Steve Deckert's article is interesting, but I have to wonder about the microphonics caused by the tube amp on top of the subwoofer.
I am also starting to wonder about the length of widow for the sweat spot for the effect.
I don’t know about the rest of you, but after about 3 hours of serious listening, regardless of the quality of the source material.
my hearings pretty shot.
I am also starting to wonder about the length of widow for the sweat spot for the effect.
I don’t know about the rest of you, but after about 3 hours of serious listening, regardless of the quality of the source material.
my hearings pretty shot.
THEM WEE HOURS...
Hi,
It will be a different experience depending on where you live but...yes, AC quality is a major factor.
I feel tubes are less prone to this kind of disturbance thanks to choke filtered supplies and...bear with me...stiff PSU designs with very high PSRR.
If you want look at the PSU I designed for a preamp, it provides very high isolation from the mains and sounds all the better for it.
Mind you, that was not the only target.
When I see the often poor, meagre PSU offered by some members here I often think: they'll never hear their circuits' potential at its best and they have no clue about PSU isolation from the mains...
On some occasions batteries are close to the ideal but a well designed PSU should come close.
Nonetheless, I still enjoy better sound way passed midnight...nothing's ever perfect?
Cheers,
Hi,
It will be a different experience depending on where you live but...yes, AC quality is a major factor.
I feel tubes are less prone to this kind of disturbance thanks to choke filtered supplies and...bear with me...stiff PSU designs with very high PSRR.
If you want look at the PSU I designed for a preamp, it provides very high isolation from the mains and sounds all the better for it.
Mind you, that was not the only target.
When I see the often poor, meagre PSU offered by some members here I often think: they'll never hear their circuits' potential at its best and they have no clue about PSU isolation from the mains...
On some occasions batteries are close to the ideal but a well designed PSU should come close.
Nonetheless, I still enjoy better sound way passed midnight...nothing's ever perfect?
Cheers,
Any Noise Annoys An Oyster....
My whole system hangs off a mains isolation transformer, and not in use audio and video items are unplugged.
Items like microwave oven and TV's and my washing machine containing SMPS are turned off at the wall when not in use.
I find that these loads on the mains can cause audible degradation despite the isolation transformer, but the ISO TX does give very great benefit in terms of smoothness and cleanliness in the sound of my hifi, and the day/night difference is very much reduced if not eliminated.
Eric.
My whole system hangs off a mains isolation transformer, and not in use audio and video items are unplugged.
Items like microwave oven and TV's and my washing machine containing SMPS are turned off at the wall when not in use.
I find that these loads on the mains can cause audible degradation despite the isolation transformer, but the ISO TX does give very great benefit in terms of smoothness and cleanliness in the sound of my hifi, and the day/night difference is very much reduced if not eliminated.
Eric.
mrothacher said:
Agreed, although #1 can and should be addressed by correct PSU design. Frank is correct in his post below that a high PSRR is A Good Thing.
Tim said,
I'd rather not have all the wideband hash that SS rectifiers generate. Snubbing and filtering seldom works anywhere near as well as not generating the problem in the first place, esp with SE circuits where the rectifier duty cycle will vary with load. Then there are a number of dampers with quite low series resistances (very cheap too), and of course a differential PP circuit is much closer to a constant draw, so the rectifier resistance is much less of an issue IMO/IME. Finally using a decent <i>regulator</i> properly implemented makes the diode resistance moot. I have CCS's as the first stage in my shuntregs with impedances (depending on which one) of 100k -> Gig ohms.
It'll be interesting to try the Cree HV Schottky's later and get Paul to measure them in circuit.
It all depends how and what you're trying to do. If you want to build an amp for $100 from junkbox parts, then there will inherently be compromises that could be aleiviated for a little more outlay, even if that simply means another choke and cap, that you don't already own, for another LC stage. Both approaches have equal merit, just depends on the results you're seeking.
Cheers
Interesting topic guys;
I agree that line noise is a big problem that helps explain the 'wee hours' phenomenon - which is one reason that I put together a JR Isofilter for my CD source.
Okay, let's go all the way then to cut out line noise - a battery supply on the amp. Anyone here tried it and if so, what are the ups and downs? I've thought about getting about a dozen of those rechargeable 12V gel cells together and using it for a headphone amp. Good or bad idea? And, with only about 144V to play with, what valve would you recommend for a headphone amp - pref something cheap (er, uh that's affordable...)!
Suggestions?
Thanks and all the best,
Morse
I agree that line noise is a big problem that helps explain the 'wee hours' phenomenon - which is one reason that I put together a JR Isofilter for my CD source.
Okay, let's go all the way then to cut out line noise - a battery supply on the amp. Anyone here tried it and if so, what are the ups and downs? I've thought about getting about a dozen of those rechargeable 12V gel cells together and using it for a headphone amp. Good or bad idea? And, with only about 144V to play with, what valve would you recommend for a headphone amp - pref something cheap (er, uh that's affordable...)!
Suggestions?
Thanks and all the best,
Morse
I highly doubt it's line noise; I have my comptuer running basically any time I'm awake, and my amps being plugged into the same strip as the computer, surely experience quite a bit of line noise.
Earlier today (or yesterday I should say) the radio didn't sound all that great at all, but now it's listenable, and the computer's been on all the same.
Think I'll try listening during the day with the computer off to complete the proof..
Tim
Earlier today (or yesterday I should say) the radio didn't sound all that great at all, but now it's listenable, and the computer's been on all the same.
Think I'll try listening during the day with the computer off to complete the proof..
Tim
Sch3mat1c said:snip...
Earlier today (or yesterday I should say) the radio didn't sound all that great at all, but now it's listenable, and the computer's been on all the same.
snip...
Tim
Tim,
If your radio is anything like ours over here, the quality is variable by the hour. It depends who puts what presets into the Optimod (generic), who sets the studio out levels, and which lines are selected.
I am currently listening to a station called BBC Radio 2 (for old fogies) on FM, and the announcers voice has clearly audible compression artifacts bordering on distortion.
The BBC used to be the pinacle of standards and quality....
Things 'aint like they used to be
Cheers,
Bas,
Go for as big as you can afford. Maybe 500 to 1000 VA.
The larger you go, the better the load regulation becomes.
If you're having it wound, I'd recommend adding some taps for + & - 5% to optimise your mean mains voltage.
Including such a transformer with an ES will reduce the mush from "outside", but mush produced "inside" will spread more, due to the increased power source impedance.
Cheers,
Go for as big as you can afford. Maybe 500 to 1000 VA.
The larger you go, the better the load regulation becomes.
If you're having it wound, I'd recommend adding some taps for + & - 5% to optimise your mean mains voltage.
Including such a transformer with an ES will reduce the mush from "outside", but mush produced "inside" will spread more, due to the increased power source impedance.
Cheers,
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