It worth pointing out the above schematic (rev 4 ?)was probably redrawn after the Technical Manual Schematic (Rev 2 8/?) which had some errors.
Its fairly obvious so and not trivial.
It worth pointing out the above schematic (rev 4 ?)was probably redrawn after the Technical Manual Schematic (Rev 2 8/?) which had some errors.
Its fairly obvious so and not trivial.
Comparison of 2405 voltage drives in various JBL Studio Monitors:
The 0.16 mH tapped autotransformer used in the 4344/4345 and 4355 is the same core with three taps. In the 4344/4345 the taps are wired so that there is an ~ 8 dB drop. In the 4355 the taps are wired to that there is an ~ 4 dB drop.
One example unit:
Primary tap 0.158 mH
Secondary tap can be either 0.026 mH ( - 8 dB ) or 0.067 mH ( - 4 dB ) depending on wiring. The actual matrix worked out by David Smith is shown below. In any case, Greg no longer uses them and prefers non-inductive fix resistor solutions as per the 4344 Mk II.
Absolutely fantastic !
Never seen such a perfect work.
And thank you for the documentation because I am beginning to follow the same lane.
For the time I collect spare parts.
I came to, precisely, this model 4345 because I had, long years ago, a new pair of 3 ways 432x with LE15A, 375 and 077 or their professionnal equivalent I don't remember.
I found that 4345 were better because of the fourth way in the medium.
But I neglected to upgrade my JBL for WAF reasons.
I search for the exact design of the cabinet. Could you tell me where to find it?
Spirou38 JBL 4344MKII 4333A 4312MKII L80T L40 L20T Ti2000
Regarding inductor DCR: in the specifications it says f.e. "<0.6ohm". Should I try to get as close as possible to the stated value, or is any value below the stated OK?
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