Headamp s 6AS7G a ine

[Wili]

Aky je rozdiel v 1n4148 a led? maju nizsi sum? Inak preco sa tolko riesi sum diody v ccs, ked je na nu oprety aj tak dost velky kondenzator? Teda aspon ja tam mam 1800uF/6,3V. Ten by mal ten bordel odfiltrovat nie?

Ja som ccs kaskadu robil takto, ako mi poradil Tomel:

Spodne tranzistory pre kaskadu som navyberal vyberove s najvyssim Hfe ake som nasiel, a prilepil ich sekundovym lepidlom na ledku a stiahol este buzirkou, je to super stabilne a nic nekolise.

[cthulhu]

Odstraněno pro nevhodnost.

[tomel]

Kniha od Cordella aj od Selfa

Pre LED referenčný prud 1mA...

1N4148 pri 10mA maju mensi sum... Ak dobre pamätám (berte s rezervou)

[BFX]

ach jaj chlapi a co takto pomerat? aha nevieme ako? ci?
Co som tym chcel povedat?
Jednoduchu vec, ze vsetky tie highend sracky ma nezaujimaju pokial niesu podoprete exaktnym meranim.

Sem tam tu vidim nejaku simulaciu a este zriedkavejsie aj to meranie, takze pani hor sa do profi triedy
Meraaame

[cthulhu]

Odstraněno pro nevhodnost.

[Wili]

Tu som našiel porovnanie merania diod, led, zener atd...

Vraj veľmi dobre su IR ledky

http://www.diyaudio.com/forums/parts/35 ... iodes.html

[platon.rado]

Ano

[hpeter]

Tu som našiel porovnanie merania diod, led, zener atd...

Vraj veľmi dobre su IR ledky

http://www.diyaudio.com/forums/parts/35 ... iodes.html

Noise measurements for LEDs and zener diodes
--------------------------------------------

(C) Christer at DiyAudio.com
You are allowed to copy and use this information for your
personal and non-commercial use.


DESCRIPTION OF TEST RIG
-----------------------

The test rig uses three current sources of approx. 1, 5 and 20 mA
built using low-noise BJTs (BC559) to feed the device under test
(DUT) alternatingly. The noise was measured using two op amps in
in non-inverting configuration cascaded, both having a gain of 34,
making a gain of 1156 in total. The first op amp is a very-low-noise
model (LT1115) and uses a gain resistor of only 10 Ohms in the feedback
network. The gain resistor is thus 330 Ohms which works since the op
amp is only expected to output very low-level signals. The second op
amp is a low-noise type (NE5534) with gain and feedback resistors of
100 Ohms and 3.3 kOhms. The output was measured using a PC soundcard
(Creative Audigy LS in 16-bit 44.1 kHz mode). Each measurement consists
of a 10 second capture of the soundcard input and the RMS value for
this 10 s. signal was computed. The program was calibrated (using a
sine wave and an oscilloscope) to give aprroximately correct voltage
readings and all measurements were divided by 1156 to give the equivalent
input RMS noise at the first op amp, ie. at the DUT. No extra filters
except what is on the soundcard were used.


TEST METHOD
-----------

A spectrum of LED types ranging from IR to blue and of approximately
the same type were measured. All LEDS were selected to have an max
If of at least 20 mA, since this current was used in the test. Further
four 0.5W types of zener diodes were tested, two of them (5.6 and 6.8 V)
were deliberately selected close to each other but such that the 5.6 V
diode should be expected to have true zener breakdown and the 6.8 V one
to have avalanche breakdown. The other two were selected to be far away
from this "transition region". Two 1.3W zeners were also tested to see
how the power rating affects noise figures.

For each type of DUT, two devices (denoted #1 and #2 and presumably
from the same batch) were tested at the three test currents 1, 5 and
20 mA and the equivalent noise at the DUT was measured and calculated
as described above. For each combination of device and current, five
10-second measurements were made.

For reference, the voltage drop at each test current
was also measured for one device of each type.


MEASUREMENTS
------------

All values are RMS values

Idle noise:
----------------------------------------------------
Measured idle noise of amplifier with grounded input:
0.19 0.19 0.19 0.19 0.18 uV
(The theoretical max value was calculated to 0.16 uV for
20kHz bandwidth and 0.22 uB for 40 kHz bandwidth).

Measured idle noise of amplifier with 100 Ohm source resistor:
0.26 0.25 0.24 0.26 0.26 uV
(The theoretical max value was calculated to 0.20 uV for
20kHz bandwidth and 0.28 uB for 40 kHz bandwidth).


LEDs:
----------------------------------------------------
(All LEDs of brand Everlight)

IR204/P1 (IR):
#1 @ 1mA: 3.7 3.7 3.7 3.7 3.7 uV
#1 @ 5mA: 0.67 0.66 0.65 0.66 0.66 uV
#1 @ 20mA: 0.24 0.23 0.24 0.23 0.23 uV
#2 @ 1mA: 3.8 3.8 3.7 3.7 3.7 uV (Vf = 1.05 V)
#2 @ 5mA: 0.65 0.64 0.64 0.64 0.64 uV (Vf = 1.11 V)
#2 @ 20mA: 0.24 0.25 0.23 0.24 0.22 uV (Vf = 1.17 V)

EL202HD (red):
#1 @ 1mA: 0.31 0.32 0.31 0.31 0.32 uV
#1 @ 5mA: 0.26 0.26 0.27 0.27 0.27 uV
#1 @ 20mA: 0.39 0.36 0.37 0.36 0.37 uV
#2 @ 1mA: 0.39 0.37 0.38 0.38 0.35 uV (Vf = 1.82 V)
#2 @ 5mA: 0.32 0.30 0.30 0.30 0.31 uV (Vf = 1.89 V)
#2 @ 20mA: 0.41 0.40 0.41 0.41 0.46 uV (Vf = 2.09 V)

EL204ID (red-orange):
#1 @ 1mA: 0.31 0.30 0.31 0.31 0.31 uV
#1 @ 5mA: 0.25 0.26 0.26 0.26 0.24 uV
#1 @ 20mA: 0.41 0.41 0.48 0.40 0.41 uV
#2 @ 1mA: 0.35 0.31 0.29 0.30 0.32 uV (Vf = 1.64 V)
#2 @ 5mA: 0.25 0.26 0.27 0.26 0.30 uV (Vf = 1.74 V)
#2 @ 20mA: 0.40 0.40 0.39 0.40 0.41 uV (Vf = 1.90 V)

EL204YD (yellow):
#1 @ 1mA: 0.42 0.30 0.29 0.29 0.28 uV
#1 @ 5mA: 0.28 0.26 0.25 0.33 0.27 uV
#1 @ 20mA: 0.42 0.39 0.39 0.40 0.40 uV
#2 @ 1mA: 0.31 0.30 0.31 0.30 0.31 uV (Vf = 1.78 V)
#2 @ 5mA: 0.28 0.47 0.28 0.26 0.25 uV (Vf = 1.87 V)
#2 @ 20mA: 0.34 0.34 0.35 0.34 0.34 uV (Vf = 2.02 V)

EL204GD (green):
#1 @ 1mA: 0.68 0.50 0.50 0.47 0.46 uV
#1 @ 5mA: 0.35 0.30 0.28 0.28 0.29 uV
#1 @ 20mA: 0.36 0.35 0.35 0.35 0.35 uV
#2 @ 1mA: 0.46 0.46 0.44 0.44 0.41 uV (Vf = 1.82 V)
#2 @ 5mA: 0.36 0.33 0.32 0.33 0.32 uV (Vf = 1.92 V)
#2 @ 20mA: 0.39 0.40 0.39 0.41 0.40 uV (Vf = 2.12 V)

EL204UBD (blue):
#1 @ 1mA: 4.6 4.5 4.6 4.5 4.6 uV
#1 @ 5mA: 3.2 3.2 3.2 3.2 3.2 uV
#1 @ 20mA: 2.8 2.8 2.7 2.7 2.7 uV
#2 @ 1mA: 4.4 4.4 4.3 4.2 4.3 uV (Vf = 3.26 V)
#2 @ 5mA: 3.1 3.2 3.2 3.1 3.2 uV (Vf = 3.44 V)
#2 @ 20mA: 2.9 2.8 2.8 2.8 2.7 uV (Vf = 3.69 V)


Zeners:
---------------------------------------------------------
(All zeners of brand Temic.)

BZX55/C2V7 (0.5W 2.7V):
#1 @ 1mA: 1.1 1.1 1.1 1.1 1.1 uV
#1 @ 5mA: 1.0 0.88 0.85 0.86 0.87 uV
#1 @ 20mA: 1.0 0.81 0.72 0.72 1.1 uV
#2 @ 1mA: 1.2 1.1 1.1 1.1 1.1 uV (Vr = 2.03 V)
#2 @ 5mA: 0.91 0.88 0.87 0.86 0.85 uV (Vr = 2.50 V)
#2 @ 20mA: 1.1 0.80 0.77 0.73 0.71 uV (Vr = 3.02 V)

BZX55/C5V6 (0.5W 5.6V):
#1 @ 1mA: 5.3 5.3 5.3 5.3 5.3 uV
#1 @ 5mA: 2.9 2.9 2.9 2.9 2.9 uV
#1 @ 20mA: 1.7 1.6 1.6 1.6 1.6 uV
#2 @ 1mA: 5.3 5.3 5.3 5.3 5.3 uV (Vr = 5.68 V)
#2 @ 5mA: 2.9 2.9 2.9 2.9 2.9 uV (Vr = 5.77 V)
#2 @ 20mA: 1.8 1.6 1.6 1.6 1.6 uV (Vr = 5.81 V)

BZX55/C6V8 (0.5W 6.8V):
#1 @ 1mA: 16 16 16 16 16 uV
#1 @ 5mA: 21 21 21 21 21 uV
#1 @ 20mA: 5.8 5.5 5.5 5.5 5.6 uV
#2 @ 1mA: 25 25 25 25 25 uV (Vr = 6.93 V)
#2 @ 5mA: 13 13 13 13 13 uV (Vr = 6.96 V)
#2 @ 20mA: 4.6 4.7 4.5 4.5 4.4 uV (Vr = 7.00 V)
(Rechecked both devices due to their inconsistent
behaviour for 1 and 5mA).

BZX55/C12 (0.5W 12V):
#1 @ 1mA: 0.35 0.37 0.37 0.39 0.39 uV
#1 @ 5mA: 0.30 0.28 0.28 0.28 0.30 uV
#1 @ 20mA: 0.24 0.25 0.25 0.26 0.25 uV
#2 @ 1mA: 0.32 0.33 0.32 0.33 0.32 uV (Vr = 11.32 V)
#2 @ 5mA: 0.26 0.26 0.27 0.32 0.26 uV (Vr = 11.37 V)
#2 @ 20mA: 0.25 0.26 0.28 0.24 0.30 uV (vr = 11.42 V)

BZX85/C2V7 (1.3W 2.7V):
#1 @ 1mA: 0.77 0.77 0.77 0.77 0.76 uV
#1 @ 5mA: 0.62 0.61 0.63 0.61 0.60 uV
#1 @ 20mA: 0.55 0.55 0.54 0.55 0.55 uV
#2 @ 1mA: 0.78 0.78 0.78 0.78 0.78 uV (Vr = 1.30 V)
#2 @ 5mA: 0.62 0.62 0.61 0.62 0.62 uV (Vr = 1.61 V)
#2 @ 20mA: 0.57 0.56 0.57 0.56 0.56 uV (Vr = 1.92 V)

BZX85/C12 (1.3W 12V):
#1 @ 1mA: 0.49 0.53 0.48 0.50 0.52 uV
#1 @ 5mA: 0.54 0.55 0.58 0.46 0.48 uV
#1 @ 20mA: 0.44 0.35 0.38 0.36 0.33 uV
#2 @ 1mA: 0.42 0.43 0.46 0.48 0.41 uV (Vr = 9.84 V)
#2 @ 5mA: 0.40 0.35 0.35 0.37 0.29 uV (Vr = 9.89 V)
#2 @ 20mA: 0.34 0.33 0.31 0.30 0.31 uV (Vr = 9.94 V)

-----------------
#1 @ 1mA:
#1 @ 5mA:
#1 @ 20mA:
#2 @ 1mA:
#2 @ 5mA:
#2 @ 20mA:

cakal som vacsiu katastrofu, najma zenerky.

[Wili]

Dnes som bol po trafko a na stole nakábloval sluchátkač ala vrabčie hniezdo a čosi som pomeral. Síce to nekmitá a nerobí nič zlé, čo ma teší ale asi tam dám na vstup nejaký silnejší VF vstupný filter ako mám, pretože to má šialený frekvenčný rozsah. Nižšie sú výsledky...



---Všetko je merané do záťaže 250R---

Max. výkon: 50mW // 3,53V RMS
Frekvenčný rozsah VF: 1540kHz pre -3dB
Slew rate: 80V/us (vid. 5 postov nizsie)
SNR cca 100dB

Merania:

1,52V RMS // cca 10mW // 0,05% THD



2,34V RMS // cca 22mW // 0,2% THD



Obdĺžnik 100kHz



Obdĺžnik 500khz



Komplexná záťaž 250R + 33n, obĺžnik 10kHz

[dan21]

odfot to v tme nech riadne vidime to led podsvietenie
Inac parada !!!

[Andrej152]

Wili: vyzera to fak nadherne , aj parametre ma to velmi dobre aj ja by som si to postavil keby v nedavnej minulosti ma nenastvali elektronky ..

[elmoto]

50mW nieje to málo? Keď tam dáš 400 alebo 600 ohm slúchadlá tak neviem či to bude dostatočné.

[Wili]

50mW nieje to málo? Keď tam dáš 400 alebo 600 ohm slúchadlá tak neviem či to bude dostatočné.

tých 50mW je podľa mňa na hranici toho čo zvládnu DT990 / moja hlava. Zrejme tiež dosť záleží od citlivosť daných sluchátok.

Výstupné napätie pre inú impedanciu sa dá dokorigovať množstvom spätnej väzby, ak by zľahčením záťaže na 600R bol rozkmit náhodou malý, stačilo by ubrať zo spätnej väzby a zase by sa to dostalo cca na tých maximálnych 50mW pri 600R slúchadlách možno aj viac lebo to viac sedí elektrónkam. Spätná vazba by sa dala utiahnuť aj o dosť viac ako ju mám teraz a nakrmiť tak aj nižšiu záťaž, aké by boli parametre neviem, ak budem mať čas skúsim premerať aj 600R a 32R záťaže. Ja som aj zvažoval dorobenie prepínača na zadný panel kde by sa dala prispôsobiť záťaž "LOW/HIGH" pre zmenu spätnej väzby, ale neviem či by som to využil.

[Wili]

Hore uvedene merania su so vstupnym potenciometrom 50kOhm na ktorom je "naregulovana" max. uroven tj. 10Vpp. Tento potenciometer ale do merania trochu keca a kazi SR. Skusal som to nakrmit priamo z generatoru a navolit velkost signalu priamo v generatore a Slew rate sa takmer zdvojnasobila na hodnotu 80V/us. Meranie SR na 10kHz:

zelená - vstupný signál
žltá - výstup

[hpeter]

I prd velebnosti
Ak sa dá headamp postaviť aj bez výstupákov, prečo teda investovať do zbytočného "železa"?
Samozrejme, niekedy sa bez nich zaobísť nedá.

By som povedal, ze bez nich sa vobec neda. Napr. trioda ma anodu vystup, ale aj zaroven vstup (najma ak funguje do vyssej impedancie trafa, ako je "datasheet standard") cize zataz reaguje s sekundarom a teda "back emf" sa z sekundaru premietne na primar - opacny smer, zvysovaci pomer, kde trioda na to zareaguje svojou vnutornou vazbou, zatlmi napr rezonanciu z repro..) Lokalne vazby su neskodne, dodatocne nevyrabaju dalsi bordel, to sa o globalnych v. povedat neda. Cize ked trioda nemaka do trafa, tato extra funkcia je "vypnuta", co je skoda.
Mrzi ma ze trafo je vnimane ako zbytocna investicia, no potom vznikaju napr. repro otl "infra-sauny" s vela global. vazbami

[platon.rado]

http://www.eddiecurrent.com/ZD.html

http://www.6moons.com/audioreviews/eddi ... zana2.html

Už dávnejšie padla otázka, pohrať sa na vývoji sluch.zosilnovača s elektrónkami 6CC33.Myslím že Zdeno niečo začal..ako si na tom ???

[cthulhu]

[zdenoeddie]

Myslienka zije, a chvalabohu (alebo bohuzial?) preco momentalne s bastelnim stagnujem, nie je v povinnostiach novomanzela, ale suvisi to so zmenou zamestnania atd... I ked je to nutena, ale priznam ze uz aj potrebna prestavka, az sa to trosku ukludni a zabehne do kolaji, pridem s novymi objavmi. Snad to bude coskoro.

[cthulhu]

[elmoto]

Si popil? Či hríbyky?