Hi Mark & Zen Mod, thanks for your quick responses. Mark, I actually have been reading, and re reading the M2 and M2x posts over and over including the posts you’ve mentioned. I find that doing so makes the over all build much smoother and often answers many of the questions I’d probably have during and after the build. It has helped with my Aleph J build and this one, resulting in only a few questions (like this one) in the end. As for the 2.5 amp fuse I used it because it was in the original manual, and I used the spec’d 4 amp fuse in my Aleph J build without issue. I’ll pop in the 4amp fuse and report back.
Help, please! Researching parts - more M2X questions I need answered:
Is Mouser part #667-ERJ-U08F2701V (ERJ-U08F2701V Panasonic | Mouser) a direct substitute for 652-CR1206JW-272ELF (CR1206-JW-272ELF Bourns | Mouser
The BOM for the M2X Main Amp board lists R13, R14 as 0.47 ohms 3W but does not seem to specify the Watts on R1 through R11.
Does this mean it is the SAME or imply that it should be different. Simply put, what Watt rating on R1-R11?
C0 (220pF NP0/COG, 5 mm) is listed as optional - how should I know whether and why? Should I just put it in?
TIA
-Ses
i
Is Mouser part #667-ERJ-U08F2701V (ERJ-U08F2701V Panasonic | Mouser) a direct substitute for 652-CR1206JW-272ELF (CR1206-JW-272ELF Bourns | Mouser
The BOM for the M2X Main Amp board lists R13, R14 as 0.47 ohms 3W but does not seem to specify the Watts on R1 through R11.
Does this mean it is the SAME or imply that it should be different. Simply put, what Watt rating on R1-R11?
C0 (220pF NP0/COG, 5 mm) is listed as optional - how should I know whether and why? Should I just put it in?
TIA
-Ses
i
Sesquipedalio,
I'd really suggest you read, if not all, at least as much as you can from this thread.
Most of your questions will be answered in the first few pages. Your last question was answered in the previous page, not 15 posts back: 100v is the right one to use.
But I strongly recommend reading this thread. It will clarify your doubts and give you a greater peace of mind instead of all the doubts you may have.
Un-rated resistors can be of 1/4W, and 1/2W is what Mark uses himself. All that info is within this pages, and now on my mind just from reading.
Good luck!
I'd really suggest you read, if not all, at least as much as you can from this thread.
Most of your questions will be answered in the first few pages. Your last question was answered in the previous page, not 15 posts back: 100v is the right one to use.
But I strongly recommend reading this thread. It will clarify your doubts and give you a greater peace of mind instead of all the doubts you may have.
Un-rated resistors can be of 1/4W, and 1/2W is what Mark uses himself. All that info is within this pages, and now on my mind just from reading.
Good luck!
Hi Ses - I have some measurement data that should help but on vacation. I'll post some 'scope shots next week. Rafa's advice is good. In general higher voltage caps are better as long as dimensions and lead spacing fit. There are exceptions from what I've read.
Phil
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Sesquipedalio,
I'd really suggest you read, if not all, at least as much as you can from this thread.
Most of your questions will be answered in the first few pages. Your last question was answered in the previous page, not 15 posts back: 100v is the right one to use.
But I strongly recommend reading this thread. It will clarify your doubts and give you a greater peace of mind instead of all the doubts you may have.
Un-rated resistors can be of 1/4W, and 1/2W is what Mark uses himself. All that info is within this pages, and now on my mind just from reading.
------
RafaPolit,
At the risk of offending the community, which is my only source of solving these problems....
You, "strongly recommend reading this thread. It will clarify your doubts..." Read? Firstly, I have been doing nothing BUT reading these forums 98% full of information that is not useful to me - either because it is jest, useless conversation, outside the scope of what I need or beyond my current level of understanding. Reading these forums, which are full of many variations by much more skilled and knowledgable people just creates more doubt. And when I do read and find differences, should I not ask questions like the one that led the author of the BOM to say, "Oops, that's an error in the BOM" as he made a mistake in the BOM data?
If you are referring to the question about 100V being answered a pager earlier, then you are referring to the kind answer from Mark to a question I had about a CAP on the norwood board. The subsequent question regarding 100V is in reference to a CAP on the M2X MAINBOARD. How would you propose I should know whether this second difference is another mistake, or something to which I should apply the same reasoning, or whether I should ignore it risking possible danger to myself and/or my build?
As to the knowledge that, "Un-rated resistors can be of 1/4W, and 1/2W... All that info is within this pages," I HAVE searched this forum and many other site:diyaudio.com forums for 1/2W vs 1/4W and come to the conclusion that in some cases it does matter. Therefore, I thought it best to ask when unsure.
As I have made myself clear that I am a noob in this arena, I would kindly ask that you, and anyone else that wishes to post a reply to my questions that says things like, "Read," or "Look in the specs" or anything that tells me to go find the answer myself, please hold your tongue and reply button. At a minimum, be kind enough to go find the answer on the right page and copy paste it with a bit more detail that might explain it to someone who wants the knowledge and fun to learn and succeed.
Thanks Mark,
I am creating a Mouser and Digi-Key cart as I type.. could use your continued kindness to get to a purchase point. BOM for the M2X Main Amp board lists R13, R14 as 0.47 ohms 3W but does not seem to specify the Watts on R1 through R11. RafaPloit says that un-rated resistors can be of 1/4W, and 1/2W. Can you please recommend the best R1-R11 Watt rating on the M2X mainboard?
Is Mouser part #667-ERJ-U08F2701V (ERJ-U08F2701V Panasonic | Mouser) a direct substitute for 652-CR1206JW-272ELF (CR1206-JW-272ELF Bourns Part)?
Thanks again,
-Ses
I am creating a Mouser and Digi-Key cart as I type.. could use your continued kindness to get to a purchase point. BOM for the M2X Main Amp board lists R13, R14 as 0.47 ohms 3W but does not seem to specify the Watts on R1 through R11. RafaPloit says that un-rated resistors can be of 1/4W, and 1/2W. Can you please recommend the best R1-R11 Watt rating on the M2X mainboard?
Is Mouser part #667-ERJ-U08F2701V (ERJ-U08F2701V Panasonic | Mouser) a direct substitute for 652-CR1206JW-272ELF (CR1206-JW-272ELF Bourns Part)?
Thanks again,
-Ses
Everything else can be 1/4 watt.
Yes, same value, both are 1206 package.
As I have made myself clear that I am a noob in this arena, I would kindly ask that you, and anyone else that wishes to post a reply to my questions that says things like, "Read," or "Look in the specs" or anything that tells me to go find the answer myself, please hold your tongue and reply button. At a minimum, be kind enough to go find the answer on the right page and copy paste it with a bit more detail that might explain it to someone who wants the knowledge and fun to learn and succeed.[/QUOTE]
I think you are way too demanding my friend.
It does not work that way I'm afraid.
If you show some kindness, understanding, appreciation people will respond to you and lead you to the spring.
If not no-one will reply.
Noob or no, it is not an excuse for being rude and reading your posts this is exactly what I see.
[/QUOTE]I think you are way too demanding my friend.
It does not work that way I'm afraid.
If you show some kindness, understanding, appreciation people will respond to you and lead you to the spring.
If not no-one will reply.
Noob or no, it is not an excuse for being rude and reading your posts this is exactly what I see.
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just take care about pins raster , and use whatever you can find - 1uF , film capacitor , 50 or 100V - both will work ...... and everything in between
Thanks for the clarity Itsmee and Zen Mod!
It is good to know the 1/4W work. Just to understand the 'theory' here, and maybe what I will use in practice... would it actually work to use the 1/2W if they fit the board? From what I thought I read, a higher wattage in resistors would only be more 'protective' as it would better handle higher voltages and heat dissipation. I also thought it might be important to get resistors with a fireproof/resistant rating as well. I would love to hear what you think on the items below. While trying to figure this out, I scoured the web for understanding and came to these (perhaps erroneous) resistor conclusions:
Ses
It is good to know the 1/4W work. Just to understand the 'theory' here, and maybe what I will use in practice... would it actually work to use the 1/2W if they fit the board? From what I thought I read, a higher wattage in resistors would only be more 'protective' as it would better handle higher voltages and heat dissipation. I also thought it might be important to get resistors with a fireproof/resistant rating as well. I would love to hear what you think on the items below. While trying to figure this out, I scoured the web for understanding and came to these (perhaps erroneous) resistor conclusions:
- Same Ohm rating should/must be followed to the schematic(s)
- A minimum wattage is necessary to properly dissipate heat or a [catastrophic] failure could occur.
- As wattage rating increases, one should pay attention to physical form factor to make sure the resistor fits the board mounting space and style.
- Generally [always?] Tolerance and Temperature Coefficient should both be as low as possible to restrict the resistor to the tightest operating parameters
- The composition makes a difference and things like metal film (and wirewound?) will work better and more within specs than carbon, for example.
- Adding moisture resistance, 'safety' and flame proof/retardant ratings increase cost and relative safety of the device and entire system
Ses
Re-M2x blowing fuses
Hello All, just a quick follow up and a few observations to my post yesterday. I installed a 4amp fuse as suggested by Zen Mod and the fuse no longer blows, thanks Zen Mod!
Now for a few observations. I wanted to check the amp draw on my M2 so I removed the pigtail and bulb from my bulb tester cord, maretted the two hot leads together and hooked on the clamp from my Greenlee multimeter to see what the amp is drawing. I'm getting 1.1 amps constant draw with my mains putting out 121vac, which translates into 133 watts (1.1*121). The firstwatt specs indicate 160 watts, 1.4amps, at 115volts, should I be concerned? I do understand that amperage and voltage are inversely proportional which accounts for the lower amp draw with the higher voltage but the wattage draw is still 27 watts lower and I'm wondering if the amp will output it's rated 25 watts at 8 ohms.
Next I measured offset with a 50watt 8ohm 1% resistor across the outputs with inputs shorted. After 1 hour with the resistor attached I was able to get the offset to 0.9mv on the left channel and 0.6mv on the right channel. I then removed the resistor and measured again after an hour and without any adjustment the offset read -1.13mv and -1.25mv respectively. Unless I'm missing something, or I've used the wrong type of resistor it would appear that there is a negligible differnce using a resistor when adjusting the offset.
This is the resistor I used;
https://www.mouser.ca/ProductDetail...=sGAEpiMZZMtbXrIkmrvidDNaDpN5VXc5P0g27agDHvk=
Hello All, just a quick follow up and a few observations to my post yesterday. I installed a 4amp fuse as suggested by Zen Mod and the fuse no longer blows, thanks Zen Mod!
Now for a few observations. I wanted to check the amp draw on my M2 so I removed the pigtail and bulb from my bulb tester cord, maretted the two hot leads together and hooked on the clamp from my Greenlee multimeter to see what the amp is drawing. I'm getting 1.1 amps constant draw with my mains putting out 121vac, which translates into 133 watts (1.1*121). The firstwatt specs indicate 160 watts, 1.4amps, at 115volts, should I be concerned? I do understand that amperage and voltage are inversely proportional which accounts for the lower amp draw with the higher voltage but the wattage draw is still 27 watts lower and I'm wondering if the amp will output it's rated 25 watts at 8 ohms.
Next I measured offset with a 50watt 8ohm 1% resistor across the outputs with inputs shorted. After 1 hour with the resistor attached I was able to get the offset to 0.9mv on the left channel and 0.6mv on the right channel. I then removed the resistor and measured again after an hour and without any adjustment the offset read -1.13mv and -1.25mv respectively. Unless I'm missing something, or I've used the wrong type of resistor it would appear that there is a negligible differnce using a resistor when adjusting the offset.
This is the resistor I used;
https://www.mouser.ca/ProductDetail...=sGAEpiMZZMtbXrIkmrvidDNaDpN5VXc5P0g27agDHvk=
you made a mistake - dummy load you're using is too cheap
for offset setting there is no need for dummy load
I wouldn't worry about an AC mains current of 1.1 amperes. "160 Watts from the AC mains" in the First Watt manual, probably includes a nice conservative safety margin. ALL correctly working FW_M2 amplifiers draw less than 160 Watts from the AC mains (in my opinion), so no customer ever calls them up to complain "Hey my M2 pulls more watts from the wall socket than the number printed in your manual!"
Instead if I were you, I would wonder "How in the world can a slow blow fuse, rated for 2.5 amperes, rupture and go open-circuit when it's only carrying 1.1 amps???"
As for offset voltage being the same very low number, with or without load resistors, it means two things. (1) Your amplifier does not oscillate when disconnected from a load. Some not-designed-at-First-Watt amplifiers, do! (2) Because your offset voltage is very low, the current that flows from the amp to the load is also very low: Ohm's Law tells us that Current = Voltage/Resistance. When voltage is small, current is small too. Your amplifier's offset voltage is the same when ZERO current flows (load resistance = infinity = open circuit) as when VERY LITTLE current flows (8 ohms load resistance).
Instead if I were you, I would wonder "How in the world can a slow blow fuse, rated for 2.5 amperes, rupture and go open-circuit when it's only carrying 1.1 amps???"
As for offset voltage being the same very low number, with or without load resistors, it means two things. (1) Your amplifier does not oscillate when disconnected from a load. Some not-designed-at-First-Watt amplifiers, do! (2) Because your offset voltage is very low, the current that flows from the amp to the load is also very low: Ohm's Law tells us that Current = Voltage/Resistance. When voltage is small, current is small too. Your amplifier's offset voltage is the same when ZERO current flows (load resistance = infinity = open circuit) as when VERY LITTLE current flows (8 ohms load resistance).
Yeah - there is definitely such a thing as 'over-improvement'
better to ask- what would be improvement?
if you made everything as prescribed , there is zero possibility of anything going to flame
same as making your Nike-es un-penetrable for X-Rays ; why?
First listening impressions
Hello All,
Got my M2x hooked up to my system this afternoon, with only about 6 hours of burn in time and offset set as close to zero as possible my listening observations so far are a pronounced softening of the upper end of the frequency range, a very W-I-D-E midrange with almost holographic depth, and a punchier bass drum kick with a slightly exaggerated upper bass range, not unpleasant but different from my Aleph J. I find the upper treble to me more of a “thhhh” as opposed to a “t” in sound. I built my M2x with the Ishikawa boards and Toshibas sourced from Alweit, a member of this forum, because I wanted to get an as close as possible rendition of the original M2. I’m currently driving it from my AirPort Extreme with an output of 2V streaming iTunes, and my CD player with a 2V output through my diy B1. Although the specs indicate an input of 3V for rated output I find it just as loud as I need it to be and very close to my Aleph J in terms of volume. I can barely hear the slightest noise at idle with my ear literally up against the tweeter of my speakers. It’s actually more quiet than my J build which I attribute to experience and a more thought out and neat layout of this build, and possibly my diy metal toroid L-bracket which may be blocking a little of the noise from the transformer. In fact, I’ve got more buzz coming from the transformer than I could possibly hear from the outputs. I’ll continue to listen while my new map ages and report back in a while. I will at some point try the other daughter boards to see what sound they offer as well.
Thanks again to Nelson Pass for gifting this great amp to us music fans, to Mark and Jim for their efforts and time to make the M2x available to all of us, and Zen Mod for his help and guidance as well! All of your efforts are truly appreciated. Keep up the great work Gentlemen!
Hello All,
Got my M2x hooked up to my system this afternoon, with only about 6 hours of burn in time and offset set as close to zero as possible my listening observations so far are a pronounced softening of the upper end of the frequency range, a very W-I-D-E midrange with almost holographic depth, and a punchier bass drum kick with a slightly exaggerated upper bass range, not unpleasant but different from my Aleph J. I find the upper treble to me more of a “thhhh” as opposed to a “t” in sound. I built my M2x with the Ishikawa boards and Toshibas sourced from Alweit, a member of this forum, because I wanted to get an as close as possible rendition of the original M2. I’m currently driving it from my AirPort Extreme with an output of 2V streaming iTunes, and my CD player with a 2V output through my diy B1. Although the specs indicate an input of 3V for rated output I find it just as loud as I need it to be and very close to my Aleph J in terms of volume. I can barely hear the slightest noise at idle with my ear literally up against the tweeter of my speakers. It’s actually more quiet than my J build which I attribute to experience and a more thought out and neat layout of this build, and possibly my diy metal toroid L-bracket which may be blocking a little of the noise from the transformer. In fact, I’ve got more buzz coming from the transformer than I could possibly hear from the outputs. I’ll continue to listen while my new map ages and report back in a while. I will at some point try the other daughter boards to see what sound they offer as well.
Thanks again to Nelson Pass for gifting this great amp to us music fans, to Mark and Jim for their efforts and time to make the M2x available to all of us, and Zen Mod for his help and guidance as well! All of your efforts are truly appreciated. Keep up the great work Gentlemen!
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I read your post, replied with answers to ALL your questions (albeit being a noob myself) and pointed to the places the answers were (without going and fetch the links myself, I would have hoped you would do at least that part of the work).RafaPolit,
At the risk of offending the community, which is my only source of solving these problems....
You, "strongly recommend reading this thread. It will clarify your doubts..." Read? Firstly, I have been doing nothing BUT reading these forums 98% full of information that is not useful to me - either because it is jest, useless conversation, outside the scope of what I need or beyond my current level of understanding. Reading these forums, which are full of many variations by much more skilled and knowledgable people just creates more doubt. And when I do read and find differences, should I not ask questions like the one that led the author of the BOM to say, "Oops, that's an error in the BOM" as he made a mistake in the BOM data?
If you are referring to the question about 100V being answered a pager earlier, then you are referring to the kind answer from Mark to a question I had about a CAP on the norwood board. The subsequent question regarding 100V is in reference to a CAP on the M2X MAINBOARD. How would you propose I should know whether this second difference is another mistake, or something to which I should apply the same reasoning, or whether I should ignore it risking possible danger to myself and/or my build?
As to the knowledge that, "Un-rated resistors can be of 1/4W, and 1/2W... All that info is within this pages," I HAVE searched this forum and many other site:diyaudio.com forums for 1/2W vs 1/4W and come to the conclusion that in some cases it does matter. Therefore, I thought it best to ask when unsure.
As I have made myself clear that I am a noob in this arena, I would kindly ask that you, and anyone else that wishes to post a reply to my questions that says things like, "Read," or "Look in the specs" or anything that tells me to go find the answer myself, please hold your tongue and reply button. At a minimum, be kind enough to go find the answer on the right page and copy paste it with a bit more detail that might explain it to someone who wants the knowledge and fun to learn and succeed.
So I won't refrain from posting my reply when it had useful replies and info. You may want people to just tell you what to do, others want to learn for themselves.
You are demanding "at a minimum" from people trying to help when it appears that you are not "at a minimum" trying to find the answer but expecting others to do it for you.
I'm probably as or more noob than you are,b ut I don't come here demanding that others "at a minimum" give me the answers.
So I, as other have commented, find your demands fairly abussive. I will refrain from trying to help you in the future. Asking for help is: I have tried and find myself lacking. Asking others to do the work for you is ordering and demanding, no asking for help.
You did the same on the power supply thread "demanding" that "at a minimum" someone post you the BOM of materials, and others have pointed you to the very first post of that thread.
So I will repeat my own "demand" since we are at it that you "at a minimum" read the first post before expecting others to just do things for you.
Or at least be grateful to those trying to help.
Rafa.