What is the voltage range that can be used for the power LED?
I know the one spec'd is 1.8 volt, but the choices in that voltage are rather limited.
Trying to find a nice panel mount LED power indicator to use there.
Any LED indicator that does not already contain a series resistor can be used. You'll find many in the 1.7-4 V range (different emitted wavelength -> different voltage drop). About 5 mA flows through the LED.
An alternative to an actual indicator is to just use a 'naked' LED. This is pretty easy if you use a chassis with a thick front panel. Drill a 2 mm hole through the panel and make a 5 mm diameter counterbore on the inside, centred on that 2 mm hole. Then epoxy the LED in place. That's what I did on the Modulus-286 Kit (LE).
Tom
An alternative to an actual indicator is to just use a 'naked' LED. This is pretty easy if you use a chassis with a thick front panel. Drill a 2 mm hole through the panel and make a 5 mm diameter counterbore on the inside, centred on that 2 mm hole. Then epoxy the LED in place. That's what I did on the Modulus-286 Kit (LE).
Tom
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There are also holders, such as these. (Mouser P/N: 593-CLP127 and 630-HLMP-0103 shown).
Plenty more in the LED Mounting Hardware section under LED Indication on Mouser: https://www.mouser.ca/Optoelectronics/LED-Indication/LED-Mounting-Hardware/_/N-b1d1n
The holders work well with thinner panels.
Tom
Plenty more in the LED Mounting Hardware section under LED Indication on Mouser: https://www.mouser.ca/Optoelectronics/LED-Indication/LED-Mounting-Hardware/_/N-b1d1n
The holders work well with thinner panels.
Tom
Attachments
Hi everyone..
The mod86 show me interest, however I'm dubitative about the 40w into 8ohm to drive my speakers.
I have a set of sonus faber venere 3 with a denon pma 2500 of 80w, a beast amp.
Do you think the mod86 would offer power similarity of a denon?
I don't listen loud, usually at low levels. The denon is wonderful at low levels
Is it possible to have two mod86 per channel in a stereo configuration and get 80w per chanel?
The mod86 show me interest, however I'm dubitative about the 40w into 8ohm to drive my speakers.
I have a set of sonus faber venere 3 with a denon pma 2500 of 80w, a beast amp.
Do you think the mod86 would offer power similarity of a denon?
I don't listen loud, usually at low levels. The denon is wonderful at low levels
Is it possible to have two mod86 per channel in a stereo configuration and get 80w per chanel?
This thread is long to read.. And sometimes technical for me..
Does the mod86 can drive with ease some sonus faber venere 3?
Correct me if I'm wrong please
For a double mono amp I would need
2 x mod 86
1 x smps 300 rah
1 x alu case with heat sinks
2 x rca
4 x bananas
Cabling
1 x switch on/off
1 x iec
1 x dac/preamp such as the Chinese topping, smsl etc (external)
I can either choose rca or xlr input ( can I have both with a switch)
My idea is to build a second system diy and learn from it
Since I'm interested in audio, I think it's time to start to diy electronics, speakers etc etc...
Does the mod86 can drive with ease some sonus faber venere 3?
Correct me if I'm wrong please
For a double mono amp I would need
2 x mod 86
1 x smps 300 rah
1 x alu case with heat sinks
2 x rca
4 x bananas
Cabling
1 x switch on/off
1 x iec
1 x dac/preamp such as the Chinese topping, smsl etc (external)
I can either choose rca or xlr input ( can I have both with a switch)
My idea is to build a second system diy and learn from it
Since I'm interested in audio, I think it's time to start to diy electronics, speakers etc etc...
Not without substantial additional engineering work... which Tom has done, and offers in the Modulus-286.
If you "don't listen loud" in the same way I don't listen loud, then I think it's a safe assumption that the Mod 86 will provide enough power for you. But with more details about your setup (room size/distance to speakers, speaker efficiency, approximate volume), we can do some rough math that will be better than an assumption. If you have a smartphone, there are free dBA meters you can use to measure your typical SPL.
My speakers are about 86 dBA/W efficient, I have a room that is about 10x11 feet, 9 foot ceilings. I like modest volumes (almost always lower than 80 dBA), and the Mod86 provides way more power than I need. How do I know? In testing a DIY DAC a while ago, I accidentally set the volume to max. It was unbearably loud!
That said, to the original question of using two Mod86's to double the power: Tom, is it possible to bridge two Mod86's at the speaker, if one is fed an inverted signal? So one amp is "pushing" the signal, and the other is "pulling" the inverted signal? I don't actually want to do this, just curious!
Thanks for your feedback
I usually listen to 70bd.. Sometimes 75/77.. Rarely over 80db in my room
Speakers are 2.5m away.. Me at the top of the triangle
The room has some treatment, it's fairly a good listening room I would say.. Clap your hands in my room and you will notice treatment effect..
Speakers are 89db.. But I dunno about the impedance.. They are rated 8ohm I think.. But graph will show that lower frequencies are a little under 4ohm.. Which sucks power... Reason I went to a denon pma 2500 that provides high current
I'm interested in a diy amp to get some learning and understanding.. My searches leaded me to Tom's work, in which I have some trust.. Otherwise, it's Chinese amp boards... Well... Hummmmm
I still need to clear couple of interrogation to jump into it.. I'm not familiar with '' 40w '' amp.. That said, it's only a number.. Then I see I have options to go to mod286 and mod686... But budget is no same.. I'd rather start by the little door
I usually listen to 70bd.. Sometimes 75/77.. Rarely over 80db in my room
Speakers are 2.5m away.. Me at the top of the triangle
The room has some treatment, it's fairly a good listening room I would say.. Clap your hands in my room and you will notice treatment effect..
Speakers are 89db.. But I dunno about the impedance.. They are rated 8ohm I think.. But graph will show that lower frequencies are a little under 4ohm.. Which sucks power... Reason I went to a denon pma 2500 that provides high current
I'm interested in a diy amp to get some learning and understanding.. My searches leaded me to Tom's work, in which I have some trust.. Otherwise, it's Chinese amp boards... Well... Hummmmm
I still need to clear couple of interrogation to jump into it.. I'm not familiar with '' 40w '' amp.. That said, it's only a number.. Then I see I have options to go to mod286 and mod686... But budget is no same.. I'd rather start by the little door
Doubling the power results in a 3 decibel increase in volume. It is said that this is the threshold of hearing when something is slightly louder.
Since you know what level you are listening at. Since it looks like you have measured your listening level then you can perform a test to see if this difference matters to you.
Using the measurement system, play some music at your normal listening levels. Note the volume control position. Now play the same music at an increase of 3dB. Note the position here as well. Perhaps use some masking tape.
Now here's what to do. Select three or more different songs. Have another person play those same songs and have them note the position of each play. Now have a 15-30 second pause between each track. And have the person adjust or not adjust the control. Now make sure the person notes the level. You being the listener, make a note of what YOU think is the level. Of course you must not know what levels are being used.
Ideally use songs from different albums and genres.
Then compare notes.
Since you know what level you are listening at. Since it looks like you have measured your listening level then you can perform a test to see if this difference matters to you.
Using the measurement system, play some music at your normal listening levels. Note the volume control position. Now play the same music at an increase of 3dB. Note the position here as well. Perhaps use some masking tape.
Now here's what to do. Select three or more different songs. Have another person play those same songs and have them note the position of each play. Now have a 15-30 second pause between each track. And have the person adjust or not adjust the control. Now make sure the person notes the level. You being the listener, make a note of what YOU think is the level. Of course you must not know what levels are being used.
Ideally use songs from different albums and genres.
Then compare notes.
For 8 Ω loads that is possible. You should get around 150 W into 8 Ω on ±28 V rails.
It would not work for 4 Ω load, though. The LM3886 can't provide enough output current for that. You can see the math here: Taming the LM3886: Output Power – Neurochrome
Have a look here: Taming the LM3886: Thermal Design – Neurochrome
Your shopping list in Post #5186 looks correct. I would recommend adding two of my output inductors. You can wind them yourself if you wish (I do provide instructions in the design doc), but the readymade ones are much nicer to work with.
Tom
Thanks for feed back, will have the reading of taming the lm3886, seems to be the starting point
150w into 8ohm sounds nice.. But would not work for 4ohm loads...
A speaker is '' rated '' at a certain value (average) but when I look at impedance curve of any speaker, the Ohm value always depends on frequencies.. So a speaker has some 4ohm and 8ohms value
Its perhaps preferable to stay with a single mod86 per chanel then
Mikett : thanks for the idea... I tried it
To get my reference listening level on a few tracks, my amp is at 8.30 o'clock...
To add 3db more on the phone analyzer, I need to push the amp only a little around 9.15.. To get 3db more, I only need to push a little more... And it gets loud.. I mean LOUD in my room... And the amp keeps going...
for those who know the denon pma 2500, this things is a beast and rated only at 80w on paper...
I had in past some amps rated 100, 150w and even a rotel at 200w... But denon seems to handle better... I guess it's a matter of gain..
That's why I'm not confortable with values rated in W
I had some reading last night on this thread... Returns of owners indicate that mod86 is enough for speakers at normal listening levels...
An owner mention he had a pmc24.. And he was happy with... His comment conforts me that mod86 would be enough
I keep on my readings
Thanks for sharing
150w into 8ohm sounds nice.. But would not work for 4ohm loads...
A speaker is '' rated '' at a certain value (average) but when I look at impedance curve of any speaker, the Ohm value always depends on frequencies.. So a speaker has some 4ohm and 8ohms value
Its perhaps preferable to stay with a single mod86 per chanel then
Mikett : thanks for the idea... I tried it
To get my reference listening level on a few tracks, my amp is at 8.30 o'clock...
To add 3db more on the phone analyzer, I need to push the amp only a little around 9.15.. To get 3db more, I only need to push a little more... And it gets loud.. I mean LOUD in my room... And the amp keeps going...
for those who know the denon pma 2500, this things is a beast and rated only at 80w on paper...
I had in past some amps rated 100, 150w and even a rotel at 200w... But denon seems to handle better... I guess it's a matter of gain..
That's why I'm not confortable with values rated in W
I had some reading last night on this thread... Returns of owners indicate that mod86 is enough for speakers at normal listening levels...
An owner mention he had a pmc24.. And he was happy with... His comment conforts me that mod86 would be enough
I keep on my readings
Thanks for sharing
"To get 3db more, I only need to push a little more... And it gets loud"
OK to clarify things here and a little off topic, it is important to understand that the volume control only controls the level of signal incoming to the amplifier stage. The same is done with the accelerator pedal in your automobile.
Now let's suppose the pedal has 3 inches of travel from start to full depression. The amount of power the automobile has remains fixed. So I can design the system so that the first 1" of travel produces 60% of power and then the next 1" will produce 30% and the final 1" will produce 10% of power. So when using the automobile the initial feel is that the automobile is powerful relative to another scheme where the first 1" produces 10% power, the next 1" produces 20% power and the final 1" produces 70% power. The same auto would feel more powerful because as soon as I tap on the pedal a lot of power is produced and the auto accelerated hard. I have to be careful. However when I floor it to the last 1" of travel, there is nothing left hardly any extra power is produced. With the second scheme, the same car will feel sluggish but not jerky and the user will think it has less power.
The same applies to an amplifier. The gain or multiplication of boosting of the incoming signal remains FIXED. What changes is the incoming signal level via the volume control. So you can make a volume control to vary the signal non linearly. The volume control can be configured by many schemes just like the automobile. ( In fact that is exactly what modern automobiles use. (a volume control connected to your foot) So realize the rotation of the volume control does not mean anything related to the power output. The reason is that the output of it, is always magnified the same amount by the amplifier. The volume control is really and is sometimes called an attenuator which is correct. It simply reduces the incoming signal to the amplifier.
It can be just like the auto where the power comes in strong after a certain point.
It gets worse in an amplifier because the incoming signal to the volume control varies depending on the recording. On some songs it may take only half the rotation of the volume control to reach the max power the amplifier can produce. On another song, that was recorded and mastered differently, it could take three quarters rotation and it will vary by each song as well.
Only by observing/measuring the actual output or listening very loud till you hear distortion will allow you to assess the real power of the amplifier. There are other reasons why more powerful amplifiers may sound better at lower volumes but do not be fooled by the rotation of the volume control. DIYing will eventually show you why as you learn.
OK to clarify things here and a little off topic, it is important to understand that the volume control only controls the level of signal incoming to the amplifier stage. The same is done with the accelerator pedal in your automobile.
Now let's suppose the pedal has 3 inches of travel from start to full depression. The amount of power the automobile has remains fixed. So I can design the system so that the first 1" of travel produces 60% of power and then the next 1" will produce 30% and the final 1" will produce 10% of power. So when using the automobile the initial feel is that the automobile is powerful relative to another scheme where the first 1" produces 10% power, the next 1" produces 20% power and the final 1" produces 70% power. The same auto would feel more powerful because as soon as I tap on the pedal a lot of power is produced and the auto accelerated hard. I have to be careful. However when I floor it to the last 1" of travel, there is nothing left hardly any extra power is produced. With the second scheme, the same car will feel sluggish but not jerky and the user will think it has less power.
The same applies to an amplifier. The gain or multiplication of boosting of the incoming signal remains FIXED. What changes is the incoming signal level via the volume control. So you can make a volume control to vary the signal non linearly. The volume control can be configured by many schemes just like the automobile. ( In fact that is exactly what modern automobiles use. (a volume control connected to your foot) So realize the rotation of the volume control does not mean anything related to the power output. The reason is that the output of it, is always magnified the same amount by the amplifier. The volume control is really and is sometimes called an attenuator which is correct. It simply reduces the incoming signal to the amplifier.
It can be just like the auto where the power comes in strong after a certain point.
It gets worse in an amplifier because the incoming signal to the volume control varies depending on the recording. On some songs it may take only half the rotation of the volume control to reach the max power the amplifier can produce. On another song, that was recorded and mastered differently, it could take three quarters rotation and it will vary by each song as well.
Only by observing/measuring the actual output or listening very loud till you hear distortion will allow you to assess the real power of the amplifier. There are other reasons why more powerful amplifiers may sound better at lower volumes but do not be fooled by the rotation of the volume control. DIYing will eventually show you why as you learn.
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Thanks, it's crystal clear..
So my understanding for that diy project is that it will depend on the preamplifier I will use in front
My current idea is a diy amp with mod86
And then get a dac/preamplifier from topping or smsl with stellar measurements
Additional questions please
For a double mono, shouldnt I have double smps?
Is there any audible differences with rca input or xlr inputs?
Some Chinese dacs come with rca or xlr outputs.. The mod86 can handle any?
So my understanding for that diy project is that it will depend on the preamplifier I will use in front
My current idea is a diy amp with mod86
And then get a dac/preamplifier from topping or smsl with stellar measurements
Additional questions please
For a double mono, shouldnt I have double smps?
Is there any audible differences with rca input or xlr inputs?
Some Chinese dacs come with rca or xlr outputs.. The mod86 can handle any?
One completed Mod86 board will drive one speaker (the lm3886 is a mono chip). So for a typical stereo build, you need two completed Mod86 boards.
You can use a single power supply to power both boards, like many consumer power amplifiers. Or you can use two power supplies, one for each board; in this route, you could put both power supplies and Mod86 boards in the same case, or have two separate enclosures.
There's really no right or wrong, there are plenty of examples in this thread of both approaches. It's really more a matter of personal preference. (I recently posted pics of my build, I use one power supply for two Mod86 boards; a compact amp was a personal goal of mine.)
Yes, the Mod86 can handle differential (XLR) or single-ended (RCA) inputs. Differential is technically superior; but there is some debate as to whether it makes an audible difference in a typical home environment with short cable runs. I personally can't hear a difference, but I'm sure others have a different opinion. Single-ended/RCA DACs and preamps are generally more readily available and cheaper, so that's another consideration.
Yep. That's how a high-gain amp behaves. Unfortunately, high gain also leads to higher noise. Tradeoffs, tradeoffs...
I would much rather that "unbearably loud" happens near 3 o'clock on the volume control. That's a much better use of the available dynamic range. The drawback of an amp designed like that is that it'll will be perceived as weak simply because you have to turn the volume past 9 o'clock for normal listening levels.
Tom
Thanks for returning answer..
My friend has a technics su-g700, and it's rotary volume knob works like u describe... It's linear all the way round... It starts at 7 o'clock with 0.. Ends at 4 o'clock at 100... It's a different feeling but no weakness, at 9 o'clock it's cool beans, 10 o'clock warm beans, 11 cooking, 12 is dancing loud...
my denon, I actually don't know what looks like after 12. That thing seems endless in power... It keeps going... At noon with my speakers and it my room it's clubbing level.. Windows are rattling.... At noon, you're not done yet... And distortion are barely audible, if any
I'm not looking for these kind of levels with a diy project like yours.. I want clean and precise amp to bring me to my usual listening levels.. No more.
My friend has a technics su-g700, and it's rotary volume knob works like u describe... It's linear all the way round... It starts at 7 o'clock with 0.. Ends at 4 o'clock at 100... It's a different feeling but no weakness, at 9 o'clock it's cool beans, 10 o'clock warm beans, 11 cooking, 12 is dancing loud...
my denon, I actually don't know what looks like after 12. That thing seems endless in power... It keeps going... At noon with my speakers and it my room it's clubbing level.. Windows are rattling.... At noon, you're not done yet... And distortion are barely audible, if any
I'm not looking for these kind of levels with a diy project like yours.. I want clean and precise amp to bring me to my usual listening levels.. No more.
Thanks
I think I found my amp chips
I'm on vacation the next two weeks, will get time to read this thread and gather all the necessary knowledge to get me started and for my personal knowledge too to understand deeper how electronic works
I started to populate cost of this project, I end up around 500e all in, the aluminum case is the pain in the butt!!
Question : i can find an old Marantz 1060 in mint condition but the amp chips are dead : is it possible to keep the casing and preamp, take out amplifier parts and build in mod86 plus smps in?
That way I would have preamp plus a very cute looking case?
It's just an idea that pop up in my head...
Since it's diy, possibilities seems end less
I think I found my amp chips
I'm on vacation the next two weeks, will get time to read this thread and gather all the necessary knowledge to get me started and for my personal knowledge too to understand deeper how electronic works
I started to populate cost of this project, I end up around 500e all in, the aluminum case is the pain in the butt!!
Question : i can find an old Marantz 1060 in mint condition but the amp chips are dead : is it possible to keep the casing and preamp, take out amplifier parts and build in mod86 plus smps in?
That way I would have preamp plus a very cute looking case?
It's just an idea that pop up in my head...
Since it's diy, possibilities seems end less