Hi Gary,
If I decide to keep this amp in this case I will tidy up the wires. This is a development and testing chassis so no point in making wires neat. It’s all about convenience and speed of build.
Hi Meanie,
Yes, the snubber boards make mounting the MOSFETs a snap. They can go anywhere and the little board acts as both a washer tonspread the clamp force and a mini heatsink on the top side.
Hi Poseidonvoice,
There are snubbers and gate stoppers built right on the little board next to the pins - it doesn’t get much better for the location to stop oscillation. The resistors are MELF carbon - great for absorbing energy.
I am running 6in leads. The quickfit jacks work really well. Pulling an amp takes literally 2 minutes. Replacing the amp is just as fast.
If I decide to keep this amp in this case I will tidy up the wires. This is a development and testing chassis so no point in making wires neat. It’s all about convenience and speed of build.
Hi Meanie,
Yes, the snubber boards make mounting the MOSFETs a snap. They can go anywhere and the little board acts as both a washer tonspread the clamp force and a mini heatsink on the top side.
Hi Poseidonvoice,
There are snubbers and gate stoppers built right on the little board next to the pins - it doesn’t get much better for the location to stop oscillation. The resistors are MELF carbon - great for absorbing energy.
I am running 6in leads. The quickfit jacks work really well. Pulling an amp takes literally 2 minutes. Replacing the amp is just as fast.
Excellent news and great work getting the AN proto build fired up X! The Alpha amp series has been very easy to work with and looks like the Nirvana will continue the trend. I have a good feeling you’ll solve the slight hum by running the speaker returns to the SLB. The single 600va trafo is a beast powering both boards with only about a 5v drop total.
Another nice development is the use of a conventional aluminum finned chassis will work fine for this project. Your timing is perfect because Modushop is running a Black Friday sale. Use code “blackfday” at checkout for 20% off orders!
A big Thanks to You, Hugh and JP for sharing another fine project with us 😀
Cheers,
Vunce
Another nice development is the use of a conventional aluminum finned chassis will work fine for this project. Your timing is perfect because Modushop is running a Black Friday sale. Use code “blackfday” at checkout for 20% off orders!
A big Thanks to You, Hugh and JP for sharing another fine project with us 😀
Cheers,
Vunce
Hi JP,
Just want to tell you this layout is perfect!
The little snubber boards are awesome. I can se how this could be used on any project needing easy separation of amp PCB and outputs.
Thanks so much!
X
Just want to tell you this layout is perfect!
The little snubber boards are awesome. I can se how this could be used on any project needing easy separation of amp PCB and outputs.
Thanks so much!
X
X,
Impressive work as usual, you made it happen in quick time... kudos on getting first sound!
Hope you manage to quality shut-eye before work. Look forward to you listening impressions afterwards.
Impressive work as usual, you made it happen in quick time... kudos on getting first sound!
Hope you manage to quality shut-eye before work. Look forward to you listening impressions afterwards.
Yes, will do some more listening with my main speakers this week to really give a good review. Also, some measurements too later. I really like the whole concept of externally mounted MOSFETs with snubber boards and flying leads. The ease of chassis installation on this build vs one with MOSFETs mounted rigidly to the PCB cannot be overstated - it will change the way you think about amp building-chassis integration (always the least favorite/most tedious aspect).
Just want to note that I am using ceramic (alumina) thermal insulator pads with paste heatsink compound (for CPU's) for the best thermal contact. 47w passing through a TO-247 pad is a lot of heat flux. It seems to work because my max temps on the MOSFET snubber board (full of copper vias) was only 72C.
Here is view to the right channel:
Closeup before connecting MOSFETs:
I will also build a v2 SLB with all the ground pins on one large STAR hub. Right now I have GND going from SLB to a screw terminal block - not the same asa true star. Vunce tells me that doing this with one trafo will make amp dead quiet as he is doing this with Alpha 20's.
Just want to note that I am using ceramic (alumina) thermal insulator pads with paste heatsink compound (for CPU's) for the best thermal contact. 47w passing through a TO-247 pad is a lot of heat flux. It seems to work because my max temps on the MOSFET snubber board (full of copper vias) was only 72C.
Here is view to the right channel:
Closeup before connecting MOSFETs:
I will also build a v2 SLB with all the ground pins on one large STAR hub. Right now I have GND going from SLB to a screw terminal block - not the same asa true star. Vunce tells me that doing this with one trafo will make amp dead quiet as he is doing this with Alpha 20's.
Attachments
Last edited:
Nice work guys... I love the idea of more options to mount. I can't wait to see what the forum does with the increased flexibility.
Well done!
JT
Well done!
JT
The other thing that these snubber boards do is that they make the whole MOSFET package very durable- You don't worry about how fragile the legs are and whether or not they will be stressed and break off. The whole assembly is very solid and the wires are connected to the snubber board, not the legs so the stress and mechanical strain is completely removed. of course, bonus is that snubber (220pF NP0 and 47R carbon film res) and gate stopper (100R carbon film) are right next to legs.
How will the forum take this new flexibility in MOSFET mounting? I hope people try it out and use it. Sure is easier. But I can already tell you that for some who don't even like to use spade connectors for the power supply connection and speaker connections, because "all connectors are evil" - nothing will change.
How will the forum take this new flexibility in MOSFET mounting? I hope people try it out and use it. Sure is easier. But I can already tell you that for some who don't even like to use spade connectors for the power supply connection and speaker connections, because "all connectors are evil" - nothing will change.
GREAT idea, better than UMS heatsinks ...we can swap the amp (input+ driver) in 5min 😉
PS or more power stage in the same heatsink....
will work better for dual mono chassis ,one mosfet for heatsink!!
Ps2
that from one that solder all ,"all connectors are evil"😀
Last edited:
I managed to get rid of the ground loop/hum issue by connecting the RCA ground to the amp input ground (as intended). Also running speaker return straight to the SLB star GND. Absolutely quiet now - no hum/hiss at all. Very good result for using only a single 600VA trafo.
I have connected the amp to my main speakers (10F/RS225 FAST) and listening to tracks now. Very good so far. Great power - sounds like a 45w+ Class A amp.
Tracks so far:
Dave Brubeck "Take Five"
Metallica "Enter Sandman"
The Who "See Me Feel Me"
Norah Jones "Burn"
Ahmad Jamal "Ahmad's Blues"
Hans Zimmer "The Might of Rome" Gladiator Soundtrack
Buddy Guy "Five Long Years"
Suzanne Vega "Headshots"
The Doors "Spanish Caravan"
Anne Bisson "September in Montreal"
Harry Connic Jr "The Last Payday"
AC/DC "Back in Black"
Pink Floyd "Great Gig In the Sky"
Tipper "Viscous"
I have connected the amp to my main speakers (10F/RS225 FAST) and listening to tracks now. Very good so far. Great power - sounds like a 45w+ Class A amp.
Tracks so far:
Dave Brubeck "Take Five"
Metallica "Enter Sandman"
The Who "See Me Feel Me"
Norah Jones "Burn"
Ahmad Jamal "Ahmad's Blues"
Hans Zimmer "The Might of Rome" Gladiator Soundtrack
Buddy Guy "Five Long Years"
Suzanne Vega "Headshots"
The Doors "Spanish Caravan"
Anne Bisson "September in Montreal"
Harry Connic Jr "The Last Payday"
AC/DC "Back in Black"
Pink Floyd "Great Gig In the Sky"
Tipper "Viscous"
Attachments
Last edited:
This is even better than I'd expected.........
Congratulations, X, this is seminal work. To have >40% efficiency from Class A, utter silence at no signal, outstanding resolution with no intermodulation, good sound stage and musical engagement - these are the essential requirements for a brilliant amp for any audiophile.
I'm very pleased with the 10R float on the signal to power ground works so well.
Hugh
Congratulations, X, this is seminal work. To have >40% efficiency from Class A, utter silence at no signal, outstanding resolution with no intermodulation, good sound stage and musical engagement - these are the essential requirements for a brilliant amp for any audiophile.
I'm very pleased with the 10R float on the signal to power ground works so well.
Hugh
Last edited:
Well done ironing out the details X, now you can continue to burning in the AN listening to more tracks, hum free 🙂
Ps: Did you give the volume knob a twist when playing Enter Sandman 😀
Ps: Did you give the volume knob a twist when playing Enter Sandman 😀
Yes volume at 90% for Metallica. And it did not sound congested or strained. Very nice amp.
Funny thing is today the heatsink external temp is 55C max. This is with the lid on - why that helps - perhaps there is enhanced internal chimney flow through the top and bottom vents. So the Dissipante 4Ux300mm can take 94w per channel?!
Funny thing is today the heatsink external temp is 55C max. This is with the lid on - why that helps - perhaps there is enhanced internal chimney flow through the top and bottom vents. So the Dissipante 4Ux300mm can take 94w per channel?!
You are amazing X, I like the speaker stands - and then they can turn into bar stools for the celebration drinks.
Where to now Hugh?
Just to confirm X, was this built as the full blown original design or Hugh's latest cut down, higher efficiency less power version?
Perhaps a chassis wiring diagram as you built it with no hum, will also help for members intending to tackle this beast. When you get time that is.
Where to now Hugh?
Just to confirm X, was this built as the full blown original design or Hugh's latest cut down, higher efficiency less power version?
Perhaps a chassis wiring diagram as you built it with no hum, will also help for members intending to tackle this beast. When you get time that is.
Gary,
I have to get cracking and move to production of this amp for commercial sale.
I suspect China may not enjoy plain sailing forever...... we might even have to manufacture some of our own products locally eventually.
Hugh
I have to get cracking and move to production of this amp for commercial sale.
I suspect China may not enjoy plain sailing forever...... we might even have to manufacture some of our own products locally eventually.
Hugh
That will be interesting Hugh, I assume you will make some tweaks and changes along the way for a commercial offering - biggest hurdle will probably be the chassis with adequate heat sinking.
Cheers,
Gary..
Cheers,
Gary..
Gary,
It will not be this circuit; it's open source, administrated by X at the forum, and it stays for the DIYers.
The case and cooling is resolved; I will be using slow speed cooling with 2xMF18 Conrad heatsinks. The case is quite straightforward, but the front panel is always difficult.
Hugh
It will not be this circuit; it's open source, administrated by X at the forum, and it stays for the DIYers.
The case and cooling is resolved; I will be using slow speed cooling with 2xMF18 Conrad heatsinks. The case is quite straightforward, but the front panel is always difficult.
Hugh