Hi!
I'm new to this forum and I'm looking for some advice for my first diy amp project.
I've spent quite some time reading through posts on this forum and some other websites and it appears that chipamps are among the easiest diy amp projects. So here's my first question: Am I right about this or are there other (easier) projects that you'd recommend?
I am currently using a rather basic setup with a Pro-ject turntable a denon 510ae amp ad some phonar 3-way speakers.
The kit I'm looking at is the LM3875 kit from audiosector. Will that be an improvement over my current denon amp? The speakers I use are rated with a sensitivity of 89db.
I'd also like to add that I live in Austria so our mains voltage is 230V - just to be taken into consideration when I start asking questions about building the PSU
Many thanks in advance! Looking forward to your comments!
I'm new to this forum and I'm looking for some advice for my first diy amp project.
I've spent quite some time reading through posts on this forum and some other websites and it appears that chipamps are among the easiest diy amp projects. So here's my first question: Am I right about this or are there other (easier) projects that you'd recommend?
I am currently using a rather basic setup with a Pro-ject turntable a denon 510ae amp ad some phonar 3-way speakers.
The kit I'm looking at is the LM3875 kit from audiosector. Will that be an improvement over my current denon amp? The speakers I use are rated with a sensitivity of 89db.
I'd also like to add that I live in Austria so our mains voltage is 230V - just to be taken into consideration when I start asking questions about building the PSU
Many thanks in advance! Looking forward to your comments!
I would recommend Neurochrome's LM3886DR along with their excellent switching supply design. Their linear supply design is also excellent for higher power with the same circuit.
https://www.neurochrome.com/lm3886-done-right/
The designer's documentation, expertise, and consumer service is one of the best I have experienced.
Best,
Anand.
https://www.neurochrome.com/lm3886-done-right/
The designer's documentation, expertise, and consumer service is one of the best I have experienced.
Best,
Anand.
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great, thanks for your replies.
may i ask why you don't recommend the audiosector kit to beginners? is it harder to build, more difficult to find the right speakers for it...?
thank you for recommending Neurocrome's kit. It really looks "plug 'n play". any ideas or comments on how such a kit would compare to an amp like the denon 510 ae i mentioned?
thank you!
michi
may i ask why you don't recommend the audiosector kit to beginners? is it harder to build, more difficult to find the right speakers for it...?
thank you for recommending Neurocrome's kit. It really looks "plug 'n play"
. any ideas or comments on how such a kit would compare to an amp like the denon 510 ae i mentioned?thank you!
michi
The Audiosector design is to minimalist to be guaranteed usable under all circumstances.
It omits parts needed to ensure complete stability under all usage conditions, and it also has the potential (literally) to destroy your speakers unless you appreciate those compromises and how to work around them.
It omits parts needed to ensure complete stability under all usage conditions, and it also has the potential (literally) to destroy your speakers unless you appreciate those compromises and how to work around them.
Buy something single supply with a speaker capacitor. There are designs for LM1875/3875 both ways, but the boards pick split supply or single supply.
That way if you make a soldering mistake you don't have to buy a new speaker. Whatever, try out with throwaway speakers, to make sure no wire pops loose in the first weeks.
If you buy a circuit board, chip amp may be easier. I build point to point, and my 6 transistor AX6 worked better when wired correctly, than my LM1875, which oscillates. http://www.diyaudio.com/forums/solid-state-236256-retro-amp-50w-single-supply-20.html
It is easier to keep the input wires away from the output wires with bigger parts.
That way if you make a soldering mistake you don't have to buy a new speaker. Whatever, try out with throwaway speakers, to make sure no wire pops loose in the first weeks.
If you buy a circuit board, chip amp may be easier. I build point to point, and my 6 transistor AX6 worked better when wired correctly, than my LM1875, which oscillates. http://www.diyaudio.com/forums/solid-state-236256-retro-amp-50w-single-supply-20.html
It is easier to keep the input wires away from the output wires with bigger parts.
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As possible digression:
Your Denon is a reasonable amp. A Chip amp may or may not equal it's performance
Suggest you Look at building a pass design Amp (pass diy forum above) Surprisingly Simple builds and by anybody's yardstick Excellent sounding.
A genuine worth the effort result
No blow up your speakers nonsense either
Your Denon is a reasonable amp. A Chip amp may or may not equal it's performance
Suggest you Look at building a pass design Amp (pass diy forum above) Surprisingly Simple builds and by anybody's yardstick Excellent sounding.
A genuine worth the effort result
No blow up your speakers nonsense either
Just curious what "beginner trouble" you envision in a 2 chipamp 8 resistors plus a couple capacitors and a PCB kit
DIY Chip Amplifier Kits, PCB's, Components and Information.
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Is there anything simpler?
Mooly has given a fair response.
If I were to add in my whole thoughts it would not be good reading.
I 2nd this. I've built Peter's audio sector kit 5 years ago. It still works, sounds okay. The improvement over my Harmon Kardom receiver is that the H/K had some kind of 40hz high pass filter built in that could not be turned off. I went through all menu's set all speakers to Large, etc, but no turning it off. Very annoying! I guess some idiot consumers need help to not overdrive their sprakers? I have no idea if this would apply to your demon. If you build your own you will not have this shortcoming.
More recently I built an Neurochrome amp (in fact I've built several). They sound great! They measure much less D.C. Offset at speakers too compared to audio sector. Much better noise rejection too. The instructions, documentation and support of Neurochrome are far superior to anything I've found.
Thank you so much for all your replies! The Neurochrome products really do look very interesting.
I also looked into the pass amps section and the Amp Camp Amp also seems to be very well suited for a first project. So I guess I'll decide between those two.
Might be a stupid question but: Am I understanding right that both amps (amp camp and LM3886DR) are power amps that will need a suitable pre-amp? If yes, which pre-amps can you recommend? what would be the easiest way to include volume control?
My ultimate goal is to build an integrated with a phono stage ..... just so you know what i'm aiming at in the long run
I also looked into the pass amps section and the Amp Camp Amp also seems to be very well suited for a first project. So I guess I'll decide between those two.
Might be a stupid question but: Am I understanding right that both amps (amp camp and LM3886DR) are power amps that will need a suitable pre-amp? If yes, which pre-amps can you recommend? what would be the easiest way to include volume control?
My ultimate goal is to build an integrated with a phono stage ..... just so you know what i'm aiming at in the long run
The LM3886DR has a gain of 26db which is fairly typical for a power amp and translates to a voltage gain of 20.
You could feed a CD player type source into that and drive it fairly well although a modest amount of gain beforehand would be beneficial to get a good 'feel' to the volume control range. Probably a gain of around 3 would be in the right ballpark.
The Amp Camp I believe has a gain of 14db which is low. That's a voltage gain of just 5 and so a higher gain preamp is definitely needed here.
Also, are you aware of how hot the Amp Camp runs ?
For each, the volume control is simply placed at the input to the amplifier with the preamp feeding the volume control.
The preamp can be a simple opamp based design which offers good performance and low parts count. It can also be fed from the LM3886 power supply if you wish, not directly but with a simple regulator to step the voltage down.
You could feed a CD player type source into that and drive it fairly well although a modest amount of gain beforehand would be beneficial to get a good 'feel' to the volume control range. Probably a gain of around 3 would be in the right ballpark.
The Amp Camp I believe has a gain of 14db which is low. That's a voltage gain of just 5 and so a higher gain preamp is definitely needed here.
Also, are you aware of how hot the Amp Camp runs ?
For each, the volume control is simply placed at the input to the amplifier with the preamp feeding the volume control.
The preamp can be a simple opamp based design which offers good performance and low parts count. It can also be fed from the LM3886 power supply if you wish, not directly but with a simple regulator to step the voltage down.
So you say that a pre-amp is not really necessary but it would be beneficial (for the LM3886DR). Can you recommend a suitable preamp module? Unfortunately I don't know what an opamp is ..... :-(
I've been looking for pictures of integrated amps using the LM3886DR but couldn't find any...... I'd just like to see how it coud look......I can't really read circuit diagrams.
No, I am not aware of the AMp Camp running hot ... but would that be a problem?
I've been looking for pictures of integrated amps using the LM3886DR but couldn't find any...... I'd just like to see how it coud look......I can't really read circuit diagrams.
No, I am not aware of the AMp Camp running hot ... but would that be a problem?
You will need some method of setting/adjusting the volume.
A volume potentiometer can do this job but there are conditions to get good performance.
Look up the sticky Thread for suggestions.
You can use a Buffered vol pot and that can remove some of the conditions giving a more flexible arrangement.
If you have sufficient gain in your system, then you don't need the extra gain of a gain stage.
Look up the system gain article in this Forum.
Most separate digital source put out a maximum signal of 1.9vac to 2.3Vac.
The amp suggested earlier (Gain = +26dB) has a maximum output of 50W into 4ohms. That requires an input of 0.707Vac to reach clipping of that amplifier when driving 4ohms speakers. It needs more input voltage to reach clipping driving an 8ohms speaker.
An output of 1.9Vac from a digital source does not need extra gain. A vol pot, or buffered vol pot, is sufficient.
If you have low output sources that cannot drive the power amp to clipping from a maximum signal level, then you may want to add in some extra gain. But most power amps already have too much gain, often around +26dB to +33dB
Again the system gain article can guide you.
A volume potentiometer can do this job but there are conditions to get good performance.
Look up the sticky Thread for suggestions.
You can use a Buffered vol pot and that can remove some of the conditions giving a more flexible arrangement.
If you have sufficient gain in your system, then you don't need the extra gain of a gain stage.
Look up the system gain article in this Forum.
Most separate digital source put out a maximum signal of 1.9vac to 2.3Vac.
The amp suggested earlier (Gain = +26dB) has a maximum output of 50W into 4ohms. That requires an input of 0.707Vac to reach clipping of that amplifier when driving 4ohms speakers. It needs more input voltage to reach clipping driving an 8ohms speaker.
An output of 1.9Vac from a digital source does not need extra gain. A vol pot, or buffered vol pot, is sufficient.
If you have low output sources that cannot drive the power amp to clipping from a maximum signal level, then you may want to add in some extra gain. But most power amps already have too much gain, often around +26dB to +33dB
Again the system gain article can guide you.
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An opamp is an integrated circuit (usually 8 legs) that can contain one or two amplifiers. They are easy to use and the gain is set by choice of the surrounding component values.
The LM3886 is really a 'power opamp' that can drive speakers, wheras the little 'uns can not.
The Amp Can runs very hot by design (as do all true Class A amplifiers) and so would need a well ventilated case, big heatsinks and a hefty power supply. The LM3886 by contrast runs very cool under no signal conditions, the opposite to the Amp Camp.
Here is a typical preamp:
Hi-Fi Preamplifier
Check out the rest of the site from the links at the bottom of the above page, you will learn a lot.
Jeff Rowland LM3886 Amplifiers
PA100 DIY 2x LM3886 in parallel gainclone audio amplifier
thanks for your suggestions for further reading .... i'll dig in over the weekend.
it appears that kits for power amps are readily availible but i have a harder time finding some for phone stages and pre-amps.
i planned on building the graham slee genera phono stage (https://www.hifisystemcomponents.com/phono-preamps/dak-genera-phono-preamp-parts-kit.html) and combinimg it with the lm3886dr (i think that's the one i want to build). if i read it right the phono stage has an output of 200mv-1V ..... so i guess that would not be enough to use the 3886dr without additional gain. is there a simple gain stage you could suggest to "go in between" the genera phono amp and the 3886dr?
thanks!
michi
it appears that kits for power amps are readily availible but i have a harder time finding some for phone stages and pre-amps.
i planned on building the graham slee genera phono stage (https://www.hifisystemcomponents.com/phono-preamps/dak-genera-phono-preamp-parts-kit.html) and combinimg it with the lm3886dr (i think that's the one i want to build). if i read it right the phono stage has an output of 200mv-1V ..... so i guess that would not be enough to use the 3886dr without additional gain. is there a simple gain stage you could suggest to "go in between" the genera phono amp and the 3886dr?
thanks!
michi
Another option is to consider a different phono stage, but I don't know a lot about them.
Lastly, you might consider that lm3886dr *should* do a fine job with a 1v input.
Will your turntable be as loud as your CD Player that probably runs at 2.v, no,... but do you really listen at full volume all the time?
It's good to have a vision of your endgame, but you can do it in stages. I would build amp first, and worry about preamp later. That's just me, and I do not currently own a turntable. As I remember, they never were as loud as CD Players in general consumer systems (i.e. Yamaha Receiver with phono stage, Technics turntable), when CD's came out, they were definitely louder,... I thought that's just the way it is....your mileage may vary.
Some other options are here. These are by Douglas Self, one of the highly regarded figures in the audio game:
The Signal Transfer Company
The Signal Transfer Company: RIAA PCB with unbalanced outputs
Signal Transfer Company: Cases
Also check out what is many ways the ultimate preamp with regard to flexibility and tone controls:
The Signal Transfer Company: Precision Preamplifier
Gain is a surprisingly difficult thing to nail when it comes to how it all works out subjectively. I would say try your chosen phono preamp first (with volume control of course) and then see whether more gain is needed.
Being opamp based it could be as simple as a single resistor value change to get you more gain from the phono stage without any additional circuitry being needed.
The Signal Transfer Company
The Signal Transfer Company: RIAA PCB with unbalanced outputs
Signal Transfer Company: Cases
Also check out what is many ways the ultimate preamp with regard to flexibility and tone controls:
The Signal Transfer Company: Precision Preamplifier
Gain is a surprisingly difficult thing to nail when it comes to how it all works out subjectively. I would say try your chosen phono preamp first (with volume control of course) and then see whether more gain is needed.
Being opamp based it could be as simple as a single resistor value change to get you more gain from the phono stage without any additional circuitry being needed.
Thanks for all your replies so far!
So I decided to go with the muffsy phono stage (https://www.muffsy.com/build-the-muffsy-pp-3-rev-a.html) and try to combine it with a Neurochrome LM3886DR to build an integrated amp.
I already build the muffsy and everything went well - it was the first time I soldered anything so I'm quite pleased.
The parts from Neurochrome are on their way.
Now I'm thinking about a way to include a potentiometer and have a few general questions.
Lots of people seem to like the alps pots. Would one of them be suited for my project?
Am I seeing it right, that the potentiometer will usually sit "between" the input signal (CD, record or other) and the power amplifier? So the potentiometer will regulate "how much" of the input signal will get to the power amp to be amplified? Much in the same way as a seperate pre will regulate the signal before it gets to the power amp. Maybe it is a stupid question but why does it work that way? The way I understand it, a record player produces a very week signal and the phono stage amplifies it before it goes to the pre/power amp. So why "reduce" that signal again before it gets to the power amp? Would it also make sense to reduce the signal after it has been processed by the power amp - so maybe have a potentiometer between the amps output and the speakers. Maybe this question is super stupid and my terminology is all wrong but I still hope to find answers
Best
M
So I decided to go with the muffsy phono stage (https://www.muffsy.com/build-the-muffsy-pp-3-rev-a.html) and try to combine it with a Neurochrome LM3886DR to build an integrated amp.
I already build the muffsy and everything went well - it was the first time I soldered anything so I'm quite pleased.
The parts from Neurochrome are on their way.
Now I'm thinking about a way to include a potentiometer and have a few general questions.
Lots of people seem to like the alps pots. Would one of them be suited for my project?
Am I seeing it right, that the potentiometer will usually sit "between" the input signal (CD, record or other) and the power amplifier? So the potentiometer will regulate "how much" of the input signal will get to the power amp to be amplified? Much in the same way as a seperate pre will regulate the signal before it gets to the power amp. Maybe it is a stupid question but why does it work that way? The way I understand it, a record player produces a very week signal and the phono stage amplifies it before it goes to the pre/power amp. So why "reduce" that signal again before it gets to the power amp? Would it also make sense to reduce the signal after it has been processed by the power amp - so maybe have a potentiometer between the amps output and the speakers. Maybe this question is super stupid and my terminology is all wrong but I still hope to find answers
Best
M
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