Hello people of the internet! I'm new to this forum and since I don't have any experience whatsoever with audio equipment, I need some help building an all in one Amplifier - Phono Preamplifier. While searching the internet I saw some designs, but after some research I think Rod Elliott has some good designs overall. In the design, he used a transformer to power things up, but I find it easier for me to use a switch mode power supply (if possible).
The model I'm hoping for is: MeanWell 36V 4.3A 154.8W.
I was wonder if it is possible to power everything up with this power supply, but my main question, since I have only experience with Arduino projects, is that the transformer power supply that he recommends has +/-35V and Ground on the output. I just don't know were I'd connect the Ground, since the Switch mode power supply has only +/-35 Volt.
Here are the links to the ESP posts: Phono Preamp , Amplifier
Here are the schematics:
Phono Preamp
Amp
Power Supply
In case that it matters, the turntable I got is a Marantz TT-42. If anyone has any other suggestion, it would be greatly appreciated. I'm also thinkinh adding a VU Meter Module. If someone would help with the wiring, it'd be greatly appreciated.
Thank you in advance, have a great day!
The model I'm hoping for is: MeanWell 36V 4.3A 154.8W.
I was wonder if it is possible to power everything up with this power supply, but my main question, since I have only experience with Arduino projects, is that the transformer power supply that he recommends has +/-35V and Ground on the output. I just don't know were I'd connect the Ground, since the Switch mode power supply has only +/-35 Volt.
Here are the links to the ESP posts: Phono Preamp , Amplifier
Here are the schematics:
Phono Preamp
An externally hosted image should be here but it was not working when we last tested it.
Amp
An externally hosted image should be here but it was not working when we last tested it.
Power Supply
An externally hosted image should be here but it was not working when we last tested it.
In case that it matters, the turntable I got is a Marantz TT-42. If anyone has any other suggestion, it would be greatly appreciated. I'm also thinkinh adding a VU Meter Module. If someone would help with the wiring, it'd be greatly appreciated.
Thank you in advance, have a great day!
The MeanWell SMPS is a single output supply, but your circuit needs a dual polarity +/- /ground supply.
The SMPS should be described as a +35V/0V single output supply.
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I am indeed confused, because clearly in the picture I can see +V and -V. I assumed that it was the right thing.
That marking is badly conceived and confusing, but the data sheet description clearly says
that it has only a single output voltage.
Using an SMPS for phono, line, and power amplifier may have noise problems, esp phono.
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This?
HRP-150-36 - 154.8W 36V 4.3A Enclosed Switching Power Supply with PFC Function
Yes - Meanwell calls what is commonly called 0 (zero) on a single output voltage unit for: "-V"... thats how they roll.
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HRP-150-36 - 154.8W 36V 4.3A Enclosed Switching Power Supply with PFC Function
Yes - Meanwell calls what is commonly called 0 (zero) on a single output voltage unit for: "-V"... thats how they roll.
//
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OK. Still has only one out. Get 2, hook them up as a +/0/- unit?
Then you need an other 2 for the +/- 15 🙁
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Then you need an other 2 for the +/- 15 🙁
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It's really good that you have saved us the hassle of looking up each of the ESP diagrams. But ESP does NOT allow posting of his copyright protected material.
You need his permission.
Without his permission you are breaking the Forum's rules. These diagrams will probably be removed as soon as a Moderator notices what you have done.
You need his permission.
Without his permission you are breaking the Forum's rules. These diagrams will probably be removed as soon as a Moderator notices what you have done.
referring to the PSU diagram at the bottom.
Keep everything to the right of "Cable"
Everything to the left of "Cable" is discarded, to be replaced with TWO switching PSUs.
Your circuits NEED dual polarity supplies.
You get this from TWO isolated single polarity supplies that are connected in series.
But YOU must check that they are isolated. A cheap multimeter with Ohms, or continuity can do this.
When you buy a cheap multimeter do ensure it has both AC and DC voltmeter scales that go right down to 200.0mV
Some omit the lower AC voltmeter scales. These will not do you any favours.
If you live in Greece, then put that in your profile along with some details about your experience. That information helps us to help you.
Just noticed that ESP has missed out a fuse to the small soft start transformer. He has a 3A fuse for the big transformer. The short lead from soft start going right to T1 should have a <1A fuse. Use either a T200mA, or F500mA
Keep everything to the right of "Cable"
Everything to the left of "Cable" is discarded, to be replaced with TWO switching PSUs.
Your circuits NEED dual polarity supplies.
You get this from TWO isolated single polarity supplies that are connected in series.
But YOU must check that they are isolated. A cheap multimeter with Ohms, or continuity can do this.
When you buy a cheap multimeter do ensure it has both AC and DC voltmeter scales that go right down to 200.0mV
Some omit the lower AC voltmeter scales. These will not do you any favours.
If you live in Greece, then put that in your profile along with some details about your experience. That information helps us to help you.
Just noticed that ESP has missed out a fuse to the small soft start transformer. He has a 3A fuse for the big transformer. The short lead from soft start going right to T1 should have a <1A fuse. Use either a T200mA, or F500mA
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The middle diagram showing the pre+power amplifier has too much gain for most users and their normal sources.
The power amp has a gain of +27.23dB
This has a voltage sensitivity for maximum power of ~ 870mVac, or 123mVac for 1W into 8ohms.
In front of that is a pre-amp stage with three switchable gains of +6.02dB, +6.93dB, or +7.86dB
That gives all your line level inputs a voltage sensitivity of <435Vac.
You will have to apply a lot of attenuation to keep the volume down to "normal levels".
Omit the gain stage and instead insert a Buffer after the volume control. The Buffer can be omitted if the cable to the power amplifier is short, or very short.
If you have a few sources that have a very low output, then add a gain stage for those sources ONLY. i.e. the main (line level) RCA inputs go straight to the selector switch, then to the vol pot.
The low level sources go to the RCAs that feed into a +6dB gain stage, then to the selector switch to the vol pot.
This way the high level sources don't overload the gain stage and the vol pot can be set to sensible attenuation.
The power amp has a gain of +27.23dB
This has a voltage sensitivity for maximum power of ~ 870mVac, or 123mVac for 1W into 8ohms.
In front of that is a pre-amp stage with three switchable gains of +6.02dB, +6.93dB, or +7.86dB
That gives all your line level inputs a voltage sensitivity of <435Vac.
You will have to apply a lot of attenuation to keep the volume down to "normal levels".
Omit the gain stage and instead insert a Buffer after the volume control. The Buffer can be omitted if the cable to the power amplifier is short, or very short.
If you have a few sources that have a very low output, then add a gain stage for those sources ONLY. i.e. the main (line level) RCA inputs go straight to the selector switch, then to the vol pot.
The low level sources go to the RCAs that feed into a +6dB gain stage, then to the selector switch to the vol pot.
This way the high level sources don't overload the gain stage and the vol pot can be set to sensible attenuation.
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