LM3886 vs LM3875, for those that have heard both only!

[homer09]

As Brian is making the jump to the LM3886 for his next set of boards, I was begining to question the differences between the two chips. Brian himself has said that he has not had the chance to compare both chips head to head, so i would like to open this thread to people's opinion about the sound of these chips.

both chips are very similar specs-wise, so i would prefer that this thread does not become a spec comparison by people who have never heard both chips! i think most people are capable of reading a data sheet.

If possible, describe your implementation of the chips, speakers used and your subjective (yes!) listening impressions.

[tschrama]

Having build both lm3886 and lm3875 amp several times, I hope that I am permitted to compare specs:


very simmilar you said?

slew rate
lm3886: 19V/us
lm3875: 11V/us

Iq
lm3886: 50mA
lm3875: 30mA

max Iout
lm3886: 11A
lm3875: 6A

My first chip-amp was a p2p lm3886, which was very satisfying, and I actually couldn't tell it a part from a lm3875 p2p amp I build later. In between I build a BrianGT chip-amp kit (premium version) which did seem to sound particularry good and has become my favorite.


cheers,
Thijs

[homer09]

Thanks for your input tschrama. I didnt want people comparing specs because more than often these dont mean much for the final musicality and sound quality of an amp. I think specs should be compared when determining the proper chip/component for the job (enough power/voltage-heat handling etc). sound quality cant really be measured IMO.

so in your P2P implementation, both chips sounded the same. Was this in inverting or non-inverting mode?

Any others have some listening impressions to share?

[tschrama]

Yehhh that's the problem... I used inverting mode in the p2p amps but my Briangt-amp is non-inverting and has lot's of different components.. so it's very hard to make a real comparison.....

[mateo88]

I've built both p2p, using the same component types and values for each. I personally like the lm3886 better because the bass has more of a punch to it than with the lm3875.

Granted, I don't have the best speakers in the world, but I can hear the difference.

[pinkmouse]

Both sound nice, but I found the 3886 much more dependant on layout and schematic. Initially I found it compressed, but after experimentation was more impressed by its control than that of the 3875, though the 3875 does sound more friendly/valve like, if thats your thing. This was in inverting mode however, as I tried NI with some of my first 3875s and OPA548s and much preferred inverted mode.

[homer09]

Posted on another thread, but i think is of value in this one:

Originally posted by soundNERD
I used the same transformer (+/-36VDC) and the same speakers (B&W DM580 I think). No, I didn't try them at the same time, but when I listened to the 3886 I remember hearing hissing, there was a turn on/off thump, and I noticed higher distortion at lower volume. The sound, although much better than the kenwood 100x2 amp I had in there at the time, didn't seem that great. It seemed to be weak with bass, and too much treble.

When I tried my 3875 stereo amp, I was unable to do a direct comparason because I had already used the 3886 amp boards in something else I've built. But I instantly noticed that the bass was perfect with the music, not too loud or boomy its annoying, but not too weak either. And, the high and mid frequencies sounded very good.

There were only slight differences with the amps. the 3886 amps were built on a PCB, while the 3875 was assembled P2P. And, except for the mute, the circuits were almost identical. They are both built using the schematic from the datasheet. The only difference was I didn't use the capacitor *Ci on the LM3875 amp.

I believe the mute circuit is in the signal path somehow, otherwise I don't know how it would mute it.

This is just my opinion, so I would see what others think before choosing one. Or, since the chips are so cheap, you can just build them both and see what you prefer.

[troystg]

I don't think Brian is leaving the LM3875 only "expanding" his offerings.

Both of Brian's boards function in NON-inverting mode.

LM3886 GC's are common in both where as LM3875 GC's are *usually* NON-inverting.

Compare apples to apples, etc....

[BrianGT]

Originally posted by rabstg
I don't think Brian is leaving the LM3875 only "expanding" his offerings.

Both of Brian's boards function in NON-inverting mode.

LM3886 GC's are common in both where as LM3875 GC's are *usually* NON-inverting.

Compare apples to apples, etc....

I am not leaving any of the chipamps. My goal is to provide a collection of boards for the LM3886, LM3875 and LM4780. The goal is diversity. One chip might be better in one application, and worse in another. I would like to try them all out and see what works best for me.

--
Brian

[homer09]

Originally posted by rabstg
LM3886 GC's are common in both where as LM3875 GC's are *usually* NON-inverting.

Compare apples to apples, etc....

Good point, lets only compare the non-inverting configuration then, since this is the one that Brian uses for his boards.

Any thoughts on the sound of the LM3886 vs LM3875 in NI mode?