Различия

Показаны различия между двумя версиями страницы.

--- 1tubes:d3a [2020/02/25 15:54]
staudio [Даташит]
+++ 1tubes:d3a [2020/03/12 00:24]
staudio [Полезные ссылки]
@@ Строка 7: / Строка 7: @@
 ----
-==== Даташит ====
+==== Характеристики ====
 {{ :1tubes:d3a_7721.pdf |}}
 ++++ Смотреть |
@@ Строка 14: / Строка 14: @@
 ==== Схемы ====
 ++++ Смотреть |
-{{:tubes:d3amp.gif?400|}}
+{{:tubes:d3amp.gif?400 |}}\\
+{{:1tubes:d3a-300b.jpg?direct |D3a + 300B}}
 ++++
 ==== Полезные ссылки ====
-https://www.hi-fi.ru/audioportal/topic/2707-lampy-c3g-c3m/
+https://www.hi-fi.ru/audioportal/topic/2707-lampy-c3g-c3m/\\
+https://www.hi-fi.ru/audioportal/topic/1509-usilitel-na-odnoy-lampe-6zh52p/ - обсуждение 6ж52п (аналог)
 ==== Отзывы ====
 http://vinylsavor.blogspot.com/2012/12/tube-of-month-d3a.html\\
@@ Строка 28: / Строка 30: @@
 <hidetext Читать дальше>
-The D3a is a quite modern tube developed for wide band amplifiers for telecommunication applications. It has a nine pin miniature base. The pinout can be seen on the left. Triode connected it has a very high transconductance almost approaching that of the EC8020. Amplification factor is 77 at a plate resistance of 1900 Ohms. See the Telefunken datasheet for all electrical parameters also for the pentode connection. The low plate resistance makes this tube very suitable for transformer coupling. With a step down transformer, for example Lundahl LL1692A in 3.5:1 configuration or LL1660 in 4.5:1 the tube is perfect to drive a 600 Ohm LCR RIAA network. In such a configuration there would even be some gain left after the EQ network. With a step up transformer after the RIAA, for example Lundahl LL7903 in 1:4 confguration this could be boosted up for further amplification in a second D3a stage using another step down transformer for low output impedance. With a Lundahl LL2745 wired 2.8:1 at the output such a 2 stage phono preamplifier would have a MM gain of about 46 dB with an output impedance of less than 300 Ohms. This gain can be brought up to suitable levels for moving coil cartridges with a MC step up transformer.
+The D3a is a quite modern tube developed for wide band amplifiers for telecommunication applications. It has a nine pin miniature base. The pinout can be seen on the left. Triode connected it has a very high transconductance almost approaching that of the EC8020. Amplification factor is 77 at a plate resistance of 1900 Ohms. See the Telefunken datasheet for all electrical parameters also for the pentode connection. The low plate resistance makes this tube very suitable for transformer coupling. With a step down transformer, for example Lundahl LL1692A in 3.5:1 configuration or LL1660 in 4.5:1 the tube is perfect to drive a 600 Ohm LCR RIAA network. In such a configuration there would even be some gain left after the EQ network. With a step up transformer after the RIAA, for example Lundahl LL7903 in 1:4 confguration this could be boosted up for further amplification in a second D3a stage using another step down transformer for low output impedance. With a Lundahl LL2745 wired 2.8:1 at the output such a 2 stage phono preamplifier would have a MM gain of about 46 dB with an output impedance of less than 300 Ohms. This gain can be brought up to suitable levels for moving coil cartridges with a MC step up transformer.\\
-Although signal levels are very small in a phonostage we want the amplification device to be as linear as possible. These are the plate curves for the triode connection from the datasheet:
+Although signal levels are very small in a phonostage we want the amplification device to be as linear as possible. These are the plate curves for the triode connection from the datasheet:\\
-{{:1tubes:d3a-curves.jpg?direct&400 |}}
+{{ :1tubes:d3a-curves.jpg?direct&400 |}}\\
-This looks promising! Let's see how this keeps up with reality. Here are the plate curves taken from an actual tube with a curve tracer. The scale is 5mA and 50V per step, 0.5V grid voltage spacing:
+This looks promising! Let's see how this keeps up with reality. Here are the plate curves taken from an actual tube with a curve tracer. The scale is 5mA and 50V per step, 0.5V grid voltage spacing:\\
-{{:1tubes:d3a-curves2.jpg?direct&400 |}}
+{{ :1tubes:d3a-curves2.jpg?direct&400 |}}\\
-Looks perfect for audio applications.
+Looks perfect for audio applications.\\
-The D3a was made by various european manufacturers: Telefunken, Valvo, Siemens, Philips. Although it has an american designation, the industrial type 7721, I'm not aware of any US based company who made this tube.
+The D3a was made by various european manufacturers: Telefunken, Valvo, Siemens, Philips. Although it has an american designation, the industrial type 7721, I'm not aware of any US based company who made this tube.\\
 This tube has been manufactured by Siemens in the former western part of Germany. It has the characteristic pinched glass around the electrode structure.
@@ Строка 59: / Строка 61: @@
 C3o - лампа очень редкая и дорогая, лучше купить или намотать накальный трансформатор на 20 вольт (для C3m).
+++++ Смотреть картинку |
 {{:tubes:d3a_1.png?400|}}
+++++
+----
+Странно, Вас отговорили от D3a, а Вы поставили лампу ещё хуже и у Вас есть результат. Может это мнение Вы составили от новизны в звуке?\\
+В моём гибриде 6Ж43п переиграли её 6Э6П EL861 и D3a. Последняя сейчас и стоит. 6Э5П не дотянула до этой троицы по звуку.\\
+У 6Ж43п много микродинамики, а вот с макродинамикой есть небольшие проблемы. Имхо\\
+Э5П и 6Э6П усиление не хватит.\\
+Если будете пробовать D3a, обязательно третью сетку на землю.\\ Звук меняется в лучшую сторону.\\
+----

Аудио-википедия

Инструменты пользователя

Инструменты сайта

Различия

Инструменты страницы