Sylvania 7F7 Chrome dome Posted on August 12, 2020 by tubemaze (3 votes, average: 5.00 out of 5)Loading...Good overview of 7F7 tubes. ReadShare this post:
Often overlooked tube type due to its Loktal base, but it’s one of the hidden gems out there and can easily take a place of any 6SL7 with an adapter. Don’t worry about 7 volta heater rating on this tube, it works great in 6 volts circuits and will last much longer that way.
As you can imagine, I have thousands of tubes in my private collection, but I’ve noticed that I return to this tube over and over and over. It just has that magical sound that is hard to beat. It’s very airy and musical (think Sylvania 6sn7 Bad Boy), solid bass and fantastic transparency with a very beautiful mid-range. The tube reminds me a lot of Sylvania 6SN7W with metal base. Just beautiful and never fatiguing. There is some info that maybe the tube has gold-plated grid wire, but that info is hard to check without chemical analysis. It’s hard to identify the tube that I have 100%, since it’s branded by Zenith, but a few things to keep in mind if you want to find the same tube, it has copper supporting rod and charcoal plates (not shiny black), which is very unusual for 6sl7 or 7f7.
As I was writing Tung-Sol 6189 review, I got tired of it and plugged back the Sylvaina – Bam! it’s like somebody removed cotton balls out of my ears 🙂
Sounds very interesting. I just got 2 adapters of ebay and will give 7F7 a try, they are so much cheaper than 6SL7, so rolling I will. Will post a review when I get them 😉
Where did you got your adapter from? I only see stuff from HK
Had to go the HK route