Bluesound Vault Output Question.

[murphydog]

My newly arrived Vault is proving to be rather a loud beast on playback. Am I correct in assuming that I could valve swap in my Croft pre/power to attenuate the output and thus give myself more scope to adjust the volume on the amp?

 

[manicatel]

Or you could just turn the volume down a bit in the BluOS app?

 

[Strictly Stereo]

You could always trim the output from the Vault using its built-in volume control. Alternatively you could use in-line attenuators to bring the output level down.

 

[murphydog]

I’m running it into a Mojo which means the output is fixed.

 

[Vinny]

Chopping and changing valves very seldom achieves what people think/expect, not least moving to lower gain valves, which generally do not produce a proportional reduction in output, if any. Certainly in a Micro and 7, you are all but wasting your time changing anything.

 

[Strictly Stereo]

I’m running it into a Mojo which means the output is fixed.

In which case, the problem is really the Mojo rather than the Vault. I am not sure about the Mojo but plenty of other Chord DACs output 3V in fixed output mode which is probably a bit too hot for your Croft preamp. You should turn down the Mojo's volume or fit in-line attenuators between the Mojo and the preamp.

 

[murphydog]

Thats exactly the problem. The Mojo sorry to be misleading. I have some Goldenjacks, I’ll try those.

 

[The Bish]

Thats exactly the problem. The Mojo sorry to be misleading. I have some Goldenjacks, I’ll try those.

Could you turn down the voltage on the Mojo output? I used to run it at 1.9 v into a Croft 25r.

 

[murphydog]

Presumably I would use the variable output on the Mojo? Wouldn’t that compromise the sq?

 

[Barrymagrec]

Assuming the circuit uses any form of negative feedback, which is pretty much any circuit, a lower gain valve will have negligible effect on gain.

Distortion, noise, frequency response....very possibly.

 

[Strictly Stereo]

Presumably I would use the variable output on the Mojo? Wouldn’t that compromise the sq?

Lowering the Mojo's volume by just a little will bring its output down to a level which is more in line with your preamp's expectations. Depending on the inner workings of the Mojo, its volume control might in theory compromise sound quality a little, but this will pale next to the harshness that you will likely get from overloading the preamp's input.

 

[mseve1]

I’m running it into a Mojo which means the output is fixed.

The output doesn't have to be fixed. The Vault 2i should allow variable output on both TOSLINK and COAX to feed the Mojo. Providing that the attenuation applied is relatively modest (say, -10dB) the Vault's variable output digital signal quality should be practically just as good as it's fixed output.

 

[Milan]

I found no discernable difference in sound uality using a Mojo with the volume control or as line in. I use the volume control to level the output to match that from my other DAC (ARCAM rDAC) so I can swith without upsetting the neighbours.