The "HiFi" binding posts tend to have a larger hole through them which allows them to clamp larger wires. The Hirschmann posts you show are standard test equipment posts. They have a 2 mm hole through them (as you can see in the dimensional drawings) so they'll only clamp a relatively thin wire. That's the only drawback that I can tell.
The HiFi binding posts are mostly about the Bling Factor. You can't sell a $50k amp with a pair of Hirschmann on the back. You need the $200 Cardas connectors for that. Never mind that they conduct electricity equally well.
Farnell used to have a set of inexpensive binding posts for HiFi use. They were maybe $5, gold plated, took 4 mm banana plugs, and could clamp a 5 mm wire (I think). I picked up four sets back in the late 1990ies and now regret not having picked up more of them. Oh, well.
Tom
The HiFi binding posts are mostly about the Bling Factor. You can't sell a $50k amp with a pair of Hirschmann on the back. You need the $200 Cardas connectors for that. Never mind that they conduct electricity equally well.
Farnell used to have a set of inexpensive binding posts for HiFi use. They were maybe $5, gold plated, took 4 mm banana plugs, and could clamp a 5 mm wire (I think). I picked up four sets back in the late 1990ies and now regret not having picked up more of them. Oh, well.
Tom
Solder the wire to a solder lug and drape the lug over the threads of the terminals. Check the dimensions, but something like the Keystone 7311 might work (Mouser: 534-7311).
Tom
The BOM and design documentation is made available to paying customers. You should be able to get it from the person who sold you the boards. Alternatively toss me an email with a picture of the front and back of the boards you have and I'll get you hooked up with the correct documentation. My email address is my username here followed by @neurochome.com
Tom
i just found these .... they are rather inexpensive and have a scrub screw so i don't have to solder to a lug (which i'm not good at anyway)
Dynavox Terminal
.... and i have a strange feeling these fancy ones are exactly the same .... Furutech
Dynavox Terminal
.... and i have a strange feeling these fancy ones are exactly the same .... Furutech
figured it would be fine to test it without the molex plug in place and it works just fine. measures 24,45 on one power out and 24,35 on the other. i have no idea why they measure differently but i guess it's within the tolerance.
the build was really easy and straightforward ... thanks to a great manual!
the build was really easy and straightforward ... thanks to a great manual!
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Thanks. Glad it came together easily for you.
The output voltage spec is 24 V ±2.5 %, so both your power bricks are within spec.
Tom
So this picture shows my current progress. As you may be ables to spot only a few parts are missing - I'll add those later today.
The blue line and the edge of the table kind of mark the outline of the size of case i'm intending to use. So all of the components have to fit in this area.
Now I'm thinking of how to route the cables and how to place the two LM3886DR on the heat sink.
- LM3886DR on heat sink. Any suggestions for placing them? I would think it makes sense to place them rather low (vertically) to allow the heat to rise (does that make sense?) and kind of evenly distribute them horizontally so they get equal amounts of "room to breathe". Any comments on that?
- Cables: Any special things I have to keep in mind? Should the signal cables for both channels be of equal length? Should there be some distance between signal and power cables? Any other things I should keep in mind?
The blue line and the edge of the table kind of mark the outline of the size of case i'm intending to use. So all of the components have to fit in this area.
Now I'm thinking of how to route the cables and how to place the two LM3886DR on the heat sink.
- LM3886DR on heat sink. Any suggestions for placing them? I would think it makes sense to place them rather low (vertically) to allow the heat to rise (does that make sense?) and kind of evenly distribute them horizontally so they get equal amounts of "room to breathe". Any comments on that?
- Cables: Any special things I have to keep in mind? Should the signal cables for both channels be of equal length? Should there be some distance between signal and power cables? Any other things I should keep in mind?
Placing the heating zone approximately 25% up from the bottom gets near the best out of the heatsink.
For a pair of devices placed horizontally, the gap between them should be double the gap to the edge, i.e. each device is located centrally in the half sink dedicated to that device.
Placing the heatsink outside the box gets better cooling performance.
Every cable Flow and Return PAIR must be kept as a close coupled pair. No exceptions.
Coax and twisted both meet that requirement, but it must be over the whole route that the connection is made. No splitting of the pair to take one wire/trace off to some remote terminal.
The power supply is slightly different but still follows that close couple pair rule.
The +ve power lead and the Zero Volts return lead are a pair.
The -ve power lead and the Zero Volts return lead are a pair.
The zero volts return lead is common to both so you end up with a twisted triplet (do not plait the three power wires - twist them).
Length matching does not matter.
LOOP AREA does matter. Minimise it inside EVERY cable pair.
For a pair of devices placed horizontally, the gap between them should be double the gap to the edge, i.e. each device is located centrally in the half sink dedicated to that device.
Placing the heatsink outside the box gets better cooling performance.
Every cable Flow and Return PAIR must be kept as a close coupled pair. No exceptions.
Coax and twisted both meet that requirement, but it must be over the whole route that the connection is made. No splitting of the pair to take one wire/trace off to some remote terminal.
The power supply is slightly different but still follows that close couple pair rule.
The +ve power lead and the Zero Volts return lead are a pair.
The -ve power lead and the Zero Volts return lead are a pair.
The zero volts return lead is common to both so you end up with a twisted triplet (do not plait the three power wires - twist them).
Length matching does not matter.
LOOP AREA does matter. Minimise it inside EVERY cable pair.
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Length does matter some as it adds impedance on the supply.
How you obtain a low loop area doesn't matter. A twisted pair or twisted triplet is not always realistic. You can obtain similar or better results in a tight bundle.
I wouldn't be overly concerned about the speaker wiring as it's a low impedance node that's pretty hard to move. Regular zip cord will work just fine, both inside and outside the chassis.
The reason the supply harness needs to be tightly coupled is that a Class AB output stage draws current in pulses. On the positive signal swing, current is drawn on V+. On the negative swing, V- provides the current. These current pulses can couple into sensitive nodes of the amp and cause rail-induced distortion.
Tom
I recommend adding the LM3886es after you've attached the boards to the heat sink. You'll get the best thermal coupling that way as everything will line up better.
I'd divided the heat sink into thirds. Place one LM3886 1/3 down the length of the heat sink. The other 2/3 down the length. Assuming that'll work with the board width and such.
Doesn't matter.
I'd try not to run the supply harness and the input signal parallel for too long. If you can't avoid a parallel run, keep them separated.
Tom
heatsink: thanks for your input - i guess that's pretty much straightforward.
i was planing on adding the LM3886s as soon as the board are screwed to the sink .... that's the reason i haven't added them to the pcb yet. thanks for confirming my idea
by supply harness you mean the cables handling the supply power, right? i'm just double checking. english isn't my first language after all.
what exactly is a loop area?
i was planing on adding the LM3886s as soon as the board are screwed to the sink .... that's the reason i haven't added them to the pcb yet. thanks for confirming my idea
by supply harness you mean the cables handling the supply power, right? i'm just double checking. english isn't my first language after all.
what exactly is a loop area?
bom
I am sure that the seller would send u all the info but you never sent any email to the seller after you received the boards and all the other parts .....