Absolute polarity is another non-issue. And even if it does make a difference the only way to know for sure is to try both ways and listen. Don't be surprised if you hear a difference. Also don't be surprised if you then discover it sounds better one way on some recordings, and the other way on others, and with the total barely noticeable if at all difference being in no way worth the hassle of switching. Which is why its a non-issue.
Balanced vs RCA between amp/preamp
I understand the Marantz components balanced connections have pin 2 wired cold and pin 3 wired hot. Does this mean I need to reverse the cables going to my speakers (if I decide to use balanced connections between amp/preamp).
I also understand the RCA connections conserve absolute polarity. But is there a performance "hit" taken by using singled ended connections between amp/preamp?
Thank you in advance......
Actually the performance "hit" is when you pay more for balanced and get less for your money than RCA. Balanced is one of those things that makes a lot of sense for professional use running long distances and lots of connections giving the locking feature value. None of which applies to home use. Absolute polarity is another non-issue. And even if it does make a difference the only way to know for sure is to try both ways and listen. Don't be surprised if you hear a difference. Also don't be surprised if you then discover it sounds better one way on some recordings, and the other way on others, and with the total barely noticeable if at all difference being in no way worth the hassle of switching. Which is why its a non-issue. |
Good point Millercarbon one other thing to consider is the Marantz actually true balanced or just single ended looking as balanced. True balanced is a lot harder to do and can give benefits in cable cost and ability to run longer runs. true balanced negates many of the issues with cables and EMI as the balanced signal cancel out the EMI more then single ended can. In theory you don't need to spend huge money on balanced cables as they require less shielding. I'm sure someone here with more background in balanced systems can inject more information and details as to the benefits losses. |
Balanced gives you better electrical noise rejection (if you need it), but costs more and requires additional circuitry to make it (less is more). I don't have a choice since my current and previous amps have only XLR inputs, but I still appreciate locking feature. In addition to locking XLR has only female end exposed - in case something gets disconnected. It is additional protection from touching "live" wire. |
Read third post down from KBK...great explanation. https://www.stereophile.com/content/balanced-xlr-vs-unbalanced-rca-1 The fact that the Marantz units and your sources are not fully balanced means you will likely experience minimal gains vs. single ended connections. in fact, there are occasion where you will find the single ended connections may sound better. I can't speak about those explicit units, bit I have an amp where the single ended connections definitely are better than the balanced. |
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Beating a dead horse... Balanced are designed for professional use. That is why they are designed with the ground making contact first- professional use sees a lot of stuff being connected/disconnected while powered up. Making the ground connection first avoids the loud annoying buzz you get with RCA. Which with home use is a non-issue, you simply power off or even just change inputs to avoid the noise. Now if you have 20 roadies running around messing with the 768 connections in your system then balanced makes a lot of sense. Balanced is locking because pro gear tends to get moved around a lot. So get balanced if you like to throw your system in a truck and set up at friends a lot. If your system stays in the room for years at a time then XLR is a total waste of money. True balanced utilizes two duplicate sets of circuitry, the outputs of which are then compared in order to reject noise. That's how it works. One of the bedrock fundamental truths of high end audio is simpler is better. Another is better parts cost more and the fewer the parts the more you can spend on each part. So this one is not only wasted but by unnecessary duplication its actually counter productive. Except for professional use where runs long enough to go from your pre-amp out the door around the house and back into the room to your amp are the norm. If that's your system go balanced. Totally. Otherwise, another feature wasted on home use. What else? Oh yeah. Like the man said half the time balanced doesn't really even mean balanced. It just means you can connect your XLR here. Decoy! Fell for it! Don't be that guy. How many even knew all the above? So on top of everything else balanced turns you into one of these gear heads talking the talk instead of walking the walk. None of this is new. I went through figuring this all out 30 years ago, at least. Not one damn thing has changed in all that time. Go and listen. You will see. |
BALANCED VS. UNBALANCED ANALOG INTERFACES https://benchmarkmedia.com/blogs/application_notes/balanced-vs-unbalanced-analog-interfaces?_pos=1&_sid=87340c17d&_ss=r With the Benchmark gear I had in the past it was XLR for best sound. |
First you must determine if your equipment is truly differentially balanced or it just has balanced connectors. I now this topic has been covered umpteen times previously on these forums; try reading the white papers of Nelson Pass (Pass Labs) , Victor Khomenko (BAT) Ralph Karsten ( Atmasphere) or Charlie Hansen (Ayre) to get an explanation from renown experts not just the ones who frequent these forums. |
Balanced are designed for professional use. That is why they are designed with the ground making contact first- professional use sees a lot of stuff being connected/disconnected while powered up. Making the ground connection first avoids the loud annoying buzz you get with RCA. Which with home use is a non-issue, you simply power off or even just change inputs to avoid the noise. Now if you have 20 roadies running around messing with the 768 connections in your system then balanced makes a lot of sense. A good deal of this is false. First- the ground. The ground connection is not made first (ground is pin 1 of the XLR). The reason you can hot plug an XLR connection is because both signal pins connect at the same time (along with the ground). The input is far less able to pick up noise during the connection- no buzz, most of the time not even a pop. Balanced operation has several nice benefits for home operation. Audiophiles often pay a lot for cables; if the balanced line system is set up properly (IOW the equipment used supports the Balanced Line standard, a.k.a. AES48) the sound of the interconnect won't be a thing. No having to audition cables- it will just work. So cables don't have to be expensive and you can run them longer distances (this is helpful if you have monoblock amps, you can place them by the speakers and keep your speaker cables short, which improves definition). True balanced circuits do not have duplicate circuitry. So there aren't twice as many parts and so on. We use differential amplifiers in our circuits and because differential amps tend to be lower noise we don't need as much gain stages to get the job done. As a result with our gear there are only 4 stages of gain from the LOMC phono input to the loudspeakers. That is **a simpler signal path** than most single-ended circuits! Balanced operation can (and usually is) done with transformers, in which case the preamp and amps can be single-ended and it can still work quite well. Other than immunity to interconnect cable artifacts, the other reason for balanced lines is elimination of ground loop noise. That is a benefit whether the cable is 60 feet or only 6 inches. Now if the amp has balanced inputs processed by circuitry that hands off the signal to the actual single-ended input of the amp (I've seen this in a few consumer grade amps with balanced inputs) then it may well be that the system will sound better with the single ended inputs, simply because there is a simpler signal path. But if the system is internally balanced there won't be any looking back, it will simply sound better. |
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@atmasphere Ralph, I agree with your comments 200% (or I would if >100% were theoretically possible), except that like Millercarbon my understanding has been that XLR connectors make the ground connection prior to the making the signal connections, upon insertion, and break the ground connection after breaking the signal connections, upon removal. And upon close examination of some XLR cables I have, which are terminated with Neutrik connectors, it does appear that on the female end the metal contact within pin 1 extends slightly closer to the front surface of the connector than the contacts within the signal pins. And likewise for female (input) connectors I looked at on the rear panel of a component. And although the pins on the male end all appear to be the same length as far as I can tell, it seems to me that the make & break sequences I described would occur regardless of which end of the cable is inserted or removed, as a result of the configuration of the female connectors. Best regards, -- Al |
In his Positive Feedback review of the EAR-Yoshino 868L line stage pre, the reviewer made the statement that, though the 868 provides XLR jacks for balanced operation, the pre-amp circuitry itself is single-ended. Designer Tim deParavicini in his manufacturer reply corrected the reviewer, stating that no, the 868 is a true balanced design. It is a commonly-held understanding by audiophiles and semi-pro hi-fi reviewers that a true balanced amp by definition has doubled parts. As atmasphere just said, that is a misconception and misunderstanding of what balanced is. A pre-amp can have single-ended circuits yet be true balanced in operation. The real concern in any piece of gear is how the balanced inputs/outputs are implemented. In the EAR 868, Paravicini accomplished that goal via transformers. In his Music Reference RM-200, Roger Modjeski does so with a resistor network. Companies with lower standards typically create balanced inputs/outputs with the dreaded opamp, and with the expected sonic compromise. A higher retail price does not necessarily buy one balanced ins and outs NOT created with opamps. If possible, inspect the schematic of any piece of balanced gear you are considering buying, to see how it’s balanced connections are created, and if they conform to AES48. |
Having been involved with every facet of Audio for over 35 years balanced if True balanced would be a bit quieter. that being said your Amplifier and preamp need to have transformers for the input,outputs to be what is considered a True balanced . Most amplifiers have whst I call quasi balanced a XLR but when you take the top off it is wired on the same grid wiring with the RCA. I is a added expense to do properly . check your components before spending any added costs. Jensen make some very good transformers for this application, there are several good transformers out there I am not certain if Lundahl make any this small . |
As has been pointed out, balanced is not inherently better sounding. A balanced signal is simply two unbalanced signals, one 180 degrees out of phase (mirror image). The you subtract one from the other - common noise cancels. That's it. It is more immune to both ground noise and pickup of noise over long distances in noisy environments - like factories or concert stages. Worse, the simple, common way to create balanced I/O is to add an opamp or other circuitry to create it - and every circuit, no matter how good, adds a little distortion and noise. There are a bunch of reasons to use balanced - for example to run stereo amps as monoblocks - and yea, i advertised this as a feature on my amps/preamps 25 years ago - and it was true! And sounded great! -- but it used inherently balanced circuitry (not one extra part, not one), and quadrupled the power. That said, 99% of the time i personally would run the simplest system possible. RCAs. Plus, you save money on cables - generally lots. Spend that on something truly useful. As to RCAs preserving absolute polarity - strange comment. So do balanced connections. Actually, absolute polarity is really a function of whether the circuitry inverts or not. If it does, well, swap the speaker leads :-) Problem solved for $0.00 G |
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If both the source and load are fully balanced......then balanced sounds noticeably better. Not just lower noise but more transparent/real and more information. I can hear the difference from the kitchen. This was tested with the same source and same type of cables. So, yes, balanced in inherently better. This is why Audio Research and many other run balanced. It is not about profession whatever......it just plain sounds better. Do what you choose. This is my experience, listening to both. By the way, you don't need transformers to run balanced. Almost all DACs have balanced outputs and you simply run each phase right out. If the preamp/amps are fully balanced.....you will get better sound than single ended. Frank Van Alstine loves his new balanced mono blocks.....the best he has ever done. Also, running balanced does not take the cable out of the equation. All balanced cables sound different from each other and that includes on Atmasphere gear. |
Ricevs 8-1-2019 Ric, I don’t doubt your experience. But see Ralph’s post dated 3-22-2013 near the beginning of the following thread for what I consider to be compelling proof of his contention regarding immunity to differences between balanced cables, **if** the components being connected meet the criteria he states in that post (which are not met by most high end components, as he indicates). Also see one of my follow-up questions later in that thread, and Ralph’s response, which it seems to me might account for your findings. The question I am referring to is in the last paragraph of my first post dated 3-27-2013, beginning with "Also, to eliminate interconnect cable differences is it necessary ..." https://forum.audiogon.com/discussions/what-tube-pre-amp-match-up-with-a-solid-state-amp Regards, -- Al |
Similar but different topic - I didn't want to start a thread. I want to take my DAC RCA outputs and feed two amps (want to bi-amp my speakers). I'm looking for a y cable that will put out the same signal rather than a left right stereo split. Q2: Is this a bad idea? DAC is Qutest and has no volume control. That is on the amps. |
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Horse puckey! I just got up, walked over to my handmade true-balanced end-to-end differential headphone amp, disconnected my Mogami XLR interconnect from my R-2r resistor ladder DAC and measured the pins on its standard Neutrik-branded male connector. ShOcKeR! All pins are the same length. So I thought, well there’s *no*way* anyone would mansplain so authoritatively if they weren’t actually knowledgeable. Better give them the benefit of the doubt and find another cable with a non-Neutrik XLR connector on it. It took some digging, but I eventually found another cable with Amphenol XLR connectors. Nope. All the same length. I’m going to trust Nelson Pass, Atmo-Sphere, and the electrical engineering professors who mathematically demonstrate how differential amplification (internally balanced components) are inherently better performing but also more difficult to engineer. Not a lot more difficult, but clearly complex enough to confuse your average solder jockey or audiophile store salesman. Now, maybe some old Korean War era PA system cables used an early version of the standard with a longer pin, but they did a lot of things differently 60-70 years ago. Today, unless you can link to a whitepaper or standards doc that specifies a longer ground pin, I say we can safely assume the pins are the same length. PS: When people say balanced is not inherently better, they mean that having a balanced circuit in a badly designed amplifier isn’t going to make that amp sound better than a really superbly engineered unbalanced amp. It doesn’t overcome an otherwise poor design. |
This is simple. If both devices was designed for full balanced support then it is clear that XLR is preferable solution. If one of the device is single ended then RCA is perfectly normal. I tested many cables and devices. This rule is in general pretty common. I I join my MC1.25 monoblocks with C2600 preamp with XLR and C2600 with Chord Dave with RCA since Dave construction is SE. Simple as that. Yea, sure. Different cables, hybrid devices, balanced architecture implementation can effect the sound eventually but the rule more or less remain. One of the earliest posts was that XLR is for long distance connections. True, but super HIEND equipment will benefit from it as well. If I adjust the position of my speakers by half of inches and I hear it then why extra clarity provided by XLR should not have the same influence. Over 20thy years of adventure with audio teach me that there are no boundaries in this hobby. |
I began my transition from rca to diff balanced kit 2 decades ago. Same nonsense appears here as back then (that they are ONLY for long runs) I have heard differences between 0.5m and 1.0m XLRs Dif balanced is basically 2 totally independent channels (hense doubling the cost), though they often incorporate the same output transformers. EVSs new EVS 1200 has 2 separate channels in it whereas most of the similar class D stereo amps do not. Appreciating his knowledge, I bought one Buyer Beware: I used to call out the hi end mag editors for giving dif balanced kit to 'reviewers' whose systems are NOT dif balanced. I finally gave up. A lot of kit has XLR I/Os but the kit itself is NOT dif balanced, therefore the listener will not hear the difference RicEVS, wrenth, and engineears have it correct |
Engineears 8-2-2019@engineears Apparently you didn’t read my post on this subject very carefully. I clearly said that the pin lengths on the male connectors of my XLR cables appear to be the same for all of the pins. It is the female connector for which I described a difference, which when mated with a male connector having equal length pins would result in the ground connection being made first, upon insertion, and removed last, upon removal. Regards, -- Al |
https://benchmarkmedia.com/blogs/application_notes/balanced-vs-unbalanced-analog-interfaces?_pos=1&_sid=87340c17d&_ss=r A lot of informative info before this summary in the link above. SUMMARY |
that being said your Amplifier and preamp need to have transformers for the input,outputs to be what is considered a True balanced .This statement is false. You don’t need transformers, but without them supporting the balanced standard gets a lot trickier. We developed a means that is direct-coupled and yet floats the same way that a transformer winding does. Many owners of Atmasphere gear (amps to preamps....all balanced) have reported the same cable differences that others have reported on other balanced gear.Oddly, they’ve not been reporting them to me. A balanced signal is simply two unbalanced signals, one 180 degrees out of phase (mirror image).This statement is incorrect. With a proper balanced signal, the non-inverted phase is created with respect to the inverted phase, **not ground** (which is for shielding only). So its not two unbalanced signals- its only one, which floats with respect to ground (IOW, if you wanted, you could run a balanced signal with only two wires by simply omitting the shield)! This fact is poorly understood, but think of a line transformer- it does not use a center tap- one side of the output winding is tied to pin 2 of the XLR, the other side to pin 3. No ground connection at all. **Balanced lines if properly executed ignore ground**. So it isn’t two single-ended signals- although a lot of manufacturers think it is, and in so doing degrade the performance of the balanced connection (and allow for interconnect cable artifacts and ground loops to creep into the system sound equation). When we built the world’s first balanced line preamps back in 1989, it didn’t occur to us that we could do that without supporting the standard. I was a bit shocked when I started to see other balanced gear that in no way supported the standard, and then exotic interconnects appeared because they were needed to work with such substandard equipment. You’d think that audiophiles would jump at the chance to no longer have to spend big $$$$ on cables and yet still get the best results... In a nutshell, here is the standard: 1) pin 1 ground, pins 2 and 3 are signal. Pin 2 in the US is non-inverted side of the signal 2) ground is ignored, the signal floats; the pin2 signal is created with respect to pin 3 and vice versa 3) the system is low impedance- if there is an output XLR, its able to drive 1000 to 2000 ohms with ease (the old standard was 600 ohms and our preamps support that) 4) the signal travels in an interconnect consisting of a twisted pair with an independent shield. I clearly said that the pin lengths on the male connectors of my XLR cables appear to be the same for all of the pins. It is the female connector for which I described a difference, which when mated with a male connector having equal length pins would result in the ground connection being made first, upon insertion, and removed last, upon removal. Al, for all these decades of doing balanced connections, I’d never noticed that. You have to look quite closely at the female connector!! @millercarbon, my apologies on this point. |
the sound of the interconnect won't be a thingMalarkey! Assuming balanced circuitry and connections are properly implemented, which far too often they are not, they can reduce common mode noise. FULL STOP. For balanced interconnects to be immune to cable, they would have to be immune to the laws of physics. Balanced lines [and connectors] have impedance and impedance controls frequency response. differential amps tend to be lower noise we don't need as much gain stages to get the job doneIf number of stages is a criteria, use a transformer. Differential amps per se are all over the map in terms of gain vs noise. The devil is in the details. the other reason for balanced lines is elimination of ground loop noiseI'll wager that 6 9's of 'balanced' home audiophile systems do not lift the shield at the destination. Depending on amplifier design, there may be ZERO ground loop improvement over an unbalanced system. The balanced line system was created to get rid of interconnect cable colorationsThe balanced line system was invented by the telephone company to increase noise immunity and power transfer over long distances. Nominally 600Ω, but at 1 frequency ONLY! Low frequency performance is abysmal.The 'telephone sound' is a direct result of balanced cables. |
A note about balanced pro audio...In my long career as a concert soundman, I can attest to the fact that NOBODY unplugs a balanced anything while the system is powered up, and if somebody does I will possibly throw them out of the building. The balanced connections DO NOT stop noise when unplugging live connections. |
audiorusty Im envious. I always lusted for A-S kit, but was always out of my budget. Perhaps the closest I got was when I had Accoustats with their OTL amps. Did a few modes to the boards + chips and cryoed NOS tubes. Even if the sound was comparable, the Accoustats were affixed directly behind each speaker, designed exclusively for their panels. Must be cool just to look at them, such a classic design honoring an important era in communications kit that looked like military hardware |
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My home system was dramatically improved by 2 instances of changing to XLR cables: the tube preamp (ARC) to SS amp (McIntosh) connection eliminated noise that was present with unbalanced cables (cables were about 7 feet long) & my Marantz SACD (SA-11S3) to the pre made a huge difference, whether only because the balanced connection was louder (as some attest) or the cable was of far better quality than the previous unbalanced one, I don't know. |
Sorry, but posts like the above are just fanboy prattle, equivalent to "I changed everything and it sounded different." Many balanced devices are bodged to accommodate unbalanced operation and coupled with generally incorrect balanced wiring, they don't stand a snowballs chance of optimum operation in unbalanced mode. If 4+ decades in electronics has taught me anything, it's that if it can be screwed up it will be:
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Regarding ground connection being connected first and disconnected last IS true if one wire the balanced connections as perhaps intended. The shell which has the 4th terminal on a 3 prong XLR connector is intended for Chassis ground. XLR connectors are available with up to 6 (7) termination points. Most however don't use this 4th connection point, including me. Pin 1 Chassis Ground, Pin2 Positive Node Pin3 Negative node. So to refer to the OP since your Marantz gear have the same termination on both pre and power amp - your in electrical phase and don't need to do anything else. As far as balanced operation which in my opinion offer vastly improved performance dynamics for an example and noise rejection and that the interactions of the cable is practically eliminated the list goes on. All the equipment we make is fully balanced form input to output. Even on our economy line Liberty Audio the gear is fully balanced. Good Listening Peter https://pbnaudio.com |
Thanks for your input, Peter (Pbnaudio). Yes, depending on the specific designs what could be connected first and disconnected last when XLR cables are connected and disconnected may be either chassis ground or circuit ground. As you are doing in your designs and as explained in this Rane application note, connection of pin 1 to chassis ground in both components is proper practice (although unfortunately far from universal practice), with connection of chassis to the shell being optional. On another note, regarding whether or not the OP’s specific components are fully balanced and whether or not they use inexpensive op amps to generate or receive one or both signals in the balanced signal pairs, I see that service manuals for these components, presumably including schematics, can be downloaded at hifiengine.com if one is registered there. I’ll try to take a look at them tomorrow, as that site imposes a limit of three downloads per day and I’ve already reached that limit today. Best regards, -- Al |
I own balanced equipment, before I had SS unbalanced amps, on my rig and judging with my ears and a professional pianist ears as well I have replaced the balanced cables with mogami 2534 shielded, mogami 2549 unshielded, wireworld eclipse and in all three instances we weren't able to notice any difference in sound. Additionally to all these, replacing other components like dac, USB cables etc. Haven't made too much of a difference, as a matter of fact there have been a small difference in instrument presentation and Soundstage when changing things at the source but almost not noticeable not like others report on similar rigs with unbalanced connextions. Some people have recommended not using balanced shielded cables as they state sounds worse, I don't doubt it I just can't tell the difference on my rig. My point is I truly suspect by empirical experience that balanced well designed equipment could be impervious, or maybe I should say apparently more resistant to changes on interconnects. Just my thoughts, Oh one more thing, there is unbalanced only equipment that price wise I seen it to be more expensive that their balanced counterpart, it might not be a general rule but it happens so cost IME is not so much of an issue. So back at wec56, yes using balanced vs unbalance there could be a difference IMO. You should experience more of a difference using different equipment manufacturers than cables anyways. Enjoy your system |
As promised, I have downloaded and examined schematics for the OP’s preamp and amp, which as I had mentioned in my previous post can be obtained at hifiengine.com if one is registered there. The amp is not fully balanced. However, while the circuit configurations used to receive balanced and unbalanced inputs are of course somewhat different, both inputs are processed through circuitry described as follows:
Two HDAM SA3's are in the path through which each balanced input is processed; one of those two is in the path through which each unbalanced input is processed. The preamp is also not fully balanced. However, a good deal of the circuitry which precedes its balanced outputs is symmetrical and is therefore balanced, although not differentially (i.e., it does not utilize differential stages). That circuitry also utilizes the HDAM SA3, followed by a number of stages utilizing discrete transistors. Given all of that, my guess in this specific case is that it is more likely than not that a balanced interconnection will be preferable to an unbalanced one.
While I suppose there may be a few exceptions, usually a preamp which provides balanced outputs when it is provided with balanced inputs will also provide balanced outputs when it is provided with unbalanced inputs. And examination of the schematic for the OP’s preamp confirms that is the case here. Best regards, --Al
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for anyone interested, HDAM module schematics are available here https://muzgdiy.files.wordpress.com/2015/05/all_versions_2.png These HDAM's consists of discrete surface mount components with short mirror image L/R signal paths.IMO, this is marketing malarkey. It is not possible to 'mirror image' active circuitry as devices have functions on specific pins. Marantz literature always shows a pair of identical HDAM modules and never a mirrored L/R pair which, if they existed, would be featured front and center. Additionally the Service Manual has only one HDAM-SA3 schematic for a bipolar amplifier circuit. Discrete circuity 'suffers' from increased parasitic L & C, component tolerance and reduced supply immunity, all of which contribute to the 'sound'. Some opine that discrete circuitry takes the edge off the literally 1000's of integrated circuits through which the signal passed before the final storage medium. Somewhat troubling is the -ve phase is derived from the post Wolfson WM8816 volume control unbalanced +ve output through an additional 2 HDAM and 2 gain stages. These then feed a pair of balanced tone control circuits. Strange. Use caution if driving an unbalanced amplifier. Best results will probably result from using Pin 3 & Gnd ONLY. A largely ignored electronics property is power supply linearity. The impedance and phase linearity of the ubiquitous LM3x7 / 7xM et al. regulators vary drastically between manufacturers and implementation. Some are positively abysmal suffering 180° phase and a couple of orders of magnitude Z change in a few Hz. Marantz makes a fair bit of 'noise' about their power supply design and examination of the schematic shows that the audio supply is discrete and well designed. A negative in the pre-amp [and any versatile control center] is the large number of relays in the circuitry. ALL switching is audible and cumulative. Bottom line, if you like the sound, don't worry about the innards. PS I have a Marantz CD-6006. I like the sound & features. I don't worry about the innards. |
Use caution if driving an unbalanced amplifier. Best results will probably result from using Pin 3 & Gnd ONLY. Hi Ian, Not sure where you are quoting this from, or if you are quoting it, but to be clear I assume this statement is intended to apply to the unusual situation in which XLR cables are used to connect the balanced outputs of a preamp to an amp which receives the signals provided to its XLR inputs in a single-ended manner, and would short one of those signals to ground if the signals on pins 2 and 3 were both routed to the amp by the cable. In most cases, of course, at least when it comes to consumer-oriented gear, unbalanced amplifier inputs would be driven by the preamp’s unbalanced outputs via RCA cables, and the statement would not apply. And in most cases involving consumer-oriented amplifiers which provide XLR inputs but are not "fully balanced" I would nevertheless expect signals provided to their XLR inputs to be received differentially, not single-ended. As is the case with the OP’s amp. In any event, thanks for providing the additional insight in your post. Regards, -- Al |