Jacek: Great looking monoblocks. You spared no expense in fitting each with the full transformer, Universal PS, and all the rest. Noted you have shielded the pcb transformer. Did this help with noise?
Which OpAmp are you using in Tucson?
Am currently building a M2X with outboard power supply using the same components. The main boards are finished along with MountainView and Tucson. Am waiting on the cases (shipped in a day from order out of Italy -- thanks Elena). Have all of the materials for the PSU save for the cable to connect the 4-pin Amphenol back panel plugs. Mouser sells 4-wire connector only in 25-100 feet lengths and don't want that much excess cable lying around (with the 35 boxes of old cables in the garage). Am going to improvise with 18 awg solid wire in "twisted-quad" format. Hope it works for the 24 volts and sometimes high amperage draw.
Lots to do with this build and ordering the parts and finding obsolete or back-ordered ones is most of the battle. Those LEDs are difficult to find these days and the BoM says "don't substitute."
Which OpAmp are you using in Tucson?
Am currently building a M2X with outboard power supply using the same components. The main boards are finished along with MountainView and Tucson. Am waiting on the cases (shipped in a day from order out of Italy -- thanks Elena). Have all of the materials for the PSU save for the cable to connect the 4-pin Amphenol back panel plugs. Mouser sells 4-wire connector only in 25-100 feet lengths and don't want that much excess cable lying around (with the 35 boxes of old cables in the garage). Am going to improvise with 18 awg solid wire in "twisted-quad" format. Hope it works for the 24 volts and sometimes high amperage draw.
Lots to do with this build and ordering the parts and finding obsolete or back-ordered ones is most of the battle. Those LEDs are difficult to find these days and the BoM says "don't substitute."
Thanks!
I did not check the noise level coming from the unshielded edcor. My transformer is big (300VA). I couldn’t mount it vertically to reduce the noise (chassis is only 3U high) as suggested by Nelson Pass and other folks from the forum. This is why I shielded edcor with 1mm copper covered with 0.1mm mumetal in the first place – I can hear some noise with my ear directly at a tweeter only.
Tucson opamp - 595-OPA1611AIDR
Regarding the LED, Mark Johnson pointed out the following replacements here:
The diyAudio First Watt M2x
Good luck with your project.
I did not check the noise level coming from the unshielded edcor. My transformer is big (300VA). I couldn’t mount it vertically to reduce the noise (chassis is only 3U high) as suggested by Nelson Pass and other folks from the forum. This is why I shielded edcor with 1mm copper covered with 0.1mm mumetal in the first place – I can hear some noise with my ear directly at a tweeter only.
Tucson opamp - 595-OPA1611AIDR
Regarding the LED, Mark Johnson pointed out the following replacements here:
The diyAudio First Watt M2x
Good luck with your project.
Thanks, Decek. Simply ordered 8 of them, all red, from DigiKey. DigiKey ships on the slow boat so they won't arrive soon. Mouser is much better although they charge for the privilege.
Couldn't get the specified trimpot so went with the only through-hole 3-pin inline 5K I could find: 3352W-1-502LF from DigiKey. Hope it works and not sure that you can test.
Couldn't get the specified trimpot so went with the only through-hole 3-pin inline 5K I could find: 3352W-1-502LF from DigiKey. Hope it works and not sure that you can test.
TA adds: "The optocoupler circuit will bias the amp right around 1.3 Amps regardless of the rail voltage. Mine runs at 1.31A."
Found this at post 3275 by grataku and am guessing that this answers my amp draw question. If so, three 18 awg solid wires (Vpos, Vneg, GNDP) from the psu to the amp chassis will serve for both boards.
But correct me if I am wrong.
Thanks, gurus.
Correct. Using the Universal Power Supply that outputs 24 volts dc (+/-) to the amp chassis with two M2X cards (and daughterboards). Have been reading on the Internet and understand that stranded offers flexibility benefits but reduces the amperage capability. 18 awg solid copper will pass 16 amps of chassis wiring current (each X3 wires) and this should be plenty for the two cards -- more than enough if they are using a steady state 1.3 amps.
Have the Amphenol connectors for the cable and they are plenty robust enough for wires up to 16 gauge. Am planning on using tube shrink wrap for the umbilical, building up both ends so they crimp under the Amphenol binding.
Will be a short cable, say 2 or 3 feet and the stiffness of 18 awg solid is not a problem. Have a mockup and it feels flexible enough.
Have the Amphenol connectors for the cable and they are plenty robust enough for wires up to 16 gauge. Am planning on using tube shrink wrap for the umbilical, building up both ends so they crimp under the Amphenol binding.
Will be a short cable, say 2 or 3 feet and the stiffness of 18 awg solid is not a problem. Have a mockup and it feels flexible enough.
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6L6: Understood and have no preference myself, just the requirement of getting the performance as good as possible. And cannot find a source on the Internet that provides the ampacity of stranded wire -- only solid copper.
AND, BTW, want to thank you for your Universal Power Supply thread that I have been reading a lot lately and benefiting from your knowledge and willingness to share. Along with the help received from PaulInWA, have been able to get the PSU ready to go and am just waiting for the chassis from Italy.
Should be plugging in this Friday or so. If you hear a small explosion from the area around Northern Arizona, pay it no heed...
AND, BTW, want to thank you for your Universal Power Supply thread that I have been reading a lot lately and benefiting from your knowledge and willingness to share. Along with the help received from PaulInWA, have been able to get the PSU ready to go and am just waiting for the chassis from Italy.
Should be plugging in this Friday or so. If you hear a small explosion from the area around Northern Arizona, pay it no heed...
You may want to check out Connex *PTFE Silver Plate Stranded Copper Hook-Up Wire
Many other suppliers of good Teflon insulated stranded wire if you do a quick search.
WKCox: Thanks for the reference. As I mentioned on the prior page, Mouser had cable from Amphenol that would work but only sold in 25-100 feet lengths. Have SO MUCH unused cable in the garage that I decided not to buy even more. Am going to improvise this one and use whatever size and stranded/solid copper cable that works.
And, btw, could not find any amperage ratings for the Connex 16 awg wire on their site. Let me know if they are there, somewhere.
And, btw, could not find any amperage ratings for the Connex 16 awg wire on their site. Let me know if they are there, somewhere.
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TA: Thanks. Have you got a source for the silicone stranded along with ampacity for the awg sizes? If fine stranded is preferred, what size is ideal for the 3 cables needed from the Universal power supply to the M2X boards -- Vpos, Vneg, and GND.P? The cables must be robust enough to feed two cards from one interconnecting cable (because the Amphenol connector is 4-pin).
If the M2X board amperage is only 1.3 as noted above, it seems that a modest, fine stranded wire will suffice -- say 18 awg. But, again, cannot find any tables providing the amperage loss when shifting to stranded and suspect that it is variable depending upon how fine the strands are.
If the M2X board amperage is only 1.3 as noted above, it seems that a modest, fine stranded wire will suffice -- say 18 awg. But, again, cannot find any tables providing the amperage loss when shifting to stranded and suspect that it is variable depending upon how fine the strands are.
This is the stuff I used:
Superworm Silicone Flexible Copper Wire 18 Gauge
– ACER Racing
Very flexible, and 18 ga is plenty large enough, plus easier to solder onto the umbilical connectdors.
Superworm Silicone Flexible Copper Wire 18 Gauge
– ACER Racing
Very flexible, and 18 ga is plenty large enough, plus easier to solder onto the umbilical connectdors.
I ordered a pair of Triad Magnetics power transformers for a rebuild of my M2x. That amp was the only one of mine that got built with a shared supply for the two channels. I’m planning to go with a pair of monoblocks this time. Synchronous rectifier PSU; CRC or CLCRC as necessary. Mostly using existing parts on hand.