In the previous post, I introduced the stereo 300B single ended amp under development. The 6SN7 has been chosen as driver tube. Since the 6SN7 was already covered in a tube of the month post, we will have a look at another type which is electrically equivalent but has a different base, the 7N7. The 7N7 is a Loktal type.

2021年2月1日 · At about 100 hours on the Cossor 300B's, they sound much better than the Gold Lions and the Treasures. The mid range is warm, detailed and balanced. The tubes have great timbre, solid imaging and the soundstage is well defined, extending well behind my speakers. The bass and treble are also better than the Shuguang and Gold Lion.

2011年4月17日 · 6SN7串叠推动300B的声音特点是高低频延伸好，中高频解析力极高，低频量感不多但是力度和延伸都很好，不属于很有“胆”味一类，但亦属于特点鲜明的线路，喜欢这类声音的朋友值得一试。 要想把300B推得全面还需足够的推动电压和电流，6SN7并管推300B是一个不错的选择，搜索老帖，找到了J版改的6SN7并管推300B线路，但是推动级需要一组单独450V的高压供电，制作成本和难度对我等菜鸟实属不易， 于是想采用妥协的办法来应对，修改后的线路如 …

2003年8月15日 · In recent posts Earl has been talking up the virtues of the 7n7 tube as a replacement for the 6sn7. The 6sn7 has become is a popular hi-fi tube, and has become increasingly more expensive, with some of the more prized NOS brands exceeding $100. Last night I received a package with three 7n7’s.

2011年8月26日 · The 7N7 is a good tube, better in the driver position than as an output tube IMHO, but in all of my systems it just does not stand up to the better 6SN7GT tubes (tung-sol round plates etc.), but we are always trying to find that odd tube for $5.00 that does sound as good as the Tung-Sol round plate or RCA VT-231.

2020年8月25日 · If you really want octal, try JJ 6V6: you can run high current and get a better grip on the 300B grid. Or turn up the gain of your op-amp stage, and use a 2A3 as driver.

2016年6月6日 · HIFIDIY论坛-近日仿真了几款300B推动线路，包括6SN7两级推、6SN7并管推、6SN7-6V6推等，主要是对比这几款推动线路输出的不削波最大推动电压（有效值）。

2003年8月15日 · I would say most of the time I prefer the 7n7 tall bottle tube. But in cases where some slight tweaking is in order to make the sound a little more forward, without losing refinement, the 7af7 is a good tube to try.

2020年7月6日 · I am using 7N7's and 14N7 in place of 6SN7's in an amp now. Good NOS Loctal sockets are not as inexpensive as regular octal sockets, but they can be found on eBay from various sellers.

2018年8月3日 · A Parallel 300B PP amplifier, rated for 40 watts. The Amp was built with two amplifiers in mind, Namely the Samson PAM-29 and the Brooks 12A as the main references but with a few tweaks.