Hi all,
I recently started assembling an NE5532 based headphone amp (HA) from AKITIKA.
AKITIKA HA
I have been using Benchmark DAC1 for headphone use. But since I really felt like I lost my ability for critical listening, and my home is not suitable for hifi loudspeaker setup, I decided to do some critical music listening using headphone system.
So what I will do is to use Benchmark DAC1 as DAC and HA, and then use Akitika HA to compared it with Benchmark HA, to see if I can hear any difference. My wife will help me do blind testing.
In the meanwhile, I would like to roll op amps in Akitika HA. This is to see if I can hear differences in op amps.
Question: Will it be more likely for me to hear difference if I roll op amps in Akitika HA, or if I add a simple op amp gain stage (PRE) between DAC and HA, and then roll it?
Thanks,
Doug
I recently started assembling an NE5532 based headphone amp (HA) from AKITIKA.
AKITIKA HA
I have been using Benchmark DAC1 for headphone use. But since I really felt like I lost my ability for critical listening, and my home is not suitable for hifi loudspeaker setup, I decided to do some critical music listening using headphone system.
So what I will do is to use Benchmark DAC1 as DAC and HA, and then use Akitika HA to compared it with Benchmark HA, to see if I can hear any difference. My wife will help me do blind testing.
In the meanwhile, I would like to roll op amps in Akitika HA. This is to see if I can hear differences in op amps.
Question: Will it be more likely for me to hear difference if I roll op amps in Akitika HA, or if I add a simple op amp gain stage (PRE) between DAC and HA, and then roll it?
Thanks,
Doug
That's an interesting and logical conjecture. I have 600 ohm Beyerdynamics DT880, and bunch of other <32 ohm headphones, so I must be able to see if lower impedance headphones make more difference for chip rolling... if I am able to hear any difference.
Thanks,
Doug
By the way, if there is anyone who actually did blind test for op amp rolling and was able to know the difference, can you share
- what was the op amps that made difference
- headphones (or speakers)
- what music (album, format, etc)
- other sound chain?
I am trying to test myself if I can hear any difference, so no debate please whether or not it can be heard. If someone heard it, then it's enough, I will try to mimic the method.
- what was the op amps that made difference
- headphones (or speakers)
- what music (album, format, etc)
- other sound chain?
I am trying to test myself if I can hear any difference, so no debate please whether or not it can be heard. If someone heard it, then it's enough, I will try to mimic the method.
My guess is because the Benchmark already contains opamps (NE5532 I believe) the opamp MSG's already added to what comes out of the DAC making further opamp rolling rather redundant.
If you'd like to hear differences between opamps, start with a source that doesn't already apply their flavouring.
If you'd like to hear differences between opamps, start with a source that doesn't already apply their flavouring.
We tried quite some time ago... it was fun. The original files are long gone but you might enjoy the reading.
http://www.diyaudio.com/forums/ever...mate-opamp-shootout-where-you-get-decide.html
http://www.diyaudio.com/forums/ever...-trying-understand-what-we-think-we-hear.html
That's a good point. I don't know what source I have doesn't use op amp output though. I am currently fixing Monolithic PS-1 phono, but it also has a pair of op amps.
Great reads. I should have searched for those.
I ordered a couple of op amps yesterday.
- OP275
- NE5532AP and NE5532P (I don't know what's the difference)
- OPA2134PA
- NJM4556AD
- NJM2068DD
- OPA2228PA
- OPA2227PA (P version has lower offset and twice as expensive, is this worth it?)
- LM4562
I was tempted to order some MUSES01 or MUSES02, but $50 each, I didn't.
Keep in mind the OPA2228PA is only stable with a gain of 5 or higher, where the 2227PA can be used at lower gains.
The NE5532AP is supposedly a "lower noise" version of the NE5532P. Most people just go with the "P" version.
The OP275 is an older op-amp that still sounds quite good.
The NJM4556 has quite high output current(70mA) and is typically used in a lot of headphone circuits as a buffer.
I haven't found many circuits where I really liked the sound of the LM4562, but I know Mooly really likes it.
One of the newer JFET input op-amps that sounds really clean is the OPA1642. I've tried it in front of a number of buffers and to my ears the sound is transparent and detailed without being harsh.
You can also try the OPA1652 and 1662. Both will have a slightly "darker" sound than the 1642.
There are a number of offerings from Linear Technology that you may want to try like the LT1057CN8 and LT1364CN8.
Always remember to measure the DC offset at the outputs before connecting anything to them if you're not using coupling capacitors at the outputs.
Have fun!
Thanks for great info and suggestions. I will definitely add OPA1642, 52, 62 and compared them. LT1057CN8 and LT1364CN8 also.
Some op amps that have p and pa versions differ only in there offset, which I think is output DC offset (I might be wrong). I didn't care that much so I purchased pa versions, which are cheaper but with higher offset. I will make sure their DC offset is low before I connect headphones. For headphone amps, what is the acceptable DC offset range?
You're welcome.
As for the TI "P" and "PA" differences, look here:
http://www.diyaudio.com/forums/solid-state/213959-opa2132p-vs-opa2132pa-whats-difference.html
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