Sesquipedalio,
Good to hear you have the M2X running, which one of the daughter boards is sounding good for you at the moment? I have loaded and listened to all except the SMD version. At the moment the Mountain View is in front, but I will change that out soon and have some extended listening on the other 3 through hole versions now that the amp has run in a bit. it will also sound better for you after a couple of weeks.
Good to hear you have the M2X running, which one of the daughter boards is sounding good for you at the moment? I have loaded and listened to all except the SMD version. At the moment the Mountain View is in front, but I will change that out soon and have some extended listening on the other 3 through hole versions now that the amp has run in a bit. it will also sound better for you after a couple of weeks.
Josh, thanks for the info and heads-up on those switches. I'm making notes for my M2 build.
The fiber optic bit really peaked my interest. Would you please provide more details about that? Specifically on how the start and end are terminated.
I was considering using plastic/polycarbonate light pipes, but can't find a small enough diameter (approx 1.5mm).
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Well Mr. Designer of the Norwood module,
do you consider enough time has passed for you to share some of the finer points on design notes and considerations of the Norwood? I am genuinely interested considering Walt Jung's favorite chip and all, moreover you had a nice chat with the chip designer himself. I am evaluating buffers to drive a ~1k input impedance simple 20dB voltage gain stage which I will share here upon completion and leaning to adopt the M2X module standard.A quick question for mounting of the RV1 trimmer. I have the Bourns 3296W 502 5K value, which is different to the BOM one from a different company. So confused with the orientation where does the screw come (which side)?
Next I got this opto coupler - 4N35 Isocom | Isocom, 4N35 DC Input Transistor Output Optocoupler, Through Hole, 6-Pin PDIP | 597-302 | RS Components and with my magnifying glass cannot find the notch to align as per the PCB board. So if someone can guide me it will be great to finish the amp boards as there are the only items pending.
thanks
Next I got this opto coupler - 4N35 Isocom | Isocom, 4N35 DC Input Transistor Output Optocoupler, Through Hole, 6-Pin PDIP | 597-302 | RS Components and with my magnifying glass cannot find the notch to align as per the PCB board. So if someone can guide me it will be great to finish the amp boards as there are the only items pending.
thanks
Per the data sheet that can be accessed through the link you gave, one side of the optocoupler package should have a ridge directly along the edge. Pin 1 would be the leftmost pin on the side with the ridge - at least, that's my guess from the data sheet
Also, according to the photo on the RS web page you linked - when you can read the print on top of the chip right side up, Pin 1 should be the lower left pin ...
Hope this helps,
best regards,
Claas
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I have the same doubt on the Ishikawa daughter board as well with the Bourns 3296W 200R trimmer what is the orientation of 1,2,3 pins?
The PCB are clearly marked;
Opto has a notch shown in the silkscreen outline, the dot (or notch, probably a dot) on the package goes on the side with the notch.
The trimmer silkscreen has a dot on one side, that's where the adjust screw should go.
Photos from earlier in the thread -
Doesn't show the markings on the PCB silk, but you can see orientation of the pots.
As for trimmer on Ishikawa, orientation does not matter.
.
Opto has a notch shown in the silkscreen outline, the dot (or notch, probably a dot) on the package goes on the side with the notch.
The trimmer silkscreen has a dot on one side, that's where the adjust screw should go.
Photos from earlier in the thread -
Doesn't show the markings on the PCB silk, but you can see orientation of the pots.
As for trimmer on Ishikawa, orientation does not matter.
.
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Thanks Jim, there is no dot on my optocoupler that I brought fom RSDelivers but instead I could see a faint mark on top left side of beside the ridge. So I think I am comfortable on that now as there are no no other marks similar on the opposite side. So Ishikawa I am good with no need for any orientation
Coming to the amp boards trimmer 5k I just took the pic and there is no mark/dot to indicate the screw side goes there. Here are the pics from my amp boards.
Coming to the amp boards trimmer 5k I just took the pic and there is no mark/dot to indicate the screw side goes there. Here are the pics from my amp boards.
Thanks once again Jim
My boards are ready except a matched pair of 2SJ74/2SK170 on the way from alweit as I already had a matched pair earlier from my Sony VFET2 build. Going to use a old SX amplifier transformer rated at 0-18v *2 @ 7A each comes to around 270VA which is less than the recommended 300VA but I think for the time being to compare with my VFET it should be fine. Maybe a long short to compare with my VFET but lets see
My boards are ready except a matched pair of 2SJ74/2SK170 on the way from alweit as I already had a matched pair earlier from my Sony VFET2 build. Going to use a old SX amplifier transformer rated at 0-18v *2 @ 7A each comes to around 270VA which is less than the recommended 300VA but I think for the time being to compare with my VFET it should be fine. Maybe a long short to compare with my VFET but lets see
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My M2x is getting there with the Ishikawa boards. Luckily I received the jfets today after I posted above
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I use the ACA with Triangle 'desktop' Comete speakers. Currently running as system main speakers for testing the M2 are a pair of Thiel 2.3. I use a HiFi-Berry (Raspberry Pi) as my source to deliver primarily FLAC files. I have tried both the M2 and ACA with a Musical fidelity X-150 as a pre-amp and found it to muddy the class A sound too much, so tend to run directly to the amp. I have a Bryston pre-amp, which I have not yet tried with the class A amps, as well as other sources, such as a turntable, an iPhone, and other digital gear. The Thiels are hard to drive and toying with going to more efficient speakers. If I do, I will probably start looking to move to something like a SET tube setup. But for now, that is unrealistic given the speakers I have.
Thanks for the advice - I was wondering about those with the integrated LED.
Any advice on a suitable round toggle switch for the front of the deluxe diyaudio store chassis? I will be drilling the hole myself so rectangular is not preferred.
I am reserving any comments until I complete all listening - stay tuned!
Have you made the Tuscon board yet?
If not, I suggest using a socket, and an adapter for the SMD chip recommended as an alternate opamp.
LCQT-SOIC8-8 Aries Electronics | Mouser
4808-3004-CP 3M Electronic Solutions Division | Mouser
watch the material type, some combinations of plating materials can be bad together (avoid gold/tin combinations).
The 2 recommended chips sound very different. Tuscon is not the right board for my set up, but it might sound good on yours. I preferred the SMD chip.
Still have not actually sat down for an extended critical session, I end up just enjoying the music - for pure enjoyment, Ishikawa and Mountain View are the best in my system.
Still waiting on Melbourne, which I suspect will be the champion.
Sorry, wish I knew of something.
I had not considered a round toggle switch. I am liking the idea though.
I still do not have a chassis for my M2. I was not sure my heatsinking method would work (it does very well). I may still end up bi-amping if it turns out different daughter boards drive highs much better than lows on my speakers. So it will be either a nice single chassis on the rack, or a pair of chassis matched to the speakers.
All I can recommend is to clamp the face plate down before you drill it, and use a pilot hole. Drill press is the best if you have access to one. Filing the hole rectangular is not hard, plenty of good vids I am sure on YouTube on how to do it. I own a nice mill, and I still do it with files - takes less time than setting up for the cut.