ShortBtwnHdset
100+ Head-Fier
Hi All!
I was hoping someone could give a little advice. I’ve been upgrading a hybrid tube headphone amp that has very limited space. Headphone amp is a Schiit Mjolnir 2. One of its constraints is it uses a non-regulated 6 volt supply for the tube heaters, just a simple RC network after the bridge rectifier (coming off a multi-secondary transformer). I’ve been shopping standalone, regulated circuit boards/kits/modules for tube heaters. As space is limited in the amp chassis, I was hoping to make this separately enclosed (with separate transformer) in an external case. The easiest method to do this would be to remove the bridge rectifier and caps from the 6 volt heater rail of the headphone amp (thus disabling that secondary tap of the transformer) and pipe in directly where the previous RC filter caps were (via an external port). But now we are tying two separate circuit grounds together, and two separate cases. So let me ask a few questions.
The other method, which would be harder (and somewhat irreversible), would be to solder the external supply directly (via the external port) to the tube sockets, but then there is the problem of having to isolate those pins from the main circuit board. It might be able to be done by cutting traces/etc., but this is a 4 layer board and there may be connections or circuit trace routing I don’t know about. . There is no schematic. This method would also make it less easily reversed if I don’t like the results and wish to restore.
What do Ya’ll think? Any experience on something similar?
I was hoping someone could give a little advice. I’ve been upgrading a hybrid tube headphone amp that has very limited space. Headphone amp is a Schiit Mjolnir 2. One of its constraints is it uses a non-regulated 6 volt supply for the tube heaters, just a simple RC network after the bridge rectifier (coming off a multi-secondary transformer). I’ve been shopping standalone, regulated circuit boards/kits/modules for tube heaters. As space is limited in the amp chassis, I was hoping to make this separately enclosed (with separate transformer) in an external case. The easiest method to do this would be to remove the bridge rectifier and caps from the 6 volt heater rail of the headphone amp (thus disabling that secondary tap of the transformer) and pipe in directly where the previous RC filter caps were (via an external port). But now we are tying two separate circuit grounds together, and two separate cases. So let me ask a few questions.
- Would that be problematic for noise, stability?
- Would you tie the chassis grounds together?
- You are now unloading a secondary winding from the original multi-secondary transformer. Do I need to compensate for extra voltage/amperage the other secondary of that transformer may now have since 6 volt secondary is now unused/unloaded? Or will other secondary be unaffected?
The other method, which would be harder (and somewhat irreversible), would be to solder the external supply directly (via the external port) to the tube sockets, but then there is the problem of having to isolate those pins from the main circuit board. It might be able to be done by cutting traces/etc., but this is a 4 layer board and there may be connections or circuit trace routing I don’t know about. . There is no schematic. This method would also make it less easily reversed if I don’t like the results and wish to restore.
What do Ya’ll think? Any experience on something similar?
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