[SoundGame]

I recognize that this question has been raised before; however, the specifics on the answer don't seem to satisfy my curiosity and my information need given my pending purchase of a bp6.

I've heard that the latest iterations of the Bryston preamps i.e. Bp6, Bp26 and Bp16 are essentially the same in performance, other than differences in connectivity and features.  It appears that this has been represented by James Tanner himself in at least one or more posts on this site.  That said, in some reviews to be found on the intranet, there are suggestions that the BP26 as well as the Bp25 / Bp20 would outperform the Bp6 - given their separate power supply and resulting lower noise floor.

The internal construction of the Bp26, Bp25 and Bp20 (other than the separate power supplies) look to be very very similar from images I've seen of them on the intranet.  This similarity goes down to the layout, volume pot, apparent chip layout etc.  The Bp6 appears to be somewhat different though identical to the b60 except for the intergrated amplifier.

My review of the specs appears to show that the main difference on paper of them is in the THD/IMD numbers.  The Bp26, 25 and 20 all show 0.0015 and the bp6 shows a higher number of 0.005. 

My questions - for James or any other knowledgeable person on this subject is whether in fact, as supported by the number, the older Bp25 and Bp20 actually would perform better than the current Bp6?

James - have there been any other enhancements to the chips, materials, layout etc. that would give the bp6 and edge over the older bp25/bp20? 

Thanks!

[Phil A]

Welcome to the forum.  Here are a couple of old threads -



http://www.audiocircle.com/index.php?topic=69141.0


http://www.audiocircle.com/index.php?topic=64141.0



I used to have an SP 1.7 which I compared at length in the store to a BP-25 and could not hear a difference.  I also compared an SP2 (which is the equivalent) to a BP-26 and thought the BP26 sounded a bit more refined (at least to me).  Not a night and day difference but I thought a step up

[SoundGame]

Thanks Phil A.  I've been reading some of the write-ups comparing the preamps on this site but the couple you pulled out are much closer to home on my question.

The two outstanding points are:
1) the internal layout of the BP25, BP20 and the current BP26 appear to be very similar from pics.  I assume this is because the BP26 is an evolution and improvement - with the improvements coming from better parts (perhaps) and possibly some layout efficiencies i.e. elimination of some point-to-point wiring.  That said the BP6 internally does not look like any of the aformentioned but only like the B60.  The question is whether the BP6 is an evolutionary step in relation to the BP25 and BP20, as is the case for the BP26.  So in short is the BP6 better in performance than all Bryston previous preamps - assuming that all current Bryston preamps should be the same in performance.
2)the second question is abuot the specs.  The Bp20 and Bp25, appear to have lower THD&IMD figures than the BP6.  Is the BP6 still an improvement over the previous, regardless of this difference.? 

Thanks.

[headshrinker2]

Soundgame,
Thanks for posting this thread. I look forward to the answers...

[jaxwired]

Soundgame,

Great question.  As a BP6 owner, I've often wondered about this myself.  One other big difference is the BP6 only offers singled ended connections.  The BP26 offers balanced and single. 

My advice is, if money is tight, get the BP6.  You will never regret it.  The BP6 is jaw dropping good.  Simply outstanding transparency.  I think the BP6 is a true gem and if you are open to buying used the BP6 frequently sells for a ridiculously low price.  This is because most people want the BP26.   The BP6 does not get the respect it deserves.  As good as my 4bsst2 amp is, I credit the BP6 even more for the great sound I'm getting. 

[SoundGame]

Well, I have a 3B-ST currently but have not been feeding it with a Bryston preamp - though it was what I could afford at the time i.e. Kenwood Basic C2 preamp. 

I'm now in the process of buying a 4B-SST2 with the BP6 (new).  The BP6 meets all my needs from a connectivity/functional standpoint but I know I could have save a few bucks going with a used BP25 and even more with a BP20, hence my question as to whether the BP6 is evolutionary (in accordance with what I believe Bryston's objective is).  My logic is that if all preamps in Bryston's line are of the same quality except for functionality/connectivity AND if Bryston lives by constant improvement THEN the Bp6, Bp16 and Bp26 should be the best preamps that Bryston has ever produced on all counts of audio performance.  The differences between these three from a pure audio performance standpoint should be marginal, at best. 

I'd be very happy to hear from anyone that has done an A/B comparison and/or well knows the sound of the older models vs. the new ones.  A comment from James Tanner on this specifics would be GREATLY appreciated.

I appreciate the positive comments from all you AudioCircle patrons - I've heard much about the forum.

[vegasdave]

Soundgame,

Great question.  As a BP6 owner, I've often wondered about this myself.  One other big difference is the BP6 only offers singled ended connections.  The BP26 offers balanced and single. 

My advice is, if money is tight, get the BP6.  You will never regret it.  The BP6 is jaw dropping good.  Simply outstanding transparency.  I think the BP6 is a true gem and if you are open to buying used the BP6 frequently sells for a ridiculously low price.  This is because most people want the BP26.   The BP6 does not get the respect it deserves.  As good as my 4bsst2 amp is, I credit the BP6 even more for the great sound I'm getting. 

Another vote for the BP6...it's a great preamp! I do wish it did have balanced outputs, but oh well. The single ended outputs sound pretty damn good.

[James Tanner]

Hi Folks,

All our preamps have the same gain stage so there is no better/best when it comes to that.  The differences are in the features around the gain stages so Balanced ins and outs and pass-through or full remote control etc. depending on the model.

The BP6 is more like the B60 preamp section but not that different from the BP26.  The new preamps are different in small ways from the previous preamps but this is an evolutionary step not a revolutionary one. I would make my decision based on budget and feature set.

james

[SoundGame]

Thanks James for your response!

Given that my needs do not demand more than what the bp6 offers i.e. 4 inputs, unbalanced innput-output and option for remote; would it be to my advantage to choose the bp6 over a similarily priced used bp25 - considering primarily unbalnced performance with my 4bsst2?

This is the key queston I face.  It's only the quoted THD specs that are my small concern.

[James Tanner]

Thanks James for your response!

Given that my needs do not demand more than what the bp6 offers i.e. 4 inputs, unbalanced innput-output and option for remote; would it be to my advantage to choose the bp6 over a similarily priced used bp25 - considering primarily unbalnced performance with my 4bsst2?

This is the key queston I face.  It's only the quoted THD specs that are my small concern.

Hi SoundGame,

Yes given your requirements I would opt for the BP6. 

james

[SoundGame]

Thanks James - that gives me some additional backing on my decision.  Much appreciated.

I'll need to report back my impressions, once I receive the gear and get it up and running.  Cheers.

[James Tanner]

Thanks James - that gives me some additional backing on my decision.  Much appreciated.

I'll need to report back my impressions, once I receive the gear and get it up and running.  Cheers.

Yes please do

James

[jaylevine]

Hi Folks,

All our preamps have the same gain stage so there is no better/best when it comes to that.  The differences are in the features around the gain stages so Balanced ins and outs and pass-through or full remote control etc. depending on the model.

The BP6 is more like the B60 preamp section but not that different from the BP26.  The new preamps are different in small ways from the previous preamps but this is an evolutionary step not a revolutionary one. I would make my decision based on budget and feature set.

james

Hi James,

Do mind taking a moment to explain the difference between having balanaced input/outputs vs the pre-amp being balanced? I probably have the phrasing wrong but I seem to have seen someone the board point out there is a difference between the two on a BP26 (my pre-amp). BTW I run XLR connections between my DAC out, my pre-amp, and my 4B SST2 so am I running a "balanced system?.

Thanks....

Jay Levine

[James Tanner]

Hi James,

Do mind taking a moment to explain the difference between having balanaced input/outputs vs the pre-amp being balanced? I probably have the phrasing wrong but I seem to have seen someone the board point out there is a difference between the two on a BP26 (my pre-amp). BTW I run XLR connections between my DAC out, my pre-amp, and my 4B SST2 so am I running a "balanced system?.

Thanks....

Jay Levine

THE BALANCING ACT

The technology of balanced-line audio wiring is quite trendy today, and there is quite a bit of information (and misinformation) in the popular press about it. For the most part, the authors are treating it as a "discovery" of some kind, and postulating all kinds of fanciful reasons as to why it is the new, the one, the only way to go. Fortunately, balanced-line technology is one of those happy circumstances, like chicken soup, which "couldn’t hurt", and sometimes can help.

Since Bryston has been producing audio products which use balanced-line technology for over 20 years; we have a great deal of experience with this type of system, and have acquired an excellent understanding of the potential benefits and costs which result from it. In general, the benefits involve a reduction in system noise. Note that I did not say a reduction in component noise.

In fact, the electrical noise floor measured in each individual component, such as an amp or preamp, will at best remain the same, and may increase a bit due to the extra circuitry involved in balancing the signal, (producing a push-pull output, or accepting a push-pull, 3-wire input).

The system noise can be helped, however, if you include everything as installed, since on occasion a normal, 2-wire audio feed can pick up extra noise on the cable, due to the interference from power lines, RF , light dimmer buzz, or ground loops in the system. A balanced line will reject the extra induced noise by subtractive cancellation between the "plus" and "minus" sides of the signal lead, thus preventing an increase in system noise. This can be a benefit in some systems, especially when the amplifier is located at a substantial distance from the preamp. However, if the system is already well-behaved in this respect, as it should be with proper installation techniques, balanced lines will not change anything.

Other benefits have been claimed, such as an "increase in slew rate", and a "reduction in amplitude-related distortions".

For the most part, these claims are specious. The limiting slew rate in an overall system, in terms of capability, is invariably the amplifier, unless the preamp is of exceedingly poor design. The only slew-rate which can theoretically be increased by balanced-line technology is the preamps (due to the double-ended output additively doubling the base volts per microsecond). This obviously does nothing for the amplifier.

The postulated improvement in amplitude related distortions is equally unlikely. In a properly designed preamplifier, distortion is essentially invariant with amplitude, and it is more possible that the increased circuit complexity would have a small detrimental effect on the overall distortion, though in most cases this would be essentially negligible. The claims that balanced-line technology could have some mysterious beneficial effect on the already illusory magical cable properties which are expounded upon at length by their manufacturers are so fatuous as to not justify a reply. Suffice it to say that the laws of physics still apply, whether the line is balanced, unbalanced or tied around your grandmother's left leg.

Balanced-lines do not enjoy any magical properties. They do have some potential advantages for some systems which could justify the moderate extra cost and complexity involved in their implementation, the disadvantages are inherently rather minor, and can be considered innocuous enough to ignore where the system cannot be brought under control though standard practices in installation.

Indeed, Bryston provides all of our amplifiers, most preamplifiers and our electronic crossovers (optional) with balanced-line technology as standard, since in complex sound systems, the chance for noise and interference is much higher.

IN CONCLUSION: balanced-line technology;

Will;
Reduce any system noise caused by ground loops, RF, power lines etc.
Allow shorter speaker leads by permitting the amplifier to be placed adjacent to speakers without extra noise.

Will Not;
Increase the slew rate of an audio system.
Affect the given cable properties.
Improve distortion characteristics in an otherwise well designed audio product.
Improve on the individual audio component noise.

james

[James Tanner]

Hi James,

Do mind taking a moment to explain the difference between having balanaced input/outputs vs the pre-amp being balanced? I probably have the phrasing wrong but I seem to have seen someone the board point out there is a difference between the two on a BP26 (my pre-amp). BTW I run XLR connections between my DAC out, my pre-amp, and my 4B SST2 so am I running a "balanced system?.

Thanks....

Jay Levine

Is Your System Out Of Balance?

One question which keeps coming up over and over is the controversy regarding audio — components being "fully balanced" versus what is sometimes referred to as "balanced converting to single ended" at uhe input of the electronic component (preamp, electronic crossover, amplifier etc). The correct term for this balanced converting to single ended is more accurately referred to as "differential amplifer balancing"

Popular mythology has seen fit to 'bless' the concept of 'fully-balanced' (meaning of course, two completely separate signal paths through a component, with its attendant doubling of parts cost and complexity, and halving of reliability). This approach completely misses the place, which is, of course. to eliminate hum and noise picked up by the audio cables feeding the component.

The reason for this is that a differential amplifier rejects any common-mode noise which appears at its input, by a factor equal to its common-mode rejection ratio, (normally over 1000:1). A 'fully-balanced' circuit has a common-mode rejection ratio of pricisely zero, since all signal, common-mode or not, is simply amplified and passed along via the two signal paths. It then remains up to the following component to attempt to reject that amplified noise, if it has a differential amplifiee.

Thus, fully-balanced circuitry is subject to passing along any noise which might be picked up on all the cables. Then it hits the final component in the system, usually the power amp, where the differential amp]ifier at its input is left to deal with the sum total of the common mode noise in the signal path, (multiplied by all the gain in the system).

I don't think this is an ideal scenario. If each component, (source, preamp, electronic crossover, power amp), had its own differential amplifier input, it would cancel any common-mode noise which appeared ahead of it, rather than amplyfing it.

Bryston makes a product which operates in the fully-balanced mode a microphone preamp (BMP 2), but this unit has an input transformer which rejects common-mode noise hy a factor of over 250,000:1. The reason it operates on two separate signal paths is to expand its dynamic range beyond what digital storage media can accommodate. Since the next step in the signal path is into digital storage media (CD, DVD etc.) from there, this separale signal path is obviously not a concern in any following signal-processing on its way to your living room, and your ears.

All the above simply points out that what has been called fully balanced circuitry has a host of disadvantages from cost to noise overload. to complexity and reduction in reliability. It has no useful advantages in the digital or analog signal chain beyond the mic preamp. Bryston audio components with the exception of our BMP-2 mic preamp, all operate their balanced inputs on differential amplifier technology.

james

[SoundGame]

Informative posts James.  Good to know. 

[werd]

I prefer S/E over bal. into my 14B. In a regular house hold setup (like mine) the best thing you can do is  treat your AC with a Bryston bit or Torus. Maintaining bal. right through seems moot when compared to an untreated AC line in. Unless your gear is considerably far apart and host a ton of inputs like a mixing board then xlr isn't going to be a huge difference with untreated AC.

[Elizabeth]

I have generally thought the 'big deal' over balanced was overblown.
I have used the balanced from my BP-26 to the 4B-SST2 because the cable is 7 meters long. So i can keep most of my stuff at my listening chair, and the amp between the speakers.

I did not know about the common mode rejection issue. Good to know.

[JBLMVBC]

Thanks James for a very informative series of post.

[rmurray]

Whatever the technology dictates I have gotten a  greater soundstage  and dynamics when I connected my CD-1 to my BP25 using the balanced method. The SE is still connected so I did many A-B comparisons and the balanced comes out better in my case at least. I still have the amps connected as SE however . : :