300b and PX4 tubes now approved for use in the Balanced Level 7 Dacs.

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That makes 3, as 101d was the only approved tube before.

Heat management is important in the design of the Balanced configuration, as the voltage drop from the power supply gets turned into heat. Tube characteristics must thus be close enough to the power supply design specs and these 3 are.


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Thank you Lukasz.


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I wonder if PX25s would work.


I wonder if PX25s would work.

I dont think so…not for Balanced.

101d has 11.2watts of heat to dissipate while the PX25 would have 22.4watts.


Here is some more news I just heard... EML Anniversary globes in MESH plate form will be available soon via Lampi. The Limited edition originals were solid plate only and for the first time they will do mesh Anniv Globes. No idea on price.