Yes, that is very possible! Eventually I'll pull the woofer and check everything, but right now I'd rather just listen to them.I'm suspicious that with your gorgeous networks and JBL's inverted polarity there is some unintended wiring snafu.
The 4345's are pretty much done, but I've been keeping myself busy working on this active crossover. It's coming along nicely, all that's really left is to drill the mounting holes in the chassis.
The design is pretty simple, pretty much straight out of Douglas Self's "The Design of Active Crossovers". I did the circuit / board design myself and I had the boards printed by BatchPCB. I'm working on a discrete version, but of course that is a much bigger project and who knows when it will be done.
- 4th order Linkwitz Riley
- 290Hz fixed crossover point
- Active balanced I/O
- High tolerance metalized polypropylene film filter caps, metal film resistors, 5532 opamps
My goodness, that x-over looks lovely! I have a set of similar 4th order opamp pcb's on the shelf - need to solder them up too. In the long run my aim is also to end up with a discrete design x-over.
Do you have any knowledge of an existing diy kit or at least some online documentation of a completed project? Designing one is out of my leauge. I know brystons are fully discrete, and Pass too, but buying a xover thats more expensive than my amps would be a bit of a misalliance. Anyway If you end up finishing the discrete design I'm sure you'd find many LH members interested as well as other loudspeaker diy nuts to be found on boards across the world.
The meat of the discrete project is designing an opamp. I was thinking it would be cool to design it so that the whole board can plug into a standard DIP8 opamp socket, using the same pinout as the 5532. Then I will upgrade the opamps in my cd player, receiver, equalizer, and so on, and I'll have a fully discrete signal chain without spending kilobucks. And it sounds like just what you're looking for, as an upgrade for your opamp crossover kit.
But I'm not going to make any promises until I at least have a working prototype
So you are aiming towards designing dual discrete opamps and plugging them into your boards? Is that nearly everything that differents a discrete design from integrated op-amped?
The crossover is done!
It is a noticeable upgrade from the m552. Midbass is more defined, bass and drums are sharper and clearer. Also there seems to be a bit more resolution in the highs.
It went together pretty much as planned. I messed up the gain structure, and I'm stuck with +6dB gain - I can fix it, but I'll have to order more parts. Also there was a defect in one of the PCB's copper layers, causing a short between traces. It was frustrating to track down - next time I need to inspect the boards more thoroughly before assembly.
So what's next? The discrete op-amp, power amps, or maybe back to the wood shop for a matching birch rack / tv table.
Your work looks very nice - small, modular and straight-forward.
Nice cabinet too!
2ch - Oppo981, JoLida502, JBL L200+, UREI 809A, VonS VR-4
HT7- XDA-2, BDP93, B&K amps, Vandy 3A, 2Ce, VCC1, TF600 & JBL 4641
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