I've searched and found a few threads close to the question I have. But not enough for me to make a decision.
I'm building an "El Cheapo" 8 channel Class D integrated amplifier for whole house audio. There's a discussion of the preamp section here.
This is my first build so keeping costs down and complexity to a minimum is a goal. The power amplifier section is two class D 4 channel amps from Sure Electronics (item AA-AB009). They're rated at 100 watts x 4 at 8 ohms, but when I look at the specs and reviews, it looks like they'll only reasonable take 30 to 40 watts before distortion becomes a significant issue - which is fine for my needs. Also, as a whole house audio solution, its more for background music volumes.
The amps call for single voltage up to 30v, but the opamp in the preamp section will need dual voltage. Connex has a 300 watt SMPS that has a single voltage primary output in the right voltage range and an auxiliary dual voltage output for the preamp. Just what I need, but I'm concerned that this might be cutting it close to drive both amps.
Connex also has a 500 watt SMPS with dual voltage auxilary, but the primary is also dual voltage. The power from this looks like a better match, but can I use just one side of the primary output, or will that cause problems?
Trying to avoid using two power supplies for cost, space and complexity reasons. If the 500 watt dual voltage is a no-no, then I'll probably just give the 300 watt version a shot.
Thanks in advance for the help!
I'm building an "El Cheapo" 8 channel Class D integrated amplifier for whole house audio. There's a discussion of the preamp section here.
This is my first build so keeping costs down and complexity to a minimum is a goal. The power amplifier section is two class D 4 channel amps from Sure Electronics (item AA-AB009). They're rated at 100 watts x 4 at 8 ohms, but when I look at the specs and reviews, it looks like they'll only reasonable take 30 to 40 watts before distortion becomes a significant issue - which is fine for my needs. Also, as a whole house audio solution, its more for background music volumes.
The amps call for single voltage up to 30v, but the opamp in the preamp section will need dual voltage. Connex has a 300 watt SMPS that has a single voltage primary output in the right voltage range and an auxiliary dual voltage output for the preamp. Just what I need, but I'm concerned that this might be cutting it close to drive both amps.
Connex also has a 500 watt SMPS with dual voltage auxilary, but the primary is also dual voltage. The power from this looks like a better match, but can I use just one side of the primary output, or will that cause problems?
Trying to avoid using two power supplies for cost, space and complexity reasons. If the 500 watt dual voltage is a no-no, then I'll probably just give the 300 watt version a shot.
Thanks in advance for the help!
Excellent question. Guess I was just too focused on using a dual supply opamp. I'll followup in the other thread I have on the preamp stage regarding alternations to the proposed circuit if a single supply chip is used instead (like the TL972). Or a discrete design like you suggested.
Thanks for the tip.
Many opamp datasheets show a single polarity supply version of their opamp.
basically what they are is an AC coupled Input and Output.
see if this helps:
http://www.ti.com/lit/ug/tidu871/tidu871.pdf
basically what they are is an AC coupled Input and Output.
see if this helps:
http://www.ti.com/lit/ug/tidu871/tidu871.pdf
Originally he wanted to know if it was ok to use just one rail of the dual rail SMPS
"Connex also has a 500 watt SMPS with dual voltage auxilary, but the primary is also dual voltage. The power from this looks like a better match, but can I use just one side of the primary output, or will that cause problems?"
"Connex also has a 500 watt SMPS with dual voltage auxilary, but the primary is also dual voltage. The power from this looks like a better match, but can I use just one side of the primary output, or will that cause problems?"
Last edited:
I'll simplify my original question. I added extra detail originally to give a fuller picture of my challenge. But as Scott pointed out, my original question is if I have a dual voltage power supply, can I use it to power a single voltage power amplifier.
For example, I have two identical class D amplifiers. Each requires 28V single voltage. I already have a +-28V SMPS power supply with enough power to drive both amps. Can I use just the + rail of this power supply to power the amps? Or will this cause problems?
For example, I have two identical class D amplifiers. Each requires 28V single voltage. I already have a +-28V SMPS power supply with enough power to drive both amps. Can I use just the + rail of this power supply to power the amps? Or will this cause problems?
A +/- 28V switcher needs a load on both rails to function OK and according specifications. When only the + rail sees a load and the - rail does not see a load it might not work OK (depends on brand and type too). For little money one can find a single rail switcher and the problem is solved.
Never use stuff designed for completely different tasks for something they are not intended for. Don't use it just because "you already have it".
Never use stuff designed for completely different tasks for something they are not intended for. Don't use it just because "you already have it".
Last edited:
Makes sense. Figured I'd ask first before buying, just in case. I ordered one of their 28V 600 watts SMPS units.
Thanks everyone.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.