I'm increasingly interested in putting the toroid(s) and caps in a separate enclosure and only having the Amp PCBs in a heat-sinked enclosure - making three boxes for an amp, two PS and one output.
It strikes me that one can gain a lot of advantage with this configuration in terms of electrical noise, cost of the heat-sinked enclosure (it can be a smaller box with the same sinks). One can go true mono for the PS and marry the amp in the sinked enclosure.
The questions:
What are common pitfalls of such a setup?
What wire and connectors have folks found useful for the PS to sinked box connections?
Do you lose the benefit of a mono set up if you have both output channels in the same box?
It strikes me that one can gain a lot of advantage with this configuration in terms of electrical noise, cost of the heat-sinked enclosure (it can be a smaller box with the same sinks). One can go true mono for the PS and marry the amp in the sinked enclosure.
The questions:
What are common pitfalls of such a setup?
What wire and connectors have folks found useful for the PS to sinked box connections?
Do you lose the benefit of a mono set up if you have both output channels in the same box?
haha again man, what is it with us having the same ideas. i was just thinking about this yesterday when pondering transformers, as i'm biamping with digi xo and it would seem to make sense to me to locate both tx and probably half the supply caps with the other half of the filtering in the amp cases.
comes from my background in headphone amps and such i guess and seems appropriate here. except i'm looking at one large ps enclosure with 2 x 500va and 1 x 800va plus bridges, softstart and crc, then crc in each separate amp case. even considering having one channel from each amp (aleph jx and semisouth circ for now till f5x is ready) in each case and that way locating each near the speaker with the separate 'balanced' output tweeter and midbass channels feeding left and right respectively, with a central psu case and heavy duty umbilicals
comes from my background in headphone amps and such i guess and seems appropriate here. except i'm looking at one large ps enclosure with 2 x 500va and 1 x 800va plus bridges, softstart and crc, then crc in each separate amp case. even considering having one channel from each amp (aleph jx and semisouth circ for now till f5x is ready) in each case and that way locating each near the speaker with the separate 'balanced' output tweeter and midbass channels feeding left and right respectively, with a central psu case and heavy duty umbilicals
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yeah speakons, or i actually prefer the amphenol 5W5 or 8W8 hybrid dsub with 5 or 8 pins respectively. i've used them for fast charging lifepo4 batteries at much higher currents than they'll see here
6awg copper pins
will possibly end up using one of the mixed high current and 2amp pin versions with a number of pins for auxiliary powered stuff like leds and momentary switches etc. can even get them with shielded coax pins for those
6awg copper pins
will possibly end up using one of the mixed high current and 2amp pin versions with a number of pins for auxiliary powered stuff like leds and momentary switches etc. can even get them with shielded coax pins for those
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The issue for me is all the great, large caps I have. I have 68,000uF 70V that are 6" high, and I'm getting 120,000uF 40V that are 9" high. I need a way to use these without redoing my cases from scratch.
An external CRC seems like the way to go. Pipe the DC into the PCB and heatsink box and you havde huge, clean, shielded power with a small(ish) output box.
An external CRC seems like the way to go. Pipe the DC into the PCB and heatsink box and you havde huge, clean, shielded power with a small(ish) output box.
yes, but probably you will still want some sort of local smoothing/reservoir, or those big caps and their low esr will be for nought
You could have the transformer, bridge, and first part of CRC in one PS box, and then some more C plus amp in another main box. Didn't NP suggest this (to keep the transformer separate) many years ago in an article?
One consideration is choosing and laying out the heat sinks for best cooling and also considering placing it higher up (off the floor) in the 'rack' where cooling is better naturally. But big class A amps mean big heat sinks, which constrains the styling a lot....
I don't even want to open the can of worms debate on stereo v monoblocs, but I prefer fewer boxes....
One consideration is choosing and laying out the heat sinks for best cooling and also considering placing it higher up (off the floor) in the 'rack' where cooling is better naturally. But big class A amps mean big heat sinks, which constrains the styling a lot....
I don't even want to open the can of worms debate on stereo v monoblocs, but I prefer fewer boxes....
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Not sure what you mean here. I was thinking CRC. Are you talking about something else?
Maybe the "R" could be part of the cable and the other C in the box as suggested above?
I have thought of this arrangement as well. I would like the power supply located near an outlet and the circuits near the speakers. One concern I have is grounding. In this configuration, would there be more of a problem with ground loops, not having everything in one grounded chassis?
slug
slug
I have thought of this arrangement as well. I would like the power supply located near an outlet and the circuits near the speakers. One concern I have is grounding. In this configuration, would there be more of a problem with ground loops, not having everything in one grounded chassis?
slug
slug
I will go the same way (no way that she let me keep the Mule as is)
Speakons or Amphenol or Lemo main thing is the carry DC so needs to be really sturdy
And loads off current and do not disconnect when powered up and not woth skimping
I will go for 20A contact rating as a minimum.
Just watch out that same require special crimping tools that work just for that type of crimps so not worth it
For just a few solder on may take a bit of time but IMO beter for DIY even beter would be no connectors at all
Hi Fi 2000 stile case for trafos soft start and CLCR same sinks there for rectifier bridges
2 300X 160 x 500 W D H separate enclosures for Amplifier speaker protection and last bit of C about 50 mU in my case.
The bit (5 meters in my case) cable just ad same more resistanceto the total CRCRC and help whit reducing riple
Earth connection is the same for bus of stars so to keep potential at same level for same part of circuit.
As simple as possible is best and you only need one Earth the one connected to the mains plug that is there for safety
At the moment I am running 5 meters of screened cable the screen is connected only on the pre amp side.
I had a bit of HUM when I ploughed the F5 to a different nearer wall socket but it disappeared when Pre and Amp where connected to the same extension lead.
Noise of the F5 is really low with the needle lifted of the record I get about 3 to 4 mV
And pre is nothing special at the momement
http://www.diyaudio.com/forums/swap-meet/182480-holco-mfr-15ppm-2w-sale.html
Speakons or Amphenol or Lemo main thing is the carry DC so needs to be really sturdy
And loads off current and do not disconnect when powered up and not woth skimping
I will go for 20A contact rating as a minimum.
Just watch out that same require special crimping tools that work just for that type of crimps so not worth it
For just a few solder on may take a bit of time but IMO beter for DIY even beter would be no connectors at all
Hi Fi 2000 stile case for trafos soft start and CLCR same sinks there for rectifier bridges
2 300X 160 x 500 W D H separate enclosures for Amplifier speaker protection and last bit of C about 50 mU in my case.
The bit (5 meters in my case) cable just ad same more resistanceto the total CRCRC and help whit reducing riple
Earth connection is the same for bus of stars so to keep potential at same level for same part of circuit.
As simple as possible is best and you only need one Earth the one connected to the mains plug that is there for safety
At the moment I am running 5 meters of screened cable the screen is connected only on the pre amp side.
I had a bit of HUM when I ploughed the F5 to a different nearer wall socket but it disappeared when Pre and Amp where connected to the same extension lead.
Noise of the F5 is really low with the needle lifted of the record I get about 3 to 4 mV
And pre is nothing special at the momement
http://www.diyaudio.com/forums/swap-meet/182480-holco-mfr-15ppm-2w-sale.html
Posting at the same time as Papa
so missed out on asking one wery important question
😀What noise?😀
so missed out on asking one wery important question
😀What noise?😀
I like the idea, any experience with noise comparisons between:
- Dual external PS to a single box with the outputs (Two toroids to one pair heatsinks in a single box)
- True dual mono (two separate PS to two separate outputs with separate heatsinks in separate boxes)
i mean what i said in my first post, also repeated above ie. crc with the central box with transformers softstart. bridges, half of the power supply and then either another crc, or just c in the respective amp cases. there really is very little point using lowz high performance caps and then throwing it all away by having the last thing before the load be a cable, 2 connectors, another cable, another 2 connectors
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Hi Zen I am just trying to be sarcastic.
(Skill that I still to have to master but then I am competing with the best on the planet)
Hi still with 5 meters of screened cable and warming up it gets beter in 1/2 hour
The case is pretty open and measurement fluctuate a bit maybe I could put the meter in survey mode and post a graph
7.14 mV DC it get down to about 2 when warm and it stays there this does not make any noise just shift the woofers a bit forward
2.21 mV AC this is noise but does not make really any noise the other amp I have brought from the shop is much worst.
And is still connected to the preamp that I still have at the moment (hint)
So really what noise?
Papa design don't make any
And I am pulling 3.5 A rail at 26 V on each channel.
All I can hear is the traffo buzzing away but is in hand and eventually it will go in it's own box till I turn the tap on a bit
http://www.diyaudio.com/forums/swap-meet/182480-holco-mfr-15ppm-2w-sale.html
(Skill that I still to have to master but then I am competing with the best on the planet)
Hi still with 5 meters of screened cable and warming up it gets beter in 1/2 hour
The case is pretty open and measurement fluctuate a bit maybe I could put the meter in survey mode and post a graph
7.14 mV DC it get down to about 2 when warm and it stays there this does not make any noise just shift the woofers a bit forward
2.21 mV AC this is noise but does not make really any noise the other amp I have brought from the shop is much worst.
And is still connected to the preamp that I still have at the moment (hint)
So really what noise?
Papa design don't make any
And I am pulling 3.5 A rail at 26 V on each channel.
All I can hear is the traffo buzzing away but is in hand and eventually it will go in it's own box till I turn the tap on a bit
http://www.diyaudio.com/forums/swap-meet/182480-holco-mfr-15ppm-2w-sale.html
Attachments
lemo high current umbilical connectors...... hey hey mr deep pockets!! superb and the perfect connector for the job, but wow, these things put some audiophile connector manufacturers to shame, although these are highly engineered thats for sure. the amphenols i'm using arent cheap either when you take the 6awg machined pins into account but a lemo male/female pair at this size will be close to 200 dollars
Oh Yes only the best for Papa amp
Thing is that running the cables troug the case directley to the PCB is even beter
after all you not on the road and once the thing is working it will stay there for a while
at least till the next project is ready.
Thing is that running the cables troug the case directley to the PCB is even beter
after all you not on the road and once the thing is working it will stay there for a while
at least till the next project is ready.
I don't think it matters that much if the circuit grounds are isolated from
each other through resistance and/or diodes.
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