ProjectPre Box S2 DigitalnewProject Pre Box S2 Digital ModificationNote: Due to some unfortunate experiences, we do not accept purchases from people with no prior purchase prior record. This ad is for the modification of the Pioneer UDP-LX500 4k Blu-ray player. Th...260.00

Project Pre Box S2 Digital Modification [Expired]

no longer for sale


Due to some unfortunate experiences, we do not accept purchases from people with no prior purchase prior record. 

This ad is for the modification of the Pioneer UDP-LX500 4k Blu-ray player. The price listed does not include the original price for the unmodified player itself, which is listed below. 

In the words of The Absolute Sound’s Robert Harley, we are a “small, but passionate” (TAS #229, Feb 2007) audio company in Gresham, Oregon (near Portland). We make our own custom-made, crossoverless single-driver speakers (that really work), modify subwoofers, interconnects, and speaker cables. We have also been modifying audio components of different makes and models for nearly a decade. We specialize in Pioneer players and receivers, Harman Kardon receivers and amplifiers, Music Hall, Rotel, Elac speakers and subwoofers, Sony players, and B&W speakers.

We have developed a new, innovative method to modify audio and video equipment. My late boss, Dave Herren, a well-known modifier in the Northwest, had previously worked on modifying equipment by replacing capacitors that ran through certain key signal paths, thereby improving electron flow and allowing the machines to have much better fidelity in both audio and video. Our new proprietary modification is simpler yet more thorough at the same time. Our process improves the functioning and efficiency of all the capacitors and other electronic components of the modified unit, affecting not only specific signal paths but improving electron flow throughout the entire machine. This modification can turn simple, less expensive pieces of audio equipment into pieces that rival others costing thousands more.

We recently came across positive reviews of the Pro-Ject Pre Box S2 Digital DAC, which is MQA capable. We decided to see how much our modification could improve this MQA DAC.

Out of the box, the S2 sounded quite good on non MQA sources. But when we played MQA tracks,  it was like we never heard music this clear before. It sounded not like a hi-fi experience, but as though the orchestra, instrumentalists, and vocalists were right there in front of you to a degree we had never experienced before. This DAC is an incredibly affordable way how to get into MQA at a very high level. After break in and modification, the Pro-Ject Pre Box S2 DAC improved noticeably in clarity, bass depth and texture. The location was more solid with better front to back giving the MQA an even more palpable feeling. Listening to MQA on this modified DAC is almost intoxicating and addictive. All of our previous favorite tracks were a new listening experience. Nearly all MQA tracks played on this modified DAC were far superior to their redbook CD counterparts, and even hi-resolution tracks. The noise floor on a stock Pre Box S2 is very low when compared to a regular disc player, which improves even more so with our modification. 

New Upgrade to Modification Discovered: 

Recently, we have found another way how to modify these Pro-ject DACs. After implementing this upgrade, all the above characteristics describing the difference in modified sound improved exponentially; to the degree that the music produced by this MQA DAC is the most stunning, amazing music and sound that we have ever heard. 

This ad is for the modification of the Pre Box S2 only. But we have found that by the addition of a certain noise reduction unit that the sound gets even better. We've been auditioning the Ifi ISilencer3.0 and found that it makes a substantial difference in the amount of noise in the signal of the USB input. It makes the sound even more clear, richer, and eliminates some hard to remove digital noise on the top end. Bass is also further improved and becomes darker. This noise reduction device seems to work very well with our modification and we would highly recommend it. It sells for a reasonable price of an additional $50. We also sell a hand soldered directional thicker 1/8" to 1/8" or RCA cable with brass ends for car stereo playing of MQA through phones that have an MQA capable DAC upon request. This hand soldered cable, when used with a cell phone with an MQA dac in it, really causes the music to play with more detail, clarity, lower more bass, more texture, and to be a lot more natural sounding. We offer this very labor intensive custom cable for $200. 

We have never had a modified piece returned from an unsatisfied customer. Our regular modification price is $260 for Pro-Ject Pre Box S2 DAC, which includes shipping in the continental US back to you once the units are modified. The modifications to the Pre Box S2 turn a highly reviewed stock machine into a piece reaches a whole a new of fidelity with MQA. 

Price for the stock Project Pre-Box S2: $399

Modification Price with shipping included: $260


We also modify all makes and models of receivers, players, music / network servers, and other pieces. We can also modify such subwoofer brands as Velodyne, JL Audio, REL, and others. We also modify Rotel, Harman Kardon, Pioneer Elite, Peach Tree, Mark Levinson, Parasound, and other pieces.

We also modify DACS, floorstanders and bookshelf speakers on a regular basis. Please call for pricing and talk to a knowledgeable person who is as interested in audio as you are, and is interested in you getting the best sound in your budget.. We look forward to hearing from you soon.

Stereo Dave's Audio Alternative


[email protected]

Customer Feedback

Every once in a while, we get emails back from customers that take the time to let us know how they liked their modified units.

"Hello Sean,

Finally received the amp (Music Hall A15.3 Amplifier) from FedEx today, been listening to the amplifier for several hours now.

I have no intelligent audio superlatives to share. This little baby sounds simply amazing. What amazing dynamics, staging and real bass weight. What was veiled and subdued previously is gone.

The AJ Pioneer Bookshelves are leaving here tomorrow for you to work your magic.

Thank you to you and your team. You have a customer for life.

Very pleased with the result.

Best regards,"

"Good evening Sean,

All hooked up. Listening to CD. Dire Straits Communique. Cant believe it Sean. Cant believe this quality of music, of fidelity, is coming from these bookshelves! They are so open, clear, airy. No grey overcast here man! The pace, rhythm and timing is exceptional now. It is just so right. They are standing beside their big brother floor stander I was listening to earlier this week. There is no comparison. I cant imagine what that modification would sound like. Damn. Cant wait for the subwoofer to land. Oh man am I going to be happy happy. Nice work folks. Friggin awesome. Take care and best regards,"

Mark from California


I love the sound of the modified (Pioneer BDP-53FD) player. I have it hooked up using the analog inputs. I didn’t change anything in my set up except to swap players. It sounds way different than the Denon 2900: better in every way. The biggest difference for me was how the player made the speakers disappear. Does that make sense? Music sounded ok with the Denon, but it was just a source to play cd’s, nothing special.

I listen to all types of music: swing music from the 30’s and 40’s, Latin or Salsa music for dancing, smooth jazz for night time listening, 70’s soft rock and classic rock. I’m all over the board. The player did make a difference in the presentation of the music. One example is the bass: the Denon’s bass was rather bloated. I didn’t notice this until i had the chance to listen to the Pioneer. The Pioneer’s bass was more natural. The bass blended better with the music and didn’t sound like it was “in your face”.

The vocals sound great as well. Even my 14 year old commented on how the voices sounded smoother and more natural. He even mentioned that it sounded like there was a center channel speaker hidden somewhere for the voices to come out of and “float in the air”. Nope, just my Tekton Lore speakers.

The Pioneer has taken my listening enjoyment to a new level. Kudos to whoever designed the mod because it does sound awesome!

Thank you,


Here is feedback from one of our modified HK 990 units from a customer:


Forgive the late feedback, but just to say I absolutely love the amp. This is just the sound I was looking for.

Thank you,



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