Pace Car Mod Fun

serengetiplains · « **on:** 29 Nov 2009, 12:10 am »

Ok, further to my adventures in audio nervosa tweakdom, I today finished hotrodding the Pace Car I use with my Wadia iPod transport. Here's what I did: I ordered several shunt modules from Paul Hynes + one serial supply. For the shunt modules I purchased separate R-core transformers. I installed all in an aluminum box. I then removed the Pace Car from its box, snipped the supply leads to the Superclock 4, and removed the 7805 and 7809 regulators. I then wired a 12V Hynes shunt to the Superclock, wired 9V and 5V shunts to the 78XX regulator inputs, and wired the remaining 12V serial supply to the 12V input to the Pace Car (I'm actually not sure this is even needed, but I don't know the Pace Car circuit).

So all in all, four Hynes supplies powering the Pace Car! Total cost was something of the order of 4 x $175 for the supplies + 3 x $40 for the transformers = $820.

My god! What a ~ s-w-e-e-t ~ upgrade! I have to say, Steve's Pace Car is one remarkable machine. I'm speechless. No grating digititis whatever, just soft, detailed, analogue-killing sound. I can hear the difference here as I type, one floor down. I'm now going to walk back upstairs and retrieve my jaw from the floor.

serengetiplains · « **Reply #1 on:** 29 Nov 2009, 12:22 am »

My hat's off to you, Steve. I think I need some new words to describe the sound this little box is producing. Like realitytone, or instrumentdelineation. High and previously unheard-by-me levels of both.

serengetiplains · « **Reply #2 on:** 29 Nov 2009, 12:53 am »

My girlfriend just listened to the upgrade. It's an upgrade to her stereo, actually. The stereo is in her painting room and she listens to it almost daily.

Her response was, "I can't believe how clear it is. Do you think the people who mix music intend all the instruments and singers to sound so separate?"

I'm still speechless. This little box is now 6 upgrades better (8?) than my Weiss firewire getup, and 5 upgrades better (7?) than my Playback Designs MPD-5. Dave Clark, you reading this?

richidoo · « **Reply #3 on:** 29 Nov 2009, 01:42 am »

Nice upgrade. What DAC do you use?
Rich

serengetiplains · « **Reply #4 on:** 29 Nov 2009, 01:57 am »

Hi Rich, the system is this:

passive line filter ---> Accuphase power conditioner ---> Wadia iTransport ---> Pace Car ---> Lyngdorf Millenium IV ---> Acoustic Energy AE-I III

Everything's modded. Super-premium, but not over-the-moon expensive. The only thing I bought new was the Pace Car.

serengetiplains · « **Reply #5 on:** 29 Nov 2009, 02:05 am »

Quite interestingly, sibilance has been reduced to vanishing levels, and even bad recordings sound interesting, even good and enjoyable, because stereo delineation is so rich and accurate.

serengetiplains · « **Reply #6 on:** 29 Nov 2009, 02:40 am »

My girlfriend noticed how the sound seemed to shift on this modification toward the midrange. She's right about the perceived effect, and I think what she's hearing is a combination of tighter bass (gone is the wool) and cleaner high frequencies (gone is the sibilance and HF fizzle). The latter effect is quite noticeable and renders the sound more realistic, with vocals taking centre stage, as they should. I've personally never heard HFs in the real, in both quality and content, like I hear them in almost every stereo I've heard. Well, this modification has walked a good mile toward rendering digital HFs very natural indeed. And this is with 16/44.1! Steve, I think you should offer a Super Pace Car absolutely maxed.

Jon L · « **Reply #7 on:** 29 Nov 2009, 02:58 am »

What? NO PICTURES! aa

serengetiplains · « **Reply #8 on:** 29 Nov 2009, 04:32 am »

You can see the four Hynes supplies one on the left bolted to the bottom, and three on the right bolted to the side wall. The Pace Car is that barely visible thing in the middle of these supplies. I need to drill two holes for the S/PDIF cables, and until then the Wadia will have to remain propped in a true DIY pose, and the Pace Car floating, as it is, on the in and out S/PDIF cables. I also think I'll add some shielding between the supplies and the Pace Car electronics.

The red patch in the back of the photo is an Invisus supply feeding the Wadia.

serengetiplains · « **Reply #9 on:** 29 Nov 2009, 04:41 am »

A slightly closer view.

serengetiplains · « **Reply #10 on:** 29 Nov 2009, 04:43 am »

And a little closer still and rotated.

serengetiplains · « **Reply #11 on:** 29 Nov 2009, 05:11 am »

Actually, I should be clear about what I actually changed in this particular modification. Before placing the Pace Car in this box, it was already being powered by two Hynes supplies, one on the Superclock, the other as the main 12V input. I thus merely added two other Hynes supplies to replace the 7805 and 7809 regulators on the internal circuitry. Those are evidently critical regulators as changing them accounts for the entire improvement I'm describing here.

Paul Hynes · « **Reply #12 on:** 29 Nov 2009, 11:43 am »

Hi Serengetiplains,

I am pleased that you are getting such good results with Empirical products. Whilst a good external power supply is generally beneficial with equipment in general, only by upgrading the key internal regulators to the highest performance will the equipment truly reach it's greatest potential.

Regards
Paul

jtwrace · « **Reply #13 on:** 29 Nov 2009, 02:20 pm »

Wonder what Steve thinks...

serengetiplains · « **Reply #14 on:** 29 Nov 2009, 04:37 pm »

I agree with Paul: any audio gear using off-the-shelf regulators, 78XX or whatever, is not running at its highest potential. That would be, oh, 99.9% of all audio gear?

A piece of audio equipment is simply and only a specialized power supply. Cheap power supply regulation thus forms a hard limit to audio quality.

audioengr · « **Reply #15 on:** 29 Nov 2009, 06:25 pm »

Quote from: serengetiplains on 29 Nov 2009, 12:10 am

Ok, further to my adventures in audio nervosa tweakdom, I today finished hotrodding the Pace Car I use with my Wadia iPod transport. Here's what I did: I ordered several shunt modules from Paul Hynes + one serial supply. For the shunt modules I purchased separate R-core transformers. I installed all in an aluminum box. I then removed the Pace Car from its box, snipped the supply leads to the Superclock 4, and removed the 7805 and 7809 regulators. I then wired a 12V Hynes shunt to the Superclock, wired 9V and 5V shunts to the 78XX regulator inputs, and wired the remaining 12V serial supply to the 12V input to the Pace Car (I'm actually not sure this is even needed, but I don't know the Pace Car circuit).

The 5VDC 7805 should not need to be improved, only the 8VDC. The 12VDC powers only the 8Vregulator and the clock module. The 8V powers the 5V regulators. The 5V regulators power the 3.3V regulators. The 7805 powers only the FIFO input circuits, so it is a dont-care.

Quote

My god! What a ~ s-w-e-e-t ~ upgrade! I have to say, Steve's Pace Car is one remarkable machine. I'm speechless. No grating digititis whatever, just soft, detailed, analogue-killing sound. I can hear the difference here as I type, one floor down. I'm now going to walk back upstairs and retrieve my jaw from the floor.

I would recommend upgrading to an Ultraclock.

Steve N.

audioengr · « **Reply #16 on:** 29 Nov 2009, 06:28 pm »

Quote from: serengetiplains on 29 Nov 2009, 02:40 am

My girlfriend noticed how the sound seemed to shift on this modification toward the midrange. She's right about the perceived effect, and I think what she's hearing is a combination of tighter bass (gone is the wool) and cleaner high frequencies (gone is the sibilance and HF fizzle). The latter effect is quite noticeable and renders the sound more realistic, with vocals taking centre stage, as they should. I've personally never heard HFs in the real, in both quality and content, like I hear them in almost every stereo I've heard. Well, this modification has walked a good mile toward rendering digital HFs very natural indeed. And this is with 16/44.1! Steve, I think you should offer a Super Pace Car absolutely maxed.

I do have a new Pace-Car 4 in the plans for 2010. Other surprises too.

Steve N.

audioengr · « **Reply #17 on:** 29 Nov 2009, 06:33 pm »

Quote from: serengetiplains on 29 Nov 2009, 04:37 pm

I agree with Paul: any audio gear using off-the-shelf regulators, 78XX or whatever, is not running at its highest potential. That would be, oh, 99.9% of all audio gear?

A piece of audio equipment is simply and only a specialized power supply. Cheap power supply regulation thus forms a hard limit to audio quality.

Actually, there are only two 78XX regulators on the board. Only other regulators run off of the 7808 and the 7805 is used only for the FIFO input, not the output. The regulators for the FIFO output are very good. I think the main improvements that you are hearing is the better regulation to the Superclock, not the Pace-Car.

Steve N.

serengetiplains · « **Reply #18 on:** 29 Nov 2009, 06:37 pm »

Hi Steve, before my modification, the Pace Car was already running off two Hynes supplies, one 12V linear supplying the input, another 12V shunt supplying the Superclock. The only change I made therefore was to swap Hynes supplies for the two 78XX regs. The improvement I noted in this thread comes from the 78XX upgrade.

audioengr · « **Reply #19 on:** 29 Nov 2009, 06:39 pm »

Quote from: serengetiplains on 29 Nov 2009, 06:37 pm

Hi Steve, before my modification, the Pace Car was already running off two Hynes supplies, one 12V linear supplying the input, another 12V shunt supplying the Superclock. The only change I made therefore was to swap Hynes supplies for the two 78XX regs. The improvement I noted in this thread comes from the 78XX upgrade.

That makes sense. The 7808 is one that I may eliminate and replace with a discrete regulator, if there is space for it.

BTW, have you replaced the coupling caps in the Overdrive yet?

Steve N.