Hi All.
Has anyone put two different Pass amps into one chassis with one shared PSU?
One channel from each amp would be mounted onto each heat sink, with the PSU switched between each amp so that I can use either amp, one at a time.
I have very large, and very tall heat sinks, on which I can easily mount two (maybe three) Pass PCBs per side.
I figure I'm almost certainly going to build more PASS amps in the future, so why not save on buying another chassis and PSU when these two expensive elements can be shared between two (three?) amps?
I have attached a photo of the chassis minus the front plate, and one of an Aleph J board lying on the heatsink for scale.
If anyone has done this, I would love to see some photos, and hear any comments you might have.
Also, if you were me, what amp would you put in with the Aleph J, and why would you choose that amp?
Has anyone put two different Pass amps into one chassis with one shared PSU?
One channel from each amp would be mounted onto each heat sink, with the PSU switched between each amp so that I can use either amp, one at a time.
I have very large, and very tall heat sinks, on which I can easily mount two (maybe three) Pass PCBs per side.
I figure I'm almost certainly going to build more PASS amps in the future, so why not save on buying another chassis and PSU when these two expensive elements can be shared between two (three?) amps?
I have attached a photo of the chassis minus the front plate, and one of an Aleph J board lying on the heatsink for scale.
If anyone has done this, I would love to see some photos, and hear any comments you might have.
Also, if you were me, what amp would you put in with the Aleph J, and why would you choose that amp?
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here is mine, J2 and M2. previously the psu has it's own box but then reconfigure it into monoblock. instead of using switch eventhough heavyduty, i prefer using Neutrik powercon just like PassLabs amplifier
I'm planning to build another 2 diy chassis for F7 and F2J, i have calculated powercon cable is enough length for another chassis on top of it
I'm planning to build another 2 diy chassis for F7 and F2J, i have calculated powercon cable is enough length for another chassis on top of it
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Ben Mah: Nice! I could add another PSU to my chassis and have each channel of whatever amp I am using amp run as a "sort of" monoblock in one chassis. Duoblock?
gadut: The separate power supply box is a good idea. A single wooden box could be tucked away somewhere or displayed. I like the idea of two PSUs in a separate box, and two (three?) amps mounted into one chassis. Using two chassis with half an amp in each is not an option in my case, as I don't think I will ever come across another pair of heat sinks like the ones in this amp. I feel like the shared chassis shouldn't be an issue, especially if there are separate power supplies for each channel.
@tizman
i just realize that you only have 1 chassis, but it's principle is the same as long as you have space on that chassis. however i follow UMS holes pattern which can't be used for 2 board in 1 heatsink. beside that it will be too crowded if 4 or 6 boards in 1 chassis, can't imagine the cabling if something need to be checked.
so for your purpose of using just 1 chassis, it's better to build separate psu box like i did, extra length on DC cable will act as another R on your CRC or CLC supply. only need to make sure to add capacitor on amplifier chassis as final filter
here is my previous amplifier layout with 1.2m dc cable
i just realize that you only have 1 chassis, but it's principle is the same as long as you have space on that chassis. however i follow UMS holes pattern which can't be used for 2 board in 1 heatsink. beside that it will be too crowded if 4 or 6 boards in 1 chassis, can't imagine the cabling if something need to be checked.
so for your purpose of using just 1 chassis, it's better to build separate psu box like i did, extra length on DC cable will act as another R on your CRC or CLC supply. only need to make sure to add capacitor on amplifier chassis as final filter
here is my previous amplifier layout with 1.2m dc cable
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gadut: I have plenty of room for a capacitor in the amp chassis. Is that a bunch of capacitors in parallel acting as a single larger capacitance in your photo?
black one is 15.000uf and metal can is motor run 60uF which is connected in paralel. considered it as just one C on final supply filter. this is considered as low value on my supply, because main capacitor is 68.000uf
I've built the F4, F5, F6 and Aleph J so far. I have a 4U and a 5U chassis. I thought about putting two boards into the 5U but got lazy and didn't buy the necessary switch. Since I have two chassis going I can A/B two builds at a time and I bought a switch off Aliexpress to make comparing easy Audio Switcher Amplifier Speaker Switch Converter 2 Input 1 Output/ 1 In 2 out 2 Amplifiers|Amplifier| - AliExpress Amazon has something similar. I think out of respect to Nelson Pass there is very little discussion on here about how these different amps sound but I will share a few brief comments about my experiences.
1) F4 requires a preamp with gain. Sonically the F4 is very pure and uncolored. It is transparent and detailed but doesn't add much character of its own. That is good and bad.
2) F5 is a beast. It's sound is big and punchy and it is the least nuanced of the builds. That makes it very appealing but I'm not sure I would like it long term.
3) F6 is incredibly pure tonally with great transparency, nuance, details, clarity etc. etc. as well as strong bass. But in my build the soundstage was very collapsed and 2D. Honestly, that seems at odds with how others have described the F6 so I wonder if something about my wiring or components was off. I loved the sound but I couldn't live with the soundstage.
4) Aleph J is my favorite so far. It has a lot of the punchy dynamics of the F5 but it retains most of the nuance and detail that you get with the F4 or F6. It is very enjoyable to listen to on a wide range of music. It doesn't have that feeling of purity the F6 had or the neutrality of the F4 but for me it just works best.
If I were building two I would choose the F4 and Aleph J. But honestly, I have really enjoyed building and listening to all of them. I am going to try the M2x next.