Elrog 300B vs Takatsuki 300B tubes

Hi Al,
Good point, but interestingly Wyan001 and Germanboxers use the same DAC with superb results. Could system synergy partially explain it?

System synergy is a possibility. I use a Tortuga Audio passive LDR preamp. May there's an impedance mismatch? Tortuga has a new software upgrade so you can vary the impedance of the preamp, which I don't have. May its time to upgrade and see if this will improve the sound.

I don't doubt the Elrog owners who heard improvements with this tube.

Dracule, This is odd. Your findings are so different from Wyan, who also had the opportunity to evaluate both the Elrogs and the Psvane 101D WE replicas. He had a strong preference for the Elrogs in his Lampi. I know the Psvanes from using them in my Coincident CSL, and they are very good tubes. Highly resolving with excellent tonality. It is possible you just like their sound better, or they do match your system better. I will say this, when my first set of Elrogs began to go bad, their sound was nothing special to say the least. I can't rule out that you have a couple tubes that are not up to snuff.

Dracule1,

Sorry for the bad news. Elrogs are supposed to be great even without breaking in. And their sound signature doesn't change much during burnt-in process.

I am not sure if Elrog change the formula a little bit and cause the difference.

WYAN

10-25-15: Charles1dad
Hi Al,
Good point, but interestingly Wyan001 and Germanboxers use the same DAC with superb results.

Thanks for pointing that out, Charles. In looking at the Lampi site, though, I see that Dracule's GG is described as having a choke (i.e., an inductor) as the plate/anode load for the output tube, while the Big 7 which the other two gentlemen have been using is described as using a resistor. I don't know if that might account for any difference in how the Elrog performs in the two designs, but it suggests that it could conceivably be a possibility.

10-26-15: Dracule1
System synergy is a possibility. I use a Tortuga Audio passive LDR preamp. May there's an impedance mismatch? Tortuga has a new software upgrade so you can vary the impedance of the preamp, which I don't have. May its time to upgrade and see if this will improve the sound.

There isn't enough information at the Lampi site to be able to say for sure, such as an output impedance spec, but I'd be surprised if there was an impedance compatibility issue here. It appears that all of the currently produced Tortuga passive preamps have input impedances of around 20K or more, regardless of the attenuation setting, which, given that it uses LDRs, figures to be essentially constant as a function of frequency. I'd be surprised if the Lampi's performance would be compromised by such a load. And while the input impedance of your amplifier will reduce the 20K somewhat, depending on the attenuation setting, since you are using a passive preamp I assume the input impedance of the amp is high and will therefore not have a large effect on the impedance seen "looking into" the preamp.

On the other hand, though, it appears that the 300B or other output tube that may be used in the GG & Big 7 is used in an anode follower/plate follower configuration, which leaves me a little bit less certain about impedance compatibility than I would be if it were a cathode follower that would undoubtedly have low output impedance.

Best regards,
-- Al