Avitkauskas,
A word of caution, I am doing this off the top of my head so double check. The diystore deluxe chassis in the 4U/400 does not have the pre drilled and threaded grid holes. They surround it with options but not on that one. For those who want the 4U/400 a lot of people go to the Dissipante which is less money and they drill and tap only holes they want/need. YMMV
Good luck,
Don
Don
Not sure what you are saying it doesn't have. It appears to have lots of pre-drilled threaded holes and options for spacing. See paste below. I am thinking about buying one so I want to know what's missing.
DESCRIPTION
The Deluxe Chassis is the ultimate DIY Amplifier playground. We don't know of another chassis for sale in the world that makes life as easy for DIY Audio enthusiasts. Packed with features so you can focus on having a good time building your amp instead of getting roadblocked by the hardest parts of custom machining.
Introducing the 4U "Jack of all Chassis"...
HEATSINKS
2 x aluminum heatsinks 40mm thick, 300mm deep and anodized in black with 23 pre-drilled, pre-tapped blind M3 threads per side (a total of 46) as specified in our universal mounting specification
Threads are tapped to a minimum depth of 5mm
FACEPLATE
1 x aluminum faceplate 10mm thick, 450mm wide with rounded corners and anodized in silver
The silver front panel only (not the black), has the following additional features:
9 blind M3 pre-tapped mounting holes suitable for mounting all kinds of things to the faceplate - diodes, PCBs, riser panels, potentiometers, etc
Mount single or dual PSU boards directly to the back of the front panel
Designed so risers can be bolted to the chassis using two axis to create stable interior platforms within the chassis and maximize all the interior space
Use with risers and easily mount front panel components such as pots and dials to the risers with extension rods going through the front panel, saving the need for complicated or messy hacking in order to attach things to the front panel
The 9th hole is perfectly centered in the chassis and approximately 1/3 of the way down from the top (or bottom - you can spin the front 180') and can be used either as a mounting hole or as LED pilot hole
BACK PANEL
1 x aluminum back panel 3mm thick and CNC routed to our back panel specification, ready to accept your choice of PEM, RCAs and premium binding posts or drop our back panel parts kit (not included) straight in
It has Neutrik XLR compatible holes on the back to accept XLR, XLR/1/4" combo or RCA-in-XLR-format connector so you can easily connect XLR, 1/4" or RCA cables to your amplifier
Please see the 4U Back Panel Specification for more details"
Not sure what you are saying it doesn't have. It appears to have lots of pre-drilled threaded holes and options for spacing. See paste below. I am thinking about buying one so I want to know what's missing.
DESCRIPTION
The Deluxe Chassis is the ultimate DIY Amplifier playground. We don't know of another chassis for sale in the world that makes life as easy for DIY Audio enthusiasts. Packed with features so you can focus on having a good time building your amp instead of getting roadblocked by the hardest parts of custom machining.
Introducing the 4U "Jack of all Chassis"...
HEATSINKS
2 x aluminum heatsinks 40mm thick, 300mm deep and anodized in black with 23 pre-drilled, pre-tapped blind M3 threads per side (a total of 46) as specified in our universal mounting specification
Threads are tapped to a minimum depth of 5mm
FACEPLATE
1 x aluminum faceplate 10mm thick, 450mm wide with rounded corners and anodized in silver
The silver front panel only (not the black), has the following additional features:
9 blind M3 pre-tapped mounting holes suitable for mounting all kinds of things to the faceplate - diodes, PCBs, riser panels, potentiometers, etc
Mount single or dual PSU boards directly to the back of the front panel
Designed so risers can be bolted to the chassis using two axis to create stable interior platforms within the chassis and maximize all the interior space
Use with risers and easily mount front panel components such as pots and dials to the risers with extension rods going through the front panel, saving the need for complicated or messy hacking in order to attach things to the front panel
The 9th hole is perfectly centered in the chassis and approximately 1/3 of the way down from the top (or bottom - you can spin the front 180') and can be used either as a mounting hole or as LED pilot hole
BACK PANEL
1 x aluminum back panel 3mm thick and CNC routed to our back panel specification, ready to accept your choice of PEM, RCAs and premium binding posts or drop our back panel parts kit (not included) straight in
It has Neutrik XLR compatible holes on the back to accept XLR, XLR/1/4" combo or RCA-in-XLR-format connector so you can easily connect XLR, 1/4" or RCA cables to your amplifier
Please see the 4U Back Panel Specification for more details"
Since the M2x uses an Edcor signal transformer for voltage gain, one needs to be careful to reduce magnetic and electrostatic interference from the power transformer. Unlike the other large Papa amps that I’ve built, my M2x uses a single Antek AS-4218 housed in the steel case which Antek sells for this size. I found it important to use a chassis that was 400mm deep in order to keep more distance between the power and signal transformers.
It’s difficult to construct an effective shield for the small Edcor. It must consist of a high nickel, “Mu” alloy that is properly annealed after being bent into shape, though not everyone takes that final precaution. So distance is the next best thing. I don’t have any extra shielding around my signal transformers, but the big power transformer is double shielded. I can just hear a faint hum from my speakers if my ear is close.
It’s difficult to construct an effective shield for the small Edcor. It must consist of a high nickel, “Mu” alloy that is properly annealed after being bent into shape, though not everyone takes that final precaution. So distance is the next best thing. I don’t have any extra shielding around my signal transformers, but the big power transformer is double shielded. I can just hear a faint hum from my speakers if my ear is close.
Damn you're timely with that post about shielding! Not 10 mins ago I finished installing the antek CA-200 shield and the hum has SUBSTANTIALLY decreased down to almost irrelevant levels (on ~100dB speakers). I am using a 200VA 20-0-20V with C-R-C, with R= 0.2ohms. Basically, I have to put my ears to the speaker and wonder if what I am hearing is hum or the central air going... MOST importantly, the sound has improved very significantly to the point I had to come here and report this finding and see if anyone else had found this out.
I now have mid-highs and the low freq is tighter as well. I would even venture that classic BS about veil lifted off the sound. ;-)
I was doing due diligence and I had no idea shielding was going to make such a difference but it seems some type of magnetic coupling interference with the EDCOR is a real issue with this design and extreme care needs to be put into this aspect of the construction. I personally don't see the need to use anything above 200VA as transformer. In fact, I did buy a 300VA antek but when I tested it the hum became unbearable and the sound much worse. Now I know why!
I now have mid-highs and the low freq is tighter as well. I would even venture that classic BS about veil lifted off the sound. ;-)
I was doing due diligence and I had no idea shielding was going to make such a difference but it seems some type of magnetic coupling interference with the EDCOR is a real issue with this design and extreme care needs to be put into this aspect of the construction. I personally don't see the need to use anything above 200VA as transformer. In fact, I did buy a 300VA antek but when I tested it the hum became unbearable and the sound much worse. Now I know why!
I use an Antek 400VA in mine. I have zero hum on 102dB sensitive speakers.
I have a 5U chassis, the toroid is mounted vertically on the front, and the boards are mounted on an internal fan cooled heatsink near the back. I also placed an iron sheet that spans the chassis side to side just behind the toroid. I designed my own PS board, and it mounts to that sheet.
I regard shielding between the Edcors and the toroid pretty important, but I also believe that over sized transformers are a very good idea.
A second small toroid powers a the circuit board on the inside of the front panel. This circuit board has an Arduino to monitor temps. A single 120mm Noctua fan runs silently at full speed (I do not use PWM) when any of the transistors reach 60C, the heat sink takes about 30 minutes to fully soak and stabilizes at about 58C. The Arduino also runs the display, and controls a pair of relays. The first relay runs through a C-60 thermister and the second relay bypasses that after 1 minute. It also prevents quick cycling the amp (which will blow the fuse), and shuts down the amp in the event of a DC fault.
I made mounting boards for the daughter board to get rid of the awful screw mounts. They now plug into headers, and can be swapped in a moment with no fuss.
All in all a very fun project and an amazing amp.
I still have a few details to tidy up, but it has been pretty much all done for months.
-Josh
I have a 5U chassis, the toroid is mounted vertically on the front, and the boards are mounted on an internal fan cooled heatsink near the back. I also placed an iron sheet that spans the chassis side to side just behind the toroid. I designed my own PS board, and it mounts to that sheet.
I regard shielding between the Edcors and the toroid pretty important, but I also believe that over sized transformers are a very good idea.
A second small toroid powers a the circuit board on the inside of the front panel. This circuit board has an Arduino to monitor temps. A single 120mm Noctua fan runs silently at full speed (I do not use PWM) when any of the transistors reach 60C, the heat sink takes about 30 minutes to fully soak and stabilizes at about 58C. The Arduino also runs the display, and controls a pair of relays. The first relay runs through a C-60 thermister and the second relay bypasses that after 1 minute. It also prevents quick cycling the amp (which will blow the fuse), and shuts down the amp in the event of a DC fault.
I made mounting boards for the daughter board to get rid of the awful screw mounts. They now plug into headers, and can be swapped in a moment with no fuss.
All in all a very fun project and an amazing amp.
I still have a few details to tidy up, but it has been pretty much all done for months.
-Josh
Attachments
![0806202120[1].jpg](/community/data/attachments/795/795470-b585e05585ab993a835d466262322508.jpg)
Not really. Follow the link to see my solution using 0.010" Mu-Metal purchased from McMaster-Carr.
https://www.diyaudio.com/forums/pass-labs/281520-official-m2-schematic-209.html#post5168474
@Joshua
Your amp looks great. I would have to hear that 'zero hum' for myself though particularly since you are running a fan. I found that what other people consider as 'zero'-something or in 'as new conditions' is not so for me... LOL
I would venture the iron shield panel goes a long way in your enclosure. However, I don't believe the M2 needs more than a 200VA trafo. I use an antek AS-2220.
Your amp looks great. I would have to hear that 'zero hum' for myself though particularly since you are running a fan. I found that what other people consider as 'zero'-something or in 'as new conditions' is not so for me... LOL
I would venture the iron shield panel goes a long way in your enclosure. However, I don't believe the M2 needs more than a 200VA trafo. I use an antek AS-2220.
Oops! I have already ordered the 4U/300 Deluxe chassis. So will this be too small for M2X?
The 4u deluxe chassis has enough cooling surface for a M2x, you certainly could entertain ways to shield your power transformer. I am using separate 4u deluxe chassis for my monoblocks.
I wrapped the coils of my signal transformers with a band of copper tape, then mu metal. As my power transformer is in the front of the box, yet centered, it is the same distance to either back corner. No hum.
I wrapped the coils of my signal transformers with a band of copper tape, then mu metal. As my power transformer is in the front of the box, yet centered, it is the same distance to either back corner. No hum.
It will not be too small, but as others have mentioned, you may need to be careful to avoid hum.
If you are not concerned about tapping holes and/or would like the larger one - write to the store and see if they'll update your order. You also have an option for a 5U at 400mm depth with UMS.
Personally, having the extra depth is very nice. Not required, but nice. This is particularly true for a first build. I needed to update an order one time, and Gianluca (from Modushop) wrote me back confirming within one day. Since it's approaching the weekend, if you would like to update your order, I'd act quickly.
I can't guarantee it will work, but I do know they'd do their best. That team is awesome.
Either way, you'll have an awesome amp.
Edited to ensure clarity around which models have tapped UMS. 4U 300 and 5U 400
If you are not concerned about tapping holes and/or would like the larger one - write to the store and see if they'll update your order. You also have an option for a 5U at 400mm depth with UMS.
Personally, having the extra depth is very nice. Not required, but nice. This is particularly true for a first build. I needed to update an order one time, and Gianluca (from Modushop) wrote me back confirming within one day. Since it's approaching the weekend, if you would like to update your order, I'd act quickly.
I can't guarantee it will work, but I do know they'd do their best. That team is awesome.
Either way, you'll have an awesome amp.
Edited to ensure clarity around which models have tapped UMS. 4U 300 and 5U 400
OK. So, I'm actually just building my ACA now, but I am planning for the FW clone next. I thought M2x would be a nice next step, but after reading all these "hum allerts" I'm a bit concerned. Perhaps Aleph J or F5 (not available at the moment though) would be a bit easier for the first real DIY project with sourcing all the parts (a bit of the challenge for the first time too) and building the PSU? What would you recommend, please?
Sorry, if I added to your concerns. With a bit of care, the M2x can be completely or nearly free of any audible hum in the chassis you've ordered. You really don't need to go to extraordinary lengths.
The M2x is an incredible project. I did it for my first "real" build.
Either way, a larger chassis is nice, but not necessary. Carry on. BoM sourcing is always a challenge the first few times. That'll be common for any of the amps.
Edited to add a shameless link - This could help. I tried to document my build and some of the experiences I had. A Noob's First First Watt - M2x
The M2x is an incredible project. I did it for my first "real" build.
Either way, a larger chassis is nice, but not necessary. Carry on. BoM sourcing is always a challenge the first few times. That'll be common for any of the amps.
Edited to add a shameless link - This could help. I tried to document my build and some of the experiences I had. A Noob's First First Watt - M2x
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Here's a pattern for an Edcor shield (rev. 5 or something =). I used .01" sheet mumetal—standoff and bolt are nylon where I attached the shield. Annealed or not—I can say beyond doubt that it makes a difference—under diagnosis with a pair of headphones. Details are in my post on this thread. #2938
My monoblocks do not have shielded transfos...but the next set will, why not?
And yes, ItsAllInMyHead's post, linked above, is required reading for anyone who's building these tasty amps. (You can see in the pics I fully support his notion of ceramic isolators on the mosfets.)
Also added MJ's sweet sweet ACPR power management boards since these pics were taken (I sleep better at night now).
My monoblocks do not have shielded transfos...but the next set will, why not?
And yes, ItsAllInMyHead's post, linked above, is required reading for anyone who's building these tasty amps. (You can see in the pics I fully support his notion of ceramic isolators on the mosfets.)
Also added MJ's sweet sweet ACPR power management boards since these pics were taken (I sleep better at night now).
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Do not let these hum issues bother you. I am very picky and a perfectionist and knowing what I know after building the M2x I would never choose the aleph or the ACA vs this amp! This is a very special design and it sounds extraordinary. It works like a tube amp (very slow turn on), it has a transformer for gain stage, no feedback and it sounds like a tube amp. Plus you can play with all the buffers!
Comparatively speaking, the transformer shielding is a very trivial thing to implement. I don't know where you are but if you get an encased main transformer or an antek with steel enclosure you'll be just fine.
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