[jimmers]

Has anybody opened a Pro-Ject DAC Box S FL?

I just wonder if they are doing any filters or oversampling, and more importantly, looking to see if they are just using resistors for I/V or have an op amp in place for this?

There are pictures here, I imagine the I/V is under the red heatsink that covers the 4 x TDA1543, not a lot of room there.
http://www.hifishock.org/gallery/electronics/pro-ject/source/cd-player/dac/dac-box-fl-1-pro-ject/

 

[Sapientiam]

Has anybody opened a Pro-Ject DAC Box S FL?

I just wonder if they are doing any filters or oversampling, and more importantly, looking to see if they are just using resistors for I/V or have an op amp in place for this?

Going from the blurb on their site and the pics, there's no filtering (digital or analog) and they're using just resistors for I/V (no opamp).

 

[mcgo]

My Pro-Ject DAC Box S FL arrived. The short summary of it... A Muse that is built-like-a-tank! It is small, but heavy! I lucked out and got it like-new, in original box and packaging. The switching power supply (9VDC 300ma, center positive) it came with has a very small diameter plug (which I measured as 3.5mm using digital calipers). No switching noise was heard with my amp cranked up, but I'm already trying to figure out how to replace it with a LPS Ideas welcome!

Build quality is great, all metal, and as I said, heavy! After a three hour listening session last night I put my hand on the case to feel the temps. I'd say it was slightly over cool, but not warm. It has an on/off button in the front and an input selector switch. Both have classy blue lights. On powerup the input selector defaults to 1, which is optical. I switched it to 2, coax, and intend to leave it there!

When I'm adventurous I'll open it up and take some pics for everyone.

 

[Bubel]

One of my buddies from DIYA who's a bit of an expert with 1543 chips says the non-A version sounds better to him. So you've another reason to stick with the usual chips in the Muse.

Just finished replacing the chip - everything sounds great! Thank you very much for pointing out!

 

[mcgo]

I replaced the OEM switching power supply that came with the Dac Box S FL with a Class 2 linear for less than $30. You can do it cheaper if you reuse the oddball connector from the old PS. I took the easy way out and picked up a couple of adapters to do the work.

The power supply is a MORLEY 9VDC 300mA REGULATED *CENTER NEGATIVE* 5.5x2.1mm (amzn: B0002PYX9C). This is an audio class power supply intended to be used with guitar effect pedals. To use this on the Dac Box S FL we need to reverse the polarity so that it is center positive (amzn: B075R64SCQ) and reduce the barrel plug down to 3.5mmx1.35mm (amzn: B00EA482ZW, now B0874RCJGP).

I also added a clamp-on ferrite bead near the barrel end (not pictured) since I have a box of them from an earlier project.

Another junk switching power supply successfully removed from the audio chain!

Edit 11/2020: I picked up another DAC Box S FL (because they literally are amazing!) and duplicated my class 2 power supply setup outlined here. Updated the amzn item # for the plug reducer, since the old one is no longer available.

 

[mcgo]

4 months in and my Pro-Ject Dac Box S FL is really rocking! NOS goodness, jet black background, musical. Something I actually want to listen to rather than bland surgical ESS crap! I upgraded my coax interface board from HifiBerry Pro to an Allo Digione and it pushed the DAC to a whole new level. USB is toxic in comparison! The femtosecond clock was my missing piece. At $170 for the DAC+PS and $100 for the rpi interface board, this combination is a steal! Highly recommend!

 

[QOOQ]

hi, guys. Can i use this adaptor with muse 1543x4?

 

[Sapientiam]

Its 10V rather than 9V so the internal LM317 regulator will run that much warmer. Worth a try - if the audio cuts out after a while then it'll likely be due to overheating.

 

[Runrunsmithfly]

I'm bringing this old thread back because I took delivery this morning on a Pro-ject Dac Box FL that I bought used for $60. It's like new in the original box and I've been looking for one of these for a while. I'm a CD spinner and use an Audiolab transport so this hefty little box is perfect. I do own a few other DACs but this little box sounds great. I'm a fan of the old Philips multibit DACs and the four TD1543 chips in this DAC do not disappoint. If you play CDs and come across one I'd recommend it.

 

[rtaylor76]

I'm bringing this old thread back because I took delivery this morning on a Pro-ject Dac Box FL that I bought used for $60. It's like new in the original box and I've been looking for one of these for a while. I'm a CD spinner and use an Audiolab transport so this hefty little box is perfect. I do own a few other DACs but this little box sounds great. I'm a fan of the old Philips multibit DACs and the four TD1543 chips in this DAC do not disappoint. If you play CDs and come across one I'd recommend it.

I almost purchased that myself. The DAC Box FL seems like a better built device. It runs on 16 ACV power supply, meaning there is a linear supply on board and regulators. No one has posted the internals of that one. Any way you can get us a shot of them?

 

[Runrunsmithfly]

I'd say the DAC Box FL is a well built little unit. Very heavy for such a small unit. Nice build quality. Two heat sinks on top of each pair of DACs. Here's a pic off the internet, I'm not going to open mine up. I've had it on for several hours and it's cooler to the touch than my Modi multibit.

 

[rtaylor76]

I'd say the DAC Box FL is a well built little unit. Very heavy for such a small unit. Nice build quality. Two heat sinks on top of each pair of DACs. Here's a pic off the internet, I'm not going to open mine up. I've had it on for several hours and it's cooler to the touch than my Modi multibit.

Wow...so pretty basic. Looks like rectifier and regulator on the right, then the input chip in the middle, the TDA153's under a heat sink, and two WIMA's for AC coupling.

Thank you!

 

[Runrunsmithfly]

Wow...so pretty basic. Looks like rectifier and regulator on the right, then the input chip in the middle, the TDA153's under a heat sink, and two WIMA's for AC coupling.

Thank you!

I suppose less really is more sometimes. I was using it this morning with my Vali 2++ headphone amp with a RCA Command 5670 in it. Source is my Audiolab transport and headphones this morning were the Sennheiser HD600. I read that this DAC sold for around $300 new. It would be outdated for some since there's no USB port.