Please Naim make a Class A amplifier

I own JBL S4700 horns, I currently have them bi-amped with a 200 and 250dr, this is so I have enough power dynamically on both sides. The speakers are efficient at 94db and 6ohms nominal and 4.5 at 80hz. I use a CD5XS into a Chord HugoTT  and then the 282 x (2) hicapsDR. I am lucky to have an engineer buddy who helps me now. I got so caught up in room acoustics I met with some fellas who also have an interest so I have picked up some great stuff from starting with nothing. I have been to Japan and seen some great horn stuff, which surprisingly had a fanatical JBL element whom used tubes or solid state. A couple I knew had tubes on top and solid underneath and the sound/power aspect was cool. The other fella used solid state (bi-amped) top and bottom, both of which were Class A. A/B. I asked a simple question, period.

Simon-in-Suffolk posted:

Huge posted:

A class A amplifier working at reduced current in the output structure is class A/B!

Huge, I didn’t  think this right, and I went to check my aging electronics engineering university undergraduate notes and this isn’t the case at least as far as my university faculty was concerned.. in class B the amplifier splits the amplification and the transistor transfer function into positive and negative portions, the class A part of class AB is about biasing each side into the edge of the linear part of the function so as to increase the linearity of the combined amplification transfer function. Class B amps are rare in audio because of the distortion caused, but are more common say in FM RF amplifiers where distortion of the carrier is irrelevant as long as it’s low pass filtered.

Class A is about having the whole cycle amplified by a single transistor transfer function, and so the bias point is set in the middle of the linear part of the transfer function... hence at zero amplification the transistor is working nominally at 50% of its full gain hence the heat..

Simon, we're saying the same thing here.  Reduce the quiescent current below that needed for class A (but maintain the output power) and the amp is, de facto, operating in class A/B!

(Yes I know there are other design changes to allow this to occur properly without clipping, but as far as the output structure is concerned that's what it 'sees' as the change.)

AussieSteve posted:

Wow, enough from Naim disciples. Since no one in this forum seem aware of the brands of far superior quality which run solid state Class A, let alone understand the real benefits of it's sound. Since I mentioned this issue, it as usual has warmed up the attitudes of you usual smart alecs.  I have been all too honest and forgiving in the past, no more. This forum is run by a team of ëxpert" owners whom have opinions on every topic, as though they are the gatekeepers of all thinks electronic and naim. If Naim think Class A is all heat sinks, I refer their engineers to Boulder Audio USA, let alone all the other top shelf brands which CAN do it, all without huge heatsinks and NO transformer hum. Use your own ears, have a listen to horn speakers NOT through tubes but solid state, it has the creamy silkiness of tubes without the power limitations, bi-amped as was my post's first intention, it would be great.  Member "Simon of Suffolk" is a decent man with the nouse to always listen and play with an idea, not shut it down like a little weed. Listen hard ALL, I bought Naim, I own Naim, do I regret it? a little however the sound is fine for mid hifi. Therefore I have no issue with putting my thoughts down, I accept other views but no more smart alec comments.

Moderated Post: Aussiesteve, I have edited your post, removed what is not strictly relevant, and the unhelpful and substituted for the unacceptable language. Please keep your posts civil, to the point and not make observations on members. I don't see any particularly rude or "smart alec" posts leading up to this one that would in any way warrant such a response. The key here is respect - for the forum, the members, your hosts - as someone mentioned on here it's a "two way street". As an aside, Naim don't think anything on this thread, as they have not commented, and likely won't - they do what they do and use Class A where they feel it is best used.  If you want their view then you will need to ask Roy George. In the meantime, if you've found something different that you prefer then go for it.  There's no law to say you must stick with a certain brand and plenty of makers out there of very fine hifi equipment.

I didn't find this offensive (despite probably being included in the smart Alec category for my post about water cooling).  The odd thing here was that was actually serious!  To get enough cooling for 110W per channel of heat dissipation and reliability in a case the size and shape of Naim's standard 'classic' case, the best method would be to use water cooling.  This was a perfectly good engineering solution to the particular problem problem posed:  That of high power dissipation in a confined space.

The heatsinks on even the lowest powered Boulder Audio power amp won't fit into a classic Naim case and so don't qualify as a solution to the actual problem posed in the original post.

And to the OP, just for reference I have designed amps using Class A and Class A/B, and have adjusted the quiescent current of the class A/B amps and observed the effect on the sound - yes I do understand the sonic characteristics and how they can be varied.  I've also experimented with different capacitor types in different locations in an amplifier and, quite honestly, this often has a greater effect on the overall sound characteristic than simply the difference between class A and class A/B operation (at least when using a higher level of A/B quiescent current in a fundamentally good amp design, suitably built).  Most commercial class A amplifier are voiced like this to give the 'characteristic class A sound' as that is what the consumer expects form a Class A design.

I'm very sure the Naim engineers have done the same.

(Before you ask, no you can't get all the way to all the properties of the 'characteristic class A sound' using a conventional class A/B design (which is why commercial companies don't do it), but you can get fairly close - the overlap in sound characteristics is greater than the fundamental difference that's due solely to the operating mode.)

Huge posted:

AussieSteve posted:

Wow, enough from Naim disciples. Since no one in this forum seem aware of the brands of far superior quality which run solid state Class A, let alone understand the real benefits of it's sound. Since I mentioned this issue, it as usual has warmed up the attitudes of you usual smart alecs.  I have been all too honest and forgiving in the past, no more. This forum is run by a team of ëxpert" owners whom have opinions on every topic, as though they are the gatekeepers of all thinks electronic and naim. If Naim think Class A is all heat sinks, I refer their engineers to Boulder Audio USA, let alone all the other top shelf brands which CAN do it, all without huge heatsinks and NO transformer hum. Use your own ears, have a listen to horn speakers NOT through tubes but solid state, it has the creamy silkiness of tubes without the power limitations, bi-amped as was my post's first intention, it would be great.  Member "Simon of Suffolk" is a decent man with the nouse to always listen and play with an idea, not shut it down like a little weed. Listen hard ALL, I bought Naim, I own Naim, do I regret it? a little however the sound is fine for mid hifi. Therefore I have no issue with putting my thoughts down, I accept other views but no more smart alec comments.

Moderated Post: Aussiesteve, I have edited your post, removed what is not strictly relevant, and the unhelpful and substituted for the unacceptable language. Please keep your posts civil, to the point and not make observations on members. I don't see any particularly rude or "smart alec" posts leading up to this one that would in any way warrant such a response. The key here is respect - for the forum, the members, your hosts - as someone mentioned on here it's a "two way street". As an aside, Naim don't think anything on this thread, as they have not commented, and likely won't - they do what they do and use Class A where they feel it is best used.  If you want their view then you will need to ask Roy George. In the meantime, if you've found something different that you prefer then go for it.  There's no law to say you must stick with a certain brand and plenty of makers out there of very fine hifi equipment.

I didn't find this offensive.....

Possibly you didn't see the utterly charmless un-moderated version

Simon-in-Suffolk posted:

I wish we wouldn’t over use the word ‘offensive’.. it’s lazy... yes a post can be distepectful, conceited, bigoted, churlish, inflammatory etc... but offensive on such a benign subject? I don’t think so.. my little request is we don’t dilute our language... people seem far to willing to take offence, and that is an issue, in my opinion, more with the person being offended and their lack of tolerance and sense of perspective rather than the person giving the perceived offence...which more often than not is simply a case of a lack of manners and can simply be ignored.

I think it’s fair to call something ‘offensive’ if it seems to be intended to offend, which i believe it was. 

I took the original as a rant, a blowing off of steam.  Yes, intended to jolt people out of a perceived complacency, but not intended to give true offence long term.  Maybe I'm wrong.

Inappropriate enough that it should be moderated out of respect for others though.

AussieSteve posted:

I own JBL S4700 horns, I currently have them bi-amped with a 200 and 250dr, this is so I have enough power dynamically on both sides. The speakers are efficient at 94db and 6ohms nominal and 4.5 at 80hz. I use a CD5XS into a Chord HugoTT  and then the 282 x (2) hicapsDR. I am lucky to have an engineer buddy who helps me now. I got so caught up in room acoustics I met with some fellas who also have an interest so I have picked up some great stuff from starting with nothing. I have been to Japan and seen some great horn stuff, which surprisingly had a fanatical JBL element whom used tubes or solid state. A couple I knew had tubes on top and solid underneath and the sound/power aspect was cool. The other fella used solid state (bi-amped) top and bottom, both of which were Class A. A/B. I asked a simple question, period.

Naim never really recommend bi-amping.... if you're open to maximising performance of what you already got, you really should run a single NAP 250 into the JBL with NACA5 or Superlumina speaker cable.

also, the CD5XS should be permanently  connected via din to the 282 preamp to ensure there is a signal earth connection, which the Hugo TT doesn't provide.

Not sure how you connected the Hugo TT to your 282, again, some ppl use Hugo with a Hi-line RCA to DIN for this.

Good luck. would be a shame to not hear your kit at it's optimal best before jumping ship to another manufacturer.

the abrasive tone of the post makes the forum a lot less interesting place. 

I'm glad the moderator changed the post.

Bob the Builder posted:

Simon-in-Suffolk posted:

I wish we wouldn’t over use the word ‘offensive’.. it’s lazy... yes a post can be distepectful, conceited, bigoted, churlish, inflammatory etc... but offensive on such a benign subject? I don’t think so.. my little request is we don’t dilute our language... people seem far to willing to take offence, and that is an issue, in my opinion, more with the person being offended and their lack of tolerance and sense of perspective rather than the person giving the perceived offence...which more often than not is simply a case of a lack of manners and can simply be ignored.

I agree Simon that people are all to ready to take 'offence' IMO more often than not it is those that find no issue being offensive that are too ready to take offence.  There are those in every walk of life today that hide behind 'homespun', 'straight talking' who are in fact just lacking in manners and also there are those that hide behind humour to be rude,

'I was only joking' is a firm favourite,  I was always taught that if you can't take it then don't give it.  Nobody wants watered down opinion and everybody is entitled to their own opinion this however does not excuse being rude.

 

Wow!  How come a thread on amplifier classes turns into a discussion on offensiveness and rudeness?  Actually, the rudest and most offensive paragraph I have read in HiFi corner for some time is: 

analogmusic posted:

AussieSteve posted:

I own JBL S4700 horns, I currently have them bi-amped with a 200 and 250dr, this is so I have enough power dynamically on both sides. The speakers are efficient at 94db and 6ohms nominal and 4.5 at 80hz. I use a CD5XS into a Chord HugoTT  and then the 282 x (2) hicapsDR. I am lucky to have an engineer buddy who helps me now. I got so caught up in room acoustics I met with some fellas who also have an interest so I have picked up some great stuff from starting with nothing. I have been to Japan and seen some great horn stuff, which surprisingly had a fanatical JBL element whom used tubes or solid state. A couple I knew had tubes on top and solid underneath and the sound/power aspect was cool. The other fella used solid state (bi-amped) top and bottom, both of which were Class A. A/B. I asked a simple question, period.

Naim never really recommend bi-amping.... if you're open to maximising performance of what you already got, you really should run a single NAP 250 into the JBL with NACA5 or Superlumina speaker cable.

also, the CD5XS should be permanently  connected via din to the 282 preamp to ensure there is a signal earth connection, which the Hugo TT doesn't provide.

Not sure how you connected the Hugo TT to your 282, again, some ppl use Hugo with a Hi-line RCA to DIN for this.

Good luck. would be a shame to not hear your kit at it's optimal best before jumping ship to another manufacturer.

However..... Naim make Snaxo. And biamping inevitably is better than single with crossover.

BUT - I am thinking only in terms of active biamping, not passive, in respect of which I confess to not really seeing the justification of cost over simply using a better power amp, and I don't know which Aussiesteve is using.

Well Steve, now you've given us enough detail to make some sense of your original post, you've got me thinking:  So if you'll entertain some serious suggestions (aka sh*t) from a middle class Naim disciple...

1   CD Transport (Digital Source)
I think there is a good case for something more capable than the CD5XS here; and it doesn't have to come from Naim.  This component has comparatively little contribution to the characteristic Naim sound.

2   DAC
Whilst the Hugo TT is exceptional in many ways, it doesn't always deliver all the excitement in the music, although it does provide a smooth sound and remarkable intellectual insight into the music.  A better option here may be a Naim DAC energised by a 555PS.

3   Preamp
282 + HiCap.  Yes.  This with the DAC are responsible for a lot of the excitement and involvement that are characteristic of the Naim sound.

4   Power Amp(s)
I don't think passive bi-amping is the best approach here, particularly not asymmetric passive bi-amping.  This can result in a loos of smooth integration resulting from the difference in the micro-dynamics of the amps below and above the crossover point.
A single NAP300DR will give you a smoother and more detailed sound that your current pairing.
On the other hand a larger format Class A amp may also be a good choice, but with caveats...
The speakers you have, whilst of relatively high efficiency aren't that high an efficiency, and the 4.5Ω load at 80Hz is a problem for most lower powered Class A amplifiers (for instance neither of the Sugdens are really suitable as they'll lack dynamic 'punch').  To get the sound you seek it may be worth considering one of the higher powered class A power amps (look in the $10k up price bracket) used in combination with the Naim DAC and the 282.  To deal with the 4.5Ω load at 80Hz and depending on the listening volume you require you may need to consider class A amps at 80W+ per channel or one rated for 2Ω resistive loads.  Do note that you won't get this in a small case like the Naim Classic series the cases, it will almost certainly be at least 125mm (and preferably 150mm) tall to acomodate the heat sinks.

5   Speakers
For reasons stated before keep to single wiring, or go to a fully active system (i.e. using an active crossover) with symmetrical HF/LF amps.

Huge posted:

Well Steve, now you've given us enough detail to make some sense of your original post, you've got me thinking:  So if you'll entertain some serious suggestions (aka sh*t) from a middle class Naim disciple...

2   DAC
Whilst the Hugo TT is exceptional in many ways, it doesn't always deliver all the excrement in the music, although it does provide a smooth sound and remarkable intellectual insight into the music.  A better option here may be a Naim DAC energised by a 555PS.

 

"Delivering all the excrement in the music" - a novel desire! Of course, to any individual, some music others like might be considered excrement, as there is no accounting for taste! 

I suspect a typo?

Innocent Bystander posted:

Huge posted:

Well Steve, now you've given us enough detail to make some sense of your original post, you've got me thinking:  So if you'll entertain some serious suggestions (aka sh*t) from a middle class Naim disciple...

2   DAC
Whilst the Hugo TT is exceptional in many ways, it doesn't always deliver all the excrement in the music, although it does provide a smooth sound and remarkable intellectual insight into the music.  A better option here may be a Naim DAC energised by a 555PS.

 

"Delivering all the excrement in the music" - a novel desire! Of course, to any individual, some music others like might be considered excrement, as there is no accounting for taste! 

I suspect a typo?

**?%$** auto-correct! (aka auto-mess-up!).
(And being dyslexic doesn't help as I often can't recognise what I've written anyway)

Thanks for pointing it out - I just got there in time to edit the reply

Richard Dane posted:

It's worth remembering that with true Class A power amps there's a large amount of waste heat.  This isn't just inefficient, it can have an impact on reliability and longevity of the components. I learned that the hard way some years ago with a well known UK class A amp that got really hot then broke down - too often for comfort.  The biggest problem was that every time it came back from the manufacturer it sounded totally different to before (not in a good way).  I got rid of it pretty quickly.

Another A1 owner! But it really sounded great-until it didn't sound at all. If you want a class A Naim amp...buy any of their preamps-they are all class A. 

Close Ron, but rather bigger and glossier...

When you live at 1000' above sea level on a N facing hillside in Wales, there is no such thing as wasted heat! I might search out the most wasteful class A amp I can find, and go with Huge's water cooling idea, then I could hook it up to my central heating system 

Richard Dane posted:

Close Ron, but rather bigger and glossier...

The SA470 home heating system (and ad big as the average boiler)?

But I don't recall it being glossy.

Huge posted:

Well Steve, now you've given us enough detail to make some sense of your original post, you've got me thinking:  So if you'll entertain some serious suggestions (aka sh*t) from a middle class Naim disciple...

1   CD Transport (Digital Source)
I think there is a good case for something more capable than the CD5XS here; and it doesn't have to come from Naim.  This component has comparatively little contribution to the characteristic Naim sound.

Used as a transport into Hugo TT I think the Phillips mechanism capable enough.

2   DAC
Whilst the Hugo TT is exceptional in many ways, it doesn't always deliver all the excitement in the music, although it does provide a smooth sound and remarkable intellectual insight into the music.  A better option here may be a Naim DAC energised by a 555PS.

Comparing a 2k dac with a 2K dac plus a psu worth 3x that isn't fair Ndac bare v Hugo TT no comparison at all Hugo all day everyday.

3   Preamp
282 + HiCap.  Yes.  This with the DAC are responsible for a lot of the excitement and involvement that are characteristic of the Naim sound.

Yes agree

4   Power Amp(s)
I don't think passive bi-amping is the best approach here, particularly not asymmetric passive bi-amping.  This can result in a loos of smooth integration resulting from the difference in the micro-dynamics of the amps below and above the crossover point.
A single NAP300DR will give you a smoother and more detailed sound that your current pairing.

Yes agreed.

5   Speakers
For reasons stated before keep to single wiring, or go to a fully active system (i.e. using an active crossover) with symmetrical HF/LF amps.

Yes Agreed

Peakman posted:

Bob the Builder posted:

Simon-in-Suffolk posted:

I wish we wouldn’t over use the word ‘offensive’.. it’s lazy... yes a post can be distepectful, conceited, bigoted, churlish, inflammatory etc... but offensive on such a benign subject? I don’t think so.. my little request is we don’t dilute our language... people seem far to willing to take offence, and that is an issue, in my opinion, more with the person being offended and their lack of tolerance and sense of perspective rather than the person giving the perceived offence...which more often than not is simply a case of a lack of manners and can simply be ignored.

I agree Simon that people are all to ready to take 'offence' IMO more often than not it is those that find no issue being offensive that are too ready to take offence.  There are those in every walk of life today that hide behind 'homespun', 'straight talking' who are in fact just lacking in manners and also there are those that hide behind humour to be rude,

'I was only joking' is a firm favourite,  I was always taught that if you can't take it then don't give it.  Nobody wants watered down opinion and everybody is entitled to their own opinion this however does not excuse being rude.

 

Wow!  How come a thread on amplifier classes turns into a discussion on offensiveness and rudeness?  Actually, the rudest and most offensive paragraph I have read in HiFi corner for some time is: 

"Some of you seriously need to get over yourselves just because you have a few quid, have a mid level IQ, drink certain wine, eat certain food, go to certain places, listen to certain music and OWN A CERTAIN BRAND OF HIFI doesn't make you better a better person it just means your a bit MIDDLE class and a bit of a wannabe!"

I wonder who posted that.  And "if you have nothing positive to say ... then don't say anything." is a bit rich coming from a poster who rarely misses an opportunity to make sarcastic and non-constructive comments about a 272/250 whenever that combination comes up in a thread.

 

FWIW, for many years I ran class A power amps, specifically a pair of Musical Fidelity MA65 monoblocks.  Initially, I used the matching pre-amp and then, when I felt that did not match up to the power amps, fed them directly from a Meridian DAC.  The sound was certainly silky smooth with excellent imaging but eventually I realised I was hardly ever listening to it.  That started a journey that led to my current 272-based system.  I now listen far more often and find a much greater emotional connection with the music than with any previous system.  So, personally, I hope Naim concentrate their resources on doing what they do so well.  If I wanted to go Class A again, I would look for another brand.

 

Roger aka MIDDLE CLASS wannabe

Roger your entitled to your opinion as much as the next man and nothing wrong with being a MIDDLE class wannabe be proud of who are Roger.

Bob the Builder posted:

Huge posted:

Well Steve, now you've given us enough detail to make some sense of your original post, you've got me thinking:  So if you'll entertain some serious suggestions (aka sh*t) from a middle class Naim disciple...

1   CD Transport (Digital Source)
I think there is a good case for something more capable than the CD5XS here; and it doesn't have to come from Naim.  This component has comparatively little contribution to the characteristic Naim sound.

Used as a transport into Hugo TT I think the Phillips mechanism capable enough.

2   DAC
Whilst the Hugo TT is exceptional in many ways, it doesn't always deliver all the excitement in the music, although it does provide a smooth sound and remarkable intellectual insight into the music.  A better option here may be a Naim DAC energised by a 555PS.

Comparing a 2k dac with a 2K dac plus a psu worth 3x that isn't fair Ndac bare v Hugo TT no comparison at all Hugo all day everyday.

3   Preamp
282 + HiCap.  Yes.  This with the DAC are responsible for a lot of the excitement and involvement that are characteristic of the Naim sound.

Yes agree

4   Power Amp(s)
I don't think passive bi-amping is the best approach here, particularly not asymmetric passive bi-amping.  This can result in a loos of smooth integration resulting from the difference in the micro-dynamics of the amps below and above the crossover point.
A single NAP300DR will give you a smoother and more detailed sound that your current pairing.

Yes agreed.

5   Speakers
For reasons stated before keep to single wiring, or go to a fully active system (i.e. using an active crossover) with symmetrical HF/LF amps.

No comment don't know Steve's speakers.

 

1  A CD transport is a lot more than just the CD mechanism, the error correction, control, clocking (inc. jitter), interference suppression and quality of the S/Pdif output can all play a part.

2  This isn't a price comparative assessment, (otherwise he wouldn't be considering class A power amps that are 1.5 to 5 times more costly at the same overall quality point).  This is about getting the right combination of sonic characteristics and the NDAC/555 will help a lot particularly when used with a Class A power amp.

5  The actual speakers are only occasionally particularly relevant in the comparison between single wiring, bi-wiring, passive bi-amping and a bi-amped active system.
Bi-wiring sometimes makes a slight improvement (although rarely worth the extra cost of the speaker cable and not worth it with Naim amps).
Passive bi-amping sometimes makes a moderate improvement (although very rarely worth the extra cost of the additional amps and not worth it with Naim amps).
Active crossover bi-amping can make a significant improvement if implemented well (and can be worth it with a SNAXO and Naim amps).

Ron Toolsie posted:

Richard Dane posted:

It's worth remembering that with true Class A power amps there's a large amount of waste heat.  This isn't just inefficient, it can have an impact on reliability and longevity of the components. I learned that the hard way some years ago with a well known UK class A amp that got really hot then broke down - too often for comfort.  The biggest problem was that every time it came back from the manufacturer it sounded totally different to before (not in a good way).  I got rid of it pretty quickly.

Another A1 owner! But it really sounded great-until it didn't sound at all. If you want a class A Naim amp...buy any of their preamps-they are all class A. 

About 25 years ago I had a Roksan Xerxes and borrowed a Musical Fidelity A100  from a dealer mate I shared my place with.The system was in a small bedroom with some small Mourdant Short speaker's.

Gourgous sound -in that room.Imaging and a very smooth HIgh frequency - I loved what it did in that system.Unfortunatly the Xerxes power supply over heated again and failed (I was on number 3)  and the A100 shutdown with a horrible electrical smell the following month.Got rid of the Xerxes and  the A100 was on loan so no big deal.Really loved that amp in that system but to much heat generated.

Richard Dane posted:

It's worth remembering that with true Class A power amps there's a large amount of waste heat.  This isn't just inefficient, it can have an impact on reliability and longevity of the components. I learned that the hard way some years ago with a well known UK class A amp that got really hot then broke down - too often for comfort.  The biggest problem was that every time it came back from the manufacturer it sounded totally different to before (not in a good way).  I got rid of it pretty quickly.

I had a Musical Fidelity A100 in the early 90's, choosing it over a Nait 2 because it had more warmth on CD replay. I too used it with a Roksan Xerxes and it sounded great, my first taste of "high end".

However I later regretted my choice, not merely because the Nait 2 is now regarded as a classic and worth more now than I would have paid for it, but mainly because the A100 died on me twice. Once when I was listening and a visitor arrived unexpectedly: we got chatting, I forgot it was on and 2hrs later I came back to a dead amp. The second time I was just listening on a hot day: hot day + hot amp = return to factory.

Regards,

Steve O.

Early 90s I worked in a shop that sold MF. We shifted a lot of A1s and A100s. Some came back for warranty work. We loved them though. I remember a Pink Triangle something or other, A1 and some ProAcs (Supertowers?) sounding superb.