I've seen quite a bit of test equipment damaged during shipping as well, including an HP3577 network analyzer which was dropped hard enough to crush one corner of the heavy gauge steel chassis. Granted, there's a big difference between a 35 kg network analyzer and a 5 kg chip amp, but still...
~Tom
~Tom
+1 ...
Where a lot of people seem to go "wrong" in audio is that the Devils In The Details Factors (DITDF) don't matter, are irrelevant when listening to midfi, or just standard hifi - they don't get in the way of enjoying the music produced from these systems. But if the listener becomes more ambitious, wants the system to perform at a high technical level, then the DITDF become more and more critical; they start to dominate the situation, in terms of being that which stops the sound being fully satisfying. And if the DITDF are ignored, or the person doesn't know how to measure them, then he is in a quandry - persisting in chasing ever more technically "perfect" performance won't solve the underlying problem - being, that some DITDF haven't been addressed ...
The most ignored factor in audio is proper interfacing between the equipment. This is why I had to go from speaker driver-enclosure-amplifier-interconnect. Which was the link that seemed to matter the most. Normally solving the system problem, you will introduce distortion in one device to compensate for distortion in another. This needs to based on detailed understanding of the cause of distortion. The mazing thing is that you learn lots in the process.
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Do make a note, I am still waiting for my boards to come in. Have my fingers crossed when the mail starts from the holidays here tomorrow. Closing in on 7 weeks now.
Seven weeks! Wow. That's a while. I'm sorry... I hope your boards arrive soon. They shipped January 6th - about 12 hours after you placed your order.
Of the 200+ orders I've shipped over the past 2-3 years, this is the first one that's taken this long. Most international orders arrive within 2-3 weeks. Canada, 1-2 weeks. I've had one that took longer - six weeks to Germany. They've all arrived, though.
~Tom
Of the 200+ orders I've shipped over the past 2-3 years, this is the first one that's taken this long. Most international orders arrive within 2-3 weeks. Canada, 1-2 weeks. I've had one that took longer - six weeks to Germany. They've all arrived, though.
~Tom
Tom, Up to now, this is the second order I can remember not receiving in my life up to now!
But I have been reading you web site and learned from it. In the past, I had used Zobels to flatten the speaker impedance creating a constant load to the amplifier. I have seen some implementation using these and never considered why it was necessary. After reading your web site, I desided to see what would happen if I used it, I can say it really works wonders in creating a more retailed sound while improving sound stage presentation. The cap does need to be connected to the LM3886 output and the resistor needs to connect to ground just like in your SPICE simulation. I would recommend it a must in any LM3886 design.
But I have been reading you web site and learned from it. In the past, I had used Zobels to flatten the speaker impedance creating a constant load to the amplifier. I have seen some implementation using these and never considered why it was necessary. After reading your web site, I desided to see what would happen if I used it, I can say it really works wonders in creating a more retailed sound while improving sound stage presentation. The cap does need to be connected to the LM3886 output and the resistor needs to connect to ground just like in your SPICE simulation. I would recommend it a must in any LM3886 design.
I have tried saying this for years but it just encourages the naysayers 🙄 with all sorts of mathmatical proofs of why it cannot be so.
Yep, Zobel at amp output and Zobel directly across speaker driver terminals cures a lot of ills and then (miraculously !) you get 3D sound presentation.
Dan.
I guess I am more open minded to try things as long as there is some reasonable engineering explanation.
This morning I ordered two PCBs and Tom shipped them before I could finish my bowl of cereals. That's nice 😀
Yes, of course.
Just about any amplifier measures perfectly with sine stimulus into pure resistive load.
The real world is entirely different, hence the need for/benefit of Zobel networks.
Dan.
I should mention that there are a couple of data points that I'm interested in personally: MyRef and Sympatico. I'll be willing to test one MyRef and one Sympatico for free for anyone willing to pay the shipping costs.
~Tom
I think it is more important to fully understand how Zobels fit into the system. I had to take one Zobel out due to amplifier design. Lots of listening, testing, and cross examination is necessary to fully understand what is going on. For the LM3886 chip, I think Tom gave some clear examples what effect a Zobel will have on performance, I tried it and noticed a positively audible improvement, this is the kind of cross examination I am used to seeing. I also noticed the sequencing of the components made a difference which means possibly under certain conditions, using different cap and resistor value combination might also make a difference. I am sure is we look at the output impedance of the LM3886, the answer might be obvious.
You need the Zobel network to ensure the stability of the amplifier. See my explanation here: http://www.diyaudio.com/forums/chip...ensation-network-cc-rf2-cf-2.html#post4235244
~Tom
~Tom
The Modulus-86 uses standard parts so premium parts are superfluous. Still, for those few who have deep pockets and money to burn go for the premium parts!
Then compare the two.
My Capacitor comparisons: Mundorfs, VCap, Sonicap Platinum, Auricap, etc
Then compare the two.
My Capacitor comparisons: Mundorfs, VCap, Sonicap Platinum, Auricap, etc
Compare these amps MyRef, Sympatico, hypex NCore NC400, to the Modulus-86.
New, our feared second generation ABX component comparitor.
New, our feared second generation ABX component comparitor.