Yes, it's those little details...
Anyway, it does seem that the Diamond buffer is doing well as the input stage to my F6. Using 10 Ohm base resistors and 10 Ohm emitter resistors on the output devices seems to be adequate. The Toshiba TTC004B and TTA004B transistors barely get warm, and I like having the CCS circuits that drop 10V off the rails for the front end devices.
I believe much of what I'm hearing with my new amp may be attributed to the sonic characteristic of this input stage. As I mentioned a while back, the Austin boards sound great in my M2x. I still like playing with the input JFets in my Mtn View vero prototypes, but that's mostly because I like to tinker. If I had to pick one of the canonical M2x input stages, the Austin has the best balance of characteristics for my ears.
Given my recent experience with the F6, it would be tempting to try higher voltage and current levels with the M2x. This version of the diamond buffer can support that. Perhaps someone with better KiCad-Fu could layout such a PCB which fits the M2x mounting scheme...
Anyway, it does seem that the Diamond buffer is doing well as the input stage to my F6. Using 10 Ohm base resistors and 10 Ohm emitter resistors on the output devices seems to be adequate. The Toshiba TTC004B and TTA004B transistors barely get warm, and I like having the CCS circuits that drop 10V off the rails for the front end devices.
I believe much of what I'm hearing with my new amp may be attributed to the sonic characteristic of this input stage. As I mentioned a while back, the Austin boards sound great in my M2x. I still like playing with the input JFets in my Mtn View vero prototypes, but that's mostly because I like to tinker. If I had to pick one of the canonical M2x input stages, the Austin has the best balance of characteristics for my ears.
Given my recent experience with the F6, it would be tempting to try higher voltage and current levels with the M2x. This version of the diamond buffer can support that. Perhaps someone with better KiCad-Fu could layout such a PCB which fits the M2x mounting scheme...
Been listening to the LT1122 in the Tucson Board. Great sound. Reinstalled the Diamond Board and I am knocked out by it.I think that is my favorite with LT1122 and OPA1611 following. It's like having three amps After 6L6 mentioned Tidal I have been discovering so much new music, Lars Danielsson and Cecilie Norby on the "Just the Two of Us" album and the song "Both Sides Now". Danielson is amazing bassist and the Diamond handles it amazingly. The Vet discount on Tidal is a great deal.
Yes, Norwood is a step-up compared to Tucson OPA604. It may have something to do with better drive capability to drive the Edcor?
I made distortion measurement using Focusrite and REW software when Tucson was installed and will be fun to measure amp with Norwood to see if there is any change in harmonics.
Few days ago I made a small interface box from power amp to Focusrite so level match and I don't burn the Focusrite input by a mistake. Same I used for first measurement (unboxed with long wires). It is nothing special and "quick and dirty" made.....but it seems to work. My theory is that I will get less noise pickup with shorter wires and mounted in a metal box.
I made distortion measurement using Focusrite and REW software when Tucson was installed and will be fun to measure amp with Norwood to see if there is any change in harmonics.
Few days ago I made a small interface box from power amp to Focusrite so level match and I don't burn the Focusrite input by a mistake. Same I used for first measurement (unboxed with long wires). It is nothing special and "quick and dirty" made.....but it seems to work. My theory is that I will get less noise pickup with shorter wires and mounted in a metal box.
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While waiting for the AS-4218 to show up from Antek, I was thinking if I can power the input stages from a smaller transformer and M2X with AS-3222. Have a bunch of 18VAC 50VA toroids which could be used.
Regards,
Subbu
While that sounds possible, I think it would be a lot of work to do it properly, such that there was no hum. The IPS boards would have to be connected to the main board in a way that isolated the power connections, but allowed the IN and OUT connections. The input stage power supply would need to be very clean and low impedance.
I have another suggestion, which is to build a power supply like the F6 Power Supply (Stereo) as presented in Nelson Pass’ F6 BAF article. This separates the second bank of capacitance for each channel for better separation. I also recommend adding high quality smaller value caps ~1000 uF to the second bank.
The choice of bridge rectifier will have a significant impact on the final rail voltage, and even the audible ripple. The LT4320 based synchronous rectifiers have shown better performance in all the amps where I have used them. The next best choice would be a set of FEP30 diodes, or the LVB2650 bridge.
Even though the M2x uses a transformer for the gain stage, it still needs the best PSU that you can manage for the best sound.
Thank you James for the feedback. I will go through the article and try it out.
I'm using individual 10A 100V Schottky diodes in a PSU for chip amps. Chip amps operate class-AB so the current drawn from the power supply is highly variable, unlike the current drawn by class-A amps like M2x. Still, when I connect the chip amp PSU to an electronic load and draw 4 amps DC from V+ and another 4 amps DC from V-, the Schottky's low Vfwd is quite a bonus. The diodes run cool, which means they don't bake the nearby electrolytic capacitors, which is nice.
Schematic and thermal images here
If you think you ought to feel some sort of nervousness about the 100V diode rating, the superdelightful components MOV1 and MOV2 might provide reassurance. They perform double duty; besides lightning arrestors, they also operate as across-the-trafo capacitors in the C+RC snubber networks.
Schematic and thermal images here
If you think you ought to feel some sort of nervousness about the 100V diode rating, the superdelightful components MOV1 and MOV2 might provide reassurance. They perform double duty; besides lightning arrestors, they also operate as across-the-trafo capacitors in the C+RC snubber networks.
I did listen to them but I was in the mode of trying out a couple of others. Not sure when I replaced the Whammy with the Korg B1. The pleasure of this amp is being able to tinker so easily. Tho I do have to give a second thought flipping around the 35 lb beauty. I did listen to my Aleph J for a couple intervening weeks and was pleased with that but your LT1122 recommendation was encouragement enough to move on. Now I'll have to go back to the Norwoods for further audition. Thanks again.
Just a quick question, off topic, and not wanting to divert a lot of attention... but a good PRE for this incredible amps is crucial! Would you say you prefer the Korg B1 to the Whammy? Thanks!
Hello Mark, do you have any red Norwoods boards spare with you? I would like to try on mine as I think I have damaged my existing Norwoods with my great soldering skills
Thanks
Both are terrific projects. I do prefer the Korg. It works well with my Aleph J and the M2x in all its various configurations. I do like the sound of tubes, so being able to dial in the 2nd Harmonic setting works for me. Tho I do like the ability to null the harmonics or to emphasize the 3rd if I want to experiment with a difference.Like the M2x you can easily have options.Build them both then you have a great Headphone amp to switch in.
Well you guys it's all your fault. I decided to build the M2x. I've been going back and forth for a while. I actually bought a ready made EL84 last year cause I chickened out! Back then I was really thinking hard about doing a project. In a way its a good thing I didn't, cause now I'll have 2 amps
It mostly ItsAllinMyHead's fault. You being so honest about your lack of knowledge, and the way you bared your sole to the community, really intrigued me. When I ran into your posts I was jumping around through the thread, you know, not in order. I wasn't committed yet to build not until after reading your experience. You got to me. Here was someone, out there, like me. Some one with little experience, building it. You are braver than me. It takes big cajones to face your ignorance and in a public forum to boot!!
The communities positive reception was encouraging to me.
Everyone was cool. So what the hey. I want to do this too.
I hope you folks will except another Noobie into the fold.
I have everything on its way pretty sure. I went with the bigger transformer 4218 400VA ....ahh just because, and its in the mail. I was surprised to see two items coming sooner than I thought. The 4u alum chassis cleared customs and the back ordered rear panel kit is being shipped. Alright!
All the mouser parts have been shipped, also the 2 Edcors. I got a 4X6 through hole PCB and 25 cheapo resistors coming to bone up on soldering. I can solder copper pipe Does that count?
I won't start building it till around January 20. Hopefully all the parts will be there. So I've got time to keep reading up on electronics and learn as much as possible. Whew this math is a tough grind on the ol noodle. When I'm at it reading the formulas, I swear sparks are flying between my ears. But its all interesting to me. What I absorb.
Thank you Mr. Pass for turning me on to such a great amp. WOW and thank you Mark Johnson and 6L6. I really admire your generosity with your time and knowledge. You both give so much to this project. I've already learned so much reading your posts. It's kinda weird to me, I feel like I know you folks a little after reading so many of your posts. Enough babbling.
Wish me luck
jj
It mostly ItsAllinMyHead's fault. You being so honest about your lack of knowledge, and the way you bared your sole to the community, really intrigued me. When I ran into your posts I was jumping around through the thread, you know, not in order. I wasn't committed yet to build not until after reading your experience. You got to me. Here was someone, out there, like me. Some one with little experience, building it. You are braver than me. It takes big cajones
to face your ignorance and in a public forum to boot!! The communities positive reception was encouraging to me.
Everyone was cool. So what the hey. I want to do this too.
I hope you folks will except another Noobie into the fold.
I have everything on its way
pretty sure. I went with the bigger transformer 4218 400VA ....ahh just because, and its in the mail. I was surprised to see two items coming sooner than I thought. The 4u alum chassis cleared customs and the back ordered rear panel kit is being shipped. Alright!All the mouser parts have been shipped, also the 2 Edcors. I got a 4X6 through hole PCB and 25 cheapo resistors coming to bone up on soldering. I can solder copper pipe
Does that count?I won't start building it till around January 20. Hopefully all the parts will be there. So I've got time to keep reading up on electronics and learn as much as possible. Whew this math is a tough grind on the ol noodle. When I'm at it reading the formulas, I swear sparks are flying between my ears. But its all interesting to me. What I absorb.
Thank you Mr. Pass for turning me on to such a great amp. WOW and thank you Mark Johnson and 6L6. I really admire your generosity with your time and knowledge. You both give so much to this project. I've already learned so much reading your posts. It's kinda weird to me, I feel like I know you folks a little after reading so many of your posts. Enough babbling.
Wish me luck
jj
Along came a cast-off. Instant insight, no doubt fueled by what I was sipping - one man's cast-off is another man's...donor-chassis.
So, with no apologies for its living quarters, here's another M2X build.
Thank you Mark and Jim and all who've contributed to the First Watt threads, you've created quite a resource.
And to the One Wizard Who Rules Them All: as we say in this part of the world, 'Nuf Respect! Thank you for the education and the hours of fun. You, sir, are a generous man.
So, with no apologies for its living quarters, here's another M2X build.
Thank you Mark and Jim and all who've contributed to the First Watt threads, you've created quite a resource.
And to the One Wizard Who Rules Them All: as we say in this part of the world, 'Nuf Respect! Thank you for the education and the hours of fun. You, sir, are a generous man.
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@jj128s -
Welcome! Congratulations on taking the leap.
I'm humbled by the mention. The community here has brought me a lot of joy, and the amp ain't too bad either.
If you haven't found it yet - here's a bit more info re: my experiences. It's still several "Walls of Text", but the last page has my "consolidated" notes.
A Noob's First First Watt - M2x
Good luck, and happy building.
Welcome! Congratulations on taking the leap.
I'm humbled by the mention. The community here has brought me a lot of joy, and the amp ain't too bad either.
If you haven't found it yet - here's a bit more info re: my experiences. It's still several "Walls of Text", but the last page has my "consolidated" notes.
A Noob's First First Watt - M2x
Good luck, and happy building.