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Old 10th February 2009, 07:45 PM   #1
Ted205 is offline Ted205  United Kingdom
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Default Preamp Opamp what to choose

Hi all

Looking for your suggestions for the 'best' sounding opamp for a simple opamp preamp stage.

I've compared the lm4562 with the opa2134 and i have to say the opa is winning me over in terms of sound(cheaper too).

I've read that the lm4562 sounds alot better in metal can form. Has anyone tried this? I'm interested to know but they cost around £20 from farnell and which is abit steep if they simply sound the same or only a slight improvement.

thoughts?
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Old 10th February 2009, 08:17 PM   #2
kaos is offline kaos  United States
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The 4562 does sound slightly better in the can package, but not enough in my opinion to warrant the huge difference in price. Donít care much for the 4562 in general though, sounds plasticy to me. Seems to lack dynamics also. Just my perception of it, opinions vary.
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Old 10th February 2009, 09:21 PM   #3
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If you want a value dual, OPA2227 is the way to go. Similar sound to OPA2134 but better control in the bass.

If you don't mind forking out a few more dollars, OPA2107 is very nice indeed.

For the best available sound quality, two OPA827's on a browndog adaptor is my preference. As far as I can tell, these are completely transparent, I've never heard anything in the sound that doesn't seem "right".

That said, OPA2134 is still a very good opamp, 90% of any of the above.
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Old 10th February 2009, 11:09 PM   #4
Minion is offline Minion  Canada
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well I guess it would depend on what type of preamp...

In a guitar preamp the LM4562 would not be ideal as it is a Bipolar Opamp and doesn"t have the input impedance needed for a Guitar preamp so a Fet Input opamp like the OPA2134 would be more suitable....

In a Mic preamp I believe a LM4562 would be more suitable because most mics are low impedance and the LM4562 has it"s best noise performance with a Low inpedance input....

Also the LM4562 is a Much more tempermental than the OPA2134 , the LM4562 is more dependant on good layout and good supply bypassing than the OPA2134 ....

It is really Hard to compare and Bipolar and a Fet opamp in the Same application as a Bipolar is generally not a good replacement for a Fet....

Cheers
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Old 11th February 2009, 01:43 PM   #5
Ted205 is offline Ted205  United Kingdom
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Quote:
Originally posted by Minion
well I guess it would depend on what type of preamp...

In a guitar preamp the LM4562 would not be ideal as it is a Bipolar Opamp and doesn"t have the input impedance needed for a Guitar preamp so a Fet Input opamp like the OPA2134 would be more suitable....

In a Mic preamp I believe a LM4562 would be more suitable because most mics are low impedance and the LM4562 has it"s best noise performance with a Low inpedance input....

Also the LM4562 is a Much more tempermental than the OPA2134 , the LM4562 is more dependant on good layout and good supply bypassing than the OPA2134 ....

It is really Hard to compare and Bipolar and a Fet opamp in the Same application as a Bipolar is generally not a good replacement for a Fet....

Cheers
That is very true. The trouble being that i use it as an all-purpose amp really as i do use my guitar with it for practising (with effects pedals), aswell as day to day music and films.

The metal can idea looks to be a waste of money then?

the only slight negative of my amp is kick drum bass could be deeper. I guess i'm not going to improve that with just opamp selection.

cheers
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Old 11th February 2009, 06:13 PM   #6
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Quote:
Originally posted by Ted205


The metal can idea looks to be a waste of money then?

That is a value question. I am pretty sure that the metal can falls into the slight improvement categorize; mainly because the die is very good regardless of the package. While they measure close, there is agreed the metal can sounds better. One theory is that the die is stressed more with thermal fluctuations with the standard package (encapsulated in epoxy). The "sounding better" was observed at the National Semi listening room with high end speakers and components.

To some people, any improvement is worth the money; but for many the improvement may be imperceptible because of the limitations of the system or the room.

I have seen the metal can version offered from china (bbp); on the trading post here. I bought a CD rom controller from him and the deal went well. He is/had(?) offering some metal can chips for $20/pair (=$10 a piece, to restate the obvious), which is about what we can get them for in the US.


Fs Metal Can-8 Opamp :lme49710ha/lme49720ha
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Old 11th February 2009, 11:40 PM   #7
Minion is offline Minion  Canada
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Quote:
Originally posted by Ted205


That is very true. The trouble being that i use it as an all-purpose amp really as i do use my guitar with it for practising (with effects pedals), aswell as day to day music and films.

The metal can idea looks to be a waste of money then?

the only slight negative of my amp is kick drum bass could be deeper. I guess i'm not going to improve that with just opamp selection.

cheers
Well If you are going to be useing it for multiple sources with different output impedances then maybe put a couple different input jacks set up for a high impedance (1m) and lower impedance (47K ?)....

It probably sounds fine with guitar as the output impedance from your effects pedals is very low.....

You can probably increase the Bass responce by increaseing the Size of the input cap , maybe 10X larger value ...If you need more bass you can configure an opamp as a Low pass filter....


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Old 13th February 2009, 01:25 AM   #8
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In my amp I find the OPA2107 to be warmer and smoother with punchier bass than the LM4562 while still having good detail. The LM4562 does have very good detail though, I use it in my CDP at the moment but I'm temped to swap them out for the OPA2107's. Sounds a bit harsh and over analytical to me.

Havent tried any others yet.
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Old 17th February 2009, 03:50 AM   #9
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Quote:
Originally posted by mikesnowdon
In my amp I find the OPA2107 to be warmer and smoother with punchier bass than the LM4562 while still having good detail. The LM4562 does have very good detail though, I use it in my CDP at the moment but I'm temped to swap them out for the OPA2107's. Sounds a bit harsh and over analytical to me.

Havent tried any others yet.

Mike,
Where did you get yours? I purchased some off ebay from HK. I think they are fakes, they slipped in and out of the sockets much easier than the DIP package TI's I have purchased from legit sources. Plus sound muddier than the OPA2134 they replaced.

George
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Old 31st May 2011, 08:13 PM   #10
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I am thinking of building a buffer-volume-buffer amp using op-amps, not particularly because I need buffers, but just out of curiosity. Would those suggested op-amps still be good for buffers?
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