Integrated DirectStream DAC/Preamp

I’d like to make a request. One that almost no one here will agree with.

Could you integrate attenuation into the next DS, i.e., make an integrated version of the DS?

I have low sensitivity Maggies. With the DS set to 90 and my Stellar at ~36, the output is well into ~80 dB at 10 ft away from the speakers. The Stellar doesn’t add gain until 72 or so. So, what I’m saying is that I just do not need the gain, and I would guess many other people don’t either. Though many systems are different.

Ted as already added a resistor to attenuate output, so why not take it the next step and add a clean stepped attenuator or something like that? With plans to have the DS output full standard voltage in the next iterations, this would maybe completely remove the need for some other device in the chain. The transformer output could max out to stay away from the noise floor, while the resistors attenuate. And it could isolate the transformer coupled output from the rest of the system.

I would even like this as an option, because surely not everyone would want it, but I very much would.

Just throwing it out there as a suggestion.

I understand the need for a better solution than the DS provides.

The TSS will have four attenuator settings: 0, -10dB, -20dB and -30dB, along with standard output levels (2 and 4 VRMS) and an option for the RCA output to be doubled most people’s systems will be covered.

There’s no cost effective way to put, say, a $6K preamp into a $6K DAC and the combination it for $6K.

A stepped attenuator puts the same or more load on the output transformer as the current attenuators at the same output level and the current attenuators are more transparent than those of a stepped attenuator (way fewer parts and no resistors in series with the signal.)

Isolating the transformer output is the opposite of what we want, capacitance of a cable will interact more with the resistance of a stepped attenuator than with the transformer.

A new version of the DS will take advantage of what we learn with the TSS.

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Thanks for the reply, Ted.

The stepped attenuator was just sort of a random suggestion, I’m sure better solutions could be made.

The basic idea being that since no gain is needed (based on my needs), the cost of the attenuation would be less than that of a full “preamp”. I would be willing to pay more to have that functionality baked in, so that I wouldn’t need a preamp. I don’t need the input switching anyway. Going forward, with streaming coming to prevalence, more people will probably be in the same position.

As far as transformer isolation, what about ultrasonic noise filtering? I’m sure there are some good solutions, but I was just wanting to throw the general idea out there.

I understand - helping with the problem you are having is important to me.


Which amp are you using? Sounds like you’ve got a lot of gain somewhere in the chain that you don’t need.

Stellar M700s. They have typical amp gain.

30.5dB is on the high side. I have a suggestion you might like to try.

The DS DAC’s digital volume attenuation is brilliant. Enable the 10dB attenuator and turn the digital volume to 0. Adjust your pre-amp’s volume level so that it’s a little lower than the point where you can start to hear the DAC’s noise floor coming through. Then play some music and use the digital volume control on the DAC. There’s nothing wrong with listening at small numbers on the DAC if you can’t hear the DAC’s noise floor anyway.

I don’t really have a “problem”. I’m just fine with the preamp and DS levels.

I’m just stating that I don’t need the gain is all, and I’d rather have the DAC and preamp attenuation wrapped up in one.

Oh OK. Well have you tried running the DAC direct to the M700’s? My guess is that with the 10dB attenuator enabled you’ll be able to hear the noise floor but only faintly. I say that because my speakers are slightly higher sensitivity than yours and my power amp has a few dB less gain, and I get just the tiniest hiss from the listening position.

I actually just hooked the M700s up directly to the DS. I avoided doing so for a good while because my sub uses RCA connections, and I didn’t want to lose the benefit of balanced to my amps by connecting both XLR and RCA to the DS output. Turns out it’s ok. With the attenuator on and the DS set to 85-86, quiet music is in the lowish 70 dB and loud music is in the mid 70s or so. So just guessing, with the DS in the mid 90s, I’d be getting in the mid 80s dB or so, plenty loud for me.

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BTW, I might be crazy, but I could SWEAR the bass improved with a direct connection to the DS! I’ll play around to confirm.