Curious how a LM3886 Gainclone would compare to.......

[THUMP LUMP]

I am thinking about doing a pair of LM3886 Gainclone amps from Chipamp.com and having never heard a Gainclone, I was wondering how they would compare to what I am running now, that being a Kenwood Basic M2A and a NAD Monitor Series 2100. They would be in a bi-amp config.

Thanks

[THUMP LUMP]

Also....would it make much difference between a 160VA 18+18 and a 250VA 18+18 tranny? 4Ohm load.

[sangram]

I'm not sure how it would compare to your specific equipment, as I haven't heard them.

I have, however, a stereo gainclone running off a 220VA transformer, and built with Blackgate NX caps and Holco reisstors - not the 'ultimate' quality parts, but better than the stuff we get locally or even midrange material like Panasonic FM/FC, which I have also used for other projects.

Compared to a vintage Sony ES222 stereo integrated, the gainclone is much sweeter and open in the midrange and treble - at the expense of overall power and heft. It's no slouch, and is fine for some pretty loud listening, but the Sony goes even louder and has a lot more headroom. The 3886 also has a much wider soundstage that stretches well past the speakers, whereas the Sony tends to be a little constricted. The Sony is built with Nichicon Muse and audio-specific PSU caps (originally built that way) and has a pretty complex discrete power amplifier, rated to 80 watts/channel but capable of over 120 watts at 0.5% THD - so, not a bad amp in its own right.

The general wisdom around here is to use chipamps for high sensitivity speakers, low levels or small rooms, and discrete or PWM for more power-dependant listening or demanding loads (4 ohms is pretty demanding for a chipamp - can be done, but the amps run hot).

My speakers are the Usher Mini-Dancer 1, 85dB/w, 8 ohms - very friendly for a chipamp, though not sensitive enough to go very loud with the ~30 watts of clean power the 3886 can produce.

[pacificblue]

Not much difference between 160 VA and 250 VA. You should provide good heatsinking for 4 Ohm loads.

Power-wise the chipamp will not nearly be able to compete with the M2A, so you will probably miss some punch, when you crank it up.

[Bas Horneman]

I am thinking about doing a pair of LM3886 Gainclone amps from Chipamp.com and having never heard a Gainclone

If you have some money to spare. I would just say go ahead and try it for yourself. The chipamp.com kits are major value for money and so are the gainclones in general. But in the end are the judge.

[THUMP LUMP]

Originally Posted by pacificblue

Power-wise the chipamp will not nearly be able to compete with the M2A, so you will probably miss some punch, when you crank it up.

Simply based on the meters on the M2A, 4Ohm scale, I hardly ever see 40 watts. I have been running these 2 amps in a bi-amp config with the M2A on the mid-woofers. A Hafler 200w Plate amp on the sub. Tri-amped config?

I saw some pics where someone had cut a CPU heatsink in half to be used on a LM3886 chip. Would a 24vdc fan be a bad idea (thinking noise)? Depending on mains supply, rails should be in the 25v area from the 18+18 tranny.

[star882]

The real solution is to use a more modern design that does not require any heatsinking or very little.

[THUMP LUMP]

Originally Posted by star882

The real solution is to use a more modern design that does not require any heatsinking or very little.

Good idea. Now can you follow up with a kit that qualifies for that? Seeing that I have never built anything like this before, Gainclones seem pretty simple to do.

[feyrerm]

Originally Posted by THUMP LUMP

Good idea. Now can you follow up with a kit that qualifies for that? Seeing that I have never built anything like this before, Gainclones seem pretty simple to do.

I believe star is refering to designs that use large brass or copper bars incorporated into the case design to use the case as a large heatsink. There are many examples of this pictured in the Chipamp gallery.

[THUMP LUMP]

OH!....I see what you are getting at. I was thinking that he was referring to another design of chip amp that needed less or no additional cooling. I'll look at some of the case designs in the gallery then.
Thanks