Transcript:

Okay, this is a topic that comes up quite a bit on audiophile forums, the subject of running a DAC directly into a power amp without using a preamp – so basically going source direct from a DAC, either standalone or built into a streamer or CD player, that has some form of volume control so you can connect it straight to a power amp.

Personally, I’ve had mixed results, mostly negative, but I know some people swear by it, so let me know what you think in the comments..

So historically I’ve never been a fan of running my system without a preamp, not just because it limits you somewhat practically to a single source, but because it’s always had a mostly negative impact on the sound.

I’ve been running my office system without a preamp for the past few days and I’ve been surprised at the results. I’ll show you what that setup looks like later on and let you hear it, but first, let’s talk about why this seems like a good idea but might not work well for everyone.

So if you take the preamp out of the chain, you’re simplifying the signal path, and in theory, that should be a good thing, right. Fewer components mean less noise, better detail retrieval, more transparency, and modern high-end DACs like the one in my dCS Rossini, have such well-designed analog output stages that a preamp shouldn’t be necessary – unless of course you need to manage multiple inputs from different sources, then you’re going to need a linestage or some kind of switching box.

So going DAC-direct should work fine in theory – you’re getting maximum transparency, nothing between your source and your amp, just pure signal passing through straight wire. You’re also lowering the noise floor, since every extra box, every extra cable, every extra power supply is another potential source of RF and EM interference. And there’s also the obvious cost factor, good preamps aren’t cheap and neither are the interconnects you need to hook them up, and the racks, and the isolation devices.

But in my experience even the best DACs don’t always sound their best when you remove the preamp. Music can sound thinner, brighter, less engaging, you lose body, depth, and weight. Volume control can also be an issue in DACs that use digital attenuation, as you start losing resolution when you turn the volume down. So if you listen at lower volumes and your DAC is using digital volume control, you’re probably losing the very resolution that you’re paying a premium for in an expensive DAC.

Then there’s impedance matching to worry about, many DACs have a relatively high output impedance, and if your power amp has a low input impedance, the mismatch can weaken dynamics, reduce bass weight and impact, and just mess with the overall frequency balance.

And then there’s also gain to consider, some DACs put out too much voltage, which makes the volume control difficult to use – you turn it a notch and there’s too much output from the speakers, you never seem to be able to set the volume levels just right.

So when does running DAC-direct actually work?

Well, if your DAC has a really well-designed analog output stage, something like an MSB, a dCS, or a Mola Mola, and your power amp has a high input impedance, say 50kΩ or higher, then it might be a good fit. If your DAC has a proper analog volume control and not a cheap digital attenuator, then that’s another point in favor. And if your listening is oriented more towards retrieval of detail from your recordings, and you like that hyper-transparent, ultra-clear, super dynamic kind of sound, then going direct might work really well.

On the other hand, if your system leans a little bright or a little thin, or if it just feels like it’s missing some flesh on bones, then a good preamp can bring back that harmonic richness, that weight and warmth, especially a really well-made tube preamp.

Now I’ve tried running source direct many times over the years in different systems and with different components, and every time I’ve tried living without a preamp I’ve always ended up going back. An experience that stands out was about ten years ago when I had a big horn array powered by Cary 2A3 monoblocks and an Aesthetix Calypso linestage. I picked up an Audio Aero Capitole MKII CD player, mainly because it had a reputation for having a really good built-in volume control, and a lot of people were running it direct into their amps. So I figured I’d try it, but the system lost depth, dynamics, and body….. maybe there was a little more detail, but the trade-off wasn’t worth it, and I’ve repeated that experiment over the years with different gear, and every time I’ve gone back to an active linestage or preamp.

So a few weeks back I picked up a pair of Voxativ Zeth speakers, which I’ll review at some point soon…. these are a small full-range floorstander with a single driver per side and are very detailed and dynamic, but they’re a bit of a pain to set up properly and I haven’t really dialed them in the way I want just yet.

I’ve been running them with a Don Sachs D2 6SN7 based linestage and a Don Saches Kootenay KT66 power amp, and it sounds good, but the Don Sachs gear isn’t fully balanced and I was hearing a little bit of unwanted background hash, nothing terrible but I wondered how things would sound fully balanced, and using a battery powered amp.

So I pulled the Don Sachs pre and power amps and ran the dCS Rossini DAC straight into the balanced Veloce Audio Saetta monoblocks.

On paper the amps aren’t an ideal match for the 96dB-efficient Voxativ Zeths, they’re rated 320 watts into 8 ohms and 400 watts into 4 ohms, and they’re a hybrid design with 6H30 input tubes driving a bridged Hypex Class D output stage. They’re really designed for a more demanding load but they’re battery-powered, dead silent, and they lean a little to the warmer side of neutral, so I figured they’re worth trying out. There’s absolutely no glare, no digital edge, and they’ve sounded great on every speaker I’ve paired them with over the last few years, including higher-efficiency speakers like the Altec Lansing VOTT A7, Altec Lansing Valencias, and even Klipschorns.

So, I pulled the Don Sachs gear, kept my Iconoclast speaker cables, and ran Iconoclast XLRs straight from the Rossini’s balanced output to the Veloce Audio Saetta monoblocks, and I was pretty pleasantly surprised. It was way more dynamic and detailed than I expected…. in past attempts at running DAC-direct, I always ran into dynamic compression, but this time, it was punchy, vivid sounding, a nice wide and deep soundstage with good tight imaging. The level of detail and transparency was way ahead of what I was hearing with the Don Sachs D2 preamp and Kootenay power amp, I could hear everything in the mix with nothing added or removed.

But—and this is the big one—a lot of the music I like to listen to became a bit bright and fatiguing. The really well-recorded stuff sounded great, but a lot of older classic rock tracks from the 80s sounded thin and sterile, more so than previously with the Don Sachs amps.

In my other system, which is all analog, running ProAc D40R speakers and a Synthesis A100 Titan tube amp, everything sounds at least good. Some recordings sound great, but nothing sounds outright bad. But with the dCS Rossini, Veloce Audio Saetta, and Voxativ Zeth setup, it could sound pretty stunning or completely unlistenable, depending on the recording.

So I might play around with cables, isolation, maybe some tweaks to speaker placement, but from experience, I think I’m going to end up adding a fully balanced preamp that doesn’t kill the detail and transparency but brings back some warmth and fullness to the sound. I’ll probably try something like an Audio Research Ref 6, or a BAT VK-53SE, trying to keep to a budget of under $10K used. If you have any recommendations, please drop them in the comments below.

So just to summarize –

**The Good stuff:** Running a DAC direct into a power amp removes a component from the chain, increases transparency, reduces noise, and simplifies the setup. If the DAC has a high-quality analog output stage and good volume control implementation, then it can sound incredibly detailed and transparent.

**The Bad Stuff** Many DACs don’t drive power amps properly, often due to impedance mismatches or weak output stages, and you can end up with a thin sound, a loss of dynamics, or volume control issues. Some digital volume controls degrade resolution at lower levels, which can obviously affect sound quality. 

And then The Ugly: If the synergy isn’t right, going DAC-direct can make a system sound bright and overly analytical, and pretty lifeless. Music loses its body and weight, and you lose the emotional engagement.

I’ve got a sound sample in the video below, this probably wasn’t the best track as it’s used more for low bass evaluation, but I think you’ll get a flavor of how things sound without a preamp.

Anyway, if you’ve watched the vids on YouTube, please hit Like and Subscribe, and/or drop a comment below – I’m particularly interested in peoples’ experiencess running without a preamp and also any recommendations you might have for a quality, balanced, tube preamp, under $10K used.

Cheers old beans.

CAH March 2025

Thinking about source-direct with a vinyl rig? Check this out: