would be the 30W ceramic rheostat, the 50W L-Pad and possibly the 0.04 mH air core inductor.
We found what may be a good replacement for the 0.04 mH inductor, Jantzen #1806, 0.24 ohms, 0.50 mm wire.
P.E. can get them, but it's 8 to 10 week lead time.
Any forum members in Denmark near the Jantzen factory what can get us a pair of samples to test? PM me if so.
Guido's checkin' into availability direct, since we also need them for AM crossovers used with 2431H. Once we check 'em out, we'll likely order up a bunch here.
In the meantime, if anybody wants a pair of the precision 0.06 Ohm metal strip resistors I bought to use with the Jantzen 0.05 mH, 18 AWG, 0.09 Ohm inductors, PM me. I bought 10 to meet order minimums, only used 2 so far. See parts list above....
Edit - Two footnotes:
1) I ended up using the series section (between pins 2 and 3) of the second L-Pad as the HF rheostat R201. Since the original 30-Ohm rheo "0" is at very low resistance, adjustability between 0 and 8 Ohms is good enough, with better resolution. AND it cranks in the "right" direction.
2) The two large inductors L2 and L102 are only 1-3/4" apart in this layout; best practice would be 3" or more. However, considering their functions in the circuit, it's apparent that any LF crosstalk between them is shunted to common. I also looked at contemporary JBL crossover layout practice and find that they violate this "rule of thumb" routinely. Finally, they are at right angles to each other to minimize inductive coupling. I'll measure them on the oscilloscope to verify my assumptions here....
I'm currently fighting with Intertechnik as they ignored my inquiry. As I'm a very good customer of them I'm sure to bring them "back on track" soonGuido's checkin' into to availability direct, since we also need them for AM crossovers used with 2431H. Once we check 'em out, we'll likely order up a bunch here.
Once I get these tuned, we'll do a double-blind A/B/C test. I'll put them in a pair of 4430's, another pair with their factory crossovers, the upgraded L200's, and relays to switch the same amp and source among them.
Your place or mine?
Some adjustment of all three inductors is required to bring them from stock Jantzen values purchased from parts list to schematic specifications. It's best to have an LCR meter to get them "spot on," but here's the adjustments that were required with these particular units:
1) L1 - removed 5 turns from outside to reduce Jantzen 0.05 mH to 0.04 mH.
2) L2 - removed 14 turns from outside to reduce Jantzen 1.8 mH tp 1.6 mH.
3) L102 - removed 6 turns from outside to reduce Jantzen 2.7 mH to 2.6 mH.
The resulting sonic character was "crisper," though playing them without the adjustements was fine, too. The change was not major.
Best tool I found for removing enamel from the cut ends to tin and solder: an emery board.
RTA measurements here:
http://audioheritage.org/vbulletin/s...age=26&p=53444
Two updates:
1) Jantzen #1318 seems like a better choice for L1 here, 0.047 mH, 0.17 ohms. Unwind down to 0.04 mH, and the resistance will be correct at 0.15 ohms without additional low-value series resistor. Probably available in Europe (made in Denmark), special order at Parts Express.
2) Crosstalk matters. Keep big L102 at least 3" away from the other inductors, and orient to minimize inductive coupling....
Just thought I would bump this up w/ a question for Zilch....I ran all these part numbers with the suppliers, the caps are still the same price, the coils have gone up, but are still available. Two parts gave me trouble. One, the rotary switch. Newark didnt show it under that part number, but when I searched the electroswitch factory part number, (on the Newark site) it came up under #06M4599. Problem is, it is described as a "3 PDT" while your original list calls it a "5 PDT".....will this make a difference? Next, the metal strip resistor by Vishay-dale. I think I found its new newark number as WSR2R0610FEK. It's a .061 ohm, 2 watt, series WSR, with package case 4527. Is this the same part? Thanks, If I can just source some 2344s I will be ready to proceed. Any idea on where to source two? Jammin jersey has some, but dont do pay pal or plastic for whatever reason.
Finding the damn resistors is the hardest part. There's only three of them (2 values, actually,) but if we want truly non-inductive, that's hard to come by.
Wirewounds are inherently inductive, but there's a non-inductive winding method (Aryton-Perry) that would be suitable. That's used in Dale type NH, but I can't find them. The Vishay Dale website is impossible.
Also, there's power thick films, inherently non-inductive, in TO-220 packages, but proper heat-sinking's not part of our typical "screw on a piece of plywood" assembly technology here.
Maybe just use the aluminum chassis-mount type RH. The two values we need are available in 25-Watt for under 3 bucks each.
Using those, the total's below for each, including the expensive switch:
Any crossover builders out there have resistor options or other better choices? The spreadsheet's an image I can update....
Russellc
If you look on the Newark catalog page, the switch is 6 poles, actually, a double stack of 3 poles, and you set the stop for anywhere between 2 and 4 positions. I used three positions, and 5 of the 6 poles, as I recall.
http://www.newark.com/jsp/level5/mod...en_US/5050.xml
So, the correct current Newark part# is 06M4599
You can forget about the Vishay-Dale resistor. Guido was right, it's not necessary, since the variable resistance makes up the difference, notwithstanding whether it comes before or after. If you want to use it anyway, PM me your mailing address, and I'll send you a couple.
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