2020年7月12日 · D3a has fantastic linearity when wired in triode mode, high current drive, and high gain. Some had reported that the D3a could adequately drive 300Bs, and so it seemed like a decent bet for 2a3. There aren't too many folks who have described their operating points using D3a as a driver for DHT.

2019年8月1日 · Trioded D3a has tremendous gain. I regularity use it as VAS device in amplifier/s/. Why not use it as CCS? The only sensible way to build a line stage using D3A is with a step down transformer. I have done something similar using c3g and is not bad at all. Balanced with permalloy UTC LS-51.

2010年1月10日 · The various original chokes are no longer available to the DIY market, but you can use alternatives. Another easy to build this whole amplifier is what I call "simple SE" and documented as "bonus schematic" in the Manual for the Film Capacitor Universal Power Supply for diyhifisupply.com.

2013年2月8日 · Looking at the layout of this D3A LCR phono preamp, it appears that perhaps you are using a combination of the classic Ultrapath circuit, and a high value electrolytic capacitor across the cathode resistor from each of the D3A cathodes to ground.

2013年2月20日 · The initial construction steps of the D3a LCR phonostage have already been shown in part 1. In the meantime the wooden frames for the chassis arrived and the phono stage got completed. The different sub modules get assembled into a …

2005年8月2日 · As I said before, I got in touch with Thorsten who very patiently helped me out to adjust the values of his original 437a/300B DRD amp to use a d3A tube in the input stage instead. After a few months of parts collecting and finding the right time to build the this, it was finally done.

2020年10月14日 · The phono was designed around a triode-strapped D3a as the input tube with triode strapped EF86 as the second gain stage. Both tubes are CCS loaded and LED biased. The output is a AOT1N60 FET buffer with a constant current sink on the source. Coupling and output caps are Miflex KPCU-01.

2016年6月6日 · HIFIDIY论坛-之前买有4支德根D3A 用于推GM70 效果还可以 后见D3A个子小 与GM70大个子不协调 就下架了 现想用D3A做国都Ⅱ线路装2A3推挽玩玩 EF86 和 EF80已用于过国都Ⅱ线路 一是仿 ...

2009年3月20日 · This project is a circuit board which, through various jumpers, can be configured for various circuits. Specifically, it is designed around the D3a vacuum tube, a high Gm, high mu pentode. Additionally, there are several other tubes such as the E180F and E810F that share the pin arrangement with the D3a allowing their utilization as well.

The D3A it is easy to find on the market and the performances in triode connection are fantastic. In my PF2007 and in my new cheap 2A3 PSE it is possible see some measurements results. The sound of this simple phono preampl. is incredible and it …