On Monday, 3 December 2012 02:04:53 UTC+11, GRe wrote:
"patrick-turner" wrote in message ... Anyone ... invited to have a look. Even(!) Audiophools agree to your findings: "The Jadis also measures worse ...; it has a severely compromised bass response" http://www.stereophile.com/content/j...ivsi-listening Don't read the rest, it's a waste of time. Impossible not to stumble over your SE transformer test jig. My 2(euro)cent about how I test transformer inductance. Use courier font! T1 Variac L1 L O-----)|( +----------------------): )|( | ): )|( T2 C1 | DUT ): )|(----)|(-----||-----o-----)|(--- +-): )|( )|( - + | )|( | )|( )|( | )|( (I) )|( )|( (V) )|( | + )|( )|( | )|( +---+ )|( )|( | )|( | | DC-supply N O--o--)|(--o--)|(---o--[R1]--o-----)|(--- +---+ | | | | | - +-------+ +--(V)---+--------------------+ Basically the same to your set-up, but with some more flexibility. R1 & C1 are identical to what you chose in your jig. For L1 I use a 8H/460mA/60ohm-DRC choke thats handy, inductance high enough to reject the ac and dcR/Idc good enough to enable adequate Idc at a reasonable DC-supply voltage. T2 is 220/2x 24V, with T1 at full trottle it's output is 58Vac. For higher Vac I use an isolating variac, without T2 of course. F.e., characterization of chokes destined for LC-filters high Vac (may) show quite different inductance than at low Vac. An Amroh 1505 choke tested this way showed 7.5H @ 200Vac/150mAdc against 5.8H @ 20Vac/150mAdc, 30% more. To measure leakage induction I'm working on a SS Amp. Probably such a set-up makes the above one superfluous. L1 SS Amp. +----------------------): +-------+ | ): | |\ | T3? C1 | DUT ): +-----| | |----)|(-----||-----o-----)|(---+ +-): | | |/ | )|( - + | )|( | | | +---+---+ )|( | )|( | (I) | | )|( (V) )|( | | + (FG*)1kHz | )|( | )|( | +---+ | | )|( | )|( | | | DC-supply +---------+--------)|(---o--[R1]--o-----)|(---+ +---+ | | | - +--(V)---+--------------------+ *Hint for Phil, see the distortion spec. of HP3325A(+HV option). BTW, you deliberately ignored "Rw" to calculate "Lp" for practical reason? Regards, Gio Patrick Turner
I find it hard to follow anyone using text to draw a schematic.
I've tested numerous transformers in various ways, and I happen to have a LV PSU which I recently rewired for something else, and was able to use it to test the Jadis OPT out of its circuit. Before condemning the OPTs, I needed a "second" opinion, and the that was provided my my test circuit shown which most competent ppl should understand. I already had tested it in the amp at low level and with 10r in series with OPT from tubes, with no loading..
There was no need to include Rw in calculations because it is a very low R figure and the measured Lp with DC flow was 1H at 50Hz, ie, XLp = approx 314 ohms.
I wasn't aware Sterophile gave the Jadis a poor review. But it is sure fixed now, and has become the music angel with golden voice.
Patrick Turner