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#1
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preamp vs. preamp
There seems to be a vocal contingent here in rec.audio.hi-end that
claims there is little audible difference between power amplifiers. One regular here pointed us at an old Stereo Review article which made a case for suggesting that a Pioneer receiver power amp section sounded almost identical to a Mark Levinson amp costing about 10 times as much. Certainly there are a number of people here who feel that an inexpensive pro grade power amp is as good a sounding power amp as you can find, at any price. This same contingent also seems to say that there is little audible difference between SACD and redbook CD. So this brings me to ask this question with regards to preamplifiers. Do you of the group I describe above, also feel there is little audible difference between solid state preamps? Pyle and Gemini both have new preamps, with phono sections, that sell for about $100 new or less. What about an Adcom preamp? Carver or Parasound? And let's not forget our more hi-end guys like Linn, Krell, Mark Levinson, McIntosh, C-J, Audio Research, or whoever. If there are real differences one can expect to be heard in preamps, then why? Russ |
#2
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Russ Button wrote:
There seems to be a vocal contingent here in rec.audio.hi-end that claims there is little audible difference between power amplifiers. One regular here pointed us at an old Stereo Review article which made a case for suggesting that a Pioneer receiver power amp section sounded almost identical to a Mark Levinson amp costing about 10 times as much. Certainly there are a number of people here who feel that an inexpensive pro grade power amp is as good a sounding power amp as you can find, at any price. This same contingent also seems to say that there is little audible difference between SACD and redbook CD. So this brings me to ask this question with regards to preamplifiers. Do you of the group I describe above, also feel there is little audible difference between solid state preamps? Pyle and Gemini both have new preamps, with phono sections, that sell for about $100 new or less. What about an Adcom preamp? Carver or Parasound? And let's not forget our more hi-end guys like Linn, Krell, Mark Levinson, McIntosh, C-J, Audio Research, or whoever. If there are real differences one can expect to be heard in preamps, then why? Russ First of all, phono preamps can sound quite different. I have seen phono preamps with almost 1 dB of error in the audio band, and I would think that those would sound different than another one with 0.1 dB of error. In addition, since a lot of MM cartridges need to work into a well-specified input impedance, you can get different responses if the preamps have different MM input impedances. It is much easier to design a line-level preamp than a power amp, so in theory line-level preamps should sound the same. In practice, there is one significant cause of why preamps can sound different: L/R Level matching. In most preamps, that is a function of the volume control potentiometer/attenuator. One can get substantial L/R tracking errors from poorly made pots/attenuators. Preamps utilizing digital attenuators are actually much better in this respect. Just like power amps and CD players, preamps have to be compared at the same output level, so level matching is necessary. There are also preamps with intentional errors so they would sound different. And some poorly designed preamps can have excessive sensitivity to picking up line noises. |
#3
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Chung wrote:
First of all, phono preamps can sound quite different. I have seen phono preamps with almost 1 dB of error in the audio band, and I would think that those would sound different than another one with 0.1 dB of error. In addition, since a lot of MM cartridges need to work into a well-specified input impedance, you can get different responses if the preamps have different MM input impedances. I used to own a Holman preamp. It was interesting in that it had switchable levels of capacitance on the phono inputs. All in all, I always thought it was a pretty good piece of gear. It had an enormous amount of functionality as well. Tom Holman always struck me as a thoughtful engineer. It is much easier to design a line-level preamp than a power amp, so in theory line-level preamps should sound the same. In practice, there is one significant cause of why preamps can sound different: L/R Level matching. What do you think of the Chinese made pro items such as the Gemini or Pyle preamps you see for less than $100 now? Gemini http://www.jr.com/JRProductPage.process?Product=3719099 Pyle http://www.digitallyunique.com/pyp-1.html Although Behringer doesn't make a comparable unit, do you feel that either Gemini or Pyle offer equipment at the same level of quality as Behringer? These are very inexpensive pieces of Chinese made gear. Can their line level sections be expected to perform as well as more commercially oriented equipment from manufacturers such as Rotel, B&K, Parasound, or the more hi-end lines such as Linn, Krell, Rowland Research, C-J, Audio Research, etc? When you spend more on a preamp, what is it that you're paying for? Russ |
#4
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Russ Button wrote:
Chung wrote: First of all, phono preamps can sound quite different. I have seen phono preamps with almost 1 dB of error in the audio band, and I would think that those would sound different than another one with 0.1 dB of error. In addition, since a lot of MM cartridges need to work into a well-specified input impedance, you can get different responses if the preamps have different MM input impedances. I used to own a Holman preamp. It was interesting in that it had switchable levels of capacitance on the phono inputs. All in all, I always thought it was a pretty good piece of gear. It had an enormous amount of functionality as well. Tom Holman always struck me as a thoughtful engineer. It is much easier to design a line-level preamp than a power amp, so in theory line-level preamps should sound the same. In practice, there is one significant cause of why preamps can sound different: L/R Level matching. What do you think of the Chinese made pro items such as the Gemini or Pyle preamps you see for less than $100 now? Gemini http://www.jr.com/JRProductPage.process?Product=3719099 Pyle http://www.digitallyunique.com/pyp-1.html Although Behringer doesn't make a comparable unit, do you feel that either Gemini or Pyle offer equipment at the same level of quality as Behringer? I have not listened to any of these. I would be concerned about (a) the kind of pots and switches they use, and (b) the type of opamps they use. Poor pots and switches will become noisy over time, or the pots may have channel mismatches. On some of the really cheap stuff, they use opamps that are sub-par in terms of bandwidth, noise, distortion and slew rates. Also check and make sure that there is no excessive noise and line pick-ups. These units do not appear to have phono inputs. These are very inexpensive pieces of Chinese made gear. Can their line level sections be expected to perform as well as more commercially oriented equipment from manufacturers such as Rotel, B&K, Parasound, or the more hi-end lines such as Linn, Krell, Rowland Research, C-J, Audio Research, etc? I think the consumer level stuff from Sony, Rotel, etc. will be the sonic equivalent of the high-end solid-state models. Or simply use a receiver as a preamp. With tubed units, you have to be careful, since there may be some intentional coloration introduced. On the really cheap stuff, I worry about the things I mentioned earlier, especially the quality of the pots and switches. When you spend more on a preamp, what is it that you're paying for? Low noise, great volume control, features, reliability, and user interfaces. Maybe a good phono stage. Never underestimate the importance of the remote control! Russ |
#5
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"Russ Button" wrote in message
... Chung wrote: First of all, phono preamps can sound quite different. I have seen phono preamps with almost 1 dB of error in the audio band, and I would think that those would sound different than another one with 0.1 dB of error. In addition, since a lot of MM cartridges need to work into a well-specified input impedance, you can get different responses if the preamps have different MM input impedances. I used to own a Holman preamp. It was interesting in that it had switchable levels of capacitance on the phono inputs. All in all, I always thought it was a pretty good piece of gear. It had an enormous amount of functionality as well. Tom Holman always struck me as a thoughtful engineer. It is much easier to design a line-level preamp than a power amp, so in theory line-level preamps should sound the same. In practice, there is one significant cause of why preamps can sound different: L/R Level matching. What do you think of the Chinese made pro items such as the Gemini or Pyle preamps you see for less than $100 now? Gemini http://www.jr.com/JRProductPage.process?Product=3719099 Pyle http://www.digitallyunique.com/pyp-1.html Although Behringer doesn't make a comparable unit, do you feel that either Gemini or Pyle offer equipment at the same level of quality as Behringer? These are very inexpensive pieces of Chinese made gear. Can their line level sections be expected to perform as well as more commercially oriented equipment from manufacturers such as Rotel, B&K, Parasound, or the more hi-end lines such as Linn, Krell, Rowland Research, C-J, Audio Research, etc? When you spend more on a preamp, what is it that you're paying for? The low end of the Behringer analog line has a reputation among audio engineers for crappy sound..too many corners cut, I guess The upper end of their line is generally thought okay, comparable to other U.S. made "mass market" pro-sumer recording gear. |
#6
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Harry Lavo wrote:
The low end of the Behringer analog line has a reputation among audio engineers for crappy sound..too many corners cut, I guess The upper end of their line is generally thought okay, comparable to other U.S. made "mass market" pro-sumer recording gear. For a time I used a Behringer active crossover, which I found to be indistinguishable from a Marchand active crossover. I have a friend who uses a Behringer DEQ2496 Ultra Curve Pro, which is an extraordinary piece of equipment for an amazingly small price. Russ |
#7
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Noise is the largest factor in making a quality preamp. Very low noise
active preamps are quite expensive. You might compare the brands you mention sonically, you can ignore the spec sheets on the budget stuff as that is only useful as toilet paper (it isn't very good for that either!...). If you haven't made some listening comparisons, you have no idea what the differences are. I have owned tons of preamps and can confirm a wide range of soncs. Passive "preamps" (an oxymoron) are noiseless, yet have other issues in practical use. Some people can live with them and they can vary in price from really cheap single input boxes to really expensive, more useful types. These can be used with line level inputs only. -Bill www.uptownaudio.com Roanoke VA (540) 343-1250 "Chung" wrote in message ... Russ Button wrote: Chung wrote: First of all, phono preamps can sound quite different. I have seen phono preamps with almost 1 dB of error in the audio band, and I would think that those would sound different than another one with 0.1 dB of error. In addition, since a lot of MM cartridges need to work into a well-specified input impedance, you can get different responses if the preamps have different MM input impedances. I used to own a Holman preamp. It was interesting in that it had switchable levels of capacitance on the phono inputs. All in all, I always thought it was a pretty good piece of gear. It had an enormous amount of functionality as well. Tom Holman always struck me as a thoughtful engineer. It is much easier to design a line-level preamp than a power amp, so in theory line-level preamps should sound the same. In practice, there is one significant cause of why preamps can sound different: L/R Level matching. What do you think of the Chinese made pro items such as the Gemini or Pyle preamps you see for less than $100 now? Gemini http://www.jr.com/JRProductPage.process?Product=3719099 Pyle http://www.digitallyunique.com/pyp-1.html Although Behringer doesn't make a comparable unit, do you feel that either Gemini or Pyle offer equipment at the same level of quality as Behringer? I have not listened to any of these. I would be concerned about (a) the kind of pots and switches they use, and (b) the type of opamps they use. Poor pots and switches will become noisy over time, or the pots may have channel mismatches. On some of the really cheap stuff, they use opamps that are sub-par in terms of bandwidth, noise, distortion and slew rates. Also check and make sure that there is no excessive noise and line pick-ups. These units do not appear to have phono inputs. These are very inexpensive pieces of Chinese made gear. Can their line level sections be expected to perform as well as more commercially oriented equipment from manufacturers such as Rotel, B&K, Parasound, or the more hi-end lines such as Linn, Krell, Rowland Research, C-J, Audio Research, etc? I think the consumer level stuff from Sony, Rotel, etc. will be the sonic equivalent of the high-end solid-state models. Or simply use a receiver as a preamp. With tubed units, you have to be careful, since there may be some intentional coloration introduced. On the really cheap stuff, I worry about the things I mentioned earlier, especially the quality of the pots and switches. When you spend more on a preamp, what is it that you're paying for? Low noise, great volume control, features, reliability, and user interfaces. Maybe a good phono stage. Never underestimate the importance of the remote control! Russ |
#8
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"Russ Button" wrote in message
... Harry Lavo wrote: The low end of the Behringer analog line has a reputation among audio engineers for crappy sound..too many corners cut, I guess The upper end of their line is generally thought okay, comparable to other U.S. made "mass market" pro-sumer recording gear. For a time I used a Behringer active crossover, which I found to be indistinguishable from a Marchand active crossover. I have a friend who uses a Behringer DEQ2496 Ultra Curve Pro, which is an extraordinary piece of equipment for an amazingly small price. It is among the pieces well regarded. But it is not analog...notice my remarks were ref their analog stuff. |
#9
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Russ Button wrote:
Harry Lavo wrote: The low end of the Behringer analog line has a reputation among audio engineers for crappy sound..too many corners cut, I guess The upper end of their line is generally thought okay, comparable to other U.S. made "mass market" pro-sumer recording gear. For a time I used a Behringer active crossover, which I found to be indistinguishable from a Marchand active crossover. I have a friend who uses a Behringer DEQ2496 Ultra Curve Pro, which is an extraordinary piece of equipment for an amazingly small price. Behringer units are quite popular for taming bass frequency room peaks, on the AV/home theatre boards I frequent. |
#10
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Uptown Audio wrote:
Noise is the largest factor in making a quality preamp. Very low noise active preamps are quite expensive. You can get noise to be 96 dB or so easily, for a line stage. Not expensive at all. There are several opamps that work very well for line-level preamps. 96 dB is better than what CD's can offer. Phono preamps are harder tp design, but then vinyl has so much surface noise that the preamp actually contributes little when a vinyl record is being played. You might compare the brands you mention sonically, you can ignore the spec sheets on the budget stuff as that is only useful as toilet paper (it isn't very good for that either!...). If you haven't made some listening comparisons, you have no idea what the differences are. I have owned tons of preamps and can confirm a wide range of soncs. Passive "preamps" (an oxymoron) are noiseless, yet have other issues in practical use. Passive preamps are definitely NOT noiseless. Resistors are a large source of noise. You can end up with more noise than an active preamp, if the *input noise current* of the following stage (typically the power amp) is high. Some people can live with them and they can vary in price from really cheap single input boxes to really expensive, more useful types. These can be used with line level inputs only. -Bill www.uptownaudio.com Roanoke VA (540) 343-1250 |
#11
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Mr. Chung wrote,
"Passive preamps are definitely NOT noiseless. Resistors are a large source of noise. You can end up with more noise than an active preamp, if the *input noise current* of the following stage (typically the power amp) is high." Agreed. However, a well designed passive line stage (such as those from Placette) that is well matched to cables and amplifier is virtually without noise in my experience. At full unity gain (probably 8-10 db beyond what would ever be employed when listening to music) noise is only faintly audible when the ear is right near the speaker. Of course, at normal volume settings this is far below the music floor, and noise is completely inaudible, even during the most quite passages. And as an aside, contrary to some popular misconceptions, with my passive line stage I am able to reproduce a level of bass slam that subjectively matches the best I have heard including that of an active pre amp based system that featured the Wilson Audio Watchdog subwoofer. Robert C. Lang |
#12
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RobertLang wrote:
Mr. Chung wrote, "Passive preamps are definitely NOT noiseless. Resistors are a large source of noise. You can end up with more noise than an active preamp, if the *input noise current* of the following stage (typically the power amp) is high." Agreed. However, a well designed passive line stage (such as those from Placette) that is well matched to cables and amplifier is virtually without noise in my experience. Sure, if you have a really quiet power amp input stage. OTOH, I have heard active preamps that are virtually noiseless, too. Remember that the passive amp does not provide any gain, so you have to make sure it's an apples-to-apples comparison. At full unity gain (probably 8-10 db beyond what would ever be employed when listening to music) noise is only faintly audible when the ear is right near the speaker. The biggest noise contribution from a passive preamp occurs when the volume is at the -6dB position, when the source is connected. That presents the highest source impedance to the power amp. If you do not connect any source, then the highest noise occurs at minimum attenuation. Of course, at normal volume settings this is far below the music floor, and noise is completely inaudible, even during the most quite passages. And as an aside, contrary to some popular misconceptions, with my passive line stage I am able to reproduce a level of bass slam that subjectively matches the best I have heard including that of an active pre amp based system that featured the Wilson Audio Watchdog subwoofer. Any problem with passive preamp is likely to occur at high frequencies, due to the high source impedance interacting with the cable and power amp input capacitance. At low frequencies there is problem only if the coupling capacitor at the input of the power amp is too small for the job. Robert C. Lang |
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