Hi everyone,
Newbie question here: I'm working on a small 2.1 console and would like to use 2 amplifiers -- one stereo amp for a pair of FR drivers (Hifimediy T2 Mundorf), and one mono for a subwoofer (Hifimediy T3 mono TK2050 amp, MCAP)...
I plan on using a Grayhill rotary input switch (Grayhill Selector Switch + PCB | Chipamp Electronics) and would like the amps to receive the same signal, use the same volume control and share a power supply.
Can anyone explain the simplest, most efficient way to accomplish this?
I've done some searching, but still have some uncertainty. Thanks in advance!
Newbie question here: I'm working on a small 2.1 console and would like to use 2 amplifiers -- one stereo amp for a pair of FR drivers (Hifimediy T2 Mundorf), and one mono for a subwoofer (Hifimediy T3 mono TK2050 amp, MCAP)...
I plan on using a Grayhill rotary input switch (Grayhill Selector Switch + PCB | Chipamp Electronics) and would like the amps to receive the same signal, use the same volume control and share a power supply.
Can anyone explain the simplest, most efficient way to accomplish this?
I've done some searching, but still have some uncertainty. Thanks in advance!
I've been thinking of using miniDSP 2x4. It would take a left and right RCA signal In, and is programmable to give you a Left, Right and Sub output. You could even program in high and low pass filters to keep the treble out of your sub channel.
For volume, you could look for a Four Gang (or Quad ) potentiometer. Like this one RK168 Series - Basic information is available at mouser for cheap. Your amps say something about 20k or 50k input resistance (depending in weather or not you use their volume pot ), so I'm not sure if this would be ideal, as it's 100kOhms. They also make 50k, 25k etc. for me I may just put the volume pot in it's own box and wire it to RCA in and out, sort of like a passive preamp with no gain, but it can attenuate the volume down, and all channels with just one knob.
Some people love their miniDSP 2x4, others complain it's noisy and clips too easily. I'm sure it depends on your amps, and how much dB gain one tries to dial into it.
I'm trying to talk myself into a miniDSP NanoDigi 2x8 B instead. It does the same thing, but it's all digital, so sound quality becomes more dependent on which DAC you use. You'll need two (one for Left&Right, and another DAC for your sub). Out from there into your quad pot, out from there to your amps. Multi DACs get expensive quick. I'm going to risk $40 to try Little Bear DAC. I saw a good review, and it's advertised as having some decent chipset & parts. Amazon.com: HiFi digital to analog coaxial Decoder DIR9001 CS4398 96KHZ 24bit DAC converter: Electronics
I can try with one, if it's crap, then needing a few $150 DACs put this option beyond my budget.
For volume, you could look for a Four Gang (or Quad ) potentiometer. Like this one RK168 Series - Basic information is available at mouser for cheap. Your amps say something about 20k or 50k input resistance (depending in weather or not you use their volume pot ), so I'm not sure if this would be ideal, as it's 100kOhms. They also make 50k, 25k etc. for me I may just put the volume pot in it's own box and wire it to RCA in and out, sort of like a passive preamp with no gain, but it can attenuate the volume down, and all channels with just one knob.
Some people love their miniDSP 2x4, others complain it's noisy and clips too easily. I'm sure it depends on your amps, and how much dB gain one tries to dial into it.
I'm trying to talk myself into a miniDSP NanoDigi 2x8 B instead. It does the same thing, but it's all digital, so sound quality becomes more dependent on which DAC you use. You'll need two (one for Left&Right, and another DAC for your sub). Out from there into your quad pot, out from there to your amps. Multi DACs get expensive quick. I'm going to risk $40 to try Little Bear DAC. I saw a good review, and it's advertised as having some decent chipset & parts. Amazon.com: HiFi digital to analog coaxial Decoder DIR9001 CS4398 96KHZ 24bit DAC converter: Electronics
I can try with one, if it's crap, then needing a few $150 DACs put this option beyond my budget.
I was hoping to not use a DAC. Is not possible to split the signal by connecting both audio inputs to the same L&R RCA connector?
I was hoping to be able to take both supplied 2.54mm connectors and solder them to the rca jacks, similar to this:
but from both amps.
Also, can two amps be connected to the same volume pot and power switch?
I was hoping to be able to take both supplied 2.54mm connectors and solder them to the rca jacks, similar to this:
An externally hosted image should be here but it was not working when we last tested it.
but from both amps.
Also, can two amps be connected to the same volume pot and power switch?
I'm not familiar with that 2.54mm connection, I assume it plugs into your amp board.
You use the phrase "one signal". I want to make sure I understand, so please confirm: do you want One Mono channel times x3 ? Or do you want One Left Channel, One Right Channel, and One Mono (L&R together) Channel (like traditional 2.1) ??
What is your source(s)?
You use the phrase "one signal". I want to make sure I understand, so please confirm: do you want One Mono channel times x3 ? Or do you want One Left Channel, One Right Channel, and One Mono (L&R together) Channel (like traditional 2.1) ??
What is your source(s)?
Exactly right, a traditional 2.1. The 2.54mm connector goes to the amp board. My source will be a phone or MP3 at most times, and a turntable with a built in preamp also.
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<< would like the amps to receive the same signal, use the same volume control and share a power supply. >>
Posted is a multi-feed power supply. The principle is that the capacitors decouple (electrically separate) the amp boards from the power supply, and from each other.
Although actually it's not unlikely you could just plug your multiple amps into the power supply and be done. If you get noise or distortion then use stronger methods as shown.
The second illustration is a signal splitter formed with two buffers. The outstanding features of a buffer are unity gain, very high input impedance (here in the megohm range), very low output impedance, and very low (3 decimals or better) distortion. Buffers give absolute separation between the input and output(s).
The 100R (100 ohm) resistors are a belt-and-suspenders arrangement that can help protect against overloading and/or oscillation under some conditions.
By the way, this same setup is used to drive a balanced line, except U1b is inverting.
<< use the same signal >>
Are you sure? You'd want to be able to control the volume of a subwoofer arrangement separately from the main volume control.
In any case, one way to do this would be to hang a volume control on the input side of the splitter.
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<< would like the amps to receive the same signal, use the same volume control and share a power supply. >>
Posted is a multi-feed power supply. The principle is that the capacitors decouple (electrically separate) the amp boards from the power supply, and from each other.
Although actually it's not unlikely you could just plug your multiple amps into the power supply and be done. If you get noise or distortion then use stronger methods as shown.
The second illustration is a signal splitter formed with two buffers. The outstanding features of a buffer are unity gain, very high input impedance (here in the megohm range), very low output impedance, and very low (3 decimals or better) distortion. Buffers give absolute separation between the input and output(s).
The 100R (100 ohm) resistors are a belt-and-suspenders arrangement that can help protect against overloading and/or oscillation under some conditions.
By the way, this same setup is used to drive a balanced line, except U1b is inverting.
<< use the same signal >>
Are you sure? You'd want to be able to control the volume of a subwoofer arrangement separately from the main volume control.
In any case, one way to do this would be to hang a volume control on the input side of the splitter.
.
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Possible yes, first class no. The reason is that you don't know what the input circuits on the amps you're connecting might be, and they might interact to cause distortion.
Oh the other hand, it won't damage anything to just hook up a Y cable and see what happens.
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Thanks so much for this. Very helpful.
I figured there may a distortion issue. Thanks again for the help.
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