Tom, have you tried boosting a 3886 chip with external power transistors instead of more chips?
Is the performance significantly lower?
Is the performance significantly lower?
I'm getting nearly 400 watt from a sextet of LM3886 right now, so I don't really see a need for more power.
Driving an output stage with an LM3886 would be a possibility, but I'd be able to get better performance by driving the same output stage with an opamp. I've used that topology in various contexts for a few decades. It works well. There're the usual issues around stability and the usual "output stage issues" such as over-current limiting, SOA limiting, etc., but it's perfectly possible to get a good circuit that way.
The LM3886 (and other chip amps) is nice in that it is plug-and-play. There's no bias adjustment to fret over. It's not suddenly going to run away thermally. It's close to indestructible. Those are strong selling points for me.
The only thing I could wish for in the LM3886 would be better performance with a 4 Ω load at supply voltages above ±30 V. I guess I can't get everything in one chip... 🙂
Tom
Driving an output stage with an LM3886 would be a possibility, but I'd be able to get better performance by driving the same output stage with an opamp. I've used that topology in various contexts for a few decades. It works well. There're the usual issues around stability and the usual "output stage issues" such as over-current limiting, SOA limiting, etc., but it's perfectly possible to get a good circuit that way.
The LM3886 (and other chip amps) is nice in that it is plug-and-play. There's no bias adjustment to fret over. It's not suddenly going to run away thermally. It's close to indestructible. Those are strong selling points for me.
The only thing I could wish for in the LM3886 would be better performance with a 4 Ω load at supply voltages above ±30 V. I guess I can't get everything in one chip... 🙂
Tom
Kudos Tom, well written article and nice to read your story.
Wish you continued success with Neurochrome!
Wish you continued success with Neurochrome!
Thank you. I plan to write more for AudioXpress too.
Tom
Tom
I recall a little while back reading about the LM4702, an audio amp module where you "just add output transistors" (looking at the datasheet it was more complicated than that, but not by much) and you'd have a nice low-distortion (check those specs!) high-power amp. I thought it was a great idea, I thought I'd eventually order some of those chips, but then of course they discontinued it. With running several LM3886's in parallel you're duplicating all the input/mute/driver circuitry to get more power transistors for the output. It works fine, but the "unnecessary" duplication bothers the engineer in me.
Yeah... The LM4702 was discontinued a while back. As were its replacements, the LME49810, LME49811, and LME49830.
I did play around with the LME49811 some 14-15 years ago. It worked pretty well. But I can't base a current product on it as it's not available through the common channels.
Tom
I did play around with the LME49811 some 14-15 years ago. It worked pretty well. But I can't base a current product on it as it's not available through the common channels.
Tom
A small suggestion from my modest point of view.
I read the article and I admire your ability to have created a business on your own and I understand that sales objectively represent the personal satisfaction and final purpose of one's work.
If I may, I believe that if you wrote in more detail the description of your items for sale, describing them for the benefit of beginners without assuming that everyone should know or even understand what it is about, perhaps it would be better.
I believe that if you also addressed beginners, explaining also simply what it is for and how it fits into a pre-existing system, how it is powered, how it is connected with the clarity necessary for a beginner, perhaps you would be able to satisfy both things, obtaining more customers and therefore more sales.
Just sayin'... 🙂
Sales are satisfying. They indicate that others like my work enough to pay money for it and that feels pretty darn good. But I also get a lot of satisfaction from learning new things and applying those learnings to push the envelope even further.
I'm not very driven by money, though I do want to be compensated somewhat fairly for my efforts. If I was driven by money I would have stayed in the semiconductor industry.
I generally write for "people in the know" and that's probably my weakness. I should try to have beginners more in mind when I write product descriptions, for example.
That said, I did introduce the products I talked about in the article. There's at least enough there that a beginner would have some search terms to start with. Keep in mind that the article isn't intended as a sell sheet for the products. Rather, it's intended to present Neurochrome and the story behind it.
As for the article, keep in mind that it goes in the printed magazine first, so it needs to be reasonably long but it also needs to fit the allotted space. It needs to be engaging to read. My first draft was probably 25% too long and contained more backstory and not so much about Neurochrome, the topic of the article - and this was after I pruned quite a bit away already. @jan.didden's edits were helpful in distilling the draft into the necessary sentence fragments that I then made flow as a story. It was a fun process. I'd do it again.
I appreciate the feedback. Thanks.
Tom
Yes, do it please.
Beginners is a general term that first came to my mind, but it could be anyone.
Sometimes just a drawing or one more word can make all the difference.
And, one of those could be just me, I don't know if I explained myself.
There is always something to learn, and also to correct in one's knowledge: sometimes a small detail explained is enough to open the door to a new way of seeing a thing.
So again, do it please.
P. S.: Even though I read your entire article and was among the first to put my Like to the first post
Congratulations, Tom! 😎
Did you have a look at the www.neurochrome.com website (check out "resources"!)?
There is a lot of background information about the products and the ideas behind them.
It's good when someone spares a thought for the beginners.
I am not a beginner so assembling 3 Neurochrome modules was easy and satisfying. It's much like assembling a kit from the DIY store.
I believe that enclosure design.. heatsinks, torroid mounts, user controls.. presents more of a challenge than assembling modules.
Yes, even before you invited me to do it.
Please note that mine wasn't a criticism at all, but a modest feedback from my modest point of view.
My point is the following, in other words: too much information equals too little information if for me as a beginner it is not easy to find what I need.
An entire page seems aimed at demonstrating that performances of a buffer are excellent, but for a beginner this, if useful, will be useful later.
What does a beginner need?
First of all, know if he can gain an advantage in SQ once he added it to his system.
Then find out if any of his system can include it.
What type of power supply, and if any, does he need.
Know how the various sockets connect.
If can it also be added inside to an existing device and how.
And may be, enough.
Then everything else comes later, in my humble opinion.
Obviously even an expert would benefit from the above, both because a review never hurts anyone and because having a drawing of how it is connected, which power supply is needed, how to connect the cables in his system certainly wouldn't make a bad service to a potential new customer, indeed.
Of course tha above is only my modest point of view, with no criticism at all (in case there was still a need to specify it).
Not forgetting that a beginner must also do the following:
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Neurochrome has obviously done loads of work and a great job.
As far as helping out beginners, I think Tom does an awesome job at that as well. I've been dragged along on the diy journey by the helpful and knowledgeable diyaudio folk for the last 16 years, building lots of amps, preamps, speakers, etc. I'm still a beginner, maybe 10 power amp builds into it. Electronics isn't my profession or my training. Audio is a passionate hobby. I'll always be a beginner. Every project, both successful and aborted teaches me something -- usually a lot.
If there is something in a generous build or design description that I don't understand, I see it as a gift of something to learn. Each to his own, but I appreciate the "what the hell does that mean" feeling from time to time.
As far as helping out beginners, I think Tom does an awesome job at that as well. I've been dragged along on the diy journey by the helpful and knowledgeable diyaudio folk for the last 16 years, building lots of amps, preamps, speakers, etc. I'm still a beginner, maybe 10 power amp builds into it. Electronics isn't my profession or my training. Audio is a passionate hobby. I'll always be a beginner. Every project, both successful and aborted teaches me something -- usually a lot.
If there is something in a generous build or design description that I don't understand, I see it as a gift of something to learn. Each to his own, but I appreciate the "what the hell does that mean" feeling from time to time.
Thanks, your post I liked it.
However, perhaps it is best if I add the following, because I see that perhaps I have not been clear enough.
Generally speaking, I prefer to say with a noble intent what I think, rather than appearing compliant with a big unfelt smile (for the more malicious, if any: this is just an example of what can happen out there, not in this thread, let it be clear!).
So, I simply shared a thought that now seems to be growing bigger and bigger for no reason.
I'm sure that Tom has done and is doing a great job and I have absolutely no criticism to make neither to him nor to his magnificent site.
I only said what I think because I would like to buy a buffer and I have not understood how to connect the cables nor the power supply nor whether or not I can add it inside my power amp.
And no, frankly I don't feel like going through so many pages of things that at the end of the day don't really interest me directly.
Since I thought that adding a buffer between my DAC and my power amp was a relatively simple task I do not feel like asking and asking and asking again since this is information in my humble opinion that I would have liked to find more easily.
Is this a criticism?
I said it for the best of purposes, and I assumed the needs of a beginner.
If someone thinks otherwise then it's not my fault.
Look. I'm not offended by criticism so please don't be offended on my behalf. I don't think anybody found your comments to be rude or out of line.
I will always welcome constructive criticism.
Tom
I will always welcome constructive criticism.
Yeah. I'd say it is. But it's constructive criticism. Your clearly state that you had trouble finding the information you needed. You clearly stated which information that was and stated a possible solution. That's useful to me, because it is specific and actionable. Not thereby said that I will take action for any and all critique, but making it easier for people of various skill levels to find the information they need and buy my products would benefit me directly, so I will likely implement your suggestions. It's something I've been meaning to do for a while.
Tom