There are a fair number of DIYers who would claim that the LM1875 sounds better than the LM3886 in a basic gainclone circuit. It's subjective, but many people report that the LM3886 is a bit bright and harsh in the upper-mids. It can be tamed, but requires careful component selection, layout and/or circuit topology changes.
Both ICs need an opamp in advance. In case none inverting DC decoupled schematic very dependable on a quality of decoupling capacitors. Also both ICs sounds much better with better power supply capacitors (Nichicon, ELNA).
LM1875 is a good replacement in chines multimedia like Microlab. For the project from scratch I would use LM3886 that provides better bass as well.
Somewhere on the forum I read that LM3886 is mimicking Naim amplifier schematics that was always considered (Naim) as a pretty descent piece of equipment in audiophile world.
Some diyers like OPA549 better then LM.
LM1875 is a good replacement in chines multimedia like Microlab. For the project from scratch I would use LM3886 that provides better bass as well.
Somewhere on the forum I read that LM3886 is mimicking Naim amplifier schematics that was always considered (Naim) as a pretty descent piece of equipment in audiophile world.
Some diyers like OPA549 better then LM.
No !
both chipamps can and do work very well without an opamp in front.
Do not add extra components that are not required.
I've been running an LM3875 in true dual mono, 2x 120VA, 18-0-18v for a couple of years now. I use a passive attenuator (Alps 50k dual Log/47k metal film shunt). It needs to be cranked up a little to make it sound (subjectively) nice, but it is very detailed and uncoloured.
Although I am in the process of building an active line level pre which I intend to try in place of my passive.
I'd guess that's a sign of having a noisy ground. At high volumes, the signal applied to the chip is mainly the input signal itself but at low volumes, the attenuation is greater and hence more ground noise gets fed into the amp.
It sounds a little coloured at low volume (slightly warm). I'm guessing it is more of an impedence issue. The amp is silent with no source playing, even at high volume settings.
Yes - sorry I didn't make it clear that I meant the noise on the ground will be RF - not directly audible but making its presence felt when music is playing.
Kits?
If you're comparing the two chipamp.com products, then I would ask:
Would you be willing to do without 4db worth of power that is only noise? If so, buy LM1875 kit and play music without noise.
However, if power is paramount, despite sporadic clipping sounding noise from the Spike circuit, then buy LM3886 kit. . . and maybe a baxandall to go with.
There are actually ways to play LM3886 without so much spike noise, and here they are:
Decibel Dungeon Buffered Inverting designs
MyRef
Nested LM3886
Parallel amp, PA100, PA150
Bridged Parallel amp BPA200, BPA300
If you're comparing the two chipamp.com products, then I would ask:
Would you be willing to do without 4db worth of power that is only noise? If so, buy LM1875 kit and play music without noise.
However, if power is paramount, despite sporadic clipping sounding noise from the Spike circuit, then buy LM3886 kit. . . and maybe a baxandall to go with.
There are actually ways to play LM3886 without so much spike noise, and here they are:
Decibel Dungeon Buffered Inverting designs
MyRef
Nested LM3886
Parallel amp, PA100, PA150
Bridged Parallel amp BPA200, BPA300
That seems mixed up. Let's separate the two issues.
Its better to use a larger than necessary transformer instead of a smaller than necessary transformer. Current handling affects bass response.
The capacitors directly at the amplifier board will have an effect on the proportion of mid-range output, the heat output, and sometimes the clarity. But, you really don't want a blast of only mids and highs (insufficient capacitance) because that's just another way to say disproportionately poor bass response.
National Semiconductor, the maker of both chips, in their AN1192 document, recommends 470uF caps at the amplifier chip in addition to a real power supply board. With parallel and solo chips, the speaker return/ground is directed to the 0v tap upon the power supply board. Their approach provides a nicely level response with non-inverting LM1875 and some of their other chips. And, it works well for Parallel LM3886, Parallel LM4780. Conversely, there are other amplifiers, like TDA7294 and many of STK that could use 220uF (at the amplifier board, and in addition to a real power board), if design permits.
So now I can answer the original question:
If you started out with a too-small [amperage] transformer, then all of the possible power cap options would be wrong. That's the "cost effective" mass market, poorer quality, retail amp sound. But it is because of a too-small transformer. The issue isn't directly related to capacitor choices at all.
^ actually that's common knowledge, the tradeoff made and scientifically based. If you don't know, I suggest you gain experience because swapping them in /same amp, it is pretty easy to hear the difference and I am not one to tout voodoo parts swaps. All else being equal, smaller transistor dies are faster.
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