georgehifi
Responses from georgehifi
| Lightspeed Attenuator - Best Preamp Ever? Here's an interesting snippet from the latest Stereophile review of the DCS Debussy Dac which has volume control in the digital domain. Yet two stage adjustable analogue level output stage 2v or 6v, this means you can use it straight into a powera... | |
| Lightspeed Attenuator - Best Preamp Ever? We are on the same wave length, like I've said on the Lightspeed Attenuator web site. The diode effect with contacts (potentiometers or single leaf switches) is a fact, and I would go further to say, that they are probably the worst component in t... | |
| Lightspeed Attenuator - Best Preamp Ever? Capacitors on output stages of dacs and cdp's are evil necessity with tube output stages, and yes they will not be a suitable match for passives, not only that, the tube output stages on dacs & cdp's are usually too high in output impedance (m... | |
| Lightspeed Attenuator - Best Preamp Ever? Sorry I should clarify a bit better the first paragraph above, the figure 100's of volts per micro second, is in reference to "rise time" in volts per micro second of musical transient figures, not what a cdp or dac can put out of it's output in v... | |
| Lightspeed Attenuator - Best Preamp Ever? To all who are not very technical, try to bear with me here.The (diode thingy) "diode effect" is bought around by very fast music transients from the source, CDP or phono, which can be in the order of 100's of volts per micro seconds (volts per uS... | |
| Lightspeed Attenuator - Best Preamp Ever? Pubul57 The one you have is already MkII. The only way I could improve to a MkIII is the versatility of the unit, that would be to have a discrete unity gain buffer (like Nelson Pass designed for the Lightspeed) on the output to lower the output i... | |
| Lightspeed Attenuator - Best Preamp Ever? The best possible way of getting the best transfer from source to poweramp is to have a cdp with a digital domain volume control, and have no preamp Lightspeed or whatever. This would be the ultimate, however a digital domain volume control in the... | |
| Lightspeed Attenuator - Best Preamp Ever? 01-14-11: Banquo363Differently, remaining with this type of amp (with volume control), if we use it in conjunction with the LSA:1. could we use the amp's volume control to mitigate any impedance mismatches between the two? I understand that these ... | |
| Lightspeed Attenuator - Best Preamp Ever? 01-14-11: Pubul57George, does that mean that with some sources, Ralphs argument is correct due to the coupling caps? Pubul57Yes, as I pointed out in my last post, but I will say that the said caps are usually big enough, not create any problem, ex... | |
| Lightspeed Attenuator - Best Preamp Ever? Some sources that have output coupling caps (series caps) and are in the order of 10uf, and are usually bi-polar (2 x 20uf electros back to back), but these sound like cr-p, better to use plastics (polypropylene) but good ones of this size are exp... | |
| Lightspeed Attenuator - Best Preamp Ever? 01-13-11: Almarg Ralph & George, thank you for the explanations concerning bass effects. Just to clarify, though, it should be noted that those effects are essentially unrelated to cable capacitance or cable length.Best regards, -- Al AlmargIf... | |
| Lightspeed Attenuator - Best Preamp Ever? Saying all that now if you have a series output cap on your source that is too small it can rolloff the bass with the combination of the Lightspeed and poweramp input impedances, to give an example for this.1: Source series output cap of 10uf into... | |
| Lightspeed Attenuator - Best Preamp Ever? To give some measured examples of interconnects 1: With IC's at 100pf per foot a 1mt = approx 300pfthis with the Lightpeed at it's highest output impedance has a HF rollof of -3db at 76khz2: Same with 200pf per foot 1mt = approx 600pfthis with the... | |
| Lightspeed Attenuator - Best Preamp Ever? Almarg Ralph is referring to the increase in output impedance of a passive preamp that occurs as the volume control POSITION is reduced from maximum,AlmargThis higher output impedance will only roll off the highs and won't touch the bass if and I ... | |
| Lightspeed Attenuator - Best Preamp Ever? And here is the Flecher-Munson 1933 study done, for percieved frequency loudness at different db levels. As you can see at low levels one needs to boost bass quite a bit to remain flat to the ear. Half way down the page is the graph everyone can u... |