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Updated: Mar 25

As a car and audio enthusiast with a passion for vintage automobiles, there's nothing quite like blending the timeless charm of a classic car with the cutting-edge performance of modern audio systems. The journey began with a well-thought-out plan (details in my previous blog), but as we all know, even the best-laid plans can change - and change they did.

The initial plan for my vintage car audio upgrade involved a straightforward speaker and amplifier setup featuring Sony RSX-GS9 with its high-resolution built-in DAC as the head unit, supporting 192 kHz/24 bit. However, after reevaluating the project, it became apparent that to truly achieve the ultimate audio experience, I needed to overhaul the entire system, starting with the most crucial component: power, continuing with the speaker selection and final locations for the fabricator.

The Alternator was again upgraded to a custom with 160-amp capability, significantly outperforming the stock 45-amp alternator. The 0-gauge oxygen-free cable remained in place, but the car battery was replaced with a Stinger SP1200 (2600 AMP) while retaining the dedicated stereo battery, the XS Power XP750. Positioned directly before the JL Audio Amplifiers is now an XS Power SB500-34 Supercapacitor Battery, offering 4000W and 500 Farad support. After consulting with an XS Power factory rep, we agreed this was the optimal power solution to support the audio system.

To further enhance the audio experience given the final speaker locations, the total speaker count was increased to 11, including the subwoofer. The JL Audio 10W6v3-D4 subwoofer joined ten Focal Utopia cabin speakers with active crossovers connected to the upgraded JL Audio amps - the VX600/6i and VX1000/5i models.

Custom cabinets were meticulously crafted to integrate the speakers into the car's classic interior, maintaining its aesthetics in a super-tight space while providing state-of-the-art audio quality. The Focal speakers were placed in the rear quarter panels, the footwells of the driver and passenger, and the rear cockpit was modified to accommodate the JL Audio subwoofer and other electronics.

The custom work continued. The trunk was transformed into an audiophile's dream, featuring an amp wall, a dedicated stereo battery, and a "beauty bar" to maintain a seamless look. Trunk quarter panels were fabricated to house the SB500-34 Supercapacitor battery and ensure symmetry. A massive shout-out to the San Diego Car Stereo team for their incredible work in designing, installing, and customizing this system while respecting the vintage charm of the classic roadster.

Of course, plans change. During the audio upgrade, the fuel pump gave out. With no engine start, the desired 14v+ for the final tuning needed to be attainable. So, it was back to the drawing board, replacing the fuel pump and the old carburettor and adding a supercharger. Once completed, it's back to the audio shop for that final touch of perfection via the tuning of the audio system in an outside environment, given it's a convertible and with 14v+ power.

Take a moment to admire some initial photos showcasing the stunning interior work by Stuttgart Upholstery in Santee, CA. Their craftsmanship is second to none, with every inch of the car's interior is hand-wrapped in leather while keeping the classic charm of the vintage vehicle.

1976 MGB Roaster Jim Cathey MySoundFiles
Amp Rack
1976 MGB Roaster Jim Cathey MySoundFiles
Trunk with Amp Rack and Beauty Bar

1976 MGB Roaster Jim Cathey MySoundFiles
Trunk Quarter Panel
1976 MGB Roaster Jim Cathey MySoundFiles
Rear Cockpit

1976 MGB Roaster Jim Cathey MySoundFiles
Passenger Footwell

So, my fellow car and audio aficionados, always bear in mind that even the best plans may alter along the way. Welcome those changes and pursue the ideal balance between vintage charm and contemporary performance. Stay tuned for updates after the final tweaks and restoration are wrapped up.

  • Writer's pictureJim Cathey

Updated: Mar 25

Happy New Year. As we drive into a new year, I am shifting gears a bit ( pun intended). Posting an update about my 1976 MGB Roadster, which has been in the makeover for the past year.

Although much of the basics are the same as home audio, car audio has significantly more challenges, especially with the after-market and retrofit of a vintage car. The listening room, cockpit in this case, is like a fishbowl with not only glass but a variety of materials and angles not conducive to the best audio performance. These challenges do not include complications from a convertible car.

The challenges continue with limited areas for ideal speaker placement or space for the right speakers. Even with custom modifications, the environment will be harsh. Where possible, treat the cockpit with dampening materials on the floors and walls, similar to what you would do with an in-home listening room. Modify other materials where possible, like the seating, dash, ceiling, and flooring, similar to a home where you need to manage reflection points. Custom speaker pods will provide flexibility in the speaker positions and the chance to raise the tweeter and mid-range to ear level or close to it. The absolute must is an amp with DSP capability and lots of power.

Because of the limitations in a car, managing the audio waves can only be done via a DSP. I would frown on 2-channel audio in a home environment, but not with a surround-sound system or, in this case, a car; it's a must.

Like all stereos, the starting point is power; lots of consistent, clean power. And in combustion automotive, the sources are your battery/alternator. Power, the source and cables often get overlooked in a DIY car audio retrofit. Often, we don't look at the alternator's amp capacity, the power cable, the health of the car wire harness(es) or the car battery and the need to separate that for the audio system. If you have a project with a vintage car, start with the power, just like a home audio system. Is the installed alternator producing enough amps for the car systems like the heater, headlights, electric radiator fan, heating/air conditioning fan, heated/cooled seats, etc? Then add what you need for the new stereo and those hungry new amps. There are many websites to check how to calculate the amps. But in the end, you may find that the alternator and cabling need to be replaced. And given the amp and distance, what is the wire gauge needed? When in doubt, go to a smaller gauge; my default is 0 gauge with oxygen-free cable. Yes, it's big, but it will have the least resistance.

I currently have an MGB Roadster in the middle of a restoration, and the original alternator was a small 45 amp capability. In addition, the battery is in the back of the car, and the new stereo amps would be in the trunk. Had to upgrade the alternator to 135 amps and replace the cable to the battery for a 15' run to a 0 gauge cable. That should be plenty of headroom for the stereo and the car electronics, but to ensure clean power, a dedicated battery will be wired in for the stereo to draw upon. Hence, unlimited power at any peak draw moment and the option to run the stereo without running the car engine or putting the car battery at risk. This should also eliminate any electrical noise from the car electronics or car battery. Also replaced the three wiring harnesses in the car; they needed to be replaced based on age and would surely have introduced noise if they were left in.

Yes, what you're thinking is right; complete overkill on the power. However, it will give the best power option for the stereo and provides additional flexibility if I add to the system later. There will be lots of power headroom for future stereo expansion and electric car upgrades. And the need for more power has already arrived. The initial test system did not have the performance I expected, so moving to bigger amplifiers, speakers, and subwoofers required additional power.

The 2nd system going in has the following key specs:

· 1976 MGB Roadster (The actual car I drove in high school).

· Front Speakers: Focal ES 165KX3 Elite K2 Power Series 6 1/2" 3-way component speakers

· Rear Speakers: Focal EC 165K K2 Power Series 6 1/2" 2-way car speakers

· Amplifier for Front and Rear Speakers: JL Audio VX800/8i 8-channel car amplifier with DSP 75 watts

· RMS x 8 Subwoofer: JL Audio 10W6v3-D4 Series 10" dual 4-ohm voice coils.

· Subwoofer Amplifier: JL Audio VX600/1i Mono Amplifier with DSP 600 watts RMS x 1 at 3 ohms.

It will be challenging to finalize the speaker placements for all the speakers, given the small size of the MG. The front will probably have a split where the footwell side walls and a part of the door will collectively accommodate the 3 component speakers. The passive crossovers will be eliminated and replaced by driving each speaker directly from the JL Audio VX800/8i, which can be an active crossover with user-selected frequencies. The rear speakers will find a home in a false wall on the bulkhead between the cockpit and trunk. It's expected to share that location with the subwoofer, provided the vibration can be managed with Sorbothane.

The front and rear speakers will require some fabrication so that the speakers will disappear in the car and produce audio with no visible or limited visible appearance. The dedicated stereo battery, amplifiers/DSPs will all be in the trunk attached to the bulkhead wall between the cockpit and trunk.

I will post an update once the final audio system is installed and include all the components, performance, and reference links. Posting some pics meanwhile that I managed to click at the garage.

Note: the cockpit and trunk floors and walls have all been treated with sound-dampening material before carpeting with Dynamat and Thermozite where needed for heat dissipation.

  • Writer's pictureJim Cathey

The 4th of July weekend required I break out the vintage McIntosh MC275 amps not from a historical perspective but out of necessity. The Acoustic Research Reference 160M seemed flat after a proper warm-up and system test. Flat enough, that motivated several tests, followed by swapping the amps with the previous champions of my system, the MC275s. However, for this quick swap, I used 2 of the MC275s in mono-block mode or a straight swap-out with no changes to the speaker driving regarding horizontal or vertical Bi-amping.

The vintage MC275s played well, in fact, better than I remembered, so I took the time to run a few sound tests and reference sources. And yes, it was better in detail and just as strong in the realization of the music. The imaging and the resulting sound stage were also at par. Remember, the system with the vintage MC275s had 4 driving the ATC 150 speakers; 2 in mono-block mode for each of the low-frequency drivers in each speaker, a 3rd amp driving both mid range drivers and a 4th driving both speaker tweeters and super tweeters coupled with the vintage C22 preamp. What changed? What made the MC275s produce an improved performance? Perhaps the MC275s just wanted to show off after being on the shelf so long and watching the ARC Reference 160M perform 😊.

Nope, not jealousy; less is more in this case as it relates to detail and the ability to match and balance 2amps vs. 4amps. But there is another change I did not test in the past, the coupling of the outstanding Nagra HD Preamp and the vintage MC275 amps. That is a significant upgrade you can clearly hear, and the pairing of the devices is spot-on perfect; they perform very well together, delivering sound you can feel.

The performance was good, I will test this again with the ARC Reference 160M after I roll the tubes. I suspect; the ARC amps need all tubes tested and ultimately replaced, which I will do next week. After I get those replaced, I will make the comparison again and post the results. Perhaps the MC275 amps will jump back into the system…..hard to predict that given the ARC performance I remember from before.

Jim Cathey set up. Nagra HD Preamp. Mc275
Nagra HD Preamp with MC275

One big takeaway; the Nagra HD Preamp is a killer with vintage MC275 amps with the correct tubes, capacitors and resistors.

#NagraHDPreamp #MC275

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