djk
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Posts posted by djk
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It would be nice to have a link to the correct post from BEC on this subject.
(only so many hours in the day for me)
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The ESR is more important than the absolute value.
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The only thing a government is good at is taking money from people at gunpoint, and then wasting it.
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Class D usually has problems at low levels due to the dead time required to prevent shoot-thru (which makes them overheat).
With low enough Rds-on specs, the DCR in the output inductors can generate more heat than the output stage (many pro designs have heatsinks on the output inductors).
I can show anyone wanting to do a commercial design how to eliminate dead time, even over temperature (for a fee of course).
(Burr Brown had a very complex design, my idea is simpler).
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I suspect he means the EV/Klipsch driver sounds better than the Aton/P-Audio/Klipsch driver.
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The first photo shows the K57 stamp (K53 with integral K700 horn used on Heresy II, Forte, etc).
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It was a trivial amount, about $60 or so (H&R Block made an error), and was paid for with a direct deposit from my checking account.
Government is dangerous.
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The state just refused to renew my car plates, said I owed them tax money.
Of course they were wrong, but the hassle to correct their mistake was a huge time waster, and my plates were going to expire (which would have caused armed thugs in blue costumes to hassle me).
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The JBL 4" titanium drivers don't sound good below about 650hz, no matter what horn they are on.
Not a problem though with the old annular half-roll edge aluminum drivers (375, 2440).
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A cheap meter with LCR can measure the inductance, and then you can calculate the turns ratio.
https://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=lcr+meter&_sop=15
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" Funny, i was one of the lead mechanics at a local Wards well before they went out of business. "
Western Auto (Sears) was the worst (locally).
The Wards issue was a simple mistake, Western Auto was a huge fraud issue, multiple times.
A misteak (sic) can be forgiven, fraud is unforgivable (the Western Auto went out-of-business).
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The question was rhetorical (Monkey Wards forgot to torque them after mounting new tires).
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If thread direction were true, why did the lug-nuts get loose on my right front wheel (and not my left)?
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" Some of those lyrics a guy really doesn't want his daughter singing. "
Love the children wearing earbuds singing along with NWA at the library.
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"Would love to protect these. Got any of the filters left? "
A key part in the filter (17.5H inductor) was obtained on a surplus basis, and is no longer available. IIRC, about 100 were all that was built. They were about 5KΩ impedance, I built some 600Ω versions but they sounded opaque (as Crown preamps couldn't really drive 600Ω and still sound good).
P500?
Should be OK, we sold the P300 (back in the day).
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JBL recommended using an amp no larger than 150W on the L-100 (123A).
Puking a 123A was usually done with an amp lacking an infrasonic filter and playing records, not excessive power per se.
I designed and sold a $30 30hz filter (for the tape loop) that virtually eliminated such failures (and made things sound better, and allowed you to play louder too).
JBL sent their vice-president out to visit our store to see what we were doing. We were also the world largest Harman Kardon ST-7 turntable dealer, in addition to having the lowest driver failure rates on JBL speakers (due to the filter and using fuses).
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"the Heresy out-performed the 4311 Monitors in every way...more bass.."
Don't think so.
I sold JBL and Klipsch. At one time (1979~1980) Klipsch told us we were the largest single dealer they had, we were also the largest single JBL dealer in the midwest (including Chicago, St Louis, KC, Twin Cities, etc.).
The JBL had better bass.
The Heresy sounded better in the mids and HF until the amp ran out of power (assuming it was on the floor up against a wall).
The mids and HF on the JBL started gradually distorting and when the amp started clipping it was a lot less noticeable than the Heresy (when the amp clipped the distortion went through the roof).
I has access to measuring equipment (delay gated), and was amazed at how good the Heresy measured off-axis (as you would be while listening). Both speakers were quite flat (the JBL having better bass).
I talked to PWK about using a better tweeter (like the JBL 077), Paul pointed out that it cost 5x that of the EV unit.
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" I believe he laughed at the notion. "
Can't hear ?
Bob Pease (RIP) from National Semiconductor had some good articles for engineers on this subject (he called it capacitor soakage)
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Blue, brown and orange.
Most people bought the orange.
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" I thought the whole reason you changed them was due to age. "
The Russian caps are hermetically sealed, the oil caps used by Klipsch after the early '70s were not. Lead failure due to ESR on non-hermetic caps is the issue, age, per se, is not.
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" I'm pretty much asking about an analog active unit. "
As was I.
The only electronic crossover I have ever seen that ran on a single-ended DC voltage (that puts DC bias on the caps) was the old A/D/S AX2 (circa mid '80s).
Lead attachment is still a problem with the caps over time, and any device with copperweld leads (as most small film caps and film resistors were).
Carver and Hafler bought NOS parts to save money, they failed much sooner than other companies products (due to copperweld failures).
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" The electronics in an active analog crossover are connected to circuitry powered by DC. "
Of course you mean ±V, the signal is referenced to 0V (ground).
Woofer facelift?
in Technical/Restorations
Posted
I have found that this works the best:
https://target.scene7.com/is/image/Target/13994825?wid=520&hei=520&fmt=pjpeg