amplificatoare de casti

[yo9hnf]

LM380 pentru casti incercat cineva?Am mai gasit si niste uA201 (in capsula metalica - tare frumos !). Merge?

[zal]

201 nu merge c? nu are protec?ie pe ie?ire ?i nici putere suficient?, poate ptr c??ti cu impedan?? mai mare.

[mistretzul]

salutare! Am pe acasa vreo cateva OPA552FA si nu imi prea sunt de folos... asa ca ma gandeam sa va uitati voi cu atentie pe datasheetul lor si sa imi spuneti daca ar merge facut un amplif de casti din ele(vreo 5 bucati montabile pe radiator + 5 in carcasa dip8).

[danzup]

salutare! Am pe acasa vreo cateva OPA552FA si nu imi prea sunt de folos... asa ca ma gandeam sa va uitati voi cu atentie pe datasheetul lor si sa imi spuneti daca ar merge facut un amplif de casti din ele(vreo 5 bucati montabile pe radiator + 5 in carcasa dip8).

Schema din fig.10 din datasheet este exact ce-ti trebuie !

[cipriyan123]

atentie la OPA552.....e fratele mai rapid al lui OPA551(SR mai mare)si tre sa ai o amplificare de minim 10(altfel oscileaza)!in datasheet se zice de minim 5 dar nu e chiar asa....m-am jucat si eu mai demult cu dracii d-astea....

[lorik199]

am incercat sa realizez schema lui ratza de pe prima pagina , dar nu mi-a iesit, semnalul nu trecea de bc-uri

am dat jos bc-urile si am dat semnal in baza bd-urilor

rezultatul a fosrt surprinzator, nici un pic de brum(chiar deloc) si o putere deajunsa pt mine

castile sunt niste A4tech pe 32ohm, si montajul l-am alimentat la 12 v

schema la care ascult muzica acum

pt mine bate operationale de zeci de lei cu thd de multe cifre dupa 0

realizat in 10 minute

[ratza]

Nu are cum s? nu merag?. Fie ai BC-urile arse, fie le-ai pus gre?it cracii. A?a cum ai tu schema acum nu amplific? nimic, ?la e repetor pe emitor.

[petre_s]

de asta http://sound.westhost.com/project70.htm ce parere aveti, l-a facut cineva? se poate alimenta la 18V?

[ratza]

Exact schema aia am folosit-o eu într-un amplificator acum vreo 4 ani, alimentat? la 24V, finali 2N3055. Se auzea bine, fiind în clas? A, dar nu am reu?it s? scap de brum în totalitate. Pentru c??ti nu va fi problematic, dac? folose?ti un multiplicator de capacitate. Va merge ?i la 18V, trebuie s? reglezi din VR1 s? ai 9V în colectorul lui Q5. O s?-?i sar? c??tile de pe urechi, chiar are boa?e ampliful ?sta.

[petre_s]

eu am un alimentator de laptop, scoate 18.5 V , e in comutatie,bineinteles, deci nu cred ca se pune problema de brum.

[lorik199]

Nu are cum s? nu merag?. Fie ai BC-urile arse, fie le-ai pus gre?it cracii. A?a cum ai tu schema acum nu amplific? nimic, ?la e repetor pe emitor.

bc-urile au fost noi, cracii pusi corect,deci se exclude problema asta, dar oricum vibrau castile pe urechioricum folosesc 6h6p in SE acum, la care e mult mai simplu montajul , si cu o dinamica deosebita

[Den]

Probabil ca sursa de semnal e destul de puternica ca sa atace bine bd-urile.Repetorul pe emitor este un amplificator in curent,suficient in acest caz.

[lorik199]

Probabil ca sursa de semnal e destul de puternica ca sa atace bine bd-urile.Repetorul pe emitor este un amplificator in curent,suficient in acest caz.

o banala placa de sunet onboard realtek AC'97

[stryx]

as vrea sa fac si eu amplificatorul CMoy, daca folosesc op: 4558d (varianta smd) mai trebuie sa fac vreo modificare la schema?

[mosfet]

M-am apucat de un Cmoy pe care vreau sa-l alimentez dintr-un traf si nu din baterii. Alimentarea o voi face cu TLE2426 si nu stiu cum sa pun conzii de filtraj, daca inainte sau dupa TLE2426, avand in vedere discutia de aici - http://www.koalakits.net/projects/mic_b ... ounds.html

Notice that there is just one capacitor across the battery instead of a cap between each rail and virtual ground as in the resistor divider supply. In the resistor divider circuit, two capacitors are absolutely necessary to the success of the circuit. Below, I will talk about the advantages of using two caps like this in an active virtual ground circuit, as well as the disadvantages. For now, assume that it's better to have just one before the active "rail splitter".

Capacitors on the Output of a Virtual Ground DriverAbove I said that when moving to an active rail splitter, you want to seriously consider putting the rail capacitors in front of the splitter. The purpose of putting caps across the resistive ground divider shown at the start of this article is because this passive splitter cannot deliver very much current, so we need the caps to do that. The resistors are only maintaining the DC level of virtual ground here. An ideal virtual ground circuit would have infinite current delivery, so there should be no advantage to putting caps on its ouptut. In fact, it can be detrimental.An active virtual ground circuit has some "bandwidth": that is, it will be effective over some range of frequencies. If you put capacitors across its output, that lowers its bandwidth: as frequency goes up, the capacitors are "in charge" to a greater and greater extent. If the caps are large enough, the virtual ground circuit's bandwidth is completely swamped. It could end up being good for no more than maintaining the DC level of virtual ground.Output caps can be a good thing if the rail splitter has a fairly low output current limit. That's the situation in the MINT amp, for example. The TLE2426 has an output current limit of between 20 to 40 mA, depending on operating conditions. When it goes into current limiting, its output goes to the negative rail, which would make for a massive shift in the virtual ground point, so we cannot allow this to happen. A heavy headphone load could indeed exceed 20 mA, so putting caps on the ouptut of the TLE2426 saves the design. Although the TLE2426 has no effect at audio frequency, it still has benefits compared to a resistive voltage divider. First, its output impedance is much lower, so the virtual ground shift described above doesn't happen. Second, it requires less operating current than the CMoy's resistive divider.Another potential problem with big caps on the output of a virtual ground splitter has to do with stability. Some circuits will become very stable in this situation: no bandwidth and no gain, hence no oscillation. Most circuits aren't made to cope with capacitive loads, however. They become less stable when driving a capacitive load. Study the datasheets for the ICs you will be using. Unless they specifically tout the fact that they can drive large capacitive loads, beware of using them in virtual ground circuits. Don't forget to consider the system bypass caps, if they go from each rail to virtual ground: there are many chips out there that will become unstable with less than a nanofarad of capacitance on their output, and the bypass capacitors will count against this. Ultimately, you will have to build real circuits and test them before you know whether a given chip can cope with the capacitive load in your setup.There's one more problem with putting caps on the output of the virtual ground circuit: it wastes capacitance. In a very real sense, two caps across the output of a virtual ground circuit are in series, so the total capacitance is cut in half. Also, you require one capacitor in front of the rail splitter, but two after it. This means putting the rail capacitance in front of the splitter is actually four times as efficient: you can have twice the effective capacitance in half the board area, or four times the capacitance in the same board area.

Tinand cont ca voi alimenta amplificatorul dintr-un traf si nu din baterii, am nevoie de conzi maricei; Cmoy-ul consuma cam 20mA deci ar fi recomandat sa-i pun dupa TLE, dar ce capacitate sa aiba? 2200uF e prea mult?Datasheet-ul zice ca TLE-ul e stabil si cu conzi de 2200uF pe iesire.