I Just got my James 6123HS transformers for my 300B SET project, and I would like to break them in on the test bench while I work on the chassis and wiring.
My guess was to hook up a solid-state amp to the primaries, blast pink noise or Cyndi Lauper into 'em, and load them with a dummy resistor on the secondaries. Use the 16ohm taps, because then I'm energizing the entire secondary coil, right?
Only thing is, I don't know how well this will work, given that the primary windings are in the kohms and a solid-state amp will put meager power into those windings... a smaller dummy load on the secondary might help a bit here...
I may also be missing DC current, but that's not necessarily what the transformers need (actually, no transformers *need* DC, and most prefer none.)
So, any ideas??? Should I use another transformer in between the burn-in amp and the SE trannies? This could up the voltage and improve impedance matching. What about running the two SE trannies back-to-back:
amp->secondary->primary->primary->secondary->load
Would that work OK? Seems ideal, actually. Umm, if it works that is...!
My guess was to hook up a solid-state amp to the primaries, blast pink noise or Cyndi Lauper into 'em, and load them with a dummy resistor on the secondaries. Use the 16ohm taps, because then I'm energizing the entire secondary coil, right?
Only thing is, I don't know how well this will work, given that the primary windings are in the kohms and a solid-state amp will put meager power into those windings... a smaller dummy load on the secondary might help a bit here...
I may also be missing DC current, but that's not necessarily what the transformers need (actually, no transformers *need* DC, and most prefer none.)
So, any ideas??? Should I use another transformer in between the burn-in amp and the SE trannies? This could up the voltage and improve impedance matching. What about running the two SE trannies back-to-back:
amp->secondary->primary->primary->secondary->load
Would that work OK? Seems ideal, actually. Umm, if it works that is...!
Xfmrs don't burn in, they burn out (BTW: that's not a good thing). 
This burn-in business is just so much audiophoolishness. Your 300B may have to run for a few hours until the bias settles down, but passive components don't need any sort of "burn-in". Capacitors polarize within seconds of power up, and so do the xfmr cores.
Any time you see something that says it needs "burn-in" really means the time it takes for you to get used to the worsened sonics of whatever fool thing they're conning you to buy, usually for $BIG BUX James are already good xfmrs. Don't screw 'em up with any such nonsense.
This burn-in business is just so much audiophoolishness. Your 300B may have to run for a few hours until the bias settles down, but passive components don't need any sort of "burn-in". Capacitors polarize within seconds of power up, and so do the xfmr cores.
Any time you see something that says it needs "burn-in" really means the time it takes for you to get used to the worsened sonics of whatever fool thing they're conning you to buy, usually for $BIG BUX James are already good xfmrs. Don't screw 'em up with any such nonsense.
Miles, why are you so sure I would screw 'em up? My understanding is that they will take up to 100hrs in the amps to settle in. There's not only the magnetizing of cores to consider, but also a ton of insulation (dielectric) in there and eventually mechanical stresses that will work themselves out.
Believe me, I'm a big skeptic of burn-in/break-in, but have come to accept it. I recently cleaned all of the tube pins on some Atma-Sphere M-60s and upon re-installing all of the tubes, could have sworn that the amps took four days of "settling-in" before the sound stabilised. This was not a new component I was getting used to! Stuff like this drives me crazy, sure it could be my ear-brain interface, but to some degree the effects cannot be denied. Subtle, but real, to me at least.
The James are just sittin' there, lookin' pretty, and I would love to have them in top form the day my amps fire up, if possible. Call me crazy!
Believe me, I'm a big skeptic of burn-in/break-in, but have come to accept it. I recently cleaned all of the tube pins on some Atma-Sphere M-60s and upon re-installing all of the tubes, could have sworn that the amps took four days of "settling-in" before the sound stabilised. This was not a new component I was getting used to! Stuff like this drives me crazy, sure it could be my ear-brain interface, but to some degree the effects cannot be denied. Subtle, but real, to me at least.
The James are just sittin' there, lookin' pretty, and I would love to have them in top form the day my amps fire up, if possible. Call me crazy!
If you want to have them in your amps from day one I would just install them. I wouldn't worry about breaking them in before running with them. I too am very skeptical of the "burn-in" stuff, along with a lot of audio business hobknobbery and whoha. Of course I am nothing but an inexperienced minor who is also on a 300B journey. There are a lot of funny ear-to-brain interactions, but there are also a lot of in-brain interactions that we cannot control...like our brain trying to justify $200 caps. The only real "ultra-audio" parts I really have experienced with "burn in issues" are my big o'l oil caps. I have "run them in" and do they sound any different from the way they where, maybe, but it could be me getting used to hearing oil caps for the first time...who knows. I have never tried any of the parts that I hear claim this, so no flaming, but in my opinion I am skeptical when someone says "It sounded really bad at first, really really bad, but then after X hours, or X weeks, it was like BANG, it totally opened up and now it sounds amazing!"
Like I said, personally, I would just install them and let them "burn-in" while you listen to beautiful 300B music.
Cheers
James
Like I said, personally, I would just install them and let them "burn-in" while you listen to beautiful 300B music.
Cheers
James
awedio said:
I'm not sure you'd ruin them, but all this talk of "blasting" them with a SS amp certainly puts them at a greater risk than leaving 'em sit in the box until you're ready to install them. So far as that "100 hours" nonsense, that's, well, nonsense.
I've never heard this. The only thing that comes close is the bias settle down that new finals require when they go into service. Yeah, I've also heard that AuriCaps take 100 hours to burn-in (isn't it amazing that that's such a favourite number
). Well, I replaced a 1uF electrolytic coupling capacitor that was outside the gNFB loop in a solid state amp I did with a 1uF AuriCap. I heard the difference from the first play after doing the replacement. Nothing cahnged over the next 1 hour or the next 100. The only other time I heard any sonic differences is when trying different levels of gNFB.I just don't buy it.
They already are.
This idea of "Burn-in" has been around for centuries, but still I haven't heard or read one single line what actually happens when something is "burned in".
How could a few milliamps change the internal structure of a cable or a transformer? And what really says that "burning in" gives a crystal structure that "enhances" the sound and not vice versa?
If "burning in" is so important, why not bake the transformer at 60 degrees C in the oven. But I guess it was baked just before being impregnated, but on THAT point I can be wrong.
Much of the ideas and myths on audio tweaks seems to be originate from people lacking all knowledge of science (physics, chemistry, maths) why those ideas never are followed with a reasonable discussion what really happens in the process.
How could a few milliamps change the internal structure of a cable or a transformer? And what really says that "burning in" gives a crystal structure that "enhances" the sound and not vice versa?
If "burning in" is so important, why not bake the transformer at 60 degrees C in the oven. But I guess it was baked just before being impregnated, but on THAT point I can be wrong.
Much of the ideas and myths on audio tweaks seems to be originate from people lacking all knowledge of science (physics, chemistry, maths) why those ideas never are followed with a reasonable discussion what really happens in the process.
These guys are telling it like it is. As for "burn in" or "break in" of things like interconnect cables, wire, power cords, transformers, sockets and connectors, resistors, etc. is pure baloney and nonsense. Their characteristics do not change with use. As Miles and others have said, the "100 hour break-in" is how long it takes your auditory system to get used to the sound of your latest creation/experiment. Just put your transformers in the amp and use them when you are ready for them. They are already as good as they will ever be.
Wade
Wade
soundbrigade said:
And I couldn't agree more, and the worst culprits are the high end equipment dealers most of whom can't tell a capacitor and resistor apart. Romantic metaphysical nostrums (notions??) In terms of knowledge not even the modern equivalents of alchemists.
Tubes have demonstrable and measurable parameter changes during the first hours of operation, and each time thereafter until thermal equilibrium is achieved. A very few sorts of caps seem to exhibit some sort of short term burn in phenomena, but this could be the subconscious manifestation of an idea planted by the modern alchemists - i.e. Irrationally I expect to hear a difference therefore I do. Note I do like expensive teflon types so I may be suspect anyway, electrically they are rather well behaved and I hear evidence of that, but as to whether or not there is any real burn in beyond my getting used to them is in my mind at least open to debate.
JMTCW...
Best judgement would have me bow out of this discussion early. Clearly there is some prejudice against burn-in phenomena on this board - that's perfectly OK...
But having said it already, I have long been skeptical of these kinds of "myths", and have only had to confront them when my own experiences made such myths into personal reality.
I too am really put off by anything, like James mentioned where - "It sounded really bad at first, really really bad, but then after X hours, or X weeks, it was like BANG, it totally opened up and now it sounds amazing!"
If it sounds bad to start with, it ain't ever gonna sound good, you're just getting used to bad sound.
But if you really think that stacking and winding a transformer does not cause stresses in the material that will change over time and that all of the insulation inside of it is not susceptible to dielectric effects, you are probably fooling yourself. Will the effects of "break-in" be night'n'day changes? No. These are subtle changes.
Vintage iron (transformers) are reputed to sound better/different, and it's not because the iron and copper they are digging out of the ground today is inferior to that dug up 50 years ago!
There is a lot of audio foolishness out there, and it's true that the worst dealers love to take advantage of the myths to their benefit. But don't close your minds and ears to the fact that there are things which can be heard that simply can't be measured easily, reliably, or at all.
And yeah, the best way to run in my James OPTs is to just stuff 'em in an amp and listen to the sweet sounds already - thanks to all for setting me straight! Happy listening!!!
But having said it already, I have long been skeptical of these kinds of "myths", and have only had to confront them when my own experiences made such myths into personal reality.
I too am really put off by anything, like James mentioned where - "It sounded really bad at first, really really bad, but then after X hours, or X weeks, it was like BANG, it totally opened up and now it sounds amazing!"
If it sounds bad to start with, it ain't ever gonna sound good, you're just getting used to bad sound.
But if you really think that stacking and winding a transformer does not cause stresses in the material that will change over time and that all of the insulation inside of it is not susceptible to dielectric effects, you are probably fooling yourself. Will the effects of "break-in" be night'n'day changes? No. These are subtle changes.
Vintage iron (transformers) are reputed to sound better/different, and it's not because the iron and copper they are digging out of the ground today is inferior to that dug up 50 years ago!
There is a lot of audio foolishness out there, and it's true that the worst dealers love to take advantage of the myths to their benefit. But don't close your minds and ears to the fact that there are things which can be heard that simply can't be measured easily, reliably, or at all.
And yeah, the best way to run in my James OPTs is to just stuff 'em in an amp and listen to the sweet sounds already - thanks to all for setting me straight! Happy listening!!!
You don't need to run electricity through them for any of that stress-strain stuff, just let it sit in a box. Dielectric effects for the materials used in transformers are not time-dependent.
edit: On reflection, a transformer ought to sound BETTER when freshly made- the windings are at their tightest.
"Running in" transformer iron is a total waste of time as the laminations have already been through an annealling process which is a vital part of destressing the magnetic domain structures within Si Fe. So in otherwords, bending the laminations or other physical work will reduce the permeability. So that's why with mumetal cores one simply doesn't bash and bend it about.
Try taking to bits an old transformer impregnated with 20 yr old varnish ? The copper windings are firmly set.
rich
Try taking to bits an old transformer impregnated with 20 yr old varnish ? The copper windings are firmly set.
rich
awedio said:
Let's review what you posted earlier:
The M-60 has eight 6AS7s, and 16 triode sections. If you clean off pin oxidization, that can definitely make a difference. Without dirt on the pins, the sections are probably pulling more evenly, and balance between phases improves. You got used to the slow degradation in sonics as the pins got dirtier over the months or years. Then, suddenly, it's performing like new again. So, yeah, that is going to sound a lot different right from the get-go. Next comes the four days it takes to get aquainted with the different sonics.
That's a whole 'nother story from claims that OPTs/resistors/capacitors/cables/etc need "burn-in". You can't extrapolate that specific experience into a generalized phenomenon. That's an error in logic.
awedio said:
IMHO, that is mostly due to the skill of the designers all those years ago. Tube gear was state of the art and expensive. I wouldn't mind betting that the better transformer manufacturers invested a LOT in R+D, and employed the best transformer designers around. They were made in numbers that made this possible.
Now, however, I think that much of this know-how has been lost (not the theory, but knowing how to apply it practically). Also, despite the current 'resurgance' in tube gear, the overall sales are tiny compared to the volumes in the 50s. I would venture to suggest that modern transformer manufacturers don't have the big budgets for R+D that their predecessors had, possibly leading to inferior performance.
All this is, of course, IMHO, but it seems to me to be the best explaination for older iron performing better than modern stuff.
Many of the same arguments apply to NOS Vs current production tubes too - Mullard etc. took their production jigs and cathode oxide formulations to the grave, as it were.
James
awedio said:
Feel free to label me deaf but i've rewound a very highly regarded vintage output with new wire and original insulation materials and can't hear any difference compared to its unmolested sister. Maybe due to all those lovely oil caps.
Still, nothing wrong with pre-burning it in, although you'll miss the fun of hearing it
Seems quite easy to do. Plug the primary into the mains and load the secondary with a suitable load. Obviously it will only burn it in for the mains frequency, so maybe use a diode to add a bit of harmonics?
Using a SS amp on the primaries is obviously not ideal - not enough voltage, but you may try powering up the secondaries. The primary will have to be loaded appropriately.
Seems like too much trouble.
My rule: if something sux at first listen, no amount of burn-in will ever improve it enough.
i keep seeing these "100 hours burn-in" on many forums, wonder who, where, when and why this started.....
what amazes me is that like the common cold many are quick to acquire it.....
i only hope that just like the common cold, it will pass, most people recover from the common cold with or without taking medicines....
sorry, i couldn't resists.........
I don't buy into any of the hi-end myths either....
But i must confess...after designing and winding transformers for 25 years.... There is a very small amount of time needed for a "Burn-IN" ....
When using man-made insulations, such as Teflon, Kapton...ect....there really is no burn in time, just like 1 minute for the di-electric to DC orient it's poles.... Di-poles have hesterisis to AC gradient...
As for core material....there is no burn-in time...
As for organic di-electric materials such as Kraft paper impregnated with varnish, that is where there is a small break in time of about 20 minutes...... I have measured the winding capacitance of a fresh built OPT...then after 20 minutes of full-power signal into a dummy load, the capacitance will go up about 5%..... this is due to curing of the varnish from hot windings....even though it is already baked ...... This also is next to insignificant if the transformer is of good design with high frequency pole up at say 90kHz...
If this is a guitar amp transformer with Pole at 30kHz then the small change in capacitance will have slight noticable phase-shift effect in the highs, since ears are more sensitive to this...but you would really have to know what to listen for...
Chris
But i must confess...after designing and winding transformers for 25 years.... There is a very small amount of time needed for a "Burn-IN" ....
When using man-made insulations, such as Teflon, Kapton...ect....there really is no burn in time, just like 1 minute for the di-electric to DC orient it's poles.... Di-poles have hesterisis to AC gradient...
As for core material....there is no burn-in time...
As for organic di-electric materials such as Kraft paper impregnated with varnish, that is where there is a small break in time of about 20 minutes...... I have measured the winding capacitance of a fresh built OPT...then after 20 minutes of full-power signal into a dummy load, the capacitance will go up about 5%..... this is due to curing of the varnish from hot windings....even though it is already baked ...... This also is next to insignificant if the transformer is of good design with high frequency pole up at say 90kHz...
If this is a guitar amp transformer with Pole at 30kHz then the small change in capacitance will have slight noticable phase-shift effect in the highs, since ears are more sensitive to this...but you would really have to know what to listen for...
Chris
I wouldn't do this. A diode in series with the mains will put a large DC component across the transformer causing a large current to flow. It may cause a short burn in period followed by an equally short burn out period.
There can be a verifiable short "burn in" period with some components especially some types of capacitors. The changes are as noted very small, and usually not audible. I have heard the "100 Hours" story before. I have a friend who spent $$$$$ for speaker cables for his $$$$$$ home theater system. He was told that they would require a lengthy burn in period. I believe the "burn in" period probably matched the burning sensation recieved in the mail from the credit card company. He, however was convinced that they did get better with time.
As for me, my speaker wire came from Wal Mart, and it worked fine right off of the roll.
On the other side of this coin, I burn in every amplifier that I build! Why? To flesh out any weak components or flakey tubes. The bias will drift over time, but most drift should happen in the first hour or so. How?
I hook up the amp with dummy loads on each speaker output. I put voltmeters on each critical point in the amp, and monitor the output tubes current. Turn it on with no signal input and watch the meters for 20 minutes to an hour. There should be no large changes. If all is well, I reset the bias, and carefully record all meter readings. Check for components that are too hot, etc.
Then the "burn in" begins. With the dummy loads still connected, I apply a signal, an extreme signal, Pink Floyd, Ozzy, Metallica, etc. I turn it up until clipping is evident on the scope, and let it run for the whole CD. Ever notice that you can hear the music WITHOUT SPEAKERS! Most of the sound comes from the OPT's but capacitors can speak too. Watch the meters for any irregularities. As soon as the CD ends, check the meters and compare to the original readings. The readings should ideally be the same, investigate any significant differences. Recheck and reset the bias if needed, attach speakers, enjoy.
If the design is something that I am not familiar with, or just invented, the testing, verification and burn in period is often extended, sometimes for days. It often involves higher levels of electrical stress. This usually means high and low line voltages (variac) 20 Hz sine waves, 10 KHz square waves, and that ultimate survival test, a dose of my guitar playing, dialed in to at least 11.
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