I have a 50ASx2se I have built into a ghent audio case and I wanted to know if this board here that I received by accident can be used with this as a Buffer. Its aOp-Amp pre amp board. It only has one Op Amp. DO I need a buffer with dual opamp? I am running the icepower single ended RCA and plan on going just output of my Dac to the icepower. If I can use this do I go from RCA input to the input on the board and then from audio out to the 7 pin connector input on the icepower?
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Hi. It’s this. Guy here. DKARDU NE5532 OP AMP HiFi Preamplifier Signal Amplification Board DC12V-35V NE5532 Preamplifier with 28awg Cable DC Female Cable for Bluetooth Pre-amp https://a.co/d/hJnlz7U
Wired it up and Im getting buzzing from Both speakers like a bad ground. I ran from the RCA in to the in on the preamp board. I tied both the grounds on the RCA Lug together with jumper wire and then the ground to the middle pin on the 3 pin input on the preamp board. Then I did same on outputs. For power for now I ran a seperate 12v dc to the preamp dc input. Heres a pic of it hobbled together. ANy ideas?
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So do I need to Add coupling capacitors at the output? Im running it as is and im getting a lot of static etc. Im powering this preamp board by itself with seperate 12v supply
1 - why complicate matters by adding a buffer?
The input of the amplifier will suit any source you are likely to connect to it.
You are adding a buffer that at best does absolutely nothing and at worst adds noise or distortion.
2 - test without the buffer.
3 - test buffer with a battery supply.
4 - buffer is located at the mains end of the amplifier. Physically move it outside the amplifier case and see if it still noisy.
5 - Aux supply is ok if your pre-amp can handle the possible max 31V and it does not draw more than 200mA. Oops 'Working current: about 600mA'. The information is there for the reading.
The input of the amplifier will suit any source you are likely to connect to it.
You are adding a buffer that at best does absolutely nothing and at worst adds noise or distortion.
2 - test without the buffer.
3 - test buffer with a battery supply.
4 - buffer is located at the mains end of the amplifier. Physically move it outside the amplifier case and see if it still noisy.
5 - Aux supply is ok if your pre-amp can handle the possible max 31V and it does not draw more than 200mA. Oops 'Working current: about 600mA'. The information is there for the reading.
The Buffer has a 5x gain. Reduce it to 1-2x.
You can take two 9V block batteries and clip them together for 18V. So you can feed it ground free for a test.
If still buzzing, you constructed still another ground loop. One ground should be enough.
If you decide to keep it, change the op-amp for an NE5532 from a reputated vendor. These fake 5532 sound terrible.
You can take two 9V block batteries and clip them together for 18V. So you can feed it ground free for a test.
If still buzzing, you constructed still another ground loop. One ground should be enough.
If you decide to keep it, change the op-amp for an NE5532 from a reputated vendor. These fake 5532 sound terrible.
Ok i think there is misunderstanding: is the board used as is? If yes it is in no way a buffer as it gives 14db gain...
My comment was in case Gaspar74 modified the resistors and maybe caps and decided to run on a single rail supply rather than a dual one.
That said i agree with you Russc, is there a need for a buffer in this case?
Gaspar74 what made you thought you would need a buffer?
My comment was in case Gaspar74 modified the resistors and maybe caps and decided to run on a single rail supply rather than a dual one.
That said i agree with you Russc, is there a need for a buffer in this case?
Gaspar74 what made you thought you would need a buffer?
Thanks, I guess my main thing was trying to get the best Match for the low input impedance of the Iceamp. Im using a Dac w variable output to drive it and I guess I expected more oomph from this with 4ohm speakers. My other Class D is a TPA3255 based amp much more power. I also Wasn't sure if I had a mismatch with the Pre Amp and the Icepower amp. I think Ill keep my Beresford Caiman dac and use that to drive the icepower amp and ditch the input buffer idea. Not sure on output impedance of the Dac but Im sure its low.
The 50ASx2se does not need a buffer.
There is a lot of confusion, as there are some ICE amps like the A250 or A500 that really sound better if driven symetrically, as the input stage is not designed for single ended input.
The 50ASx2se is made for single ended use. So any buffer should be a disadvantage.
There is a lot of confusion, as there are some ICE amps like the A250 or A500 that really sound better if driven symetrically, as the input stage is not designed for single ended input.
The 50ASx2se is made for single ended use. So any buffer should be a disadvantage.
Gaspar it makes sense you want best electrical match.
So your icepower amp is 8k input Z and single ended. Your Dac is single ended and from what i've gathered on web, it seems at worst using the variable output it has around 1k ohms out Z.
A factor of 1/8 for impedance is not the best but still ok ime -as long as you don't try to drive long line with it ( i've got a sampler which has 1k out Z and used it with wide range of input Z gear without real drawback as long as it wasn't 600 ohm gear where i spoted difference in sound with more recent gear).
So maybe you could gain from a buffer as the out impedance of your dac could be changing with different levels. You might be bothered by it... or not.
So like Russc and Turbowatch2 suggested i would try without first.
If you want to try a buffer (and this have to be tryed imho...) you should but not from a random board with random chips and components. Even if it is free
Don't you have a protoboard and components lying around? It is not complicated to implement ( the psu could be more an issue if you don't have one around but it is not your case it seems).
Once prototyped you'll see if it is worth the hassle or not to implement it definitely.
So your icepower amp is 8k input Z and single ended. Your Dac is single ended and from what i've gathered on web, it seems at worst using the variable output it has around 1k ohms out Z.
A factor of 1/8 for impedance is not the best but still ok ime -as long as you don't try to drive long line with it ( i've got a sampler which has 1k out Z and used it with wide range of input Z gear without real drawback as long as it wasn't 600 ohm gear where i spoted difference in sound with more recent gear).
So maybe you could gain from a buffer as the out impedance of your dac could be changing with different levels. You might be bothered by it... or not.
So like Russc and Turbowatch2 suggested i would try without first.
If you want to try a buffer (and this have to be tryed imho...) you should but not from a random board with random chips and components. Even if it is free
Don't you have a protoboard and components lying around? It is not complicated to implement ( the psu could be more an issue if you don't have one around but it is not your case it seems).
Once prototyped you'll see if it is worth the hassle or not to implement it definitely.
Thanks for all the feedback. I am going to get a prototypng board to have for experiments and such. Im new to Amp building and a lot of DIY at least of this type. Im disabled and have lot of free time on my hands and Im a techie by nature. Im enjoying the satisfaction of building my own audio albeit still very early stages of this and look forward to learning a lot from some of you folks been at this a lot longer than myself.
There is a cheap and compact SMD buffer (pre amp) out there (Aliex, eBay etc) that is good for modifications. Get a dual+-12-18V supply to accompany it. The one with the servo is quite clean and cheap. Reduce the gain, of the amp. You must solder SMD resistors for that task. Insert a real NE5532. This is a very good low cost (relative) part. The ebay parts make experimenting cheap and easy.
People that rave about "other" expensive opamps may have experienced such a fake NE5532. I had the same effect when I put an old, real NE inside an Chinese mini amp. The difference was incredible. I wonder what opamps are inside these fakes, that can sound so ugly, distorted and far away, like hearing music over a phone line.
If you want to change the sound really audible, experiment with tube buffers. Some, not all (!!!) can add sparkle and room to the music. Of course, this is artificial, maybe by 2nd order harmonics, but a lot of people like this sound.
https://www.ebay.com/itm/275054014641
https://www.ebay.com/itm/333556857681
People that rave about "other" expensive opamps may have experienced such a fake NE5532. I had the same effect when I put an old, real NE inside an Chinese mini amp. The difference was incredible. I wonder what opamps are inside these fakes, that can sound so ugly, distorted and far away, like hearing music over a phone line.
If you want to change the sound really audible, experiment with tube buffers. Some, not all (!!!) can add sparkle and room to the music. Of course, this is artificial, maybe by 2nd order harmonics, but a lot of people like this sound.
https://www.ebay.com/itm/275054014641
https://www.ebay.com/itm/333556857681