if you make it dual mono , it is irrelevant where PSU is situated , regarding ground loops
each channel having own audio GND with NTC going to chassis, is all you need for complete separation
in case of externally cased PSU , I would go with CRC , where last C is in amp case
R can be just umbilical , or 0R1 and umbilical
each channel having own audio GND with NTC going to chassis, is all you need for complete separation
in case of externally cased PSU , I would go with CRC , where last C is in amp case
R can be just umbilical , or 0R1 and umbilical
With silent I mean "mechanical" silent.
Another thing I like using a large transformer is that voltage is very stable. It won't drop from idle to full load of the M2X (very small drop).
(The 2x18V rarting is with full load (many amps)).
A small trafo may have a few volts voltage drop from idel to full load depending on how small it is. Then during startup it takes some time for the amp to reach full bias. During this time you have higher output voltage until bias is settled.
For high voltage PSU for tube amps it is really something to consider…..but I am sure you are safe with your 300VA transformer
And if it is mechanical silent…...and it does not get very hot.....everything is fine.
I like big iron and that is the good thing with DIY....you can decide yourself!
Looks like everyone is going crazy with shielding/covering/grounding the Edcors on the M2X. . Now among all the amps that I have built surprisingly this is the most hum free one
It depends a lot of the speaker sensitivity. I can hear 2 mV of hum in the listening position and 0.5 mV with ear close to speaker. When I read many had hum problems and I also saw that Nelson had the Edcor with a mu-metal shield around…...I took no chance
…..I can't tolerate any hum it would spoil the listening experience completely My speakers are 94 dB.
Thank you for the tips! If the umbilical itself did not have the required resistance, would I hear some noise to let me know? Or should I actually measure the resistance of the umbilical?
I can't figure out how to also quote 6L6's nodding acknowledgment.
I'd love to do this. I typed a book and deleted it and wound up with what's still a long post. See a pattern here?
The simple response is - I seriously considered doing that and then paused and went back to a single case. However, if two great folks think it's a good idea, I would certainly do it, but I may need a bit more help. It goes against keeping the build as simple as possible, but I think the benefit of the modularity (and potentially better performance) outweigh the potential pitfalls. I'm personally not too concerned with the noise, but I would like to make smart decisions. Modularity wins.
Keep in mind - I am a total newbie. I would have NEVER thought to ask the question @aljordan did. That question and the answer flew right by me. I thought all the smoothing capacitors would go in the power supply case on the UPS board. This is what you're working with...
What kind of case would be used for the PSU. Is it correct that I only really need a case that is big enough to house the unit? No heatsinks necessary? Is the galaxy series right for this application? I can fit that into the budget.
Is it correct that in addition to space (now reduced) the primary concern for the case that holds the "amps" is heat dissipation - the heatsinks? So, in theory, the 5U (now woefully empty) would be fine, but a case with smaller interior volume, but with the same heatsink (capacity?) would be suitable. If so, I don't know how to pick it. Clearly the 4U will work b/c 6L6 used it if for no other reason.
Is that generally right?
I'm game and would love to do it, if you guys can help. Otherwise I'll stick with the big honking single chassis.
ItsAllInMyHead - For my M2x, I'm using the 4U chassis from the diySTORE. Enough interior room for a stereo amplifier.
I'm in the process of building F5T mono blocks, lots of work, very expensive since I will have 4 enclosures. I was able to complete the Power supplies and enclosures with both umbilical cables.
Now, I'm struggling to find heat sinks to buy, and then build my own enclosures. The raw heat sinks, no drilling or anodizing will cost me $400. Add to that the time involved with a rear panel (around $100) and I'll probably use wood for the front panel. Who knows how much for that.
If you can buy an enclosure, do it. It will save time and money, not to mention you have a better chance to finish the project if it doesn't get stalled. Just my opinion.
So for the 4 enclosures I'm looking at around $1000.
I'm in the process of building F5T mono blocks, lots of work, very expensive since I will have 4 enclosures. I was able to complete the Power supplies and enclosures with both umbilical cables.
Now, I'm struggling to find heat sinks to buy, and then build my own enclosures. The raw heat sinks, no drilling or anodizing will cost me $400. Add to that the time involved with a rear panel (around $100) and I'll probably use wood for the front panel. Who knows how much for that.
If you can buy an enclosure, do it. It will save time and money, not to mention you have a better chance to finish the project if it doesn't get stalled. Just my opinion.
So for the 4 enclosures I'm looking at around $1000.
In regards to my post #1914. When testing the daughter boards, the only current draw should be 1mA for the LED on Mountain view.
The Austin boards I built, I swapped the base and collector on both Q2 & Q4. Of course since I was double checking my work, both boards had Q2&4 leads swapped.
I was able to remove the leads from the base and collector spots on the PC board and position them correctly.
Now when I test, 0 mA at 24 volts, no heat, no smoke, no sparks and no damage to other components (I hope).
The Austin boards I built, I swapped the base and collector on both Q2 & Q4. Of course since I was double checking my work, both boards had Q2&4 leads swapped.
I was able to remove the leads from the base and collector spots on the PC board and position them correctly.
Now when I test, 0 mA at 24 volts, no heat, no smoke, no sparks and no damage to other components (I hope).
ItsAllInMyHead:
Galaxy is not the right chassis for M2X. It has to be a chassis with real heatsinks like the Deluxe chassis. It also makes it easier that you have the predrilled holes for mounting the PCBs. Also nice that there are cutouts for connectors in back panel so you just need to buy a connector kit from DiyAudio store. A little bit expensive but it should ensure you reach the target of building a working amp. Keep it as one chassis for your first build…….would be my advice.
Galaxy is not the right chassis for M2X. It has to be a chassis with real heatsinks like the Deluxe chassis. It also makes it easier that you have the predrilled holes for mounting the PCBs. Also nice that there are cutouts for connectors in back panel so you just need to buy a connector kit from DiyAudio store. A little bit expensive but it should ensure you reach the target of building a working amp. Keep it as one chassis for your first build…….would be my advice.
MEPER, I think you missed the fact that ItsAllInMyHead is asking wether the Galaxy case would be enough to host the PSU alone, as people are encouraging him to go PSU in one chassis and amp boards on another.
Perhaps with that in mind someone can offer him reassurance regarding the case for a PSU?
For what is worth, I thought of that myself, but, as you have read, it's not as easy as putting one in one case and the amps in the other. Still there is need for filtering inside the amps chassis. But there are lots dong it, so it's not impossible by any means!
Rafa.
Perhaps with that in mind someone can offer him reassurance regarding the case for a PSU?
For what is worth, I thought of that myself, but, as you have read, it's not as easy as putting one in one case and the amps in the other. Still there is need for filtering inside the amps chassis. But there are lots dong it, so it's not impossible by any means!
Rafa.
Correct, enough room for the components and working room for your comfort, no heatsinks necessary. I would want the top and bottom vented, and rectifiers will need some thermal consideration. Small sinks or case-mounted is good for that. Toroid, caps and any PCB's are the major players in determining necessary square footage. My budget demands I scrounge and reuse things, so I'm not familiar enough to answer about the Galaxy case.
Yes. IMHO heatsinks are #1 concern, whatever it takes to house those and your PCBs/connectors/switches is #2. In a prebuilt case, the heatsink is the decision maker. Just from reading this thread, I know that 4U+ is successful.
It's odd that thermal resistance of the heat sinks is not included with the description of the diyAudio Store chassis. Am I overlooking that?
I seem to remember shooting for the 0.25°C/W range in a heat sink to get around 25°C above ambient.
In this instance, the chassis would be for the FW power supply alone.
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For the PSU alone maybe a Pesante chassis (steel version) could be an option. I know that for this chassis the Baseplate can be selected as an option. I have one I never used so far and was purchased for a PSU alone. But the components was too heavy. But for a standard M2X PSU it will be fine (if Baseplate is included).
Some datas to the DISSIPANTE case (and the related heatsinks):
DISSIPANTE 04 / 300:
4 units high = 165 mm / 300 mm deep
uses 2 heatsinks (one on each side):
heatsink measures 300mm x 165 mm x 40mm (fins)
Modushop Italy: 0,31 C/W (for one heatsink!)
DISSIPANTE 04 / 400:
4 units high = 165 mm / 400m deep
uses 4 heatsinks (two on each side)
one heatsink measures 200 mm x 165 mm x 40 mm (fins)
Modushop Italy: 0,38 C/W (for one heatsink)
Just for info! These are values I have directly from their website.
I built my case for the M2X with the 5U heatsinks
this means 4 heatsinks
200 mm x 210 mm x 40 mm (fins)
each heatsink gives you 0,28 C/W
After 1 hour of listening in a room with 24 C (temp.) I measure around 45 -
52 C at the outside of the heatsinks (between the fins where the MosFet is
mounted).
Only some experiences from me. But I think the 4 U heatsinks should work.
And if you build monoblocks you put 1 M2X pcb into 1 case - so you need the
heatsinks only on one side of the case.
PSU case doesn't need heatsinks. But for sure : 4 cases = more cases =
more costs....
Greets
Dirk
DISSIPANTE 04 / 300:
4 units high = 165 mm / 300 mm deep
uses 2 heatsinks (one on each side):
heatsink measures 300mm x 165 mm x 40mm (fins)
Modushop Italy: 0,31 C/W (for one heatsink!)
DISSIPANTE 04 / 400:
4 units high = 165 mm / 400m deep
uses 4 heatsinks (two on each side)
one heatsink measures 200 mm x 165 mm x 40 mm (fins)
Modushop Italy: 0,38 C/W (for one heatsink)
Just for info! These are values I have directly from their website.
I built my case for the M2X with the 5U heatsinks
this means 4 heatsinks
200 mm x 210 mm x 40 mm (fins)
each heatsink gives you 0,28 C/W
After 1 hour of listening in a room with 24 C (temp.) I measure around 45 -
52 C at the outside of the heatsinks (between the fins where the MosFet is
mounted).
Only some experiences from me. But I think the 4 U heatsinks should work.
And if you build monoblocks you put 1 M2X pcb into 1 case - so you need the
heatsinks only on one side of the case.
PSU case doesn't need heatsinks. But for sure : 4 cases = more cases =
more costs....
Greets
Dirk
M2X temperatures
Some temperature measurements at my M2X (after 1 hour running):
heatsink temp. between fins (where MosFet is inside): 52 C
temp. topcover of case: 40 C
temp. frontpanel: 40.7 C
temp. of the CL60: 52.4 C
So, this baby is
Greets
Dirk
Some temperature measurements at my M2X (after 1 hour running):
heatsink temp. between fins (where MosFet is inside): 52 C
temp. topcover of case: 40 C
temp. frontpanel: 40.7 C
temp. of the CL60: 52.4 C
So, this baby is
Greets
Dirk
