Hi
after more listening and comparisons with Lightspeed preamp and KR Audio P150 (with input and output buffers only with OPA2134) I remarked with a friend a very remarkable lack of deep bass with the LME49710. The details and sound stage is great but the bass is too weak. That is a fact.
So, I am now looking for some adequate circuits for preamps with a different opamp setup for the different buffer stages.
I will try the LM4562 as input buffer together with OPA 2134, OPA 2227 and OPA2228 and vice versa to get a good compromise between details and bass.
Has anyone some ideas or experiences?
Regards
Tolu
after more listening and comparisons with Lightspeed preamp and KR Audio P150 (with input and output buffers only with OPA2134) I remarked with a friend a very remarkable lack of deep bass with the LME49710. The details and sound stage is great but the bass is too weak. That is a fact.
So, I am now looking for some adequate circuits for preamps with a different opamp setup for the different buffer stages.
I will try the LM4562 as input buffer together with OPA 2134, OPA 2227 and OPA2228 and vice versa to get a good compromise between details and bass.
Has anyone some ideas or experiences?
Regards
Tolu
Dear Jackinnj,
Do big companies send "second selection" (below standard) units as "sample"???
One sample LM4562 used as input buffer (active XO) exploded with no apparent reason on the third day of use. One LME49740 began to make "popcorn" noise and I had to change it...
Was it only bad luck?
Thanks,
M
Do big companies send "second selection" (below standard) units as "sample"???
One sample LM4562 used as input buffer (active XO) exploded with no apparent reason on the third day of use. One LME49740 began to make "popcorn" noise and I had to change it...
Was it only bad luck?
Thanks,
M
Magnetar said:
Yes, but this thud must be hearable when it is on the CD. The OPA 2134 does a little too much bass. It is a very warm OPamp or a velvet blanket for the ears. I like both. I almost think that you can't have the mix of both. A full basement and clear highs.
I just ordered the LM4562 to test as input buffer and OPA 2134 as output buffer. Perhaps a benefit.
Do you have a circuit of a nice preamp with the LM4562?
Otherwise I think the opamp per se is so dominant for sound quality that the surrounding parts (Rs, Cs ..) will influence the sound very little. They are just necessary for correct technical function (no distortion, no oscillating, no explosions).
Hoping to find the best compromise one day...
Tolu said:
It's just the Rod Elliott project 88 circuit, using his board. It's upgraded with a large toroid and S Power regulators . Decoupling caps are Cerafine, nothing close to the chips.
http://sound.westhost.com/project88.htm
I'm not convinced this circuit is one to look to for inspiration, but it does a job.
I do have an excellent CD player, and without this perhaps the sound would be lacking in some areas. The CDP has a discrete output stage and before this using LM4562 the sound could be a bit "cold".
Simon
Thomas,
I'm not sure of the gain
For a while I enjoyed one 2134 and one 4562 as this gave a more euphonic or warm character. As other things in my system improved I found it sounded best with both sockets filled with 4562. Changing them noticably increases detail, reduces treble grain and bass congestion. I feel like I've had to make certain parts choices elsewhere to accommodate these op-amps.
I've also tried OPA2132 (no different to 2134), LM6172 (like 4562 but with added coarseness) and a couple of others I can't remember. I did like OPA627bp in my CD player, but it is surpassed in detail and clarity by LM4562, again! This op-amp also has the closest sonic character (or lack thereof) to the class A single ended FET output stage I replaced it with, only the op-amp doesn't manage to sound quite like music.
Ultimately I'd like to have no op-amp ICs in the signal path. I heard a couple of other preamps vs mine and mine was the weakest. I think they were called "Lightspeed passive" and "Heretic". Everyone present (this was at the UK meet) was impressed by the 4562, however.
Simon
I'm not sure of the gain
For a while I enjoyed one 2134 and one 4562 as this gave a more euphonic or warm character. As other things in my system improved I found it sounded best with both sockets filled with 4562. Changing them noticably increases detail, reduces treble grain and bass congestion. I feel like I've had to make certain parts choices elsewhere to accommodate these op-amps.
I've also tried OPA2132 (no different to 2134), LM6172 (like 4562 but with added coarseness) and a couple of others I can't remember. I did like OPA627bp in my CD player, but it is surpassed in detail and clarity by LM4562, again! This op-amp also has the closest sonic character (or lack thereof) to the class A single ended FET output stage I replaced it with, only the op-amp doesn't manage to sound quite like music.
Ultimately I'd like to have no op-amp ICs in the signal path. I heard a couple of other preamps vs mine and mine was the weakest. I think they were called "Lightspeed passive" and "Heretic". Everyone present (this was at the UK meet) was impressed by the 4562, however.
Simon
I used LM4562 on my soundcard (Emu1212m) and LM4562 + buf in my headphone amp,thought it sounded nice,clear highs and tight bass etc.Then I tried AD8672 in the headamp, and to my surprize it was better...more relistic cymbals bassguitar,room voices,and more.
Will later try AD8672 on soundcard to..
If you have the chance try it!(AD8672)
Will later try AD8672 on soundcard to..
If you have the chance try it!(AD8672)
Hello
Looking at the data sheet graphs of the LM4562, the THD+N vs output voltage show a very big raise of distortions at low level output and it should be higher in a dynamic situation, this is a sign of high crossover distortions.
Any though about that ?
I can not access the Bob Pease article on the LM4562, does he say anything about that high crossover distortions of the LM4562 in his article ?
Anyone try class bias on the LM4562 ?
Thank
Bye
Gaetan
Looking at the data sheet graphs of the LM4562, the THD+N vs output voltage show a very big raise of distortions at low level output and it should be higher in a dynamic situation, this is a sign of high crossover distortions.
Any though about that ?
I can not access the Bob Pease article on the LM4562, does he say anything about that high crossover distortions of the LM4562 in his article ?
Anyone try class bias on the LM4562 ?
Thank
Bye
Gaetan
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