Curt Campbell's Halcyon build thread

I tried Halcyon with Amp Camp Amp (ACA)

As requested, I tried the Halcyons with the ACA. The sound was good, but not much bass and while the volume was loud enough to be uncomfortable, it was not really "big" as they sound with more powerful amplifiers. 88dB spec seems about right. I ran it off a little bluetooth device from the phone, so no comment on fidelity, but I know it puts out about the same amount of voltage as the DAC in the main system, where the speakers usually play.

I have a decent class D - Purifi (400 watts) and a VTA (Dynaco) ST-120 tube amp (60 watts) and both sound great with the Halcyons, but the ST-120 has the edge. Both go louder than I would ever want to listen, and both have plenty of bass, but the VTA has the tube thing.

I have not really experimented with preamps other than a Schiit Valhalla, which introduced so much hum I had to take it out. Not sure what's going on there because I've run it in other setups with no hum at all.

Any preamp suggestions appreciated.
 

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Alan,

you have me more intrigued about more power. My experience with the ACA is quite magical with plenty of bass to the point I'm going to stuff another pound of filling in the cabinets. I just found the sound gets "hard" when I push the volume all the way up. I'm actually not sure where the issue lies since it could be the DAC pushing its limits. Thinking more about an F5 with what you relayed so I appreciate the inputs.

As for preamps, if you're looking to sling some solder, I've had much fun in the past building various Glass-Ware boards. Some are simple enough to just require a walwart or a 12-18VAC transformer. I was in the midst of building some buffer boards but with the inputs from the thread contributors, I realized I'd need something with gain. GlassWare Line Stage & Headphone Amplifiers Kits and PCBs

-tom
 
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Tom,

Not saying that you trash the feet right away, but it is possible you can put them up for sale on other forums where folks like expensive tweaks. 😉 😀

And worry not, this all part and parcel of one's audio journey...

Regarding amps, if you want a simple, low cost project, you can kick it off with the FH9HVX. The parts for the amplifier are low cost and available, you will spend less on the PSU, and much less on the chassis and heatsinks vs a Class A amplifier. And power to boot (100 watts per channel IIRC).

And of course build the Pass F5 clone too in due time!
 
Sent the fancy feet back. Mounted the cone foot kit I got from parts express. $100 later, happy with how they bolted up and anchor the speakers in place. Haven't done any critical listening as I still have to aim them (in both planes) but string bass has a more distinct attack with a woodier sound. Not sure if I need to add anymore stuffing now.

Starting to plan out more of the next Nelson Pass designed amp to build.

-tom
 

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Alrighty, had some fun yesterday and this morning. Got the feet installed. Found the bass to tighten up. Did some measurements and some quick trig calculations and got the Alpairs pointed at my ears. My awesome GF took some time to measure my ear height in the listening chair. (ever since she loaded JRiver remote on her phone, I've found her "reading" in the listening chair quite a bit.) Raised the back end of the speaker 1/4" and there is a bit more shimmer to cymbals, sounding a bit more detailed in the upper frequencies. This morning, hooked up the ACAs in balanced mono. They seem to be playing well with the Halcyons as I still have nice bass with some good slam. There is a bit more spookiness, I'm assuming due to some of the noise floor dropping with CMR that balanced gives. There seems to be more space and a greater sense of floaty.

Hankering more to start an F variant amp. In the meantime, using one of these new fangled iPhone apps to start measuring the room and speaker response.
 
or a nice 12AU7 preamp!


I've got some reading to do. Considering an F4, F5, F6 but need to dive into the build threads and figure out my decision criteria. Started looking at the F4 as I saw some mention that it is designed to be operated as a balanced monoblock as well as a single ended stereo amp. It just needs some gain. Things turn to avalanches in this hobby. Good times!
 
Tom,

You are right... in this hobby a project or an idea kind of snowballs into something much bigger that what you expected at the beginning! 🙂

From my experience, we do spend a lot of time in "analysis paralysis"... sometimes KISS is good.

With the F4, you will need a preamp with some gain. So then it becomes 2 projects - the F4 and a suitable preamp. I was reading that a DIYer was very happy building the F4 with a Pass BA-3.

Even if you build an F5 or an F6 now, you can always repurpose the case (if it is large enough) and power supply for an F4 if you fancy. 🙂
 
I highly recommend the F6. I have the SDW Bordeaux speakers and the F6 was a huge step up in clarity to the amp i was using previously. The kit, case, power supply board etc are available on the diyaudio store. The only thing you have to source is the power supply parts to stuff the board. You can use the little diode bridges to save space time and money. I built out the rectifier section of the board and am not sure if that was worth it.

I mulled over it for quite a while and came to the conclusion that alot of people feel it is better sounding than the F5

Best of luck!