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Speakers for a Class A TRANSISTOR amplifier

SeshatCZ

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Hi, I have a question as for building a new hifi system, the second one, mainly for relaxed quiet listening in a normal room circa 4x6 meters, a position from speakers circa 2 meters.
I have bought a vintage combo of Sony TA-E86B preamp + TA-N86 amp recently. I use the preamp combined with a vintage Sony TA-3200F + modern Elac speakers in my main hifi system right now. I plan to use the new Sony amp separately. Now to my problem.

What speakers should I use for the new Sony TA-N86 amp, which has a switchable Class A and Class B section. It is not an hybrid one Class A/B. It has a separate switch in a power supply for each Class. It is not a tube amp, purely Transistors, without any ICs. A wattage for Class A is 2× 15W. Class B has circa 75W. Class A should be a preferred way of usage. Now, what speakers as for wattage, sensitivity, and so on? I think about Beovox S 45-2 3-way vintage speakers, but it has 45 W. Is it useable/not too much wattage difference?? And they will not be too efficient as modern speakers ...

I have an information from previous owner, that it works great in Class A with Magneplanar Mg III speakers, but I do not know them.

Sorry for a long question of a Newbie, but I have not found any objective answers on my problem in net.

Thanks in advance for any advice.
Pavel
 

Willem

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It is a very nice class A or class AB design: https://zstereo.co.uk/2020/12/08/sony-ta-e86-ta-n86/ I would use the class AB setting and enjoy whatever nice speakers you can afford. Personally I would avoid older speakers because, first, speakers do deteriorate with age (some more than others) and, second, speaker technology has advanced more than any other component apart from the advent of CD to replace vinyl.
 

DSJR

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I always say you can never have too much power, so my head suggests to use it in 'AB' setting.

BUT - and here's where the psychological brainwashing part comes in....

I was all but ridiculed for saying this here a while ago, but back in the mid 70's, Yamaha did two popular integrateds - CA800 and CA1000 with an optional Class A switch on them. Doing a quick switch either way there was no difference, but I was convinced that after ten seconds or so for the bias changes to stabilise (?), I thought or imagined the reproduction of atmosphere and 'air' in a good recording was better in the Class A setting. Again, going back to 'AB' took a few seconds and the sound 'appeared' to 'dry up' a bit... Not sure anyone ever did an objective assessment of the distortion differences (if you can hear it, you can measure it i feel), but there ya go. Hearing a well cared for CA800 a few years back in Class A mode - again, lower volumes so not taxing - it was delightful...

So, in the OP's case, try an evening one way and an evening the other and just go with the flow as it's your sound setup an dnot for objective analysis at the end of the day. Low levels shouldn't tax the amp in it's lower powered Class A setting but if it runs hot in the location you place it in, I'd switch back to 'AB' and leave it there!!! My regular pro amp (MOS-FET output) runs quite hot on the heatsinks after two hours or so even idling and I monitor the temperature as I don't want to totally kill it in its retirement from its original editing suite 24/7 duties (I've checked the offsets inside and it's fine)
 
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SeshatCZ

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It is a very nice class A or class AB design: https://zstereo.co.uk/2020/12/08/sony-ta-e86-ta-n86/ I would use the class AB setting and enjoy whatever nice speakers you can afford. Personally I would avoid older speakers because, first, speakers do deteriorate with age (some more than others) and, second, speaker technology has advanced more than any other component apart from the advent of CD to replace vinyl.

However, I am not able to comprehend exactly, if the selection of speakers will constraint an optimal usage of the amp for only one Class. This particular amp should be better in Class A, in which it is unique. Therefore I have inclined to go in an unknown way with lower specs speakers...

Thanks for an advice as for the old speakers, I have similar opinion, but wanted to go this way due to some idea of compatibility ( vintage with vintage, as it was developed). It is a bad idea apparently.
 

ZolaIII

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Depending of how convenient switching is or how delicate stages are done (that the stage A is used more as OPAMP) you might want or not to use it as A class.
Regarding speakers try to stay in 50W RMS @8 Ohm's, 90 or more LPS/W declared range.
 
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SeshatCZ

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N
I always say you can never have too much power, so my head suggests to use it in 'AB' setting.

BUT - and here's where the psychological brainwashing part comes in....

I was all but ridiculed for saying this here a while ago, but back in the mid 70's, Yamaha did two popular integrateds - CA800 and CA1000 with an optional Class A switch on them. Doing a quick switch either way there was no difference, but I was convinced that after ten seconds or so for the bias changes to stabilise (?), I thought or imagined the reproduction of atmosphere and 'air' in a good recording was better in the Class A setting. Again, going back to 'AB' took a few seconds and the sound 'appeared' to 'dry up' a bit... Not sure anyone ever did an objective assessment of the distortion differences (if you can hear it, you can measure it i feel), but there ya go. Hearing a well cared for CA800 a few years back in Class A mode - again, lower volumes so not taxing - it was delightful...

So, in the OP's case, try an evening one way and an evening the other and just go with the flow as it's your sound setup an dnot for objective analysis at the end of the day. Low levels shouldn't tax the amp in it's lower powered Class A setting but if it runs hot in the location you place it in, I'd switch back to 'AB' and leave it there!!! My regular pro amp (MOS-FET output) runs quite hot on the heatsinks after two hours or so even idling and I monitor the temperature as I don't want to totally kill it in its retirement from its original editing suite 24/7 duties (I've checked the offsets inside and it's fine)
Well, it is all material, which my brain went through in similar ways already.

The temperature will be enormous according to reports I have read (I have not used it till yet, because of 100 V PS, and I am waiting for an converter). So, it would be only to listen in Class A maximally 1-2 hours of relaxation from time to time. I am a very quiet type of listener, mainly old tuners of higher qualities on FM, from time to time some audiocassettes or CDs with old music, which is nicely reproduced by vintage technics. So, it will let my amp also in Class A to be alive for a while hopefully .

But should I go with speakers with more wattage, and could I then hope for a subjectively other listening experience in class A? And not even worse than in AB?

I have a pair of unused modern smaller bookshelf speakers with circa 40 Watts , so I will try to use an amp with them to do some Class A/AB testing you suggested. It is all about fun in the end.

But it will be subjective, and the speakers with not so excellent specs will be a bottleneck. So it is to large extent meaningless. However, I seek some objective information as for eventually optimal combo of speakers + Class A, in terms of concrete parameters of the speakers, i.e. their maximum power, sensitivity or some other measurable parameters. Do exist some old materials from 70's or 80's as for this problem, some objective results from measurements? Or was it only a pure empiricism in those times, to use blindly speakers, which were available?

Thank You for Your time to think about my unusual questions.
 
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SeshatCZ

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Depending of how convenient switching is or how delicate stages are done (that the stage A is used more as OPAMP) you might want or not to use it as A class.
Regarding speakers try to stay in 50W RMS @8 Ohm's, 90 or more LPS/W declared range.
Thanks a lot, it is a type of information I am after. Is it Your own experience with something similar? It appears to be somewhere between the wattage specs of the 2 in 1 amp, so it seems to me rational way.
 

ZolaIII

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Thanks a lot, it is a type of information I am after. Is it Your own experience with something similar? It appears to be somewhere between the wattage specs of the 2 in 1 amp, so it seems to me rational way.
I have newer dirty cheap AB class Yamaha (with separate input analog stage) but there is not much to it. You need sensitive speakers that won't deep to much regarding impedance (disregarding of the amp class even) that have reasonably big bass and or midrange driver's (at least one 7.5") and are rated 50~70% of given amp output RMS.
 

Mart68

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These are very nice indeed. Nevertheless, it is a vintage, and that we have already excluded some post up. I will study them, and maybe some repassed pair of them could be a solution.
wasn't really a serious suggestion but they probably are quite good even by modern standards.

What you need are high sensitivity (89db or more) speakers that do not present a reactive or low impedance load, have an anechoically flat frequency response with good on and off axis dispersion, and which are affordable and available to buy.

Should help you narrow it down a bit ;)
 

Mnyb

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wasn't really a serious suggestion but they probably are quite good even by modern standards.

What you need are high sensitivity (89db or more) speakers that do not present a reactive or low impedance load, have an anechoically flat frequency response with good on and off axis dispersion, and which are affordable and available to buy.

Should help you narrow it down a bit ;)

Reason enough to try the 75w position most of the time and only the class A 15w on occasion at low volumes with the right material .

Modern speakers are rarely very sensitive , as nowadays cheap abundant amplifier power is not a problem .
very sensitive speakers comes with a lot off other idiosyncrasies ? so .

Interesting topic you try to find a match for your vintage SONY's . Maybe you have to accept their limitations and just buy a good speaker , it might outlast the amps ? so why not just aim for a good speaker .

Usually you first pick the speaker you like then find the amp that can drive them at a reasonable cost
 

Zek

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....but it has 45 W. Is it useable/not too much wattage difference??
It is on safe side, but most important spec would be sensitivity of the speakers - better than 90 dB/1W/1m.
 
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SeshatCZ

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Reason enough to try the 75w position most of the time and only the class A 15w on occasion at low volumes with the right material .

Modern speakers are rarely very sensitive , as nowadays cheap abundant amplifier power is not a problem .
very sensitive speakers comes with a lot off other idiosyncrasies ? so .

Interesting topic you try to find a match for your vintage SONY's . Maybe you have to accept their limitations and just buy a good speaker , it might outlast the amps ? so why not just aim for a good speaker .

Usually you first pick the speaker you like then find the amp that can drive them at a reasonable cost
I MAYBE have had the right speakers at first, already before I bought the new Sony amp . The unused ones are Italian Indiana Line Nota 260X, their specs are in this link to Nota 260X. It appears that these speakers have the right sensitivity 91 dB, and 30-100W suggested power of an amplifier, 4-8 Ohms load impedance. But I have not seen any measurements of them as for some eventual deeps, so I do not know how much demanding they are to drive, to use them successfully with a Class A part of the amp. But based on advices above, they seems to be a good point to start from.

The reason behind my opposite direction in new hifi system building is this: I was happy with my preamp Linn AV5103 to control my vintage Sony TA-3200F, it was better than Yamaha C-60 as for more quiet idle background (maybe subjectively), and have more strong and articulated Bass to my Elac Debut Reference 6.2 speakers, which are a bit more demanding as for more pronounced lowers. But it started to restart from time to time, maybe a defect Power supply. So I was on the market for a decent preamp, and the Sony combo was the only one refurbished, so the amp was such byproduct...

Nevertheless, I am happy with the new SonyTA-E86B preamp, because it sounds with the Sony TA-3200F to the Elacs still far better than the Linn AV5103. And I am waiting similar unexpected effect with the new Sony TA-N86. But it has to have a good synergy with speakers and preamp (maybe the a bit weaker, repaired Linn preamp will be an elegant solution).

Thanks a lot to all advisors. I am able to start with finding an ideal solution in a bit more sophisticated manner than several hours before. ASR is apparently a great forum.
 
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