baeijsman, what is the part number of the Nichicon 15k caps you used? The EPCOS are out of stock everywhere in the US and I need to get something. Can anyone recommend anything? Are these CD SLPX153M025A9P3 from Cornell-Dublier as good as the EPCOS? Thanks!
There's nothing special about the caps. 25V rating and same pin spacing are the key items - I just used what I had boxes of from old inventory. Digikey and Mouser are usually where I shop for caps...
Many thanks for that! I have some Cornel-Dubliers I used on the original build and just ordered some Nichicons for new builds.
Here is my ACA Mini temporarily running with the stock heat sinks. Plan is to put them on small cabinet with 2 side sinks to properly manage the heat as I am running them with 0.350V VO per Papa article 🙂
Right now its making beautiful music on my test Wharfdale D310 monitors via Macbook.
Thank you.
Right now its making beautiful music on my test Wharfdale D310 monitors via Macbook.
Thank you.
Hi Sorry to trouble you, I live in the UK and I am retired after working as an Electrician in the aircraft industry. I have over the years built a few loudspeaker my last being the Alerons from Jon ver Halen in the USA who kindly sent me the plans for a small fee that was 12years ago I have been back in contact with jon fairly recently regarding the amp camp mini which I would like to build which he rates highly but my Alerons have Lowther full range DX55 drivers and require the voice coil to be warmed up on little gain so I require a volume control or a pre amp, I have reached out to you after seeing the fantastic build guides. I have the skills to assemble the kit but my knowledge of Electronics is fairly limited, I do have a good multimeter. I believe I can put a pot in the circuit or buy a pre amp or make the amp camp pre amp ?? any advise would be of great help.
Kind Regards.
ALAN D UK
Hi Alan
A transfomer volume control like the Silk TVC could help as a simple
passive preamp. It has + 6dB gain and it works fine for my setup ‚ACA with Triaxiom 212c‘. I think, it will work with the ACA mini in the same way as with the ACA, without exhausting the amp.
Eric
A few pages ago I mentioned I was interested in having my own layout ..... laid out. And so I employed the services of @prasi at Analog Design and I hope we came up with a nice design. The royal 'we' there, I can't take much credit.
So with thanks to Nelson Pass for the schematic, Mark Johnson for always inspiring us and to Prasi, I took delivery of some of 'my' boards.
They measure 133x127 and I had them made in black.
Note I have yet to test but assuming all is well then I can offer some spare boards. I had 15 made and one will be winging it's way to a kindly gentleman in The States. I can safely offer 10 but maybe a couple more.
Not in this to make money so just recouping some cost and so to that end I shall ask if £7 per board is acceptable. Plus postage at cost. Won't be much.
Thanks again to all
So with thanks to Nelson Pass for the schematic, Mark Johnson for always inspiring us and to Prasi, I took delivery of some of 'my' boards.
They measure 133x127 and I had them made in black.
Note I have yet to test but assuming all is well then I can offer some spare boards. I had 15 made and one will be winging it's way to a kindly gentleman in The States. I can safely offer 10 but maybe a couple more.
Not in this to make money so just recouping some cost and so to that end I shall ask if £7 per board is acceptable. Plus postage at cost. Won't be much.
Thanks again to all
Adding a simple volume control in front of the amp is straightforward.
A typical value would be 10k or 20k (22k) dual gang pot with a log taper. Any solid state source component will have no issue driving those.
A linear taper with the addition of a single resistor from wiper to ground which 'fakes' a log law can be a better option with regard to channel matching.
Packing up the Essentials kits today, and tomorrow they go off to the store.
@nicoch58 , Assuming you have the NOS Harris IRF520 & IRF9520, these parts have metal backs. They need isolation. My very brief investigation suggests all manufacturers are using TO-220AB packaging, and this appears to include an active back.
My "Almost Clone ..." boards do not have any active connection for the heatsink mounting holes, but I will still use an isolator pad + grease. As clumsy as I am, I don't want potentially active heat sinks that could be accidentally shorted.
Kind regards,
Drew
My "Almost Clone ..." boards do not have any active connection for the heatsink mounting holes, but I will still use an isolator pad + grease. As clumsy as I am, I don't want potentially active heat sinks that could be accidentally shorted.
Kind regards,
Drew
In this post Pass indicates isolation for the MOSFETs isn't required. But if having 12V on the heatsinks will be an issue for your intended use, you can add isolating pads. Others have.
I used Dow 340 compound and no pads in my build, and did not experience any issues.
If you want to isolate the sinks from the Drains of the transistors, you will also want to cut the top
and bottom traces from the Drain to the mounting holes of the sinks, as they are tied together there.
If you do that I suggest connecting them to ground.
and bottom traces from the Drain to the mounting holes of the sinks, as they are tied together there.
If you do that I suggest connecting them to ground.
As I am going to mount the transistors on proper sized heat sinks of the cabinet using thermal pads as well as TO-220 plastic bushes, I presume I am good with the isolation and not required to cut any traces of sink pads to the mosfet drain pin?
thanks
thanks Nelson no problem for volts on heatsink , just asking to avoid bada
boom 🙂and to be sure that diystore put all in kit that just arrived ,my first look