I agree and believe it is useful instuction for any audio equipment which can work simulataneously to both types of outputs, no matter if there are transformers or any other components are used before connectors.
Yes indeed. Guess what I was measured with cut-out RCA connector from the cable - 40pF cca. That is 2 x for 2 sides + main cable capacitance cca 80-100pF/meter... And that is without 2 times female chases connectors normally employed...
.
It is not bad idea to measure capacitance of any cable with connectors used. Because in this direct way of connection this part of reactive component could be of significance in whole secondary load and transferred with square to primary?
.
I like to use buffer (preferably SE at the outputs of intersage, because of high input impednce and very low capacitance. In that way transformer ale "locked" to the given Load and almost without any reactive load also. Offcoure to full target galvanic isolation this additional buffes should have own power supplys with separate transfprmers and regulators to awoid direct ground sharing and capacitive path if same power transformer used.
.
Last edited:
Your suggestions are again very right, but relates more to the whole audio equipment and in this terms your tip have no relation with my transformers directly because, even if as you said:
Clicks\pops is a bit another story and relates more to DAC side but not to the output stage. But! Yes, I know solutions where the muting relay are presented before the RCA\XLR outputs. They are working from digital analyzing of the incoming (I2S\DSD) source and unmutes the sound only after the right I2S\DSD incoming status.
losts any negative effect immediately after offset gone (there is no any memory effect).
Clicks\pops is a bit another story and relates more to DAC side but not to the output stage. But! Yes, I know solutions where the muting relay are presented before the RCA\XLR outputs. They are working from digital analyzing of the incoming (I2S\DSD) source and unmutes the sound only after the right I2S\DSD incoming status.
In transformers presented on the market there is the very more bad situation with capacitance and it is not the "parallel" capacitance you are talking about. 100pF of the cable is nothing compared to the "in series capacitance" between coils.
I suppose I have much easier method for checking phase (absolute phase) - it is the audio file with the saw signal. If it is the same in the audio editor and at the osilloscope then the absolute phase is correct.
Yes offcourse, but many folks dont have cpecific file, while for instance any soft for measuring transfer have in same time Step/Impulse response
. Anyway booth methods are not complicated exept in simple transfer mode You can measure direct all-sustem and phase at one sweep?
That sounds funny.
Why would single ended tube preamps not shift phase, and all single ended gain stages shift phase??
Better to make a distinction between current gain and voltage gain stages.
Single ended current gain stages like for example cathode / source / emitter followers do not shift phase.
All single ended voltage gain stages like anode / drain / collector followers shift phase.
Dear bisesik,
I want to buy I/V hat for Ian’s DAC, please PM detailed payment information to me. Thanks!
Of course you can use my transformers this way. There is one only restriction of the amplifier sensitivity vs input impedance. If the input impedance of your amplifier is higher than 4kOhm then you will have no problem to provide 2Vrms of the signal to your amplifier input directly from transformers. If your amplifier have 1kOhm of input impedance, then the output level from the transformers will be 4-5 time less. Again without any sound quality degradation. You can use the direct connection to amplifier anyway.
In case if the signal after transformers is higher than needed for comfort listening, then it is better to use less value of the resistor after transformers. I suppose that -30dB can be a bit too much for the digital attenuation (due to SNR decreasing compared to analog attenuation). You can leave some amount of digital attenuation possibility. Say, 15dB instead of 30dB. I do not know the input sensetivity of particular amplifier, but to decrease the level gap you will need to use something about 200-500 Ohm after transformers if there was 4k previously. I suppose it will be better in terms of resulting SNR and SQ at least at the DAC side.
My latest AK4499 prototype DAC using bisesik's transformers uses the output level attenuator in the DAC chip to control output level. This works perfectly & the DAC's transformer output will drive power amps perfectly.
I have been doing this with all my top level DAC's for years now & lots of my customers successfully directly drive their power amps in this manner.
I have been doing this with all my top level DAC's for years now & lots of my customers successfully directly drive their power amps in this manner.