[vendu] Dac Altmann Attraction

[manu67]

Bonjour,

Je revends ce remarquable dac NOS du fabriquant Allemand Altmann à base de tda 1543 alimenté par batterie.
Il S’agit de la version Attraction avec toutes les options :
- Entrée toslink (en plus de l’entree coaxiale d’origine)
- Filtre d’entree JISCO
- Flux hd (testé jusqu’à 24-192 sur Qobuz)






Il y a beaucoup de littérature à propos de ce dac sur internet.
Il est livré avec l’ensemble de la câblerie électrique et des cosses pour batterie d’origine ainsi qu’avec la notice d’utilisation.
Je peux livrer en option une batterie type AGM redtop Optima récente qui est le modèle préconisé par Altmann en personne mais le poids est conséquent. (Valeur 190€)
Certaines personnes le font tourner avec une alimentation secteur en 12V, mais elle doit être d’excellente qualité.

Type : DAC
Marque : Altmann
Modèle et options : DAC Attraction, full options
Prix de vente : 790 €
Département où la marchandise est visible : 67
Possibilité d'expédition : oui
Montant des frais d'expédition : FPDAI
État de la marchandise : très bon
Première main : non
Prix neuf : +4000€ 
Facture disponible : non
Date, pays et lieu d'achat : 2022, Finlande
Garantie et date d'expiration : non
Numéro de série : à communiquer lors de la transaction
Emballage d'origine conservé : non
Documentations conservées : oui
Site web du constructeur et Liens divers :

http://www.mother-of-tone.com/attraction.htm

http://www.jitter.de/german/ger_navfr.html

Citation : Hi everyone,

to answer your questions:

On the Attraction DAC I use the TDA1543 because it is R2R and because it can be used with a single-ended power supply.
As you already know, the Attraction DAC is designed to be powered by a Optima Red Top 12V car battery which eliminates the need of wall powered (noisy) supplies.

I use active I/V conversion 1 OPA134 per channel, and 4 OPA134 per channel as output buffer. The DAC can power a speaker directly

The output level is as high as it possibly gets with a 12V supply, so it is 
about -3.5 Volts to +3.5 Volts full scale (which btw. seemed to be enough to 
overdrive DUC's preamp).

The input (spdif) receiver is custom. I programmed it into a Xilinx device. It 
has a switchable JISCO option and all DACs come with the UPCI (ultra-precision 
PLL) which synchronously reclocks the data.

There is 2 custom made VCXOs for the frequency generation and tuning and one 
custom XO for the JISCO function.

All features programmed into the Xilinx, which was really fun, but no walk in the park, btw

The Attraction DAC runs up to 192kHz on spdif input. It uses neither upsampling nor oversampling. Just straight conversion.

So above the more obvious stuff. But why is it so damn good ?

Okay, the pcb is flat on the bottom, which means that all through-hole 
solderjoints have to be flat.

There is no housing and the high-quality RCA jacks are not connected via wire, but directly soldered to the pcb.

Then this pcb is screwed on a spruce board which is the reason the pcb-bottom has to be flat.

Mounting to the spruce board adds body to the sound (which otherwise is not 
there).Then there are a couple of other tricks I apply with the DAC which I better not mention here, in order to prevent some avalanche-kind of response

However, now you have something to play with ...

Fun

Charles

ALTMANN MICRO MACHINES

Quote:

Charles, have you experimented powering the OPA134s with a separate battery? 
Would be easy to implement and probably would further improve performance.


I think it would mess up performance.

However, the OPAs get the pure battery current, then comes the DAC (regulated) 
and then comes the digital section (regulated separately). Ground plane 
separation plays an important role too among other things.

I think if anyone of you would spend 5..10 years of his life tweaking with DAC 
issues - add a portion of luck - add an extra portion of ignorance - you would 
all come to quite similar results ...

Charles,


Quote:

If I may ask how do you make a dual supply for the op-amp with a single 12vdc ?


Hi Will,

I feed the signal at 6V, just about in the middle.

That's the reason that the Attraction DAC has coupling caps at its output.

Charles

Des essais :

https://www.omycamisaudio.com/altman-attraction-dac

http://www.enjoythemusic.com/magazine/eq...ng_dac.htm

http://thehbproject.com/nl/testen/74/0/A...action-DAC

http://www.6moons.com/audioreviews/outside2/outside.html

[manu67]

Vente annulée, désolé 
je n’arrive pas à me séparer de ce dac si attachant (surtout depuis que j’ai upgradé les condos de sortie)

On peut fermer, merci

[manu67]

Salut,
La vente est de nouveau d’actualité

[Van Der Graaf Generator]

Corrige ton titre, alors ...
Merci !

[manu67]

Vendu
Merci