"ZD cited just above." Is again not a technical explaination. Could conscrewed as getting used to the sound so you don't take it back for refund.
As for trimpots Peter (Csontos), yes if they are left in one position for a while they do tend to loose contact between the wiper contact point (metalic), and track (carbon or conductive plastic) because of current flow between dissimilar materials.
Part of the same reason for the Lightspeed Attenuator, no contacts of dissimilar materials (diode effect). When ever I see this, I take out the single turn trimpots and replace with Bourns multiturn, they last a bit longer but still have the same problem after a while. Maybe we should use the Lightspeed system as bias pots as well, now you've given me another idea.
Cheers George |
Interconnects can sometimes alter things, all are different in construction, and parameters such as impedance, capacitance and inductance, of the cable can have filtering effects when used on high output impedance devices, such tube preamps and passive volume controls.
But anyone who says they need "burning in" with burn in gadgets and burn in cd's needs to be taken with a grain of salt.
Cheers George |
"Burn in" believers imply that something will change for the better after a period of time.
The only way this can happen is if the characteristics of the components change.
All good equipment is measured, tested, calibrated and designed to perform it's best before it leaves the factory.
If any of the above characteristics change after this with "burn in". Then this equipment will not test the same, be in calibration, or measure the way the designer wanted it to remain when it left the factory. And could only sound worse after "burn in".
Ok lets say things do change after "burn in", how does any designer compensate for this, in his calibrations, measurements, tests and design????
The only thing in audio I know of that can change "sound" for better or worse, are mechanical things like speaker suspension systems
Cheers George |
06-18-14: Bifwynne
Btw, maybe not so crazy. I understand that low temp cryo "cooking" of metallic parts like gun barrels, engine parts and so forth changes the crystalline structure. The result is stronger and longer lasting parts, so the cryo proponents maintain. I think cryo'ing has been overdone in audio, it's fine to do material of one substance like a gun barrel. But when people start doing tubes, this is just not on. As the rates of expansion and contraction of unlike materials like metal tube pins that are an air tight seal with the plastic base and the glass that is a seal with it, just think of what happens to the vacuum in the tube when this is cryo'ed. Then lead solder on plated metal interconnects with silver or copper wire three different materials all contracting at different rates, solder is bound to get cracks in it. Cheers George |
06-16-14: Almarg
06-16-14: Zd542
I have some Cardas cables that take forever. 100's of hours.
ZD, as I'm sure you realize I have great respect for your experience and your sonic perceptions. But a question: How do you know that the improvement you are perceiving after 100's of hours is due to the cables, and not to something else in the system that has changed in the meantime? Or, for that matter, something that has changed in the AC power, or even the temperature or humidity of the room?
Best regards,
-- Al Yes as Al has pointed out this this greatly overlooked. Take any hybrid ESL speaker for instance, they are tuned for a certain sound by the factory. The esl panel on a day when the humidity is 70%-100% can loose as much as -3db efficiency, making the balance sound bass heavy as the dynamic bass driver has not lost this -3db. I have measured it on my new panels, dry day 5kv bias charge and on a humid day 3kv-4kv bias charge, I tend not to do any evaluations or serious listening on days when the humidity is above 70%. Or if I have to, I can with some trouble turn down the gain of the bass electronics by the appropriate amount so all is balanced again. Cheers George |
So it seems like we are in agreement, that to us "break in" for better or worse can occur with the mechanical devices such as speakers drivers, cartridges, and tubes, as you also said.
And you and I will not commit without skirting around the edges and state to "break in" periods of semiconductors or active components can get "better sounding" with said "break in" times of 100's of hours, unless some technical proof is brought forward, forgetting hearsay of friends and customers.
Cheers George |
So Al, by disagreeing respectfully, are you saying that you believe that "breakin phenomena" does exist??
Or just to my assumptions that there should be a measurable difference in component specification?
And if so, in which do you believe the "breakin phenomena" exists, passive cables or active electronic components?
Cheers George |
06-22-14: Csontos
It makes no sense that the expectation is for parts to fall out of spec in order to fall into a desired lower cumulative level of performance. Ridiculous. And how would this be accomplished within a reasonable time frame? By using inferior quality parts? Again, ridiculous. Exactly, when a unit is tested and adjusted up before it leaves the factory, it should stay this way for some time, for years we all hope. To say that components change their characteristics after this because of "burn in" hours, means those adjustments will out out of spec, after the burn in. Brand new capacitors do what's called "form" but this only takes minutes and they should already be "formed" by the time it takes to do the final spec adjustments in the factory before shipping. The only thing in audio I know of that degrades relatively quickly from the first time it's switched on is tubes. And if they don't have auto bias circuits to keep them in spec, they need to be measured and adjusted every now and again. As they do loose the bias adjustment, depending on how many hours they are on. Cheers George |
06-22-14: Zd542
"Ok lets say things do change after "burn in", how does any designer compensate for this, in his calibrations, measurements, tests and design????"
They compensate for this by breaking the prototypes in before they listen and measure. For example, a designer may want to try several different capacitors when building an amp to see which one sounds the best. If they want to try 5 different options, they break the amp in 5 different times. They don't do any serious listening or measurements until they break the amp in first. This is the way they all do it. I don't think you could find one company that doesn't break their equipment like this. You don't have to take my word for it, either. Call some manufactures and ask them. Ok if this is true, then this means all production units sent out that are not "burnt in" have been purposely miss-adjusted/calibrated for currents, bias, dc offset etc, NOT for the best ideal performance. Hoping then that all these parameters of adjustments will all come together after the customer has "burnt it in" for a few weeks??? I think not. Cheers George |
06-17-14: Mapman
Makes sense.
I do think I hear a difference with some new power cords, but so subtle its hard to be certain. These can be a bit different sound, as they have earth, neutral and live. Some shifty mains cable makers swap the neutral and live around, while all still works, they are attached then different within the primary winding of the equipment's mains transformer, as it has an outer feed and inner feed. And this even though it's AC can this sound different, making the user think it's the actual mains cable itself causing the difference. You can prove this to yourself with some cdp's that only have a two wire main cable with a reversable 2 pin mains plug on the back of them, each way sounds different to the other even though it's the same cable and plug. Cheers George |
