I think this can can get high current spikes on first capacitor - what is not clear to me how would the opposite work in practice, if the transformer has moderate current regarding the load ( not really double the current, just little over the load needs ), on a bigger core for lower induction.... ?
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That is mandatory / standard practice when using one transformer for high voltage & heaters - have them with HV sec & 2 heater secondaries, for example.
Electromagnetic & electrostatic protection is standard practice, locally for custom wound ( toroids ).
I think with a non DHT tube a standalone transformer with separated secondary for the heater and B+ is sufisant. I of course talk about a tube I/V and not about feeding the dac supply with it.
YMMV,
after there is self expectation, for illustration my main daily tda1541A based has 8 secondaries on 4 different R-Core.
YMMV,
after there is self expectation, for illustration my main daily tda1541A based has 8 secondaries on 4 different R-Core.
Just putting a feeler out....
I'm thinking about ordering a small batch of AD1862 chips from Rochester, would there be any takers for a pair at $80 including shipping in the USA only? Not a big group buy, probably 5 or so pairs.
Best,
Vunce
I'm thinking about ordering a small batch of AD1862 chips from Rochester, would there be any takers for a pair at $80 including shipping in the USA only? Not a big group buy, probably 5 or so pairs.
Best,
Vunce
I'm no expert on transformers. I always have that brute force approach, stronger is better. Undersizing the secondary certainly leads to overheating and a reduction in the raw DC voltage. If it is necessary to limit current pulses on the first capacitor in CRC or CLC schematics, I would rather use a current limiting resistor (which I can change the value of) than a weak secondary.
Some transformers sound better than others for reasons i certainly don't understand. R-cores are generally not my taste in analogue circuits, but for purely digital supplies they can be very good.
Best not to have preconceptions and rather spend some time listening before committing to a transformer.
Not sure it is the good words, and btw some have still a screen like mines. I do not remember exactly ans Maxwell things are also way above my head. But I remember some talked about a better isolation of the two Windings, because their position on the ring core and the way it is isolating or canceling "things" in the magnetic area.
In my main system r-core is sounding also better for the i/V stage. In the PS after, the smoothing caps are not sounding the same related to the traffo layout.
I have found most of the time r-core gives better results. Iirc I am the one that launched that in that thread early.
People followed. Hope I am not wrong, ahaha. There is no doubt many here have not rcores but still good sounding DAC.🙂 😉
Quality of the traffo matters. Here @jean-paul writted if i am not wrong he noticed serious difference between a Tamura R-Core and a classic chineese wounded R-Core made for mass market!
No. I just enjoy the superiority of r-core transformers even those without UL etc. certificates. It is hard enough to find r-core transformers. The ones by Kitamura Kiden are excellent. I have a few from an Indian brand to test and I had a large number cheap but good chinese ones (meant for microscopes). The latter were used in a groupbuy here.
When wound correctly coil windings mutually cancel each other's magnetic flux by means of balanced, symmetrical winding on the two “legs” of the “racetrack”. Leakage is then also lowest. Point being that not all are wound this way so some only have the looks.
When wound correctly coil windings mutually cancel each other's magnetic flux by means of balanced, symmetrical winding on the two “legs” of the “racetrack”. Leakage is then also lowest. Point being that not all are wound this way so some only have the looks.
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ah yes kitamura, I remember now, old thread. So the Kitamura you had had not special better hearble behavior ?! I have one 14-0-14 from Kitamura but never benchmarked it... all of my supplies are not center tapped traffo made.
Mines are indian made with a screen. good quality....
Mines are indian made with a screen. good quality....
Almost done moving my AD1862 build from temp chassis to permanent home in a Pesante case. Only need to order a USB cable to run from the jlsounds board to the USB terminal on the backplate.
Thank you 🙂. Next will moving the 1541A to its permanent home. Then putting together the AD1865 in a temp chassis.
