Thread: Amp Camp Amp and GR-Research X-LS Encore speakes DIY projects!

I'm buidling up a pair of the Amp Camp amps (ACA), which are a full Class A amplifier designed by Nelson Pass. These come as a kit for $327, including all parts, the heat sinks and chassis, and can be used as a stereo amp or bridged or paralleled monoblocks. I bought two and will be configuring them to run as bridged monoblocks. They will put out about 15 W of Class A power into 8 ohms in bridged mode. I completed all the boards this weekend and have started putting the chassis and connectors together.


Thought I would share some pics of my ACA 18 "Premium" Parts build. This is subsituting some of the stock components with more premium parts and changing a few resistor values. This my first build since I built my Hafler DH-101 more years ago than I care to remember...

Photos from my wondrous little Fujifilm X100F, shot with available light and/or TTL fill. Even the base kit uses really nice parts, e.g., Vishay metal film resistors and Elna capacitors, but I've upgraded some of the caps with a Nichicon Gold Tune cap at C1 and the aluminum organic polymer Nichicon caps at C2 and C4 that comprise part of the premium parts build.

The boards for each channel or "half", depending on the configuration.






Close-up of one fo the boards; here R4 is run parallel with another resistor to lower the resistance in this part of the circuit to optimize current to the transistors.



The rear panel with information on how to make connections and setting to run in different output configurations. One can use the amp in stereo or as a monoblock simply by using the switch at the top of the rear panel.






I'll post more pics of the amps as I progress with finishing the build.

The speakers I am planning on using these will are the X-LS Encores designed by Danny Richie of GR-Research in Texas. These are also sold as a DIY kit for a whopping $249 for the base configuration.

The X-LS Encores are 87 dB/1W-m sensitivity which should be fine as I typically listen at levels 68-72 dB when sitting 7 ft in front of the speakers in my small listening space. They have a nominal impedance of 8 ohms.



My cabinets were built up by one of Danny's employees, who is also a woodworker. He's veneered them for me and stained and oiled the cabinets.

Here's a pic of my cabinets...



Once I receive the cabinets and speaker components, I'll wire up the crossover, connect and mount the drivers, and assemble the parts into a finished loudspeaker.

More pics to follow on this project, so stay tuned...

Originally Posted by joeinid

Thank you so much for posting and detailed write up. Awesome job PC.

Thanks, Joe, more to come...

Tonight I mocked up the chassis and boards assembled to determine the length of the hookup wires required from the boards and switches to the rear panel. Because the boards are "asymmetric" with respect to their positions on each heat sink, I wanted the wire lengths for the respective connections to the boards and each amp to be identical, so this was the best way to do it.

Nice. The X-LS Encore has great imaging capability so I hear. I wanted to build the NX-Otica at some point.

Looking forward towards listening impression.

Originally Posted by Devg

Nice. The X-LS Encore has great imaging capability so I hear. I wanted to build the NX-Otica at some point.

Looking forward towards listening impression.

Yeah, the NX-Otics looks killer...

Just an update pic of the rear panel, wired up to connect to the circuit boards once they are installed on the heat sinks and the complete chassis is assembled.

The blue/black wires are power out from the boards to the speaker outputs, the white/gray and red/gray are input wires from the source RCA inputs to the boards, and the red and black straight wires are for the front power switch and grounding, respectively. There is a bridging resistor of 68.1K between the L output and R input for use when the amp is switched to bridged mono mode.

Okay, so I finished up the first amp with premium parts and the resistor changes.

Here are some pics...





Here it is making music...


I listened to it all day yesterday and its starting to sound really good. Very impressive for...$344, including the premium parts upgrade.

Originally Posted by joeinid

Excellent photos, pristine wiring and solder job. Wow! I’m in awe. Keep up the great work.

When fall/winter rolls around, I’d love to try something like this but I’m so chicken.

Its really easy, Joe. If you can solder, you can build one these.

Originally Posted by joeinid

Excellent photos, pristine wiring and solder job. Wow! I’m in awe. Keep up the great work.

Ha! The mods at DIYAudio liked my build so much they want to use photos of it in the Build Guide. LOL...

That's a very impressive build and something to be proud of. I built the stock mono blocks a few months back. To me, building kits is the most satisfying part of this hobby. It's a blast during the build process and very exciting and kind of scary the first time you power it up. Soldering is super easy to learn in about 10 minutes and if you can follow the pictures ( super easy) you have it beat.

Originally Posted by joeinid

Yep, just watched this. Kudos to the builder taking all the time-lapse photos...

Their assessments of the sound qualities are pretty accurate, I would say..

I sold my Amp Camp kits to my buddy (he has been bugging me for over a year) and he is using them with a pair of Klipsch mid-towers, he loves them. I am betting they will make your Vikings' sing. The version I built were 6wpc, isn't the new version 7 or 8wpc?