@sthcoaster.
I am glad you made the observation about how the temperature of the system changed by just sticking a coupe of pencils to space the heatsinks from the surface of the furniture. I would highly recommend that you spend some time looking for actual legs for the eclosure that much taller than what is provided with the kit. If you get ambitious you can increase the amount of ventilation by adding holes to the top and bottom plates. Another thing you can do is to hang the heatsinks over the edge of whatever you use to hold your ACA (like a small pedestal) that will markedly increase air circulation over the heatsinks. Just give it a bit of thought.
I am glad you made the observation about how the temperature of the system changed by just sticking a coupe of pencils to space the heatsinks from the surface of the furniture. I would highly recommend that you spend some time looking for actual legs for the eclosure that much taller than what is provided with the kit. If you get ambitious you can increase the amount of ventilation by adding holes to the top and bottom plates. Another thing you can do is to hang the heatsinks over the edge of whatever you use to hold your ACA (like a small pedestal) that will markedly increase air circulation over the heatsinks. Just give it a bit of thought.
Thanks fr your comment oc11
I'm not using the kit - this will be all DIY, mostly from what I have to hand and using hand tools. My top and bottom plates will be holey. See post #7402 for some early pics.
For feet on other projects I have recently been playing with plump bobs that are available at my local hardware they are just mild steel or at least nothing special but I think they work very well and look great - if I use the smallest ones on this build I would have close to 2 inches clearance under the amp. I'm certainly thinking about it.
Currently the two channels sit on top of the enclosure of my passive pre. and they look like they were made together - same footprint. If I add taller feet to the ACA it will become more separate from the pre below. But I may have enough venting with 1/2inch clearance or so and still maintain the illusion that they are one unit. Aesthetic considerations are important!! 🙂
I've seen on this thread I think someone used wood turning blanks as a plinth - they looked great and I am sure companies selling them would have had a run on that product from DIYA people having seen them in use this way - was that you?
I'm not using the kit - this will be all DIY, mostly from what I have to hand and using hand tools. My top and bottom plates will be holey. See post #7402 for some early pics.
For feet on other projects I have recently been playing with plump bobs that are available at my local hardware they are just mild steel or at least nothing special but I think they work very well and look great - if I use the smallest ones on this build I would have close to 2 inches clearance under the amp. I'm certainly thinking about it.
Currently the two channels sit on top of the enclosure of my passive pre. and they look like they were made together - same footprint. If I add taller feet to the ACA it will become more separate from the pre below. But I may have enough venting with 1/2inch clearance or so and still maintain the illusion that they are one unit. Aesthetic considerations are important!! 🙂
I've seen on this thread I think someone used wood turning blanks as a plinth - they looked great and I am sure companies selling them would have had a run on that product from DIYA people having seen them in use this way - was that you?
@sthcoaster.
Got it, the legs provided with the kit are very small diameter adhesive backed plastic, I would say they are approximately 3/8" tall. The legs i bought at ebay were about 7/8" tall and 40mm in diameter, very nice aesthetically speaking and tall enough for my purposes. If you are concerned with aesthetics be aware that most legs available go from ugly to very ugly, keep on looking until you find what you want at the price you want. You could try buying something and then tooling it if you have a friend that can use a lathe.
I did see the wood block plinths you are talking about and thought this was a very functional way to cool the amps, and also a very elegant way to display them. I priced the wood blocks, this was some time ago, and if I remember correctly they were about $40 per block. Be aware that the wood used is green wood, therefore prone to develop cracks as it dries out. The wood blocks come covered with thick wax which apparently is a major pain to clean out to finish the wood as you may like it.
Got it, the legs provided with the kit are very small diameter adhesive backed plastic, I would say they are approximately 3/8" tall. The legs i bought at ebay were about 7/8" tall and 40mm in diameter, very nice aesthetically speaking and tall enough for my purposes. If you are concerned with aesthetics be aware that most legs available go from ugly to very ugly, keep on looking until you find what you want at the price you want. You could try buying something and then tooling it if you have a friend that can use a lathe.
I did see the wood block plinths you are talking about and thought this was a very functional way to cool the amps, and also a very elegant way to display them. I priced the wood blocks, this was some time ago, and if I remember correctly they were about $40 per block. Be aware that the wood used is green wood, therefore prone to develop cracks as it dries out. The wood blocks come covered with thick wax which apparently is a major pain to clean out to finish the wood as you may like it.
I’m currently using a starving student headphone amp as a pre-amp for an ACA, it sounds great adds a lot of gain. I was previously using a WHAMMY set up as a pre-amp which also sounds fantastic. Both are cost effective solutions. My speaker are a similar sensitivity.
I use the Discovery 15 from Troels website. I think their sensitivity is around 85db, so even a bit lower. Yes, a preamp with some gain is needed if you want to achieve somewhat "loud" levels.
Other than that: How do you like those speakers?
I'll add to the "yes it will work great" crowd. My speakers are 8 ohm 84db, recommended power is 30-100 watts. With a Schiit headphone amp in front of them on low gain setting, the 5 watt ACAs put out plenty of volume for my office space.
I use mine with a pair of 8 ohm JBL's that are about 86 db with an O2 headphone amp on the low gain setting and it drives them plenty loud for normal listening.
It turns out my cheap ACA was quiet because I had an incorrect feedback resistor. For R11 I'd mistakenly used 26k (red,blue...) instead of 10k (brown,black…). Now much better! There was a horrible high pitched warble from the laptop PSU. I've stuck a 6800uF 50V cap across the DC supply which eliminated it. Magic!
Hi guys, thanks heaps with your feedback. That gives me big confidence that my speaker will work fine.
Hi Mixi, to answer your question about how I am liking my speaker. I am very much enjoying it and the sound quality is actually very good.
Hi Mixi, to answer your question about how I am liking my speaker. I am very much enjoying it and the sound quality is actually very good.
Hello,
Does anyone know the dB gain of the ACA 1.6 (standard 24 volt supply) wired in parallel mono mode?
Thanks!
Does anyone know the dB gain of the ACA 1.6 (standard 24 volt supply) wired in parallel mono mode?
Thanks!
I have the monos with the board that have the extra resistor , didn’t give them much of a listening chance have almost a dozen tube amps , has the amp gotten any better with 24 volt PS or the stereo iteration, thanks
both channels in one chassis. what do you have to do to make it 24 volt, 19 now???
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According to the build guide, the differences between v. 1.5 (19v) and 1.6 (24v) are limited to the chasis (on off switch in the front) and the voltage used. There is no difference in the schematic or the value of the parts used. I believe you must readjust the bias to 12.5 after increasing the voltage from 19 to 24.
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