New TT : Balanced vs. Unbalanced Connection?


I am in a six-month process of assembling a system will last me for the next 5-10 years. I’m set on the components, so please do not try to talk me out of my selections. My question here is a technical one.

I have purchased a Thorens TD–1601 and a Nagaoka MP–200 cartridge. I am trying to decide on the Integrated amp between Yamaha’s A-S3200 and A-S2200. The key difference for this question being the A-S3200 has two balanced inputs and the A-S2200 has one. I will use the first balanced connection to connect a recently purchased HiFi Rose RS-150b Streamer/DAC.

Now to my real question. The semi-automatic Thorens TD-1601 has both balanced and unbalanced outputs. I am considering buying a Schitt Skoll phono pre which has balanced in-and-out. In that case, I would buy the Yamaha A-S3200, needing two balanced inputs.

So, ASSUMING the phono preamp on the Yamaha A-S2200 is comparable to the Schitt Skoll, will I get markedly better sound by going fully unbalanced, with the Skoll and the much more expensive A-S3200, or unbalanced direct from Thorens TT into the highly regarded phone pre of the A-S2200?

What benefits will I get by going balanced? How much benefit? It is worth the complexity, extra box, cables, $2,000-3,000? I can afford it if much better, but don’t want to spend money unnecessarily. The TT and the integrated will be right next to each other, so distance is not a factor. Or is the A-S3200 that much better? …I like the BIGGER meters.

My current speakers are Paradigm Reference Studio 40 v2, which I love and have two pair, a super sleeper. They are not likely to be changed…one day Fyne Audio.

To reiterate, this is a technical question about the merits of balanced turntable connections. Thanks for the input. I have learned much from this forum over the last few years.

 

gemoody

If you run a cartridge "balanced" (technically, it's floating) into a differentially balanced phono preamp such as an ARC Ref Phono 2SE, you will have 6 dB more gain in balanced mode than unbalanced.

@cleeds Emphasis added, and no, you don't. 

I think this might be coming from a misunderstanding of how differential amplifiers work. So let's look at that:

A differential amplifier gets its name from the fact that it amplifies what is different between its two inputs. In a balanced phono situation, normally that would be pin 2 and pin 3 of the XLR input.

However, what if the cartridge was connected to pin 2 and pin 1 (ground) instead (as would be the case if running that phono section single-ended)? It wouldn't work right unless you tied to pin 3 to pin 1; otherwise you'd likely have a lot of hum and buzz.

So you tie pin 3 to ground and there's your signal. Exactly the same as before, not increased by 6dB, for the simple reason that the differential amplifier is amplifying what is different at its inputs, and that difference is the cartridge signal. The diff amp doesn't care that one side happens to also be ground.

That's is your opinion and I respect it. But many others think the advantage is:

... good rejection of common-mode noise and interference ...

... as noted in the Wikipedia link I previously provided.

Wiki isn't wrong on this point. Those are advantages of balanced line operation. But imagine a recording studio, with 50 or 60 different devices- a mixer, tape machines, mic preamps, compressors and other effects devices. You can see that if you had a ground loop it might take days or weeks to find it! So one of the advantages of balanced line operation is also ground loop immunity. (that's also a Wiki link FWIW)

I knew Robert Fulton (as did Bill Johnson, founder of ARC, and Warren Gehl, Kalvin Dahl, who still work there, along with Rich Larson, who was ARC's engineer for a long time; I know or knew those people too and they knew me as well since we did listening sessions at Bob Fredere's house in south Mpls). Fulton created the first high end audio interconnect cables and speaker cables, and thus founded the high end cable industry. We all know what happened after that.

So what do you suppose was going on prior to Robert Fulton? How were record labels able to run 200 feet of interconnect cables between their microphones and the inputs to their tape machines as Mercury did when they recorded at Northrup Auditorium in Minneapolis?

I know you know- they used balanced lines. This was to prevent the cables imposing an artifact (in addition to all those other benefits). Quite literally with the equipment they used, you could swap out a cable with one a lot more expensive and not hear any difference. That is still true today (get yourself a refurbished tape machine and some Neumann mics and you can see for yourself). Put simply, the system is immune to the artifacts of the cable as long as the standard is observed.

I'm sure your preamp works fine, but as you've already noticed, you have audition the cable and find the one that works best that you can also afford. That's up to you; all I'm saying is if the standard is supported you no longer have to worry about that.

And where this makes the most difference is the phono cable, where the signal absolutely must arrive intact if you want best performance.

 

 

atmasphere

I think this might be coming from a misunderstanding of how differential amplifiers work. So let’s look at that: A differential amplifier gets its name from the fact that it amplifies what is different between its two inputs ...

Pedantic.

I’m going to do you a favor, Ralph. After this post, I’m going to allow you the last word on this matter in this thread. You have my word. Based on your past practice, I know you’ll have many!

For the last time let’s look at that phono cartridge into a ARC Ref Phono 2SE using its balanced out into an ARC Ref5SE. That is the exact combination I’ve mentioned in this thread, and its results are not unusual.

Here is the ARC factory specification for the Ref Phono 2SE:

There are two separate sets of inputs, with selectable gain between Low (51dB BAL / 45dB SE) and High (74dB BAL / 68dB SE).

I can confirm that these products meet specification. My best to you.

 

Ralph,

"@elliottbnewcombjr That is a bit odd- XLRs are a lot more rugged than RCAs."

I agree, I have many times said I like that XLR positive lock, perhaps desirable for that feature in residential systems with no other advantage.

 

However:

Did you watch the video? (posted above by veerossi)

What this guy did is far from robust as he readily admits.

I repeat: stubborn or obsessive absurdity.

There are two separate sets of inputs, with selectable gain between Low (51dB BAL / 45dB SE) and High (74dB BAL / 68dB SE).

I can confirm that these products meet specification. My best to you.

@cleeds If this is correct then the input isn't differential. It might be balanced, but differential amps don't behave that way.