Do I really need a potentiometer? Can't just use my source to manage the volume?
The possible scenario to use the amps is:
1-. PC sound card --> unbalance/balance converter --> buffer --> hypeX amp --> speaker
2-. sony avr --> minidsp nanoAVR HDA --> unbalanced/balanced converter -> input buffer --> hypeX amp --> speaker
To manage my volume, in scenario (1) I would use my computers volume controls and (2) my AVR volume knob.
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OK. I will need to buy a "balancer" and make some hearing tests...
Do you have any "balancer" recommendation? On ebay most are based on the DRV134 chipset butey vary from USD7.00 to over USD80.00 (if I consider the ones from Ghent Audio which are for a single channel).
Don´t expect the more expensive OP-amps in Chinese kits to be the real thing. Even the unexpensive NE5532 often is fake. So best seems to buy a kit without OP-amp (DRV134 for example) and get the Op-amp from Mouser, DigiKey, Farnel or any other trustworthy dealer. Please note: a bad power supply can make your high end Op-amp sonud much worse than a well sourced NE5532. So ad a dual voltage LM317 supply to your list, to power the buffers/ balancer boards´s.
On the other hand, if you come from the NU3000D (about clean 500W/4Ohm/rms/channel) as sub amp, only a minimal set up differences between the DSP´s will have a larger effect than a Hypex or ICE amp modul instead of the Behringer D-amp near reverence IRS2092S. This chip is not the worst one.
Amps for subs are a bit like V8 engines, where nothing beats cubic inches. At the end, with decent designed amps, the rail voltage and amps of the power supply make the better "umpf" in the sub 100 Hz region.
I don´t really think you will positively identify different chips in a subwoofer "blind test".
On the other hand, if you come from the NU3000D (about clean 500W/4Ohm/rms/channel) as sub amp, only a minimal set up differences between the DSP´s will have a larger effect than a Hypex or ICE amp modul instead of the Behringer D-amp near reverence IRS2092S. This chip is not the worst one.
Amps for subs are a bit like V8 engines, where nothing beats cubic inches. At the end, with decent designed amps, the rail voltage and amps of the power supply make the better "umpf" in the sub 100 Hz region.
I don´t really think you will positively identify different chips in a subwoofer "blind test".
Balancer: This one would be nice but the price makes it very unrealistic the OP-amps are real...
DRV134 Unbalanced to Balance Converter Board Matched Input Amplifier New | eBay
DRV134 Unbalanced to Balance Converter Board Matched Input Amplifier New | eBay
Maybe take this one and supply it with good parts?
New Unbalanced to Balanced Dual Channel Converter Bare PCB Board Pre-amplifier | eBay
New Unbalanced to Balanced Dual Channel Converter Bare PCB Board Pre-amplifier | eBay
Something like this to power the buffer:
AC-DC LM317 LM337 Adjustable Regulated Power Supply DIY Kits Voltage Regulator | eBay
AC-DC LM317 LM337 Adjustable Regulated Power Supply DIY Kits Voltage Regulator | eBay
Thanks for your reply.
So, you would recommend getting just the board and then getting all the components from a reliable source?
I can do that... in fact I was willing to do that and buy this board:
unBalanced to balanced stereo pre-amplifier PCB ultra low distortion ! | eBay
or this:
Stereo opamp pre-amplifier PCB featuring good rail decoupling ! | eBay
The last seem to have enough gain for my needs.
The thing is I ended buying an assembled board with a NE5534. Once I get them I will make some hearing test.
Regarding the NU300DSP, I am happy with it, and really don't expect a ton of improvement when using hypeX or ICEpower modules. The thing is that I want a silent amplifier. My NU3000 has a modified fan (noctua) and still annoys me when watching a movie.
Anyways, the modules I bought will not be enough to power my subwoofers, so I will use them to understand the very basics of assembling an amplifier and use them get rid of my AVR, and use only the miniDSP nanoAVR HDA.-
So, you would recommend getting just the board and then getting all the components from a reliable source?
I can do that... in fact I was willing to do that and buy this board:
unBalanced to balanced stereo pre-amplifier PCB ultra low distortion ! | eBay
or this:
Stereo opamp pre-amplifier PCB featuring good rail decoupling ! | eBay
The last seem to have enough gain for my needs.
The thing is I ended buying an assembled board with a NE5534. Once I get them I will make some hearing test.
Regarding the NU300DSP, I am happy with it, and really don't expect a ton of improvement when using hypeX or ICEpower modules. The thing is that I want a silent amplifier. My NU3000 has a modified fan (noctua) and still annoys me when watching a movie.
Anyways, the modules I bought will not be enough to power my subwoofers, so I will use them to understand the very basics of assembling an amplifier and use them get rid of my AVR, and use only the miniDSP nanoAVR HDA.-
Once assembled I hoped I could power all the input buffers also with a Mean Well like the LRS-70-15
Also, Is there any "problem" in using an unbalanced/balanced converter and then an input buffer? I know Khron told me it was not necessary, but is it doable without inconveniences?
... Buuuuut why would you need / want to?
OK OK... sorry.
I just read that to get my signal to properly feed professional audio equipment, I need a gain around +12db.
I looked my alternatives for "balancers" and "input buffers" on ebay, and none offers more than +6db on gain. Within my ignorance in the matter, I thought a "balancer" followed by an input buffer, would offer enough gain.
By definition, "buffer" is unity-gain, so... At least technically, that wouldn't have helped you anyway
But back to the math:
1) What's the gain of those Hypex modules?
2) What's the supply voltage for those modules?
3) What's the max output level of your signal source(s)?
In the mean time, some additional reading:
- Balanced Line Driver with Floating Output
- Balanced Interfaces
- Balanced I/O
But back to the math:
1) What's the gain of those Hypex modules?
2) What's the supply voltage for those modules?
3) What's the max output level of your signal source(s)?
In the mean time, some additional reading:
- Balanced Line Driver with Floating Output
- Balanced Interfaces
- Balanced I/O
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From the uCD180LP OEM datasheet (attached):
Power supply = +/-45V, Load=4Ohm, MBW=40Khz, Source imp=40Ohm,unless otherwise noted
Item Symbol Min Typ Max Unit Notes
Voltage Gain total Av 12.8 13.1 13.3 dB
Required input level for 5.96 V
180W / 4Ohm
Max Output level for my signal source it's unknown... haven't measured. But it's a standard sound card.
The nanoAVR HDA specifications say:
Output Max Levels OUT: 2Vrms
Power supply = +/-45V, Load=4Ohm, MBW=40Khz, Source imp=40Ohm,unless otherwise noted
Item Symbol Min Typ Max Unit Notes
Voltage Gain total Av 12.8 13.1 13.3 dB
Required input level for 5.96 V
180W / 4Ohm
Max Output level for my signal source it's unknown... haven't measured. But it's a standard sound card.
The nanoAVR HDA specifications say:
Output Max Levels OUT: 2Vrms
An externally hosted image should be here but it was not working when we last tested it.
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If you use a DRV134PA to go from asymetric to balanced, you get +6dB.
Ab buffer before the DRV134PA makes sense, as it needs stable conditions at the input.
If you wire it up with a DSP the output of the DSP might be the buffer.
If you want an universal unbalanced input that drives a power amplifier stage in balanced mode, than you should ad a buffer before the DRV134.
Puh!
A buffer has no gain, a buffer with gain is an amplifier. A buffer makes an input impedance independent from the source that feeds it.
Some ICE Power amps are said to have frequency dependend input impedance and different impedance symetrical + and - inputs. Because of this it is not good to drive them asymetrical, unbuffered. Like putting the inverting input at ground level.
If this is true will depend on your build and application, maybe taste, too
Ab buffer before the DRV134PA makes sense, as it needs stable conditions at the input.
If you wire it up with a DSP the output of the DSP might be the buffer.
If you want an universal unbalanced input that drives a power amplifier stage in balanced mode, than you should ad a buffer before the DRV134.
Puh!
A buffer has no gain, a buffer with gain is an amplifier. A buffer makes an input impedance independent from the source that feeds it.
Some ICE Power amps are said to have frequency dependend input impedance and different impedance symetrical + and - inputs. Because of this it is not good to drive them asymetrical, unbuffered. Like putting the inverting input at ground level.
If this is true will depend on your build and application, maybe taste, too
For my taste Hypex is extremly over priced. It is rediculous that you are advised to buy some regulators that give a better sound, which tells me in stock form they sound under average. The "special" regulators, made from a few cheap parts,cost more than a very well sounding complete amp board from china.
So Iám not familiar with their inputs.
So Iám not familiar with their inputs.
Thanks for you explanation!
I would like to have an universal unbalanced input, so I will follow your recommendation of use a buffer before the "balancer".
Also, following your recommendation of getting the PCB and populate it with components form a reliable source, I think this board might work:
Unbalanced to balanced driver board w/ buffer input low distortion 0.006% PCB ! | eBay
How does the SSM2142 compare to the DRV134?
Probably the same for my purpose, correct?
I would like to have an universal unbalanced input, so I will follow your recommendation of use a buffer before the "balancer".
Also, following your recommendation of getting the PCB and populate it with components form a reliable source, I think this board might work:
Unbalanced to balanced driver board w/ buffer input low distortion 0.006% PCB ! | eBay
How does the SSM2142 compare to the DRV134?
Probably the same for my purpose, correct?
The last bare board you mention is exactly what I meant: A buffer followed by a balancing OP-amp. There are 4 balancer IC´s to my knowledge, the TI /BB Drv134PA (in different variations), the two new That IC´s and the Analog Devices SSM2142. The last is the oldest, the new That seems to be the most advanced.
They all can be interchanged with small adjustments, look up the data sheets.
I don´t think you will hear any differences, if they are used in the right way.
In Pro Audio other things than "sound" count, like long distance tollerance and rejection oft psu noise. In that field there may be advantages for one or the other.
As a buffer you will be fine with a NE5532, more expensive OP-amps are not so different in an audio sense, but might be better when used in instruments. They may, in extreme situations, reproduce a minimal different "sound". I don´t say worse or better, just a little different.
PS most old Audio IC´s have their best performance around +-15 Volt. Don´t give them less than 12V.
They all can be interchanged with small adjustments, look up the data sheets.
I don´t think you will hear any differences, if they are used in the right way.
In Pro Audio other things than "sound" count, like long distance tollerance and rejection oft psu noise. In that field there may be advantages for one or the other.
As a buffer you will be fine with a NE5532, more expensive OP-amps are not so different in an audio sense, but might be better when used in instruments. They may, in extreme situations, reproduce a minimal different "sound". I don´t say worse or better, just a little different.
PS most old Audio IC´s have their best performance around +-15 Volt. Don´t give them less than 12V.
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Just to maybe give you an idea what I mean, when I write about "sound".
I know that some parts, like electrolitcs compared to film capacitors, are audible in passive frequency x-overs and audio cirquits.. Soemtimes, even wires can degrade the sound significantly and amplifiers can have a different sound, while frequency response and distortion are similar (low).
Some even call this Voodo.
But at some point things become more a matter of taste than right or wrong. And then, at last there is the wide field of pure imagination and snake oil, the point where I get off the bus.
How you weight your points, might be different.
Just as a friendly warning!
I know that some parts, like electrolitcs compared to film capacitors, are audible in passive frequency x-overs and audio cirquits.. Soemtimes, even wires can degrade the sound significantly and amplifiers can have a different sound, while frequency response and distortion are similar (low).
Some even call this Voodo.
But at some point things become more a matter of taste than right or wrong. And then, at last there is the wide field of pure imagination and snake oil, the point where I get off the bus.
How you weight your points, might be different.
Just as a friendly warning!
I understand what you say regarding the sound. I am no audiophile, and I am pretty sure I am not that demanding either, I just like good dynamics (because I mostly listen movies in low volume) and sometimes I require a little bit of power and grunt to listen to some action flicks with a higher volume (around 80db). But for this project I am just interested in make it work "properly", not the best quality just good enough.
Regarding the "balancer" board with input buffer, the ebay seller says that board has 1 gain. I think he meant +3b gain.
The seller says this one has a +12db gain, which IDK if it is correct, because you said op-amp don't have gain:
Stereo opamp pre-amplifier PCB featuring good rail decoupling ! | eBay
Regarding the "balancer" board with input buffer, the ebay seller says that board has 1 gain. I think he meant +3b gain.
The seller says this one has a +12db gain, which IDK if it is correct, because you said op-amp don't have gain:
Stereo opamp pre-amplifier PCB featuring good rail decoupling ! | eBay
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