Douk Audio T8 Tube Preamp Equalizer XLR

[dsd4life]

I had the bright idea of using multiple Douk Audio T8 Tube Preamp Equalizer XLR units between my processor and amplifier for my Left, Center and Right speakers.
Presently I have my left and right routed thru a Douk Audio T8 Tube Preamp Equalizer and my center speaker routed thru a adjacent Douk Audio T8 Tube Preamp Equalizer. I notice if you un-plug the tube from either the left or right tube circuit the machine does not play sound from the tube is still plugged into. So I guess even with XLR this is not a true differential balanced topology.

In addition on the Douk Audio T8 Tube Preamp Equalizer I use for the center channel. I find that my test tone to the center sounds full strength if I shift the balance knob 100% to the extreme side of the channel (left in my case) the processor center channel XLR is plugged into on the Douk Audio T8 Tube Preamp Equalizer. I wonder if I would benefit from just using another Douk Audio T8 Tube Preamp Equalizer x 3 for all Left, Center, Right with the balance knob dedicated the channel the Douk Audio T8 Tube Preamp Equalizer is input. Almost like a mono block design.

 

[Drengur]

What problem are you trying to fix? This looks like fun, but I wouldn't say it has the potential of being beneficial unless there is something very specific going on with your system.

 

[dsd4life]

What problem are you trying to fix? This looks like fun, but I wouldn't say it has the potential of being beneficial unless there is something very specific going on with your system.

Looking for insight into why the balance needs to be shifted all the way to one side.

 

[DVDdoug]

I notice if you un-plug the tube from either the left or right tube circuit the machine does not play sound from the tube is still plugged into. So I guess even with XLR this is not a true differential balanced topology.

Something seems wrong. The left, right, and center channels should be separate.

Bypassing the preamp and connecting one amplifier channel at a time might give you some clues. You can try swapping cables too in case you've got a wrong one.

I find that my test tone to the center sounds full strength if I shift the balance knob 100% to the extreme side of the channel (left in my case) the processor center channel XLR is plugged into on the Douk Audio T8 Tube Preamp Equalizer.

I'm not sure what you're saying... But since you should only be using one side of the preamp for the center I'd leave the balance control at the neutral position.

 

[dsd4life]

I'm not sure what you're saying... But since you should only be using one side of the preamp for the center I'd leave the balance control at the neutral position.

Precisely not what I am hearing. When using the Douk Audio T8 Tube Preamp Equalizer with only one channel; the sound is attenuated with the balance knob in the mid point.

My thinking is that just use 3 x of them independently with the balance knob positioned to either extreme Left or Right depending on which Left or Right XLR input you are using.

I think there is a design flaw with these machines; there is sound attenuation with the balance mid point knob.

 

[LetterRip]

So, your solution to pan to the side you plug into is correct, but it's not necessarily due to a flaw; it's because it's a stereo unit with a pan pot. There is pan law in effect at the mid-point, essentially attenuating the signal several decibels. I guess a way to check this would be to insert a cable on one side, middle the pan pot, and then check to see if you are outputting audio from the opposite output.

 

[dsd4life]

What problem are you trying to fix? This looks like fun, but I wouldn't say it has the potential of being beneficial unless there is something very specific going on with your system.

Not trying to fix any problem. I am so tired of all this Dirac DSP garbage. I listen to a lot of high bit rate multichannel Music like Pink Floyd 50 anniversary Wish You Were Here and I enjoy a little tube buffer middleware (I am a tech guy) with some analog equalization.

Someday McIntosh (maybe not with Bose) will make a home theater processor with tube preamplifiers buffers in-front of Left, Center and Right channels.

I probably need to deploy separate Douk Audio T8 Tube Preamp Equalizer PRO XLR units with power supplies into a good power conditioner. I hope the equalizer channels don't suffer the same balance knob attenuation issues.

My next upgrade should be the Emotiva + platform with reference differential balance topology.

 

[Floydian Trip]

I had the bright idea of using multiple Douk Audio T8 Tube Preamp Equalizer XLR units between my processor and amplifier for my Left, Center and Right speakers.
Presently I have my left and right routed thru a Douk Audio T8 Tube Preamp Equalizer and my center speaker routed thru a adjacent Douk Audio T8 Tube Preamp Equalizer. I notice if you un-plug the tube from either the left or right tube circuit the machine does not play sound from the tube is still plugged into. So I guess even with XLR this is not a true differential balanced topology.

In addition on the Douk Audio T8 Tube Preamp Equalizer I use for the center channel. I find that my test tone to the center sounds full strength if I shift the balance knob 100% to the extreme side of the channel (left in my case) the processor center channel XLR is plugged into on the Douk Audio T8 Tube Preamp Equalizer. I wonder if I would benefit from just using another Douk Audio T8 Tube Preamp Equalizer x 3 for all Left, Center, Right with the balance knob dedicated the channel the Douk Audio T8 Tube Preamp Equalizer is input. Almost like a mono block design.


View attachment 506977

You can use a Y cable on both the in and out and see how it sounds. You may or may not have phasing issues that may or may not be solved by reversing phases manually (solder cables) or mechanically with a DI box

 

[dsd4life]

You can use a Y cable on both the in and out and see how it sounds. You may or may not have phasing issues that may or may not be solved by reversing phases manually (solder cables) or mechanically with a DI box

Which still means devote a Douk Audio T8 Tube Preamp Equalizer XLR for each channel. I still think that is a defect in the design that the machine sounds better with balance set the extreme position of the channel being operated.