Benchmark DAC1 Pre - anybody heard a mod?

I have a Benchmark DAC1 Pre that I am fairly happy with. I have seen and read several posts from people offering modifications to the DAC1 that apparently increase warmth, resolution and imaging. Does anybody own a modified DAC1 or DAC1 pre that has been modified? What were the modifications, costs and sonic improvements? Your advice will help me decide if this is the right decision for me.

Beaster - Empirical Audio used to make modds to DAC1. One of them was to replace NE5532 amps with OPA627. Benchmark engineers stated that OPA627 is inferior to NE5532 (more THD) but Steve from Empirical Audio said that microlevel details are improved. In addition he was converting whole DAC to NOS, therefore loosing advantage of jitter rejecting property of usampler. If you already have good transport you might enjoy the sound of NOS.
I have a benchmark Dac 1 that I had modified by Stephen Balliet at Reflection Audio. I am very happy with this dac and use it in a Mac based system with an RME digital interface and an isochrone master clock.
This setup replaced Meitner seperates.

The effects of the upgrade were exactly as you describe hearing.

I chose reflection audio and Stephen because of his singular focus on modding this dac and his musical priorities which matched mine.
He is also a very fine man to work with....highly recommended. The cost was about the same as the Dac 1 but I found the improvements wholly worth it in the context of my overall system.
Thank you for the replies.

I am based overseas (Singapore) and have someone here who can offer a mod. Unfortunately it does cost almost 40% of the price of a new DAC1 Pre. I was wondering if I should go ahead with the mod or use the money to purchase a tube pre-amp to get the warmer / fuller sound.

Rigth now my unmodified Benchmark pre goes directly into my ATI 2002 power amp which goes to the Usher BE-718.
The benchmark is wonderful, I actually own one too. However, the sound is far from warm and full. If this is the type of sound that you are looking for, as stated above, then I think you would do better by putting your money into a Tubed Preamp as opposed to modifying the Benchmark. Mods should be use to improve the underlying characteristics of the component, however I doubt that it will change the Benchmark into something that it's not.

I know people like the purity of plugging the Dac right into the Amp, I've been there and done that too, however you will be amazed at just how much better, warmer and richer the sound could be from a nice tubed preamp.
Richlane - I agree, sound is far from warm and full but clarity and transparency is unprecedented. I drive directly class D power amp with good results but also know that people who combined Benchmark with tube gear were very happy. I would still bypassed preamp to drive tube power amp directly.
Less is more (and cheaper too).
Hi Kijanki,

I'm glad you're getting good results with your DAC plugged directly into your AMP. I too had good results with my Bel Canto DAC3 plugged directly into my Class D Bel Canto REF1000 Monoblocks, however when I re-tubbed my VTL Preamp and then put it back in my system; the sound improvement was astonishing. The soundstage opened up further, and there was better depth, width, imaging and PRAT. The Vocals were also more palpable and real with more flesh on the bones.

Sometimes less is more, but sometimes less is less.

I think that Beatster has basically 3 choices to get the warmer, richer sound that he desires.

1) Buy a Tubed Preamp
2) Buy a Tubed Amp or perhaps a high quality Class D Amp.
3) Buy a Tubed DAC

Since he already owns a Great DAC and a SS AMP, I think his best purchasing decision; in order to get a warmer and richer sound would be to add a Tubed Preamp instead of modifying his Benchmark DAC.

I happen to like the combination of a SS Amp matched to a Tubed Preamp.

Not only will a good quality Tubed Preamp warm up the sound, but as I stated above, it will also open up the soundstage dimensions, as well as provide better imaging, and PRAT.

Happy Listening!
Richlane - I agree he should at least try tube preamp (I should too).
Thank you all for your replies. I was also of the opinion that less is more and thus was looking at options of modifying the Benchmark DAC1 Pre. Now I am inclined to try a tube pre before deciding on next steps.

On another note, I also considered changing the Benchmark to another DAC. Came across a tube DAC called Chime made by Hagerman Technology? As I need USB input, this sounds very promising.
Hi Guys,

I think it's great that you're both willing to try new things. That's what makes our hobby so much fun. Beatster, as a mentioned earlier, I too own the Benchmark DAC, and I think it is absolutely wonderful,

I initially bought it for my Living Room, but now I have it hooked up to my Mac Pro in my home office, with a pair of Audio Engine 5 speakers and I'm getting wonderful results. I was able to find the sound that I was looking for in the Bel Canto DAC3 used last year for $1750 now it goes for around $1600. But, it was the Benchmark DAC that initially lit a fire under me to upgrade my entire audio system over the past year, and I haven't looked back.

As Kijanki mentioned, the Benchmark DAC does really excel in; clarity, transparency and resolution as well as sound stage width. I think it is a little weak in midrange purity, timbre, harmonics, and sound stage depth, but for $1000 I think it is is still one of the best buys in all of HiFi and I continue to wholeheartedly recommend it to anyone looking for a new DAC. I think if someone's system is on the warm side, too laid back or to slow then it's a great choice. If someone's system is too dry, analytical, or too forward then I would go for a used Bel Canto DAC3. The Bel Canto also has a smoother midrange than the Benchmark, without sacrificing transparency, speed, or resolution.

The best thing to do would be to try and demo or borrow different components that you may be interested in, without committing to purchase it just yet.
Oh, one more thing!

True, sometimes, less "is" more. If a component or cable, is not transparent to the source and it gets in the way of the music, than in fact less is more.

So, trust your ears, in your system, that's all that matters.
I also own the DAC1 Pre and I think it's absolutely a great match for my system. I use a tube preamp, the Convergent Audio Technology SL1 Ultimate, and a tube power amp, McIntosh MC275, to power my Harbeth Super HL-5 speakers. My system tends to be warm and musical and the DAC1 Pre is just the DAC for my system. I use a Rega Saturn for the transport. I plan to connect a hard drive system to the DAC1 Pre in the near future. Also, in my system, the Benchmark is better than the Rega Saturn used as a stand alone CDP. I get the warm and rich sound that the tube components and Harbeths provide while getting all the clarity and resolution that the Benchmark can provide. I have no desire for additional warmth from the DAC1 Pre so I would not consider a professional mod.
I've considered modding my DAC1 USB to see what that could really bring, but really just don't have the desire to do so. I use a BAT VK300xSE which has a tube pre-stage, with SS amplification. Speakers are Totem Hawk. I really like the way this setup sounds.

If you do mod, please report back on your impressions!
This discussion is interesting. I've read more than a few posts that suggest a tube preamp brings some warmth to a system using the Dac1. Perhaps this is a naive question, but would a integrated tube amplifier + Dac1 have a similar warmth as a system having a separate tube preamp? I have a Dac1 USB - not the Dac1 Pre. Thank you.
Yes it would, but only to the degree that a stand alone Tubed Preamp, may be better than an Integrated Hybrid Tubed Amplifier. In other words it will warm up the sound to the the best of it's ability, based on the weakest component in the chain, which in this case may or may not be the Integrated Component as compared to top quality separates.

One month down and I am still contemplating options...

1. Mod the Benchmark DAC1 Pre
2. Get a tube pre
3. Sell the Benchmark and start from scratch! (a upgrade bug! but I really do not want to do this)

I am tempted by option 2. There are a couple of used tube preamps that have come up in the market here:

Audio Space Line 2 or CAT SL 1 and others...

I am currently using the XLR outputs of the Benchmark to my ATI 2002 power amp. Most tube pre amps have RCA inputs and outputs. Are the RCA and XLR outputs on the Benchmark equal? I do not have RCA cables so unable to try this out for now.
Hey Beatster,

Say hello to Singapore!

Let's look at your entire system:
ATI Amp; sort of a home theater heritage and on the clinical side
Benchmark; also on the clinical side, it already excels in resolution and imaging, I can't see it turning into a warm piece of equipment.
Usher; very nice...., no complaints here.

I would approach your upgrade path with a look forward towards the future, as opposed to a one and done sort of upgrade.

The way I look at your system, you're plugging an analytical DAC/PRE into an analytical Amp, no wonder you're not happy with the sound.

I think you should buy a tubed preamp that can remain in your system for years to come, and then in the future I would consider a warmer SS amp, I would probably recommend one of the new excellent Class D Amps. I could certainly vouch for the Bel Canto Ref1000. If you do this, than I think the Benchmark will shine, remember I also own the Benchmark in my office system.

If you buy a tubed preamp, and a Class D Amp, with your Benchmark DAC and Usher Speakers, I think you will get the warm analog sound that you're looking for, without sacrificing detail and resolution. If you still don't like the sound than I would sell the Benchmark, not modify it, and I would buy a Bel Canto DAC3, once again I have extensive experience with this DAC and it has everything that is lacking from the Benchmark.

Hi Beat,
I too own the Benchmark (DAC1), I was planning to use it as a preamp to my tube/SS hybrid Butler amp, but have been waiting years for BM to make a remote control. They now have one in the new $1900 model, which seems very nice. But a new contender has arisen - Peachtree Nova. It is an integrated amp, with a killer ESS Sabre dac, an 80 watt amp, remote control and tube preamp, all with HT bypass. It has the ability to turn off the tube if desired, and had preamp outs to use with an external amp. It was recently compared to the BM Pre in a review and held its own well. It seems like a steal at $1200. I am going to sell my Dac1 soon for the Nova.

Check out the review:

I have no affiliation.
The RCA outputs on the Benchmark are fine. I'm not familiar with Audio Space, but don't go by that, I do like the CAT a lot though.

I'm not sure of your budget, however, I would also like to add; VTL 5.5, Atma-Sphere MP-3, Joule Electra LA150, Aesthetix Saturn Calypso, PrimaLuna ProLogue3, and Rogue Audio Metis to your list. Some are more costly than others, but at least this list will give you a good starting point.

I haven't listened to many of these, but they have all received wonderful accolades and awards from TAS and Stereophile alike.

I have the benhmark and once I upgraded cables & power cords (tara labs the one rca & shunyata python Vx Alpha Helix PC) and set all on a symposium shelf (w/nordost digital cable from digital source) the sound is awesome. The cables made a huge difference in my system (solid state/electrostatics so pretty critical, unforgiving and revealing and not clinical at all).

Only upgrade path I would take is the Berkley-maybe the new PS Audio but not sure the PS would be a large enough improvement for me.
Cerrot - what changed from power cable on Benchmark alone? I'm planning to put power conditioner (Furman 20PFi) and very short power cable (Belden 83803) to Benchmark.
I have an upgraded Zu Audio Bok power cable on my Benchmark, and it basically lowers the noise floor, and provides for a clearer, cleaner presentation which is really cool, so the notes sound like they are more isolated projecting out of a darker background. I'm not using any power conditioning though.

Richlane - Thank you. It sounds very clear on my system with stock power cable but exact location of notes/instruments is a little fuzzy. I will try conditioner and/or different cables.
I would try an upgraded power cable first, then do power conditioning only if necessary. As stated many times here before, sometimes power conditioners can suck the life out of a system, and then again sometimes they're necessary.

Good Luck!
Thank you all for your suggestions. I took the plunge...bought a MHTD Labs Havana DAC. The Havana is a NOS non-upsampling DAC with a tube buffer. The unit arrived today and I am running it through the analogue inputs of the Benchamrk Pre. So far so good! The DAC still needs to be run in but the 'harshness' of the Benchmark is gone. The sound is 'fuller' and the clarity and resolution of the Benchmark is still there. The bass sounded a little muddled at fist but this is clearting up as well.

I could have possible gotten the same outcome from a tube pre but there are not that many good deals in the Singapore market.

So now I have 2 DACs. Will probably sell the Benchmark in the near future and get a proper pre-amp once the Havana is run in. The question would be tube or solid-state. The journey goes on...
I have just bought the DAC1 USB to replace my XDACV3. The XDAC has a sweeter treble but not quite as much resolution. I agree that the DAC1 does sound a bit tipped up in the high mids and treble. I suspect that some of this is due to the LM4562 output op-amps which do have a pronounced 'presence' but I also feel that the power supply caps are largely responsible. I have some experience with the 4562 op-amps and have found that bypassing with Elna Silmic or Cerafine mosly eliminates the glare and the result is much nicer and sweeter mids and treble. There are also a couple of 5532 op-amps used for I > V from the DAC. The XDAC also used these devices and I ended up substituting them with OPA2134 amd the result was less grain + smoother and sweeter as well as a much fuller bass. I will probably do a full range of mods to the DAC1 USB in the very near future and will report back here.
I have confirmed that the DAC1 USB uses 4562 op-amps for the output buffer which is an upgrade from the standard DAC1 which uses 5532's.

The newest 'DAC1 Pre' uses LM4562 op-amps throughout. These are very superior op-amps so the Pre version should sound better than previous versions - and measure better too. Upgrading an existing DAC1 USB is possible but requires the replacement of the +/- rail regulators to reduce the rail voltage to +/- 17V.

I just finished the power line conditioner. It uses a 240V primary and a 36V secondary which is in series (opposing) with the 'active' on the load side. This is a neat way of reducing the mains voltage by 20%. There are ferrite beads on both sides to reduce EMI. I measured the DC voltages inside the DAC1 PRE and the input to the 18V regulators has dropped from 31 to 25. There is still > 5V between input and output all all regulators (3.3V, 5V, +/-18V).
After an hours use the unit is now barely warm. Out of interest I tried several transformers - for different output voltages. From a SQ POV this voltage seems to be the sweet spot. The treble seems to be slightly more 'analogue' - smoother and sweeter.

Please e-mail me if you want details on this mod.