Balanced XLR interconnects

[Al ears]

I had an email this morning from Thomas Abrahamsen and he confirmed that the v2.0UP is fully balanced.

That is astonishing for the price...!

Indeed it is. All the more reason to invest in one if the other reports about them are correct.

When I said astonishing perhaps I should have said deeply sceptical. Partly due to the cost, partly due to the lack of publicity and partly because of the fact that their is only one balanced input.

Surely the whole point of a balanced amplifier would be to use balanced sources...*unknw*

I still wonder if something has been lost in the translation here.

Perhaps they figure that nobody has more than one fully balanced source. Which is probably true for most members of this forum. ;-)

Sceptical you may rightly be but how do you prove fully balanced without ripping the thing open?

 

[davedotco]

I had an email this morning from Thomas Abrahamsen and he confirmed that the v2.0UP is fully balanced.

That is astonishing for the price...!

Indeed it is. All the more reason to invest in one if the other reports about them are correct.

When I said astonishing perhaps I should have said deeply sceptical. Partly due to the cost, partly due to the lack of publicity and partly because of the fact that their is only one balanced input.

Surely the whole point of a balanced amplifier would be to use balanced sources...*unknw*

I still wonder if something has been lost in the translation here.

Perhaps they figure that nobody has more than one fully balanced source. Which is probably true for most members of this forum. ;-)

Sceptical you may rightly be but how do you prove fully balanced without ripping the thing open?

Circuit diagram or open it up I guess.

I think that some folk do not understand what a 'fully balanced' amplifier entails.

Two completely separate and discrete amplifier channels, per channel, if you see what I mean, very carefully matched and laid out side by side.

So four separate audio channels in a £900 amplifier....*unknw*

Wow.

 

[Al ears]

I had an email this morning from Thomas Abrahamsen and he confirmed that the v2.0UP is fully balanced.

That is astonishing for the price...!

Indeed it is. All the more reason to invest in one if the other reports about them are correct.

When I said astonishing perhaps I should have said deeply sceptical. Partly due to the cost, partly due to the lack of publicity and partly because of the fact that their is only one balanced input.

Surely the whole point of a balanced amplifier would be to use balanced sources...*unknw*

I still wonder if something has been lost in the translation here.

Perhaps they figure that nobody has more than one fully balanced source. Which is probably true for most members of this forum. ;-)

Sceptical you may rightly be but how do you prove fully balanced without ripping the thing open?

Circuit diagram or open it up I guess.

I think that some folk do not understand what a 'fully balanced' amplifier entails.

Two completely separate and discrete amplifier channels, per channel, if you see what I mean, very carefully matched and laid out side by side.

So four separate audio channels in a £900 amplifier....*unknw*

Wow.

We'll never know until someone voids the warranty and opens the box. Unlikely the circuit diagrams are readily available. ;-)

 

[Blacksabbath25]

There have been pictures of the abrahamsen on here before but I would not know were the components are inside the amp to see were the balanced components are so could not say but going by the company's history I would of thought the abrahamsen is fully balanced but still this amp is a bargain what ever way you look at it .

 

[rmatthew]

I doubt a photo of the internals will resolve the debate but here is one anyway.

http://www.mygarage.ro/attachments/vanzari/326359d1432577051-vand-amplificator-abrahamsen-v2-0-up-5_f.jpg

I can see 2 blue squares, 2 sets of 6 brown things, 2 sets of power feeds and a bunch of other paired components if that helps.

 

[davedotco]

I doubt a photo of the internals will resolve the debate but here is one anyway.

http://www.mygarage.ro/attachments/vanzari/326359d1432577051-vand-amplificator-abrahamsen-v2-0-up-5_f.jpg

I can see 2 blue squares, 2 sets of 6 brown things, 2 sets of power feeds and a bunch of other paired components if that helps.

You really need to see the amp boards in detail.

In a true differential (balanced) design you will see the two (+ve and -ve) 'legs' of each channel layed out side by side in the same manner. The whole point of a differential design is that any distortion or noise that affects one 'leg' of the circuit will affect the other leg in exactly the same way, hence cancelling each other out when phase inverted and combined.

For this to be effective, both 'legs' of each channel need to be identical and as close together as possible, I can see no obvious sign of this in the photo above.

BTW Most modern dacs produce a differential (balanced) outbut by default, as indeed do phono cartridges and microphones, so this is not rare. It makes a certain sense to to keep these signals balanced from their outputs via balanced interconnects to balanced inputs on the amplifier.

It is at this point that a differential amplifier is used to produce a single ended signal (unbalanced) which is then amplified in the normal manner.

That is possibly what is happening here but as I have never laid hands on the amp in question, I might well be wrong, as all the Electrocompaniet amplifiers, including the 'budget' Prelude models appear to be fully balanced...*unknw*

 

[nopiano]

As the designer was previously with that brand (did he originate it?) it would seem more likely than not, Dave? Especially as you note all those amplifiers are balanced - which I'd not appreciated before.

 

[Blacksabbath25]

As the designer was previously with that brand (did he originate it?) it would seem more likely than not, Dave? Especially as you note all those amplifiers are balanced - which I'd not appreciated before.

i think they are balanced like i said before as the same designer is buliding the abrahamsen 2ups and would of thought he would be doing the same as he did with electrocompaniet inside as i think both electrocompaniet and abrahamsen 2ups amps are the same inside just the casing is different that's all

 

[davedotco]

Is not a good idea in this industry, I was caught out many times in my youth...*new_russian*

I do not think people realise just how rare fully balanced amplifiers are, expensive too, the v2.0 being by far the cheapest I have see. Most that I have seen have been from serious us hi-end manufactures such as BAT, Rowland, Krell or Audio Research.

Early Primare were balanced designs, not sure about their modern product, and I thought at the time that they were the most affordable balanced designs on the market. Nearly 20 years ago now, but even then they were 2 or 3 times the price of even the v2.0up.

 

[NSA_watch_my_toilet]

The result, definitely much better than the RCA connections. The RCA is software sounding so clearing loosing some detail. I should add that my RCA cable cost about a fiver and is about 3m long. Not a fair comparison I know but it does show that the cable makes a difference. Unfortunately I don't have a good set of RCA's to compare but if someone wants to send me one then I will give it a listen the post back.

Hello everybody. You probably read the OP. Unfortunately, some little errors where made during this review and I apologise to say that the conclusions where rushed and must be declared irrecevable.

1) Compairing was made impossible due to lack of volume check.

2) Some builders are not treating all of their analogues outputs the same. Even if the builder is reknowned. You can have poorly built RCA with very first class XLR out or the other way around. But not only that, even if both are from equal quality, both could have different power out intensity (sorry, I'm not fluent in english), resulting in different output volumes when pared with different amps. For a true head to head compair, you should stay on the same output architecture.

3) 25 seconds are the maximum amount of time to compare accurately two sounds. Generally, this never occur on hifi portals where the peoples need mor time than that to swap their cables.

4) Crossover section of the cable should be comparable. Length too. This is putting more and more variables in this compairing. A shorter cable will be less resistant, resulting in higher volume at the end of the chain. For giving you a visual example :

0.5v are coming to your amp (purely hypothetical), this signal goes through the whole amp and is powered over a 100 times is initial force.

0.5v X 100 = 50

At the other side, 0.3v are coming to your amp (more losses in this example). The signal is amplified 100 times too :
03.v x 100 = 30

In the end, those are several dB's. The cable allowing more loudness will be clearer to identify to your ears ("more details, room information, blabla..."). The cable that is quieter will be, often, considered the worst one. In fact, you could achieve the same in turning your volume knob 1 or 2mm to the right.

I must precise that I'm speaking exclusively about RCA/XLR interconnect, and that my statement only is valid if both cable have sufficient cross section.

EDIT : Just for information, it's not expensive to make a symmetric output. You have those on 120 bucks studio gear.

 

[Al ears]

The result, definitely much better than the RCA connections. The RCA is software sounding so clearing loosing some detail. I should add that my RCA cable cost about a fiver and is about 3m long. Not a fair comparison I know but it does show that the cable makes a difference. Unfortunately I don't have a good set of RCA's to compare but if someone wants to send me one then I will give it a listen the post back.

Hello everybody. You probably read the OP. Unfortunately, some little errors where made during this review and I apologise to say that the conclusions where rushed and must be declared irrecevable.

1) Compairing was made impossible due to lack of volume check.

2) Some builders are not treating all of their analogues outputs the same. Even if the builder is reknowned. You can have poorly built RCA with very first class XLR out or the other way around. But not only that, even if both are from equal quality, both could have different power out intensity (sorry, I'm not fluent in english), resulting in different output volumes when pared with different amps. For a true head to head compair, you should stay on the same output architecture.

3) 25 seconds are the maximum amount of time to compare accurately two sounds. Generally, this never occur on hifi portals where the peoples need mor time than that to swap their cables.

4) Crossover section of the cable should be comparable. Length too. This is putting more and more variables in this compairing. A shorter cable will be less resistant, resulting in higher volume at the end of the chain. For giving you a visual example :

0.5v are coming to your amp (purely hypothetical), this signal goes through the whole amp and is powered over a 100 times is initial force.

0.5v X 100 = 50

At the other side, 0.3v are coming to your amp (more losses in this example). The signal is amplified 100 times too :03.v x 100 = 30

In the end, those are several dB's. The cable allowing more loudness will be clearer to identify to your ears ("more details, room information, blabla..."). The cable that is quieter will be, often, considered the worst one. In fact, you could achieve the same in turning your volume knob 1 or 2mm to the right.

I must precise that I'm speaking exclusively about RCA/XLR interconnect, and that my statement only is valid if both cable have sufficient cross section.

EDIT : Just for information, it's not expensive to make a symmetric output. You have those on 120 bucks studio gear.

You lost my interest after point one I'm afraid.

 

[Andrewjvt]

Is not a good idea in this industry, I was caught out many times in my youth...*new_russian*

I do not think people realise just how rare fully balanced amplifiers are, expensive too, the v2.0 being by far the cheapest I have see. Most that I have seen have been from serious us hi-end manufactures such as BAT, Rowland, Krell or Audio Research.

Early Primare were balanced designs, not sure about their modern product, and I thought at the time that they were the most affordable balanced designs on the market. Nearly 20 years ago now, but even then they were 2 or 3 times the price of even the v2.0up.

 

If it says balanced in the specs does that sometimes not mean true balanced as you already explained?

 

[Al ears]

Is not a good idea in this industry, I was caught out many times in my youth...*new_russian*

I do not think people realise just how rare fully balanced amplifiers are, expensive too, the v2.0 being by far the cheapest I have see. Most that I have seen have been from serious us hi-end manufactures such as BAT, Rowland, Krell or Audio Research.

Early Primare were balanced designs, not sure about their modern product, and I thought at the time that they were the most affordable balanced designs on the market. Nearly 20 years ago now, but even then they were 2 or 3 times the price of even the v2.0up.

If it says balanced in the specs does that sometimes not mean true balanced as you already explained?

I don't think fully balanced actually occurs in the specs. Maybe wrong. If it was I would be shouting about it.

 

[Blacksabbath25]

I just wish there was a way to find out if the abrahamsen stuff is fully balanced the only person I can ask is Colin as he has had the lid of a abrahamsen as this would mean that my cd playing is balanced too

 

[davedotco]

As I keep trying to explain, true differential amplifiers are pretty rare and I have never seen such a product at a comparable price to the v2.0.

Many amplifiers have balanced inputs, which are sensible for reasons outlined in an earlier post but this does not mean that the amplifier that follows is a true differential design (fully balanced). I consider this to be rather a big thing and the marketing guy that resides inside me is wondering why much, much more is not made of this.

 

[busb]

My Primare Pre32 is marketed as being "fully balanced" - it has balanced inputs, balanced outputs plus standard RCA inputs. The unbalanced inputs will be converted to balanced then back again at the unbalanced outputs. The balanced inputs will remain balanced.

My A34.2 power amp has fully balanced inputs. However, Primare's A60 power amp that costs considerably more is more fully balanced! Both are class D where mine has only one PWM output stage per channel, the A60 has two differential output PWM stages per channel so is fully balanced probably to the speaker terminals.

The term "fully balanced" needs to be interpreted with care with power amps! My A34.2 is only fully balanced up to the input stages then get converted to single-ended then Amplified. The exception being if it is used in bridge mode with one power amp per channel.

 

[Al ears]

My Primare Pre32 is marketed as being "fully balanced" - it has balanced inputs, balanced outputs plus standard RCA inputs. The unbalanced inputs will be converted to balanced then back again at the unbalanced outputs. The balanced inputs will remain balanced.

My A34.2 power amp has fully balanced inputs. However, Primare's A60 power amp that costs considerably more is more fully balanced! Both are class D where mine has only one PWM output stage per channel, the A60 has two differential output PWM stages per channel so is fully balanced probably to the speaker terminals.

The term "fully balanced" needs to be interpreted with care with power amps! My A34.2 is only fully balanced up to the input stages then get converted to single-ended then Amplified. The exception being if it is used in bridge mode with one power amp per channel.

Agreed. If the Abrahamsen integrated is similar to your A34.2 then I wouldn't consider it fully balanced as the A60 appears to be . The fact it applies to a power amp here is irrelevant. The amp is either fully balanced or it isn't.

 

[rmatthew]

nsa-watch-my-toilet thanks for reading my post but clearly you have missed the point.

1. It wasn't a scientific test, just an observation. As pointed out the RCA cables are very low budget however many on here argue that the cables make no difference.

2. There is no need to swap cables as the DAC has balanced and RCA outputs so just press the remote on the amp.

3. The amp remembers the volume set for each source so even though at the same number the balanced is louder I just turned up the RCA so the level were the same. Therefore I can simply flick between the sources using the remote and listen to both at the same volume.

 

[davedotco]

My Primare Pre32 is marketed as being "fully balanced" - it has balanced inputs, balanced outputs plus standard RCA inputs. The unbalanced inputs will be converted to balanced then back again at the unbalanced outputs. The balanced inputs will remain balanced.

My A34.2 power amp has fully balanced inputs. However, Primare's A60 power amp that costs considerably more is more fully balanced! Both are class D where mine has only one PWM output stage per channel, the A60 has two differential output PWM stages per channel so is fully balanced probably to the speaker terminals.

The term "fully balanced" needs to be interpreted with care with power amps! My A34.2 is only fully balanced up to the input stages then get converted to single-ended then Amplified. The exception being if it is used in bridge mode with one power amp per channel.

Agreed. If the Abrahamsen integrated is similar to your A34.2 then I wouldn't consider it fully balanced as the A60 appears to be . The fact it applies to a power amp here is irrelevant. The amp is either fully balanced or it isn't.

Normal topology for balanced power amplifiers is to maintain the differential circuit right up to the driver/output stage, not convert to single ended at the input. That said, I can see why conversion to single ended at the input of a power amp might be attractive cost wise.

Point of order. Although I have had experience with fully balanced designs, (ARC, Jeff Rowland, Primare) I have no evidence that shows this type of construction to be superior to conventional single ended designs. The only occasion I believe I could hear genuine benifits was using a balanced source with a fully balanced phono stage and pre-amp, however their were so many other variables in play that it was far from conclusive.

 

[busb]

Agreed. If the Abrahamsen integrated is similar to your A34.2 then I wouldn't consider it fully balanced as the A60 appears to be . The fact it applies to a power amp here is irrelevant. The amp is either fully balanced or it isn't.

Normal topology for balanced power amplifiers is to maintain the differential circuit right up to the driver/output stage, not convert to single ended at the input. That said, I can see why conversion to single ended at the input of a power amp might be attractive cost wise.

Point of order. Although I have had experience with fully balanced designs, (ARC, Jeff Rowland, Primare) I have no evidence that shows this type of construction to be superior to conventional single ended designs. The only occasion I believe I could hear genuine benifits was using a balanced source with a fully balanced phono stage and pre-amp, however their were so many other variables in play that it was far from conclusive.

I don't know if my A34.2 has any gain before sampling but is at a minium, buffered in balanced mode. I don't consider it to be fully balanced but I'm not going to loose any sleep 'cos it sounds fabulous to my ears. I would expect more preamps with balanced input to be "fully balanced" than power amps to be. I would not argue that balanced is better than single-ended in the context of home Hi Fi. It has better Common Mode rejection so long runs at line level will benefit. The greatest theoretical advantage at home is probably from pre to mono blocks next to speakers in large rooms with minimum length speaker cable.

I do use XLR cables where possible (0.5m) - because I can rather than for any real sonic reason. XLRs are also better engineered than the truely dreadful RCA design that connects the ground after the live - bad, bad, bad!