Schiit Freya+ Tube Stage is Silent


I have a Freya+ and replaced my passive balanced crossover with an active one, reducing resistance significantly. I noticed two changes:

 

The SE output to my sub voltage dropped considerably (expected and addressed by moving to differential buffer mode and turning up the gain on the sub).

 

The gain stage for the tubes stopped output completely. Any idea why? I can give you additional history, if it is relevant. Please ignore it if it isn’t.

 

When I had the passive Marchand 80Hz LZ high-pass between the Freya+ and the Tyrs over balanced connections, I had too much resistance and had to take my DAC out of Unity mode (3.7V) and manually drove it to nearly 6.5V to get the volume up to drive the Maggies. The sound was awful and when in tube mode; it sounded distorted. Therefore, I bought the active crossover and reset the DAC back to Unity mode. The sounds coming from my Magnepan 3.7is are now magical and while the bass is adjusted upward for changes in output voltages, I’m disappointed the gain stage stopped working. Thinking I potentially overdrove them with the 6.5V, I ordered a replacement set of gain stage tubes. Is there a possibility I have something else going wrong in my setup?

The gain stage is a set of mid-1960s Sylvania 5687wa long black plates in VIC Audio 6SN7 to 5687 adapters. The follower stage is a set of 1947 Telefunken 12U7s diamond tips with comparable VIC adapters. 

dunham_john

That happened to mine too. It was just a resistor inside the unit that blew. Repair cost was $50 +shipping. Less than a new set of tubes.

Only gain can distort the signal. Volume can't. So, when you set your gain, use as much as you need, but no more. Rely on your volume control as much as possible it can't distort the signal no matter how much you turn it up.

You also have to be careful when mixing balanced and single ended gear. The 2 modes of operation are not compatible. I suspect your no sound problem may be due to comparability. What are you plugging the output of your preamp into? If you are using the balanced outputs, you need to make sure the input on the next component is balanced. Just having an xlr jack on the back of a component doesn't mean its balanced. Its just a connector. A lot of manufacturers short one of the hot pins to ground on the input, so if you plug a cable carrying a balanced signal into it, it immediately creates a short circuit. If that's the case, you may have a ready damaged something. Try the single ended outputs and see if it works. 

The balanced output from the Freya+ is plugged into a Marchand XM44-1FB    Electronic crossover, 1-way, fully internally balanced. The Marchand XM44-1FB connects to 2 Schiit Tyr monoblocks. The single ended output from the Freya+ plugs into a Rhythmik FS-12E with a built in 80hz low-pass crossover at 12dB/oct.

Send the Freya signal into the Tyrs to check. You want to remove as many possibilities as you can while you troubleshoot this.

@koestner Help me understand the logic? The pass and JFET buffer stages work with the crossover in place. What about the tube would be different, other than putting out +12dB worth of voltage?