ACA V1.6 Alternative LED’s
Hi,
Getting closer to the finish line on my two V1.6 Bridged Monoblocks. I am looking for recommendations on alternative LED’s. I would like diffused white, but I have no idea what specs I am looking for. I also don’t want them too bright, but I am not willing to take apart the amps to change out R13 for a different resistor. So I was thinking that the diffused my be a bit easier on the eyeballs.
Thoughts?
Thanks in advance for any help.
Jim.
Hi,
Getting closer to the finish line on my two V1.6 Bridged Monoblocks. I am looking for recommendations on alternative LED’s. I would like diffused white, but I have no idea what specs I am looking for. I also don’t want them too bright, but I am not willing to take apart the amps to change out R13 for a different resistor. So I was thinking that the diffused my be a bit easier on the eyeballs.
Thoughts?
Thanks in advance for any help.
Jim.
Jim / hamelka,
This is a problem which cries out for DIY experimentation. Spend $20 and buy seven or eight different LEDs. Fool around with each LED, and a potentiometer, and a laboratory power supply. For each LED, find the operating current that pleases you the most. How? Futz around! Twirl the pot, look, and evaluate. When you've decided what makes you the happiest, write down the data in your lab notebook.
Once you've got the optimum current for each LED, go back and evaluate enjoyment versus viewing angle. When you're 30 degrees off-axis to the LED, how does it look? 60 degrees off-axis? You will probably discover that a few LEDs look great from every angle, while other LEDs soil their diapers badly at any viewing angle except straight-on.
And now you've got a decision. You know the LED that works best for YOU and you know what current to run through it. Plink out the arithmetic on a calculator and buy the appropriate current setting resistors for your amplifier, and poof. The problem is solved.
This is a problem which cries out for DIY experimentation. Spend $20 and buy seven or eight different LEDs. Fool around with each LED, and a potentiometer, and a laboratory power supply. For each LED, find the operating current that pleases you the most. How? Futz around! Twirl the pot, look, and evaluate. When you've decided what makes you the happiest, write down the data in your lab notebook.
Once you've got the optimum current for each LED, go back and evaluate enjoyment versus viewing angle. When you're 30 degrees off-axis to the LED, how does it look? 60 degrees off-axis? You will probably discover that a few LEDs look great from every angle, while other LEDs soil their diapers badly at any viewing angle except straight-on.
And now you've got a decision. You know the LED that works best for YOU and you know what current to run through it. Plink out the arithmetic on a calculator and buy the appropriate current setting resistors for your amplifier, and poof. The problem is solved.
I'm going to suggest utter blasphemy here. I was in the exact same boat. What I did was find a plastic folder (in my case blue) that is fairly translucent yet amounts several f stops of less light through.
I cut some square 'labels' and put that between the leds and the chassis and now I am not blinded when I turn out he lights to watch tv at night.
It is the least electric approach and I think it's the poorest one, but it works great as a temporary solution until I try new resistor values and / or different led brightness.
Best regards,
Rafa.
No thought of that at all. Sharing things learned while learning how to manage the drivers in high efficiency drivers with low power amplifiers.
I remember some piece of audio equipment that had little condoms that went over the bulbs..they def dim it, and you can pick a color too.
As a test, I hooked up the ACA straight to the Sabre DAC and surprisingly, it sounds great. There is not much gain in the DAC, so I can't use it like that for all types of music, but it's certainly usable for most of my music.
So, I'm wondering if there are any drawbacks to running the ACA directly off a DAC. Can impedance mismatch cause damage to any of the equipment? I'm asking because I normally use a B1 buffer which apparently takes care of impedance matching.
That is a very interesting question. I currently run my system, with no trouble, from my Theta Chroma DAC via a McCormick buffer (no gain) preamp and it works quite well. The amp I use currently is a Lynn with the Spark power supply. Of course, the Lynn has more gain than the ACA does.
For example the Pass F4 (no voltage gain) does not work well with the BoSoZ preamp unless the voltage gain of the BoSoZ is significantly increased to a level the F4 likes. However, the same high gain BoSoZ connected to a different amplifier with voltage gain (I believe it was an A3 they were discussing) will produce a fair amount of clipping. This is all information from the "Improving on X-BosoZ" thread. There are all kinds of issues that can increase of decrease the quality of the music produced by a given system. Finding the right combination of units and gain may take some effort.
For example the Pass F4 (no voltage gain) does not work well with the BoSoZ preamp unless the voltage gain of the BoSoZ is significantly increased to a level the F4 likes. However, the same high gain BoSoZ connected to a different amplifier with voltage gain (I believe it was an A3 they were discussing) will produce a fair amount of clipping. This is all information from the "Improving on X-BosoZ" thread. There are all kinds of issues that can increase of decrease the quality of the music produced by a given system. Finding the right combination of units and gain may take some effort.
Hi RCV, having built the ACA and paired it with the Objective2 headphone amp, I can tell you they match each other beautifully.
IMHO though, the sound is so detailed, that a soft room is required, I've tested mine out in two hard floored rooms and I found the sound does tend to bounce around, of course it would do that for any system, but I found it a little tiring after a time due to the extra detail I'm now hearing.
So, not the fault of the amp at all, but under those conditions a warmer amp would've been better for me, the recordings I've tried could've had an impact, as could've the source: Marantz CD6005 and speakers: Q Acoustics Concept 20.
Of course it's all subjective, for me: I'll start to throw some rugs around to dampen things a lttle
I'll refrain from entering the subjective, as has been mentioned, so many factors enter into what sounds good.
I will say this, a 0 gain preamp gets more volume than I want out of my ACA monoblocks to 94db, single full range driver speakers.
Listening position approximately 9' from the speakers in one end of a
12'x17' room.
I will say this, a 0 gain preamp gets more volume than I want out of my ACA monoblocks to 94db, single full range driver speakers.
Listening position approximately 9' from the speakers in one end of a
12'x17' room.
When first starting, my dad pointed out this same thing to me. I got worried so, while I was sanding away the chassis, he set up a proto board with the locally available leds and a variable PSU... the led more or less remains off until arround 1.8mA and then almost jumps to its maximum brightness fairly quickly.
The way to really dim them is with PWM. That works REALLY well. Controlling them through current (at least the generic garbage that is available locally) requires really fine precision.
Perhaps better manufacturers provide LEDs that behave better.
edit: So, to answer to your question about them being 'too dim', quite the contrary. Most everyone is trying to reduce their brightness as they can be really annoying on dark rooms.
The way to really dim them is with PWM. That works REALLY well. Controlling them through current (at least the generic garbage that is available locally) requires really fine precision.
Perhaps better manufacturers provide LEDs that behave better.
edit: So, to answer to your question about them being 'too dim', quite the contrary. Most everyone is trying to reduce their brightness as they can be really annoying on dark rooms.
Last edited:
Thanks for the reply! The last time I played with LEDs was as a teen more than 35 years ago (yes I'm old), and I think we needed 15-20mA of current to get normal brightness...I guess LEDs have become a lot more efficient since then!
Can't wait until the kit arrives...
2 - 4 mA is plenty for blue LEDs.
As Rafa said above, once they are on they are on and you'll need to try many different value series resistors until you find the one that suits you.
But.. it is not a big deal, it's part of the fun.
Most times I fit an external LED to something I end up running a preset type variable resistor in line to tweek the current down to get my desired brightness. I rarely by the same LED from one project to another so I have very little repeatability with them. Some of the new LEDs are incredibly bright now, I have some 3mm orange ones you can light the room with!
Hello Everyone,
New here but not to electronics...finished 1.6 (stereo) couple days ago. All what I can say is “wohhh”...incredible sound and getting better by the hour. Running in my lab with a old Marantz CD63 SE player, into a prototype Candela preamp (tubes) and to a pair of Epos 11 bookshelves speakers...sound is well balanced with incredible detail listening to Patricia Barber live music! Running the 24V PS. Waiting for a 200VA transformer and build a linear PS with one of my boards ...35A bridge rectifier and 60,000 uF of filtering using four 15,000uF German (Symphonic Line) caps - external chassis w/soft start of course!
I will hook it up later on to my main system driving a pair of Sonus Fabers Cremonas M.
Attached a couple pics on this initial build.
All the best.
Alex
New here but not to electronics...finished 1.6 (stereo) couple days ago. All what I can say is “wohhh”...incredible sound and getting better by the hour. Running in my lab with a old Marantz CD63 SE player, into a prototype Candela preamp (tubes) and to a pair of Epos 11 bookshelves speakers...sound is well balanced with incredible detail listening to Patricia Barber live music! Running the 24V PS. Waiting for a 200VA transformer and build a linear PS with one of my boards ...35A bridge rectifier and 60,000 uF of filtering using four 15,000uF German (Symphonic Line) caps - external chassis w/soft start of course!
I will hook it up later on to my main system driving a pair of Sonus Fabers Cremonas M.
Attached a couple pics on this initial build.
All the best.
Alex