2. amps-preamps
  3. 124255-73035

Dual Differential / Balanced?

Hey all I’ve got that itch to upgrade power amps, and was wondering how valid the dual differential aka "balanced" monoblock or dual mono design is in terms of increasing fidelity compared to a conventional SE amp. note my preamp is also fully balanced

how much noise is avoided by using a fully balanced system?

right now I use 2 haflers horizontally biamping NHT 3.3. using mogami gold XLR
p4000 200wpc mids/highs p7000 350wpc lows

from what I’ve read it only matters if both the preamp and power amp are both truly balanced

I have a nice Integra Research RDC 7.1 fully balanced pre/pro, it was a collab with BAT, I would go for the matching RDA "BAT" amp but its pretty much unobtanium

So far I’ve looked at classe ca200/201, older threshholds, older ksa krell, as fully balanced monoblocks/ dual mono stereo

I was also told to look at ATI amps, they look very impressive but expensive

I’m looking to spend 1500-2500 preferably used products, I dont have an issue with SE amps I just want to exploit the fact my pre is fully balanced, and perhaps get better sound. If anyone has recommendations for awesome dual differential power amps. the NHT 3.3 are power hungry so at least 150wpc, class A/AB

I’ve also come across the emotiva XPA-1 monoblock, I can get a good deal on one of them I wonder if its worth picking this up and praying for a lone one to come on classifieds on ebay- note this is the older model in the silver chassis 500wpc 8ohm / 1000 4ohm

for context prior to the realization that I should use a fully balanced system I was looking at brystons and mccormack amps.. thanks
nyhifihead
almarg's avatar
Ag insider logo xs@2x
almarg
9,670 posts
 
My thanks to you also, Kirk.  Always great to see you posting here, and for us to have the benefit of your invariably brilliant insights.

Speaking of Bill Whitlock, since the interface-related noise that is being discussed may in many cases be caused or contributed to by ground loop effects, you'll probably find pages 31 through 35 of this paper to be of interest.  To whet your interest, its introduction states that "this finally explains what drives 99% of all ground loops!"

This was called to our attention a while back, btw, by member Jea48 (Jim), who as you may be aware is our resident genius when it comes to electrician-type matters.  I'd welcome any comments you may have on what Mr. Whitlock has to say on those pages.

Best regards,
-- Al
  
meerzistar
232 posts
 
There are separate case mono blocks and dual mono two channel designs that share a case but it should have two power supplies per channel, one per channel in the preamplifier section and per channel for each power amplifier section in order to be considered a dual mono amplifier, or "true" dual mono. Who makes these terms up either its a "dual mono" or it is not? I form that in a question because I’m not entirely sure what the rules are or if I’m missing some. I know of some 2 channel power amplifiers that are labelled as being dual mono by the manufacturer yet they have but one power transformer.
cousinbillyl
190 posts
 

This is going to be a weird response.

A few years ago, Jeff Bagley built a 'quasi' second order (balanced) 2-way. By all accounts, it was the best 2-way all in attendance had ever heard. After the fact, the naysayers started commenting 'you need appropriate drivers for the circuit'. Now I'm not the brightest bulb in the chandelier, but if it's the best 2-way to date, and you need the appropriate drivers, than choose the appropriate drivers?. Simple.

The fact remains, there will always be skeptics in every field.

Kijanki: your statement; 'sound is the only proof' holds true here. Those people in attendance called it the best. The question is: did he drive his balanced speakers with balanced amplification, or where they un-balanced?

Here's where I turn into a partial salesman.

I believe I've invented the first 'quasi' second order 4-way crossover. My speakers are driven by all Atma-Sphere Dual Differential amplification, and they will be unveiled at this years TAVES (Toronto Audio Video Entertainment Show). I put forth, since 99% of all speakers use parallel crossovers, and these are un-balanced, then dual differential circuits have never had a speaker which will highlight the difference (I wanted to say 'highlight their superiority', but that would have opened up a whole new set of insults. Being married, I already get enough of those)

The only industry person whose heard them is George Klissarov from eXasound. He called them magical. There was not enough time to get them to Axpona. They may be at The Newport show.

Since my website, and speakers, are still under construction, I'll leave it at that.

On my website "let your ears be the judge" is a common statement. In the end, "Sound is the only proof".

Time will tell if a)I'm delusional, or b)I've done it.

Sorry for partially highjacking a thread. Buy Dual Differential amplification. To my ears it is a lot better.

almarg's avatar
Ag insider logo xs@2x
almarg
9,670 posts
 
Meerzistar 4-25-2016
Who makes these terms up either its a "dual mono" or it is not? I form that in a question because I’m not entirely sure what the rules are or if I’m missing some. I know of some 2 channel power amplifiers that are labelled as being dual mono by the manufacturer yet they have but one power transformer.
As far as I am aware there are no formal rules, and my impression is that different manufacturers use these (and many other) terms with varying degrees of looseness. My single-chassis VAC Renaissance 70/70 amplifier is dual mono even to the extent of having two power cords, as well as completely independent power supplies and multiple power transformers for each channel, while I’m not surprised to see your statement indicating that a so-called "dual mono" amp from some other manufacturer has a single power transformer serving both channels. And certainly there are "dual mono" amps from other manufacturers that fall in between those extremes.

Regards,
-- Al

atmasphere's avatar
atmasphere
11,861 posts
 
Thanks kirkus for your comments.

Bill Whitlock's paper is excellent. I like the Rane page on balanced operation (http://www.rane.com/note110.html) as a succinct description of the balanced line standard, AES file 48.
More to discover