Amplis pour ls : best of the best?

[Jo Ki]

Dear All,

The topic asks for "BEST of THE BEST", it can only be one, which is the best among all.

My answer to this question  is FM Acoustics FM155 preamp driving FM108 monoblock power amp into LS3/5A is best of all the best amps. Comparing all the other vintage amplifiers that I owned, bought specifically and ONLY to drive my LS/35A of various makes and versions, this transistor amplifier system beats all them.

[Time Window]

Hello Jo Ki

Voilà, pour l'anglais c'est fait...

Jolie collection d'amplis, et sur la gauche de l'image, une belle collection de "garces" (LS)
Il y en a peut être autant que sur le forum... J'exagère à peine...

Quand à l'amplification FM, dites moi ce que ça ne fait pas marcher...

Fabien

[PFB]

this transistor amplifier system beats all them

When using LS3/5a in abnormal condition, I mean relatively too far away from design listening position such in our living room, I appreciate my Sonosax FD-A100 because this amplifier integrates a limiter to avoid any speaker damage. The limiter allows the user to drive the LS very loud without exceeding power limits. Sonosax limiters are subjectively quite discrete, inaudible for most of us.

Jacques Sax analog design are excellent you can find his design in numerous audio products such like Weiss AD converters.

PFB

[Jo Ki]

Hello Jo Ki

Voilà, pour l'anglais c'est fait...

Jolie collection d'amplis, et sur la gauche de l'image, une belle collection de "garces" (LS)
Il y en a peut être autant que sur le forum... J'exagère à peine...

Quand à l'amplification FM, dites moi ce que ça ne fait pas marcher...

Fabien

Hi Fabien,

Firstly, let me explain that I did not want to get as far as FM Acoustics, which is costly especially when compared to the cost of a pair LS3/5A. I used to be very happy with passive preamp Cello Etude partnering with Quad II; the music was a bliss when I first heard it. The idea came from my friend Paul Whatton and Ken Kessler. I never listened the same again since.

What happen after that was the beginning of what I am today. I got greedy with the performance of the music, the repertoire of the music collection grew, and my power amp grew at the same time as my music demands increases, starting with vintage tube collections, etc. Then, I moved to Leak Stereo 20, TL12+, TL12.1, Radford STA15, Marantz 8B, etc. etc... and all the old tubes collections...

One day, a friend suggested that I should try a good active preamp, started with single stage gain tube preamp, then to a few other pre before FM Acoustic 155 transistor pre. FM155 opens the vault of musical world for me, and soon FM108 mono came in about 5-6 years ago.

What FM Acoustic cannot do is very easy for me to round up saying, none is my answer.

It is remarkable amplifications for this speakers. FM108 simply is made for this speakers. I had also tried other FM like FM F10B, FM 111 were all found to be over-driving the LS3/5A. But the 108, with gain control, together with its pre is very good. especially with the gain control behind the FM108, adjusted together with 155 volume pot, can fine tune the sound to suit.

As an architect by profession, I am into natural sonic spectrum, and reality is what I am pursuing in music reproduction. I find not lacks in the FM acoustic system I have with, perhaps only one thing, to make it even more close to the realistic reproduction with a balance output pre like FM245 or 255. BUT FM108 is indispensable for me.

The above are my sincere sharing. No commercial interest in any of the products I mentioned.

Regards,
Jo Ki

-- 16 Apr 2018 à 10:20 --

When using LS3/5a in abnormal condition, I mean relatively too far away from design listening position such in our living room, I appreciate my Sonosax FD-A100 because this amplifier integrates a limiter to avoid any speaker damage. The limiter allows the user to drive the LS very loud without exceeding power limits. Sonosax limiters are subjectively quite discrete, inaudible for most of us.

Jacques Sax analog design are excellent you can find his design in numerous audio products such like Weiss AD converters.

PFB

Dear PFB,

I fully agree with the limiter to avoid over-driving the LS3/5A, but it will give out a "quake!" when it is over-drive or the bass would sound as if it hits a flat bed, then it signified the limit of the speakers. This is goo to avoid causing damages to the speakers.

However, in my humble opinion, LS3/5A can be driven loud, PROVIDED (ONLY) when the signals feeding it has very low distortion signals. If music signals feeding it is full of distortion, it will clips an over-drive at much lower volume. I had done a demo before with the same piece of music, one without proper isolation and control of resonance to the electronics and one with, and the recorded amplitude before it show signs of clipping varies. There is more than 10-15 dB difference.

My system in my listening room measured 4.3M x 2.9M x 3.1M, on demo with visitors is running at average of 90-94 dB. Common daily listening is around 82-87 dB.

Regards,
Jo Ki

[pelleas]

Je n'ai pas essayé sur des ls3/5a mais le sugden est un ampli mou, doux diront certains. Sur des enceintes agressives type cabasse ou triangle pourquoi pas mais pas sur des ls3/5a qui ont besoin de  quelque chose de plus énergique:

Audiolab ou naim par exemple.

Le mariage Sudgen A28 et LS3/5A donne des résultats excellents. Et c'est tout sauf mou ! Je ne connais pas le Sudgen A21.

[gilles13]

A Munich Falcon faisait sa démo ls 3.5a avec un À 21 .

[SudPigalle]

J'alterne un LEBEN 300 et un intégré AYRE

Les deux ont des qualités , le LEBEN avec sa petite coquetterie dans le médium qui le rend très sensuel sur les voix, le charme de la 300B avec des EL84
Et
L'AYRE qui justement n'en manque pas et envoie grave sur du jazz ou du rock

JP

[jeanpascalg]

Le mariage Sudgen A28 et LS3/5A donne des résultats excellents. Et c'est tout sauf mou ! Je ne connais pas le Sudgen A21.

je ne parle que des nouveaux modèle pas de ceux des années 80.

[simon33]

J'utilise un Bryston 4B sur mes Ls depuis quelques temps et le résultat est très satisfaisant.

C'est un ampli très " flat " du coup on entend toutes les sources et le qualités d'enregistrements , j'écoute quasi que du vinyl .

Il est largement surdimensionné pour ces enceintes mais au moins il les "tient" parfaitement.

J' ai fais défiler quelques 25cms de Férré ce matin , çà sonne superbement juste .

[slabadabada]

Le mariage Sudgen A28 et LS3/5A donne des résultats excellents. Et c'est tout sauf mou ! Je ne connais pas le Sudgen A21.

J'ai eu un temps ce combo mais cette association plaisante ne donne pas la pleine mesure de ce que chacun est capable, je regrette encore d'avoir bêtement laché mon A28 mais pour pour les LS