to evaluate a electrical system like the mains transformer supplied with the DAC you would need to know the PS circuitry inside the DAC
as an example
while "better transformer" in isolation may seem to be higher VA rating, bigger core, lower winding resistance from more copper - it could also give larger inrush current, lunch the diodes if their DAC PS design, component sizing actually allows for, expects a certain higher winding R in the mains transformer they spec
and a big mains transformer design option can't really be had without getting them custom wound - lower operating B in the core - all off the shelf mains transformer designs push the core B to the margin to save on core and copper weight, size
Hi and thanks again. I completely agree with the scientific approach. But we have in the end to select a brand and a part.
I have here in my hand a very very cheap product. It is
a usb to spdif converter.
It sounds ok to me but i am not in the position to judge in a dependable way beacuse my present system is not resolving enough.
And it uses a toroidal transformer in the PS.
For curiousity i looked at one of the best similar devices available in the market. It uses a different type of mains transformers.
I tend immediately to give much more credit to the design choice of the better unit. Immediately without any exitation.
I agree that the transformer is just a part and not the all unit but it is an important element.
Clearly for the more expensive unit any transformer around could have been selected because cost is less of a constraint.
For what i know the Talema in the cheap unit could even be a fake one ... it would be not the first time.
I am completely sure that an Hammond transformer with split bobbins would be a better part also for the cheap unit. Like some of the filters/chokes used in the better unit.
I would never think to mod an almost perfect and usually very very expensive unit (of course)
Like by instinct i think to mod a very very cheap unit already decent because i am sure that some mods on strategic components can have a great outcome.
It is fundamentally sane and with some mods can be very good.
And i think i am not alone in this thinking. And for sure i cannot afford the better unit.
If this were not possible, to elevate the performance of a cheap unit, i would agree with leaving it as it is.
But i am instead sure that it is possible. So why not do it ?
maybe the problem is to do it properly ... of course.
Just to make an example i will try a external filter and listen for any change in sound. Is this a mod ? i would say yes.
I am quite sure that the same filter on the better unit will have very little effect because the unit has a so much better filtering already.
Usually cheap units have to skip on something for cost reason. A 10 USD mod will increase the total cost of the unit of 100 USD in the end of the process.
For me instead it will cost 10 USD. Modding when done properly on a already promising unit is a very smart decision. Just look at how many modders are around.
Sometimes the mod is just a part replacement.
I remember to have read a very interesting comment about a mod on a dvd player. The mod consisted in just bypassing some parts.
The sound was better !!!! with less parts the sound was better ... unbelievable.
These non needed parts are like some dressing on a very good food ... they just ruin it.
Often the parts are not what makes the final cost. Is the labour that costs.
Something they skip on parts that instead are fundamental for performance.
I would always look at what is fantastic and try to copy the design solution.
I bought for instance some service manuals to try to understand something of the design.
Another problem is that i do not have necessary instruments to see for noise or similar.
This is another top class dac ... and it does not have toroidals ... and i see a mains filter at the input.
http://schiit.com/public/upload/general/imagecache_thumbnail_product_gallery_large/yggdrasil_pcb_1000.jpg
So my reasoning is that the same parts (with the right ratings of course) put in the cheaper unit could give some benefits
For the best units that provide the best sound possible the parts selected can be the best available. Cost is less of a constraint.
There is a lot to learn looking to the best units around. To the benchmarks. I think.
But if i spotted the same Talema (supposing that mine is not fake) in a similarly top unit i would be willing to think again about the mod.
Thanks again, gino