Looking for a simple and good circuit design for an opamp preamp to go with my ACA that uses the dual "Burson Audio V5i Hybrid Opamp" that just became available on the site. It will need to use the same 24V single rail power supply as the ACA. Volume control not needed as I have that already with my source. Any suggestions? A project with available bare boards would be ideal, but not required. Thanks!
And... a simple and good design for a preamp using the same opamp with a differential/balanced input and the usual V+/V- supply. Thanks x2!
I've ordered the opamps already, cause, why not, and also got a number of ne5532's from digikey as guinea pigs.
And... a simple and good design for a preamp using the same opamp with a differential/balanced input and the usual V+/V- supply. Thanks x2!
I've ordered the opamps already, cause, why not, and also got a number of ne5532's from digikey as guinea pigs.
The Amp Camp Amp has much distortion, perhaps "good" here would be a DSP unit which could be trained to cancel the ACA distortion? Not likely to need your opamps though.
For "simple" you could use a standard instrumentation amp circuit for balanced->single-ended conversion followed by volume control and buffer. 4 opamps per channel, so 4 dual opamp packages.
Differential to single ended conversion is actually the hard part, if you want proper balanced high-impedance inputs and low noise. A single differential amp circuit using one opamp has significant issues, although apparently simple.
For "simple" you could use a standard instrumentation amp circuit for balanced->single-ended conversion followed by volume control and buffer. 4 opamps per channel, so 4 dual opamp packages.
Differential to single ended conversion is actually the hard part, if you want proper balanced high-impedance inputs and low noise. A single differential amp circuit using one opamp has significant issues, although apparently simple.
Let me refine my question. Looking for a circuit design for a two, dual opamp stereo Preamp with a 24V+ input. How's this for a starting point? Yes, it's +/- V power, but thought I would throw a noodle on the fridge and see what sticks.
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The circuit shown is a method for augmenting opamp output with another one to improve drive capability. If you need high current drive you should look at the datasheet application note for the LME49600 which is a high current buffer in the overall feedback loop of an input opamp stage.
Not sure what +24V input is needed for. Most common opamps have +/- 18V supplies. TI does make a few higher voltage models.
Not sure what +24V input is needed for. Most common opamps have +/- 18V supplies. TI does make a few higher voltage models.
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They appear to work well, but not better than many good standard audio opamps that are far cheaper (and which fit in small boxes!). Its hard to find all the key specs for them.
Why they don't just sell LM4652's or similar in a plastic case and increase their profit margin's is a mystery(!) They could even screen them for noise.
Why they don't just sell LM4652's or similar in a plastic case and increase their profit margin's is a mystery(!) They could even screen them for noise.
Firstly I have to pass on my thanks to Carlos from Burson for giving me the opportunity to hear these opamps for myself. It was very generous for him to allow many of the members at diyAudio try these out for themselves and proof that he is willing to stand behind his product. I've always been a curious person and wondered whether the expectations and gushing words posted over the internet forums about discrete opamps met reality. Based on the online comments I had formed the conclusion that the discrete opamps colour the sound, perhaps with H2 and that is what many people found appealing, indeed I would have as long as it wasn't excessive.
I tested the opamps in a headphone amplifier that had buffer transistors on the output. It was the Silicon Chip studio series which I tested with both Beyerdynamic DT880 and Etymotic ER4XR phones. I could readily switch between the Bursons and stock opamps or any other I wished to compare. Switching the Bursons in and out at the flick of a switch I could never tell the difference even with a large amount of different source material. The two sets of phones used are very revealing and would have definitely shown up differences of the magnitude that others were claiming to be hearing when using the Bursons in their devices.
The Bursons do work well for what they are, they have been intelligently designed and are blameless in nature if used correctly. I've been experimenting with the pair over the last six months and as far as I can tell they are indistinguishable from an NE5532 in a listening test. For me that is high praise because I hold the 5534 and 5532 in very high regard. Correctly implemented I have not been able to reliably hear any differences between them and any other competent opamp in a blind test.
Now the crunch. The hype surrounding the Burson opamps and their associated price tag is very hard to rationalise. Given they are indistinguishable from a 50c part in a blind test I would have to question the logic in their purchase.
I had not intended to post a review of these discrete opamps but Carlos had requested I do despite me mentioning in an email what my findings were.
As always, your mileage may vary....
I tested the opamps in a headphone amplifier that had buffer transistors on the output. It was the Silicon Chip studio series which I tested with both Beyerdynamic DT880 and Etymotic ER4XR phones. I could readily switch between the Bursons and stock opamps or any other I wished to compare. Switching the Bursons in and out at the flick of a switch I could never tell the difference even with a large amount of different source material. The two sets of phones used are very revealing and would have definitely shown up differences of the magnitude that others were claiming to be hearing when using the Bursons in their devices.
The Bursons do work well for what they are, they have been intelligently designed and are blameless in nature if used correctly. I've been experimenting with the pair over the last six months and as far as I can tell they are indistinguishable from an NE5532 in a listening test. For me that is high praise because I hold the 5534 and 5532 in very high regard. Correctly implemented I have not been able to reliably hear any differences between them and any other competent opamp in a blind test.
Now the crunch. The hype surrounding the Burson opamps and their associated price tag is very hard to rationalise. Given they are indistinguishable from a 50c part in a blind test I would have to question the logic in their purchase.
I had not intended to post a review of these discrete opamps but Carlos had requested I do despite me mentioning in an email what my findings were.
As always, your mileage may vary....
How about just one of these:
Preamplifier NE5532 Audio Amplifier Module PCB DIY Electronic Board | eBay
Preamplifier NE5532 Audio Amplifier Module PCB DIY Electronic Board | eBay
Package Includes:
1 Piece NE5532 Board
Not clear wether that is a working preamp or just a PCB.
I presume the schematic is the one here:Electronique - Realisations - Preampli micro 005
1 Piece NE5532 Board
Not clear wether that is a working preamp or just a PCB.
I presume the schematic is the one here:Electronique - Realisations - Preampli micro 005
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