I often wonder if labyrinth is simply a computer generated clown here for grins and giggles.
If so, it works.
If so, it works.
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Audiolabyrinth -- Hi, no my source (direct to poweramp) is 24-bit as described in reply no. 3 from above. I would gladly convert to a 32-bit source and digital volume control if it really meant providing that extra last "ounce" of insight, clarity, resolution, organic quality or whatever to the sonic presentation (most notably perhaps at lower volumes), and it is only a matter of time when this occurs rather than "if." Until this happens there is much to treasure with a (24-bit sourced) dithered volume control a la JRiver MC19. Several who have listened to my setup have - without in any way being lead by me to this observation - noted very positively the level of clarity, information, and "ingition" at lower levels, though I believe this could be an affect of the use of a compression driver with waveguide as well. Still, had the digital volume control here used been a limiting factor at especially lower levels it remains questionable whether reports of the very opposite had flourished as they did. It is not, as you can deduce from above, that I believe 24-bit sourced dithered digital volume controls to be flawless, but they are, many things being equal, extremely capable. And when a 32-bit source is finally implemented, bit depth and any associated thought of truncation would not be my concern at all. |
another situation is that I cannot use typical tube pre-amps or sources direct to amp, or I would have to activate the coupling capacitors that are not active inside the amp to protect is from tube unstableness! Audiolabyrinth, best I can make out, this is some form of myth that solid state people seem to transmit. Its not actually true. In the case of our preamp, its output is direct-coupled and servo-controlled. We've had people using it with all manner of solid state amps over the last 20 years; doesn't seem to be a problem. FWIW our MP-1 was the first balanced line preamp made. It can drive the Krell just fine. |
I'd wager whether "Bit stripping" of the signal with 24-bit digital dithered volume controls isn't mostly of academic order (32-bit dittos wouldn't, in this regard, pose any in-use limitiations, at all) - that is, where it is stated it's very often based on a theoretical non-listening experience foundation. Only high sensitive speakers and high-gain combinations could tend to pose a possible sonic limitation here, and highly sensitive speakers is not what overflows the market as is.. For what it's worth my own setup includes moderately sensitive speakers (~93dB), and it sounds terrific at lower volumes with the digital volume attenuation named above. If for whatever reason one doesn't like the final sonic outcome where digital attenuation is involved without a separate hardware preamp, the bit stripping (i.e.: truncation) is by all accounts not a factor as much, or at all as the totality of this implementation; if one has carefully tuned a setup through the use of a hardware preamp the negation of this preamp (leaving in its place a software-based digital ditto) could easily tilt the sound in a direction reflecting back negatively on the preamp as a source of more or less outspoken coloration and synergy-effect, than what is an inherent limitation of its digital stand-in solution. I'd rather rid my setup of a hardware preamp so long as the analog output stage of the source can be made to drive the poweramp suitable (which is certainly possible) - hereby doing the same as the hardware preamp, yet without an extra hardware component and set of cables. |
@ swampwalker, Hi, sorry my post did not meet your standards of puntuations, LOL!,, never knew I needed to be thorough!, It's ok, I do not care to be so thorough with posting on a thread, of course If I were writting a book to make money, I would care to do better!, You gave me a good laugh, I needed that, Happy Holidays to you. |
Michael (Swampwalker) & Charles, thanks very much for the nice words. 12-14-13: AudiolabyrinthKeith, the comments and calculations I already provided are based on a thorough look at the manual and the specs, so anything further I might add regarding the 18 volt number would be highly speculative. A speculative guess that comes to mind, though, is that perhaps it represents how much voltage the input circuitry of the amp can tolerate without the possibility of damage when the amp is in standby mode, or is turned completely off, or both. Regarding "their pre-amps put out around 6 to 8 volts for balanced operation," keep in mind that what any preamp puts out is dependent on the setting of the volume control, and on how much voltage is sent into the preamp by the source component, as well as on the gain of the particular preamp (preamp "gain" being the relation between its output and input voltages when the volume control is turned all the way up). So it's a bit misleading to speak of a preamp as putting out 6 to 8 volts, or any other particular number. Also, as Ralph and I both indicated earlier, the MAXIMUM output voltage spec that is often provided for preamps should be (and usually is) much higher than the highest output voltage that the preamp would ever be called upon to put out under reasonable usage conditions. Regards, -- Al |
@audiolabyrinth- Pleased to meet you as well. I just wanted to make sure it didn't come across as snarky; I'm glad it didn't. I'm gonna risk it again, however, and ask you to do us all a couple of favors: 1. get a new computer that actually has a "period" key. You know, the one in between the "," and the "/" ;-) You may have just set the record for the longest sentence ever posted on Audiogon: Almarg, Can you look into this for me, the spec of 18 volts input to clip, this is the max input told to me over the phone by krell, you can do more of the math and engineering calcalating for me to find a explanation for me?, LOL!, I will never use over 10 volts to input anyway!, just currious to know my amp,, when I said that the 3.58 is the min that krell told me, they said that because all of their pre-amps put out around 6 to 8 volts for balanced operation, and this will not do nothing harmful to the krell 700cx, its the normal that I am told by krell if useing a krell pre-amp, regardless of the voltage input to drive the krell 700cx, I will not realize the power of this amp with out the speced gain you provided of the krell 700cx that a source direct to amp does not have, atleast I have not found a source with the gain I need to drive the krell 700cx, I enjoy the clarity a source direct to amp provides, but this is why I have said that the krell 700cx sounds to be half the volume its suppose to be, its still loud enough without the gain, LOL!, I just believe the amp will sound better with the appropriate db gain, do you believe that?, can you imagine the cost of a pre-amp that can do the clarity and realism a direct to amp source does with the gain I need?, thats a thought I do not like to entertain!, this is why I said, a pre-amp that would be to my liking would be very costly and you would have to provide more interconnects, in my case, very, very, exspensive, I use Taralabs zero gold, retail $14,500.00 new, around $5,000.00 to $8,000.00 used a meter balanced, yes, I bought My zero gold used, I am not that crazy to buy new, I do not agree with esoteric cabling pricing!, however, the I/C is worth what I paid used to me!, to keep the performance to my standards, I would want to buy another zero gold i/c for use with a pre-amp, there you have it, this entire conversation on this thread is a big deal to me$,, I have to be sure and carefull at the same time, this is why your input is most welcome to me, thankyou. 2. Seriously consider switching to decaf! My blood pressure went up to 249/135 just reading your post!!! If decaf doesn't float your boat, maybe some 'ludes??? All said w tongue firmly planted in check, I hope you understand. |
@ swampwalker, LOL!, I can see Almarg being an asset to us all, and called mr. spock!, we all need a mr.spock in this hobby!, thankyou for the introduction between us,I am not offended, there seemed to be a mis understanding here with what I was saying,I enjoy learning, no one knows it all, so far, I have not been corrected, misinterpreted, yes!, however, If I am wrong and corrected, I embrace it and enjoy being corrected, this is how I add to my exsperience, It would be quite foolish to do other wise!, I have never talked to you, good to meet you as well, I do require all of us to be gentleman, I do not believe someone is not a gentleman if they correct me or help me, and I hope all here does not believe if they do, they are not a gentleman, that is not the case for me, cheers. |
@ Almarg, Hi, I enjoy your input and post that I have read numerous times, I appreciate that you posted the krell 700cx specs, and explained them, kinda bailed me out here!I agree with what you are saying about the 700cx input spec, you said, sensitivity specs are usually niether min or max, they are simply the approximate input voltage required to drive the amp to its rated maximum output power. the miscommunication is here, when Krell said that 3.58 is min spec for input of the krell 700cx, that is the same as max input to be able to drive the amp to potential full power, however, the amp will take more voltage input into the amp that most pre-amps do for their out-put into the amp, and the 18 volts is the over load point to this amp to clip.,, Almarg, Can you look into this for me, the spec of 18 volts input to clip, this is the max input told to me over the phone by krell, you can do more of the math and engineering calcalating for me to find a explanation for me?, LOL!, I will never use over 10 volts to input anyway!, just currious to know my amp,, when I said that the 3.58 is the min that krell told me, they said that because all of their pre-amps put out around 6 to 8 volts for balanced operation, and this will not do nothing harmful to the krell 700cx, its the normal that I am told by krell if useing a krell pre-amp, regardless of the voltage input to drive the krell 700cx, I will not realize the power of this amp with out the speced gain you provided of the krell 700cx that a source direct to amp does not have, atleast I have not found a source with the gain I need to drive the krell 700cx, I enjoy the clarity a source direct to amp provides, but this is why I have said that the krell 700cx sounds to be half the volume its suppose to be, its still loud enough without the gain, LOL!, I just believe the amp will sound better with the appropriate db gain, do you believe that?, can you imagine the cost of a pre-amp that can do the clarity and realism a direct to amp source does with the gain I need?, thats a thought I do not like to entertain!, this is why I said, a pre-amp that would be to my liking would be very costly and you would have to provide more interconnects, in my case, very, very, exspensive, I use Taralabs zero gold, retail $14,500.00 new, around $5,000.00 to $8,000.00 used a meter balanced, yes, I bought My zero gold used, I am not that crazy to buy new, I do not agree with esoteric cabling pricing!, however, the I/C is worth what I paid used to me!, to keep the performance to my standards, I would want to buy another zero gold i/c for use with a pre-amp, there you have it, this entire conversation on this thread is a big deal to me$,, I have to be sure and carefull at the same time, this is why your input is most welcome to me, thankyou. |
@ Atmasphere, Hi good to meet you, I took a peek at your products, impressive to say the least!, for some crazy reason my friend here, jmcgrogan2 believes I am in over my head, I suppose he does not know me enough to make that call, as far as the 3.58 volts min to input of my krell 700cx, I will again call krell and talk to Ray Munchler, the service manager to confirm if that spec is min or max input spec, I have had this conversation with him more than once, so I hope he does not think I have a bad memory! anybody can make a mistake, this is why I will ask for the third or fourth time, as I said, Ray said, the spec of 3.58 is what it takes to drive the amp, and it can take max of 18 volts to over load the input, I assumed the 3.58 was max spec too!, Thats when Ray munchler corrected me! another situation is that I cannot use typical tube pre-amps or sources direct to amp, or I would have to activate the coupling capacitors that are not active inside the amp to protect is from tube unstableness!, Its a direct coupled amp, a real one!, this is in my owners manual that I have, and Ray confirmed that as well, He also stated not to activate the coupling caps, they will degrade the performance of my amp, so he said make damn certain if you use a tube product, make sure it is designed to be able to work with the amp, he said they are out their, an example of what he says is this, a tube source with the tube buffers before transformer or transformers, in other words, the signal comes thru the transformers before out-put, now thats if I am useing a tube source with volume control direct to amp, not useing a pre-amp, I will post my findings from Ray here by tuesday, I do enjoy tube sound, so my question to you was, will any of your tube pre-amps work with this extrodinary amp?, Thankyou so much, Its a privelege to talk with you and an honor! |
Keith- I hope you were not offended. I know how foolish I once felt when I tried to explain to a client how difficult and expensive it would be to build a certain type solution to a coastal erosion problem he was facing, only to find out later that: 1. the guy was one of the most experienced and competent architect/builders on the northeast and 2. he had more $ than god! 3. he was too much a gentleman to tell me either. |
Keith- Meet Al, our resident technical analyst and voice of reason on all things electrical/quantitative. He's not a manufacturer or designer. He's kind of like our Spock but with a love of music ,a keen dispassionate "eye" for techno-babble, and a willingness to help all of use non-EE types understand some of the basic science, math, and engineering behind things audio. |
An additional point: The 700cx is spec'd as being capable of putting out a maximum output voltage of 84 volts RMS. Based on the amp's voltage gain of 20.89x (see my previous post), that output voltage would be produced by an input voltage of: 84/20.89 = 4.02 volts. Therefore if someone indicated to Keith that the amp can handle an input of 18 volts without clipping either what that person said was misunderstood, or that person misunderstood the question, or that person didn't know what he was talking about. Regards, -- Al |
The specs indicated in the manual for the Krell 700cx are 3.58 volt sensitivity (for its balanced input), 26.4 db gain, 700/1400/2800 watts into 8/4/2 ohms respectively. 26.4 db is a voltage gain of 20.89, based on db = 20log(Vout/Vin). 20.89 x 3.58 = 74.79 volts. (74.79 squared)/8 = 699 watts into 8 ohms, corresponding almost exactly to the 700 watt rating. Double that into 4 ohms (= 1398 watts), and double it again into 2 ohms (= 2796 watts). The results again correspond almost exactly to the rated power capabilities. Ralph, I think you were right in the first place! Concerning Keith's reference to "3.58 volts min," that is probably the result of a miscommunication. Sensitivity specs are usually neither min nor max, they are simply the (approximate) input voltage required to drive an amp to its rated maximum output power. And based on these calculations, that certainly appears to be the case here. Regards, -- Al |
Audiolabyrinth, Krell states that the gain of their amps is only about 25db. FWIW that is quite unusual (I had assumed their gain to be a more typical 30db), so in a high power amplifier you would indeed need more than 4 volts to full output. The spec on your amp is 3.58 volts for full output, so your amp probably makes right around 500 watts, assuming a similar gain structure. The industry standard is 1 volt FWIW; that standard is really eroded at this point. However, most audiophiles do not push their amps to full output all the time- you still have to knock down the signal from a digital source if you want to use it. So a preamp is still useful. |
@ Atmasphere, Hi, I do apoligize for my post, However, I am correct with the pre-amps of krell, I am only saying what they told me on phone, on their site, it only gives out put over load specs of all the current pre-amps of 8 to 16 volts out-put, regarless, because of the gain a pre-amp gives, I believe I need a pre-amp to drive my Krell 700cx to full capacity!, I enjoy your post, and appreciate your input here,I run balanced, so the 16 volts out-put is over load, thats why krell told me pending on an older pre-amp or newer, 6 to 8 volts out-put is the norm for a krell pre-amp balanced out put, thankyou. |
@ Atmasphere, Hi, what are you talking about?, I am talking about the voltage out-put of a pre-amp of the signal to the amp, There is no way that 2 volts will drive my Krell 700cx correctly, the input sensativity is 3.58 volts min!!, all the krell pre-amps ever made put out more volts than that!, call Krell, I can tell you that with confidence!, the 18 volts was a given spec before clipping with the krell 700cx amp.,,BTw, I have used over a period of time, a source componet with analog 2.5 volts out-put direct to amp!, Thats funny!, the amp sounded like it was at half volume compaired to useing a pre-amp by anybody!, that BTw, do more than 2 volts out-put, I also understand the gain a pre-amp can give as well, LOL! |
"So far all digital products have had a short shelf life as digital continues to evolve. Analog is a bit more stable design-wise." No doubt. I always wait as long as I can even to buy my next home computer because I know the longer I wait the more I will get for my investment. I don't see that changing anytime soon. |
Wadia is still very much around. Owned by the same company that owns ARC. They are a good example of why an analog preamp is handy- their volume control is an example of what I was talking about earlier. Audiolabyrinth, I can tell you with great confidence that you have your numbers wrong. Krell amps can be driven to full output by any preamp made, so they have at least 30 db of gain. That means that they need less than 2 volts. I bet though that their *preamps* can make 18 volts (we can make 32 volts with ours) before clipping; this is done to keep the preamp totally unstressed while doing its job. Mapman, the reason not to own a digital preamp is simply that you will have to sell the unit to upgrade. So far all digital products have had a short shelf life as digital continues to evolve. Analog is a bit more stable design-wise. |
"Might be controlled from ones phone." I can control my Squeezebox Touch device (which includes digital volume) wirelessly from any mobile device including phone or tablet on my home wifi network today. The technology exists to control anything from a phone today. All that is needed is a market. I use a pre-amp mainly because I have analog source (phono and tape) in addition to digital. It may sound better this way as well. Never tried it without the (tube) pre-amp), so don't know. Even if direct does not sound sound as good as with pre-amp in my case, I see no reason why a separate pre-amp is required for better sound. It may or may not be better case by case it seems to me. |
@ Almarg, Hi, I am sorry, I did not mention my source of info was from krell, when we were dicussing the input sensativity of the krell 700cx, the 18 volts is max, that is never used!, the amp gets 6 to 8 volts,pending what model krell pre-amp being used, that has nothing to do with cast, thats balanced!, then I was saying a source componet with a real analog or transformer based volume control running direct to amp has the performance I mentioned above, not the digital volume control that likly will do bit stripping of the signal!, and if you actually have a very high quality pre-amp that has the transparency of a direct to amp source componet has?, thats likly due to the gain that pre-amps have, you hear more information, more sound, sometimes, more dynamics, pending on the pre-amp used, not really more transparency!, |
They'll evolve and stick around for a good while but I would not invest in analog ones. Various forms of digital pre-amps have a healthy future in store still I suppose in various forms only a small % of which will remotely resemble what most of us would recognize as a traditional hifi analog pre-amp. |
Ralph (Atmasphere), thanks for the link and the comment about CAST. I see what you mean, and I agree. So I have no idea what the 18 volt figure mentioned by Audiolabyrinth would pertain to. That figure does not appear anywhere in the manual, btw, which includes a fairly comprehensive set of specs. Perhaps it was a miscommunication he had. I would expect that 18 volts into that amp would stand an excellent chance of destroying the speakers, the amp, and the eardrums of anyone nearby, if a fuse didn't blow first :-) Regards, -- Al |
The loss of transparency introduced by the preamp needs to be counterbalanced by other sonic benefits. Actually if the preamp is working right, most people experience an increase in transparency, not a loss. I have already mentioned one reason why; an additional one is that many digital controls don't work that well. So the digital device works better if run at full volume, run through an active line section and the preamp's volume control is used instead. |
I agree that phonostages are here to stay. But it seems to me that digital sources with volume control, and various types of all-in-one products (including integrated amps) could marginalize the role of the preamp. The loss of transparency introduced by the preamp needs to be counterbalanced by other sonic benefits. Otherwise, the preamp is little more than a fancy switchbox. |
Hi Al, take a look at this link on DIYaudio: http://www.diyaudio.com/forums/solid-state/161371-krell-current-audio-signal-transmission-c-s-t-current-mode-technology-cmt.html Scroll down a little and you will see something very similar. I rather doubt that such a setup would see much in the way of voltage swing- current mode suggests that the current of the driver is being drawn through the interconnect cable from the receiver. |
Audiolab, what Atmasphere said about voltage levels is essentially correct (given my subsequent clarification), although his comment is most probably not applicable to the proprietary CAST interface that is provided on your amplifier. For conventional (non-CAST) preamp outputs, the max output spec that for most high-end preamps is much greater than 4 volts represents the maximum output voltage they are CAPABLE of providing. That number SHOULD be much greater than the maximum output voltage they will ever be called upon to provide under reasonable input voltage conditions, in order to provide margin and assure good distortion performance. For the non-CAST balanced input of your amp, the 3.58 volt sensitivity spec represents the approximate amount of input voltage that would cause the amp to put out its maximum rated output power (700/1400/2800 watts in this case(!), into 8/4/2 ohms respectively), assuming that spec is defined in the same manner that nearly all other amp manufacturers define it. Most amps will be driven to their maximum rated power by inputs in the range of about 0.5 to 2.5 volts for unbalanced inputs, or around twice those numbers for balanced inputs. If you research the specs for amps from various manufacturers you will see that. I have no knowledge of the voltage levels that the current-mode CAST interface operates at; perhaps the 18 volt figure you mentioned relates to that. Regards, -- Al |
One way or another, there has to be sufficient gain to go from line level, or phono cartridge level, to eventually be able to drive loudspeakers, such that any stages prior to the final power amp gain stage should be considered as preamp. So, in my logic, preamps will always be required as long as we are driving louspeakers. |
@ Atmasphere, Hi, Who told you that 4 volts was to much for an amplifier?,, LOL!, Nearly all pre-amps output to an amp is way more than 4-volts, an example of what I am saying is, My krell 700cx amplifier min sensativity is 3.5 volts input, in other words, if you do not have atleast the 3.5 volts, the amp is not being driven correctly, the krell 700 cx amp input max is 18 volts!, then you have every krell pre-amp ever made that puts out 8 to 12 volts to to the amps, I have personally talked to krell about this issue, they ex-plained the input specs of my amp, because I was under the impression that the 3.5 volts was max, turns out to be the minimum!, most digital cd-players and dacs do not have enough volts out-put to drive amps to their potential, and then you have bit stripping of the sound quality if you have a pure digital volume control at low volumes, on the bright side, a digital componet running direct to amp with a analog volume control, or a transformer based volume control yeilds way more transparency than most pre-amps could ever do in alot of systems, your signal does not have to go thru another chip board, there is some pre-amps out there that can give you all that you want for sound, very few can surpass running direct to amp, the pre-amps that can are very exspensive!, cheers. |
Based on my experience the preamp is the heart and soul of a system. Sure one can argue I don't need fine food or Parma ham to survive, but these foods are simply more enjoyable than bread and water. Ya, I can survive without them. Yes, my system works without my tube preamp, but it does not taste as good:-) Pretty simple stuff. |
