It's been a while since the last update about the ER300B.
In the meantime I received more feedback from users of the tube which I'd like to share. But first I am happy to announce that the data sheet for the ER300B is now finally released. Please click on the link to download it. Many people have asked for this since my initial report about the tubes which mentioned some deviations from the Western Electric specs. Now the characterisation is complete and the data sheet is released. The main differences to the WE 300B are the increased plate resistance of 950 Ohms vs. the 700 Ohms of the WE and the reduced amplification factor of 3.3. There is also an Application Note for the ER300B which explains the impact of this and the optimal use. This can also be downloaded by following the link.
Here are the plate curves from the data sheet:
Note the extension of the curve set into quite high voltage territory. The design of the ER300B is derived from the ER845 and is capable of higher plate voltages than the WE. I am planning some new amplifiers which take advantage of the parameters of the Elrog tubes.
But all this technical stuff is boring for many people and they are more interested in the performance of these tubes in actual amplifiers. Here a feedback which I received from Theo from Norway:
Here a photo of Theo's DRD 300B monos:
The impressions above were only after a few hours of listening. After some more listening Theo provided another update:
- The Elrogs are way better in the bass, the control and resolution is just in a different league, WE are soft and unresolved in comparison.
- My impression is that the Elrogs are much more dynamic than the WE.
- The Elrogs are highly resolving from bottom to top, very smooth sounding, very natural highs, I think the WE have too much sparkle in the top.
- Good perspective and 3d properties with Elrog, better than WE, Elrog puts the soundstage at a larger distance than the WE. WE are quite close and "up in the face" which I do not like too much.
- The Elrogs are more open, they have a leaner sound and more delicate colours in a way.
- The WE seems to have a little more harmonic richness, or "magic" or euforic colour or whatever it can be called. The Elrog tubes outperform the WE in all other respects. I do not think the WE colouring is correct, but it is a very alluring and appealing property.