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View Full Version : JBL 4435 upgrade path ---> advice needed



DonBocadillo
09-05-2014, 06:13 PM
Hi All,

I have recently acquired a 5235 crossover with the 4430 / 4435 cards installed and have a few questions as to how to proceed.

1. I plan on bi-amping the 4435's with my McIntosh MC2500 and my MC30's (both amps use either an output transformer or an autoformer) and I read in the manual that amps with such output stages require that "a 20w resistor equal to ten times the compression driver impedance should be installed across the output terminals" I gather that only the MC30's driving the horns will need this treatment? and what do I exactly need to do here to ensure safe operation? what resistance do I need to use and where should this resistor be installed and how?

2. Is it worth upgrading the 5235 with new op-amps and caps?

3. Should I forego the 5235 and upgrade or charge couple the 4435's stock crossovers (new caps / remove the external/passive crossover switch from the signal path?)

4. Should I upgrade the 2426H's to TAD 2001's? from the research I've done Guido highly recommends this upgrade, I'm very interested in this option and am wondering what changes would need to be made to the passive crossover and or the 5235 to accommodate the 2001?

Any and all feedback , links and ideas would be greatly appreciated to assist me in the next step of my 4435 journey!

Cheers,

Paul.

honkytonkwillie
09-06-2014, 12:51 AM
Since you already have the 5235 it's sensible to start with that and see what happens. When you get bored with that, move along to charge coupling, because I'd really like to get peoples impressions. A few times I've begun pricing out parts to cc a pair of 4430 and it gets daunting really fast. I wish I knew more about tube amp circuitry, as my amp's perfectly happy with a dead short according to the manual.