Balanced or single ended phono stage?
The Liberty B2B-1 can do both, for balanced you'd need two of them for a truly differential amplifier, IMO Vastly superior performance to running them Single ended, if the rest of your system is balanced. And yes I do make them, there reviews here on AG and on Stereophile and Positive feedback too. Good Listening Peter |
Not all units with balanced outputs have true differential circuits. Also, running two single ended units in bridged mode is not the same as true differential. With a bridged connection there will be two AC current loops per gain stage. A differential gain stage has only one. There is no reference to ground with a differential circuit as there is with the bridged connection. In my experience this does have sonic consequences. |
John, there is no reference to ground when running the Liberty B2B-1 as a differential amplifier, Each end of the coil in the cartridge is connected its own amplifiers positive input, with their negative input tied to each other. The signal is fully differential from input to output. Good Listening Peter |
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The length of the cable is not relevant- balanced will sound better even if its only 6". There are several advantages to balanced operation, particularly with a phono setup. First, the cartridge is a balanced source. That is why you have that separate ground wire when you run a phono single-ended, that ground wire that no other source seems to need :) Now its not just because the cartridge is balanced. The reason the balanced line system came into being was to eliminate or reduce artifact from the interconnect cable (it was the phone company that benefited from this initially, but the recording industry saw the same advantage and switched over right away). Now you would think that getting rid of the sound of the cable would be a thing that any audiophile would want! In practice, it does work out that the cable ceases to be a variable in the sound of the LP playback when you run the cartridge in the balanced domain, as long as the cable is built properly. If it is, ground will be on pin 1 of the XLR and will not have to be hooked up separately. If the phono section is also balanced and differential, you have a further advantage of lower distortion and lower noise. This is because distortion is not compounded at each stage throughout the preamp. In addition, a differential gain state in theory has 6 db less noise that the equivalent single-ended gain stage. This means that you may not need as much gain with a differential phono section. Less gain stages means it might be that much more transparent. People ask often why we don't have separate outboard phono sections. The reason is connectivity to the line section. If you really want transparency (and its analog- who doesn't??) then you don't want the connectivity of connectors and interconnect cables getting in the way (as well as the variable of what sort of load the phono section is being asked to drive). As long as your power supplies are up to it, you have a better chance of getting it sound right if the phono section is built-in to the preamp. So we rely on our line stage to drive the interconnect and it can easily drive over 100 feet, even though its an all-tube preamp. That way you can put the turntable and preamp where you want it (and hide the cables), instead of being stuck between the loudspeakers (which is not usually the best place, and often does not fare well with the WAF). |
I'm partial to balanced phono stages, using one myself. Lots of benefits as Atmashphere has pointed out. As to the OP's original question, I would point out that the Ayre has both balanced inputs and outputs, the Parasound only balanced outputs. The big benefits of balanced in a phono stage are IMO realized at the input, not the output. If you're really interested in balanced, seek out a phono stage that is fully balanced at the input as well as the output. That would be worthwhile IMO. |
A great and informative thread with only one contributor thus far claiming that the only benefit of differentially balanced circuitry is with long interconnect runs (would like to know more of her direct personal experience with true differentially balanced equipment). I use an Ayre K-1xe phonolinepreamp and, as good as the line stage is, the phono section is substantially better IMO. Very quiet, dynamic, open, and detailed. I am told that the standalone P-5xe is a touch better sounding still, so definitely worthy of serious consideration among the truly differentially balanced phono stage options out there. Just be sure to consult with the good folks at Ayre regarding the proper tonearm/interconnect wiring scheme to ensure that the balanced signal is preserved from cartridge to phono stage. Dave |
Listen to Atmosphere on the advantages of balanced designs. I have no connection to him but I have been using balanced systems for a long time and I am a believer. Not to say single ended equipment can't sound better in a scheme of things. System dependent. Having owned the Ayre P-5x it is a very good reasonably priced phono pre. Its a true balanced input to output unit. That is vs some units that add balanced circuitry at the end, an extra stage at the end of single ended design. Not the way to do it. The Ayre P-5xe is nice in that you can use the RCA single ended input and still take advantage of the balanced input. Just flip the bal/single ended switch to balanced. There is a slight difference in signal path but I verified with Ayre that both sides of the signal get to the diff input though there is a slight difference in signal path length which should not matter for practical purpose. I used it as I described and also with the proper xlr input with the same tone arm, a Tri planar VII, which I had converted from RCA to XLR. Did not notice a difference! Great unit. For me it took a major step up in price to better it. |
ASR Basis Exclusive offers both single ended and balanced ins and outs. The sound is far superior using the balanced ins and the RCA outs. It just depends I think on your system and the phono stage. Since it's easy to try balance ins, I always give it a shot when the pre offers both. It's usually, but not always better. |
Great responses everyone, I appreciate the feedback.......of course an in home demo would be the best. You read just a ton of excellent things about the Manley Chinook which is pretty much the same price as the Ayre, yet it has quite a few more options but is single ended. Same goes for the Ayre which is balanced of course. Maybe it's a matter of tube vs. solid state, which will affect my system in ways I have no idea. I haven't purchased the table yet, but will most likely go with the VPI Classic 2 or 3. I suppose I could buy both to demo......figure it wouldn't be too hard to sell the one I decided against. As of right now I've got a slightly warmer McIntosh based system with sightly cooler Avalons.....so I figure an analog setup will put my room into audio nirvana. Demoing the table at home this weekend. Can't wait. If I go off the wealth of internet feedback, you'd think that the Manley is the way to go. |
To concur, support Peter's response. I initially purchased one Liberty B2B-1 than shifted my phono setup to balanced operation. The use of two B2B-1s, in mono configuration, is quite something. I was able to compare this to much more expensive gear (ASR, Boulder, Audio Research) and the Liberty remains my reference - for what is a relatively expenditure. No risk, contact Peter at PBN and demo these. |
Dear Audioguy3107: IMHO maybe the subject could be not if is balanced or not but to understand the critical role that a phono stage has in the analog quality performance level where you need an item/unit where the sensible cartridge signal lost and added the less, this is that we need to preserve through the POS the cartridge signal integrity. Balanced or not a good PS design can do it, we need at the PS accuracy, very low noise, very low distortions and neutral unit. A good SS design normally does " things " in a better way. Other subject you have to take in count is: with which cartridges will you run that phono stage?, this is very important before you can choose the unit. Regards and enjoy the music, R. |
^^Its not a matter of tube vs solid state! A balanced solid state unit has a better chance of sounding like music than a single-ended circuit, the same is true of balanced tube preamps. Balanced line operation is simply a better way of handling cables, and if the circuit is balanced differential, then its a better way of processing the signal as well. The signal path of a balanced differential circuit can be as simple as single-ended circuits. For example our preamps have only three stages of gain between the LOMC input and the line state output (in the case of our MP-1 that line stage can drive headphones directly, yet we are still talking about only three stages of gain from the stylus on the LP). Now it is true that there are more parts but it is not true that there are double the parts- that depends on the design. |
Tdaudio: " The Ayre P-5xe is nice in that you can use the RCA single ended input and still take advantage of the balanced input. Just flip the bal/single ended switch to balanced. There is a slight difference in signal path but I verified with Ayre that both sides of the signal get to the diff input though there is a slight difference in signal path length which should not matter for practical purpose. Interesting! I would think that you would, at a minimum, sacrifice the 6db of noise reduction by using single ended interconnects in the signal path. From the K-1xe owners manual: "As the phono cartridge is an inherently balanced device, the phono stage is also balanced, using XLR jacks at the input. This configuration yields maximum sonic performance with minimum noise and hum. Since most tone arms and/or turntables are not equipped with XLR connectors, there are two choices for making the proper connection: 1) Use an RCA-to-XLR adapter. This often may be the easiest solution to implement, but introduces an extra set of contacts into the signal path. In addition, this converts the balanced input into an unbalanced input and causes a slight loss of sound quality. 2) Use dedicated cables with XLR connectors at the preamplifier end and the appropriate connector (RCA or DIN, depending on the particular installation) at the turntable end. This is the preferred solution and offers the highest level of sound quality." Tdaudio, I am not challenging your experience, but genuinely curious: was your XLR cable configured per one of the schematics on this link from the Ayre website: http://www.ayre.com/acc_phono_schematics.htm#phrca Perhaps the balanced/single ended switching function on the P-5xe that you describe explains your results since there is no such feature on the K-1xe? Thanks, Dave |
Another balanced phono stage advocate here. I started off using the Ayre K-1xe's phono boards, which are setup for balanced inputs only, (i.e. XLR terminations). Originally, I used adapters, (RCA -> XLR), as my tonearm cables, (Rega RB900 tonearm), were setup for RCAs. The sound was very, very good, (near reference in fact), and much better than the ARC PH-3 that I had been using, (using the standard RCA inputs of course). However, when I upgraded to the Basis Vector M3 tonearm, I had AJ Conti upgrade the tonearm cables to XLRs. This upgrade, (combined with my upgrade to the turntable itself), really made a huge difference in the sonics. The background became even darker, and the bass response was even tighter. Some (most?) of this sonic improvement is probably due to the change in turntable and tonearm, but nonetheless, I think some of it was due to the use of balanced inputs, and the elimination of the adapters. FYI: I recently upgraded my Ayre K-1xe, (after nine happy years with it). A friend offered me his Basis Exclusive, model 2010, phono stage for a great price, (a price I just could not turn down). I plugged this into the Ayre to compare the Basis Exclusive to the Ayre K-1xe's phono boards, and while the Ayre's phono boards were very good, they just were not the equal of the Basis Exclusive. (And nor should they have been, given the large difference in price!) I will also point out that the VTL TL-6.5 line stage preamp that I bought to replace the Ayre K-1xe was better as a line stage also, albeit only slightly better. (No where near the upgrade that the phono stage upgrade was.) The Ayre K-1xe, with its phono boards is a true bargain, especially on the used market, IMHO. |
One thing to remember - slapping XLR connectors on the end of a RCA tonearm cable does not (generally) magically transform it into a balanced cable. And RCA cable (generally) contains 2 conductors: (+) and ground (usually a shield). A balanced cabled contains 3 conductors: (+), (-), and ground (a shield). If you put an XLR connector on an unbalanced cable, the ground (usually a shield) carries the (-) component of the balanced signal. What else gets carried on that conductor? All the EMI that was sent to ground in the unbalanced configuration. Often, you'll need to run your balanced phono pre in an unbalanced mode to shunt that noise. Therefore, if you can't run a fully-balanced cable from your tonearm to your phono stage, you may not be able to realize all the value of the balanced circuitry. |
Dave, no worries. It was several years ago. Let me back up a bit. I had a VPI Aries II TT when I picked up the Ayre P-5x. I did indeed order a custom made phono cable that was configured per the Ayre link you provided. The RCA end plugged into the RCA termination block on the Aries and the other end had XLR connectors for the Ayre phono. Worked well. I still have the 1/2 meter cables. I don't think VPI had a XLR term block at that time. I then picked up a used Triplanar VII which had single ended RCA connectors on the built in phono cable. After a while I realized that I had never flipped the bal/se switches to the single ended position! When I did it sounded a tad worse so I left them in the balanced position. No doubt the change in gain made it hard to compare. I later converted the Triplanar phono cable to have XLR connectors thinking it might be better. Again I did not notice anything after that process. Curious, I pinged Ayre's Charles Hansen on Audio Asylum and asked him what was going on. It was a while ago but iirc he said with the switches in the "bal" position the negative or inverted part of the RCA input used of course for unbalanced inputs was allowed to float thus the inverted signal from the cartridge made it to the inverted input of the diff amp. Not the best way, but as long as the inverted signal in the cable is allowed to float, never grounded, it works because of his design. I did a quick search on the Asylum to try and find the thread but could not locate it. The search has some quirks to it and I will spend some more time tomorrow watching football. Might be quicker to repost on the Asylum. Hope that helps. |
I too have heard that balanced is the way to go for a turntable source. When I recently switched from a good to moderate RCA to XLR cable outputing my phonostage, the XLR was clearly better. This is gpoing to show my ignorance, but if the Phono cable has RCA not XLR connections. Does that not undo the benefit of XLR outs from the phonostage? |
Some pretty basic reality: 1. There are many reasons for the quality of sound of a phono stage, differential design being one of many. Balanced might be beneficial, but many non-balanced phono stages beat balanced phono stages. This single factor certainly is not the most critical determinant. I don't sell, make, or endorse any phono stage makers, I have absolutely no commercial or personal bias. I own both balanced and unbalanced phono stages. 2. Differential circuitry certainly does not eliminate cable influence. * An inappropriate impedance will still be just as deleterious to the sound. * A cable design that rings will still ring. And this sounds horrible, balanced or not. * A cable with leading edge overshoot will still have it. And this too sounds horrible, balanced or not. * A cable with changing impedance relative to frequency will still have phase distortion, balanced or not. * A cable that rounds transients will still round those transients, balanced or not. Balanced design does not change any of the above at all. Years of interface design experience in high tech, outside of audio, is my background for this statement. In the audio field technical testing and listening confirm this. |
Kiddman is 100% correct, but a preamble is really necessary to give his response context (as his truths apply to all circuits and cables). There is rhyme and reason to cable design and geometry. This simple statement could spawn myriad tangents to this discussion, but as it relates to differential balanced circuits, ONE of the benefits of a properly-designed balanced cable is noise rejection. Now, you can take any 3 pieces of conductor and connect the (+), (-), and ground and it will "work". But you ideally want the (+) and (-) conductors to be arranged symmetrically so that any externally-generated noise impacts the (+) and (-) legs identically. When the (-) leg is inverted and summed with the (+) leg, that noise cancels itself out. |
I think your "preamble" is not "really necessary", as you state, to give my response context. My assertions stand on their own, balanced is not a sonic guarantee of anything. Neither is it a detriment. Maybe it will be quieter in your system. As for noise, not all is cancelled out. We often will see a circuit with additional parts. Not perfection! I have no horse in the race but I don't like "black and white" statements, high end audio is too full of them, and most of them are wrong. And if you have ground loops, balanced dies not kill those. To get back to your original question, "My question is whether the balanced option should tilt me in favor of one type vs. another", don't let this one feature tilt your decision. I never heard it be the make or break for any phono stage, and I have tested a lot of them, including many of those reviewed as the best, and own a lot of them. Listen to everything you can get your hands on, don't pre-judge or limit your field based on things like balanced or not, use of signal transformers or not, specifications, circuit design features claimed by the manufacturer, or reviews. Go to lots of concerts without PA systems, listen to solo instruments whenever you can, and try to match that feel. Again, no connection to retail sales or electronics of any type. Just a guy who hates the hype in this industry. It's about the music. Don't get lost in the technical claims. |
