After LM3875...minimalistic project suggestions?

[imaginarytime]

I just finished an LM3875 build with an audiosector premium kit. The dc offsets are ~18 and 22mV, dead silent when it should be, and overall pretty sweet. I think I did a nice job with grounding everything carefully, scaled up the gauge from start to chassis to the wall, read about that somewhere---maybe that helped. Overall, pretty straightforward once I got the picture of how it all comes together.

I was replacing a pretty sad amplifier setup, so any change would have been big, and my speakers are in serious trouble so that doesn't help either, but I'd say my first impressions were of a kind of silkyness and cleanliness of the sound. (I'll describe it as reminding me of these little semisweet and semihard candies that I haven't seen in decades. They were cyliners, almost gummy with a glyserine smoothness--and that's not bad.)

Anyway, I like it. Unfortunately, it will be put in to service at another location and I won't be able to compare it directly to the next build which will have ohmite and vishay resistors instead of caddock and rikens. (Maybe I'll have the opportunity for a listening comparison down the road.)

Having a sense of how it all comes together now, I plan on being more deliberate about the location of the components in the chassis and try to have a more elegant presentation.

Many thanks to all the people who have contributed to this forum answering questions for those of us trying to understand things that are somewhat obvious once they are done.


The question of this post is...then what?

I think I like the idea of learning more about what solid state means. I get the impression that it is kind-of the same, except all the things that are done in the chip are done with the actual components. I might be wrong, as I didn't really know what chipamp meant 60 day ago either.

I was drawn to the PD LM3875 because of the appeal of the minimalistic approach. Is there an analog (in terms of minimalistic design with excellent results) in the solid state (or other) domains that one might advise as a next project to learn more?

I realize that 'go look at the forums and pick a project' might be the instinctual reply here, but my appeal is for suggestions or thoughts on projects that favor results while emphasizing clarity and simplicity of design. Something like the solid state version of the audiosector kit, but solid state is just an idea.

Might be nice to think about the kinds of projects you wish you had thought of starting earlier on?

Thanks!

[Peter Daniel]

Originally Posted by imaginarytime

I was drawn to the PD LM3875 because of the appeal of the minimalistic approach. Is there an analog (in terms of minimalistic design with excellent results) in the solid state (or other) domains that one might advise as a next project to learn more?

I realize that 'go look at the forums and pick a project' might be the instinctual reply here, but my appeal is for suggestions or thoughts on projects that favor results while emphasizing clarity and simplicity of design. Something like the solid state version of the audiosector kit, but solid state is just an idea.

I would go with F5:

http://firstwatt.com/f5.html
F5 pcb group buy...

[Robert Kesh]

You could try a pass zenamp.

http://www.passdiy.com/pdf/zenamp.pdf

You'll need a big PSU for it.

[counter culture]

Buy Bob Cordell's book on SS audio amplifiers, or Morgan Jones' book on valve (tube) amplifiers, or Douglas Self's book on small circuit design or active crossovers.

It's hard to read one of these and come away without a desire to build something, and usually something specific. Even if you find them a bit advanced, a bit of stretching doesn't hurt, and you will grow into them.

The Cordell book has a good section on simulating designs. This is the modern approach to designing and understanding circuits. There are plenty of example circuits to try inputting. If you can get your head round it, you will never look back.

[danielwritesbac]

If you want to learn a lot from a doable solid state project, the Circlophone features minimal transistor count, more than twice the power of a chip amp and epic dynamics. Building Elvee's Circlophone: Documentation, Parts, Accessories, & beginner friendly

I managed to pick through one of these on phenolic perfboard. However, there are published board designs and elsewhere on diyaudio.com is the directions to print a board at home. Some designs are credit card sized. It features MJL21194 linear outputs run in dynamic Class A, (a more efficient version of class A), a wide range of gain settings and non-blaring audio like strong wind.

[imaginarytime]

Didn't have a chance to look in over the holiday. Thanks, all! Great suggestions.