Ok, here's what Aaron of Don Audio offers.
Buy a pair of Edcor PC600/15k transformers and get 10% off with the discount code DIYAUDIO.COM.
This results in a price of EUR 15.27 for one piece, EUR 30.54 for two.
Shipping starts at EUR 5.99 for Germany. Shipping to Austria (and probably many other European countries) starts at 12,90 for a tracked DHL shipping.
I assume the typical order of a pair of transformers will be:
30.54 for the transformes,
12.90 for shipping
-----------
43.44 EUR total
Comparing that with ordering from Edcor:
14.46 for 2 transformers
00.86 tax
52.15 shipping (!)
--------------------
67.47 USD = 58.7 EUR
I can't calculate customs fees for every country but in Austria it would usually add 20% plus a fixed fee of 10 Euros. That would result in a total of 80 Euros for two transformers if ordered from the US.
To make a long story short:
Order from Edcor in the US and pay EUR 80.00 for two transformers shipped to your door or order from Don Audio in Germany and get the same thing for EUR 43.44.
Pretty sweet deal, easy decision I assume.
Here's the link: Edcor PC600/15K Übertrager, 16,97 €
Use code DIYAUDIO.COM
More information: IF demand pics up massively (at least 50 pieces) we can get it even cheaper from Don Audio. So it's for you guys to decide. Buy your transformers now and have them ready for your M2 build or sign up to the list and we'll see how demand develops. To prevent confusion: Please don't do both
Buy a pair of Edcor PC600/15k transformers and get 10% off with the discount code DIYAUDIO.COM.
This results in a price of EUR 15.27 for one piece, EUR 30.54 for two.
Shipping starts at EUR 5.99 for Germany. Shipping to Austria (and probably many other European countries) starts at 12,90 for a tracked DHL shipping.
I assume the typical order of a pair of transformers will be:
30.54 for the transformes,
12.90 for shipping
-----------
43.44 EUR total
Comparing that with ordering from Edcor:
14.46 for 2 transformers
00.86 tax
52.15 shipping (!)
--------------------
67.47 USD = 58.7 EUR
I can't calculate customs fees for every country but in Austria it would usually add 20% plus a fixed fee of 10 Euros. That would result in a total of 80 Euros for two transformers if ordered from the US.
To make a long story short:
Order from Edcor in the US and pay EUR 80.00 for two transformers shipped to your door or order from Don Audio in Germany and get the same thing for EUR 43.44.
Pretty sweet deal, easy decision I assume.
Here's the link: Edcor PC600/15K Übertrager, 16,97 €
Use code DIYAUDIO.COM
More information: IF demand pics up massively (at least 50 pieces) we can get it even cheaper from Don Audio. So it's for you guys to decide. Buy your transformers now and have them ready for your M2 build or sign up to the list and we'll see how demand develops. To prevent confusion: Please don't do both
Servus Mixi,
Thanks a lot for the effort in contacting don-audio. At least we have a starting point.
For myself I will stay on the list for now, too many projets, not sure m2 will be next...
For obtaining 50 pcs in total you might check the other thread, maybe even start a new one in the group buy section and inform about here in the PL forum.
Regards,
Max
Thanks a lot for the effort in contacting don-audio. At least we have a starting point.
For myself I will stay on the list for now, too many projets, not sure m2 will be next...
For obtaining 50 pcs in total you might check the other thread, maybe even start a new one in the group buy section and inform about here in the PL forum.
Regards,
Max
The GF is out of town so I finished the M2x with the Ishikawa front end. Letting it bake a bit, smoking some ribs, watching soccer and drinking beer. I’ll report on how it sounds. Bias at 620 cool?
Attachments
Congratulations! Try the Mountain View daughter boards too, I think you'll be pleased. Compare to the sound you get from Ishikawa, which do you prefer?
I think I'd twist the pairs of wires together, that run from each RCA input jack to each PCB's input pins. I'd do this to reduce hum, and also to feel good that I did something, I took active steps, toward reducing hum.
M2 uses Nelson Pass's patented autobias; as long as you stuffed and soldered his exact choice of optoisolator and his exact choice of resistor values, you'll get the same bias current he got, and it'll work great. Put the amp on a "Kill A Watt" $20 household wattmeter, it ought to draw 135-160 watts with input signal jacks shorted, if everything's assembled correctly.
I think I'd twist the pairs of wires together, that run from each RCA input jack to each PCB's input pins. I'd do this to reduce hum, and also to feel good that I did something, I took active steps, toward reducing hum.
M2 uses Nelson Pass's patented autobias; as long as you stuffed and soldered his exact choice of optoisolator and his exact choice of resistor values, you'll get the same bias current he got, and it'll work great. Put the amp on a "Kill A Watt" $20 household wattmeter, it ought to draw 135-160 watts with input signal jacks shorted, if everything's assembled correctly.
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Pardon my lack of knowledge.
Looking at the Tuscon schematic I am thinking that the 10V zeners reduce the supply voltage by 10V. So if using a standard Pass PSU with 18V transformer the voltage at the op amp should be +/-(23V-10V) = +/-13V.
I am asking because I would like to try Muses03 and/or Sparkos single op amps.
I have had these in a drawer for a bit waiting for the right experimental platform.
I think the M2x is that platform
Thanks
Bob
Looking at the Tuscon schematic I am thinking that the 10V zeners reduce the supply voltage by 10V. So if using a standard Pass PSU with 18V transformer the voltage at the op amp should be +/-(23V-10V) = +/-13V.
I am asking because I would like to try Muses03 and/or Sparkos single op amps.
I have had these in a drawer for a bit waiting for the right experimental platform.
I think the M2x is that platform
Thanks
Bob
Congratulations! Nice to see another one built. I’ve got almost all of my main board parts, just need to figure out what I’m going to use for the daughter board standoff’s, then get a psu board and other bits at the diystore. What did you use for the toroid bracket?
Whoops, you left out one step: the Antek AN-3218 transformer has dual 18VAC (RMS) secondaries. After converting AC_RMS to DC, and then smoothing out the DC via the CRC filter in the standard First Watt power supply, the final DC voltage applied to the M2x amplifier boards is ±23V DC to ±25V DC. It's some number between ±23 and ±25 depending on which rectifier bridge you picked, and a host of other second-order details.
If you install an X volt zener in series between each supply and an opamp (like the M2x Tucson boards do), then that opamp's power pins will be somewhere between (±23-X) volts, and (±25-X) volts. The official Tucson Bill Of Materials calls for an X=10 volt zener diode {1N4740A}, so the opamp on a Tucson board receives somewhere between ±13 volts and ±15 volts. But nobody can stop you from stuffing and soldering whatever diode you like. Might be a totally different diode with a different Zener voltage.
That is a shrewd observation: yes you could. It works because bias resistor R1 is in the circuit. Even when the opamp is removed from its socket, R1 guarantees there are a few mA of bias current flowing in both zener diodes, and so the voltages at the opamp power pins, nodes "VCC" and "VEE", will be their correct and final values (plus or minus a wee little ooch).
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