Thanks - I've seen the outline schematic before, but not the whole article with pictures. The pics have a lot of additional info relating to the placement and layout which were not obvious before. I used a different routing of the power traces in the MyRef-X2, which wastes a bit of board area but allows the chipamps to be mounted on the edge of the board and simplifies heatsink mounting. It also helps that the MyRef-X2 is a monoblock and completely through-hole.
If I ever respin the MyRef-X2, about the only thing I'd add is the LM317 series-shunt regulator (similar to the MyRef FE).
For Fast Eddie:
I have a maximum respect for this designer. I think he had realized the project what you aim for.
https://drive.google.com/file/d/0BzbIeQI27LjoV21seUw4MG5jQWs/edit?pli=1
Some graphs and pics:
diyaudio.hu • Téma megtekintése - LM3886-QUAD
One day I will give a listen to it, for sure..
Ciao, George
I have a maximum respect for this designer. I think he had realized the project what you aim for.
https://drive.google.com/file/d/0BzbIeQI27LjoV21seUw4MG5jQWs/edit?pli=1
Some graphs and pics:
diyaudio.hu • Téma megtekintése - LM3886-QUAD
One day I will give a listen to it, for sure..
Ciao, George
Thanks. I tried to make it big enough to see, but alas, my eyesight is extremely poor.
It looks like it has some of the ideas I'm working on, but I just can't see it clearly enough to get the big picture.
I have a circuit in mind, where the output chips are nested into the feedback loop on each side of the diff amp. But I'm getting ahead of myself; I need to optimize the single ended amp first, and I have to order some stuff before I can do a physical prototype.
I'm sure that it's been done before. It seems like such an obvious concept.
Uhm, sorry i thought i have given the link to the pdf..
let's have another try - this is a link to the 'big brother'
https://drive.google.com/file/d/0BzbIeQI27LjoN0RwODB1emtsODQ/preview
let's have another try - this is a link to the 'big brother'
https://drive.google.com/file/d/0BzbIeQI27LjoN0RwODB1emtsODQ/preview
Had a look again: i'm able to navigate, zoom in in both google drive links..
Anyway, mzperx, the author is a member here. And the project is definitely worth some considering.
It's a composite totally differential amp, where the bridged/parallel output buffers are encompassed in the outer loop.
the idea might be obvious but a well proven, working realization is very very far from obvious..
So you are onto a great project, wish you all the luck!
Ciao, george
Anyway, mzperx, the author is a member here. And the project is definitely worth some considering.
It's a composite totally differential amp, where the bridged/parallel output buffers are encompassed in the outer loop.
the idea might be obvious but a well proven, working realization is very very far from obvious..
So you are onto a great project, wish you all the luck!
Ciao, george
Yes, I can see it now, thank you.
That is exactly the concept I am thinking of. But first I must parse a practical single ended circuit, order the parts, and then build it. If I am satisfied with it I might move on to build the bridge-parallel.
Right now I am figuring out what I have and what I have to order. One of the links above recommended these bypass capacitors 35SEPF22M+TSS Panasonic Electronic Components | P16407CT-ND | DigiKey for local bypass and after looking at their datasheet I'm going to give them a try. They have much lower high frequency impedance and much higher resonance than comparable electrolytics. It looks like they might be the answer to tantalums, which I have experienced a high failure rate with.
That is exactly the concept I am thinking of. But first I must parse a practical single ended circuit, order the parts, and then build it. If I am satisfied with it I might move on to build the bridge-parallel.
Right now I am figuring out what I have and what I have to order. One of the links above recommended these bypass capacitors 35SEPF22M+TSS Panasonic Electronic Components | P16407CT-ND | DigiKey for local bypass and after looking at their datasheet I'm going to give them a try. They have much lower high frequency impedance and much higher resonance than comparable electrolytics. It looks like they might be the answer to tantalums, which I have experienced a high failure rate with.
I've used full-rangers, 2-way with 1st-order crossover, 2-way with 2nd-order crossover, and 3-way commercial. They all seem to work pretty well, but it does better with 8-ohm woofers/full-range units. The tweeter impedance doesn't seem to matter much as long as it can be padded to 8-ohms.
For normal listening, I have been using a 6" Sharp driver and a generic Mylar dome tweeter with a 1st-order XO in a sealed enclosure.
Hi
I m from Kolkata, India. I want to assemble a LM3886 based stereo amplifier system with Bass Treble control. Can someone please suggest good AMP, PSU & BT kit available in India. Do i need any PREAMP if i want to drive it directly from PC or my Mobile?
How about these kits:
1. AMP KIT: Wintek - 68W Mono (LM3886) W/o Heat Sink
2. PSU KIT: Wintek - Dual Rail PSU Module
ALT PSU KIT: Lumin - Dual Rail 150W PSU
3. BT KIT: Wintek - Stereo Tone Control (X-Bass)
ALT BT KIT: Wintek - 3 Way Tone Control
I m from Kolkata, India. I want to assemble a LM3886 based stereo amplifier system with Bass Treble control. Can someone please suggest good AMP, PSU & BT kit available in India. Do i need any PREAMP if i want to drive it directly from PC or my Mobile?
How about these kits:
1. AMP KIT: Wintek - 68W Mono (LM3886) W/o Heat Sink
2. PSU KIT: Wintek - Dual Rail PSU Module
ALT PSU KIT: Lumin - Dual Rail 150W PSU
3. BT KIT: Wintek - Stereo Tone Control (X-Bass)
ALT BT KIT: Wintek - 3 Way Tone Control
I don't know the specifics of the kits you listed, but the MyRef Rev C monoblocks don't need a pre-amp if driven from almost any PC sound card. From a mobile, you may or may not need a small gain stage to drive a MyRef - it depends on the signal level on the headphone-out jack of the mobile.
I offer monoblock kits for the MyRef Rev C - PM or email me for details if you're interested. It does not however include a bass-treble control, for which you may need an additional board.
atupi: Thanks. Why is that? What happens if I use low sensitivity drivers? Or is it just that high sensitivity drivers are the in-thing? This will help me make an informed decision.
Siva: It's such a pain to get good drivers here. Which one did you go for? What are my options other than Sharp?
My eyes sparkle at Visaton B 80 though
. Coupled with a TIW 300 in a 150L tower. Is it in my stars? 
Siva: It's such a pain to get good drivers here. Which one did you go for? What are my options other than Sharp?
My eyes sparkle at Visaton B 80 though
. Coupled with a TIW 300 in a 150L tower. Is it in my stars? Of late, not many inexpensive driver options - what I've seen recently are some surplus Panasonic consumer-grade 6" drivers (from Mexico and Brazil), the Sharp 6" driver I mentioned earlier, a Daewoo 5.25" paper-cone woofer and a Robertson Audio 5.25" mid-bass driver that I'm playing around with. The last one seems to prefer a ported enclosure, and is a bit bass-shy, but that's fine with me. I haven't got around to evaluating the Daewoo - it appears to be a close cousin of the Robertson Audio driver (maybe the same OEM in Malaysia or China, just a guess). Of course, the Philips Hi-Q 8" octagonal frame dual-cone driver is still around, if you're into full-rangers. It has limited power handling, but that's not an issue for normal indoor listening.
They're still manufactured and available new, but under different ownership (Philips sold the plant and designs to the new owners):
Premium Sound Solutions Private Limited
I'd recommend the HQ48414P - 8 ohms, 25W, paper, dual-cone.
What a shame. I had the HQ48001 lying around all the time. They are brand new but I only used them when I was troubleshooting the myref. I also have the Philips Woofers (from the time when Philips manufactured it). I don't know which models though.
So Siva, the laziest thing for me to do is to order MDF towers of around 150L and put these in (or buy HQ48414P). Should I stick the woofers in as well? I plan to go sealed. How many Litres?
Mods: If this is not relevant here please move to a new thread. Thanks.
So Siva, the laziest thing for me to do is to order MDF towers of around 150L and put these in (or buy HQ48414P). Should I stick the woofers in as well? I plan to go sealed. How many Litres?
Mods: If this is not relevant here please move to a new thread. Thanks.
Attachments
Thanks for setting me straight Andrew 
Here's the new thread for Philips fullrangers. http://www.diyaudio.com/forums/full-range/266698-fullrange-refs-myref-v3.html#post4159338
Here's the new thread for Philips fullrangers. http://www.diyaudio.com/forums/full-range/266698-fullrange-refs-myref-v3.html#post4159338With low sensitivity speakers You trigger spike protection of lm3886 and this result in very bad sound.atupi: Thanks. Why is that? What happens if I use low sensitivity drivers? Or is it just that high sensitivity drivers are the in-thing? This will help me make an informed decision.
Siva: It's such a pain to get good drivers here. Which one did you go for? What are my options other than Sharp?
My eyes sparkle at Visaton B 80 though
I experienced this with some Spendor sa1 speakers