4real said:Sound all like a good idea
I still would like to know about the advantages of those correction networks though...
I'll also check out the large UcD thread to check for power supply preferences. I head good thinks about the slitfoils, but I'm a bit sceptical looking at the poor ERS ratings. Well, a lot to reed I guess
You could take on HG supply for three UcD180 for every channel...
Jan-Peter
4real said:Sound all like a good idea
I still would like to know about the advantages of those correction networks though...
I'll also check out the large UcD thread to check for power supply preferences. I head good thinks about the slitfoils, but I'm a bit sceptical looking at the poor ERS ratings. Well, a lot to reed I guess
If you can swing it I can't recommend T-networks highly enough, at least, if you like an amp that's ultra revealing, it's easily far too revealing, and doesn't even need further snubbing to get that kind of action out of it.
The advantages of the zobels are to linearize the response of the speaker. The UCD amp is highly load independant, so you might say it's not as important as it would be with other types of amps, it will drive them with an iron grip.
The price tag of that thing (HG supply) is a bit to high I guess, so I'll make my own supply. Capacitance seems a bit low for tree amps. For the same money I van get eight 22.000uF slitfoil caps, or even ten super low ESR 33.000uF caps! Sure it has DC detection, but I can also fix that.
I could also get a few T-networks, but those things are very expensive. And I'm not sure that two of them per three amps will keep up with four 33.000uF caps or a bunch of slitfoils.
You can always buy the best of the best of course, but I'm more interested in value for money
I could also get a few T-networks, but those things are very expensive. And I'm not sure that two of them per three amps will keep up with four 33.000uF caps or a bunch of slitfoils.
You can always buy the best of the best of course, but I'm more interested in value for money
Well I go against the grain and still say break up the PSU Hi-Mid-Lo, not left right. There is more difference between frequency bands than there is between left-right.
Have you guys ever run an active system and looked at what the amps are doing? It might surprise you.
I do agree on the use of all the same modules. If the bass if 94dB/W that's pretty good. The mid might not be any better. So equal power all around! Sure makes the voltage choice easier.
Have you guys ever run an active system and looked at what the amps are doing? It might surprise you.
I do agree on the use of all the same modules. If the bass if 94dB/W that's pretty good. The mid might not be any better. So equal power all around! Sure makes the voltage choice easier.
panomaniac said:
Yes, but summed, they will put equal strain on the PSU as if just one amp would be used for the whole speaker. And will they even interfere that much since they all have different frequency domains?
Bass is actually two 94 dB/W woofers, but I'll easyly loose 10 dB in a dipole setup of course. The mid is nowhere that efficient, about 89 dB/W, but in a closed box.
classd4sure said:I say 8 power supplies, C or R cores and all, 8 UCD700 modules, run the subs bridged, T-networks all the way, but what the heck, won't cost me a dime
Then you're lucky I guess. Well, I'm not, so I'll have to look at my wallet and see what's best for the budget that is in there
4real said:Then you're lucky I guess. Well, I'm not, so I'll have to look at my wallet and see what's best for the budget that is in there
No I'm not at all! I just meant that since I'm not building it....
That's a great first step though! Don't forget to account for that extra 150~200% just to be on the safe side.
Okay. I skimmed the UcD threads for more info about PSU's.
Found that indeed the slitfoils should be very good, but I could find any confirmation form various sources. I also saw some good things about the caps I mentioned, the BC 154 series. But apparantly those are not made anymore, yet they are still sold here and there for a nice price. The new series, with yet lower ESR are much more expensive though. the price difference between BC154 and slitfoil is 3 euro's for the 10.000uF and about 5 euro's for the 22.000uF's versions.
Can anybody tell me about the life of the slitfoils? the 154 have 12K hours at 85C.
Found that indeed the slitfoils should be very good, but I could find any confirmation form various sources. I also saw some good things about the caps I mentioned, the BC 154 series. But apparantly those are not made anymore, yet they are still sold here and there for a nice price. The new series, with yet lower ESR are much more expensive though. the price difference between BC154 and slitfoil is 3 euro's for the 10.000uF and about 5 euro's for the 22.000uF's versions.
Can anybody tell me about the life of the slitfoils? the 154 have 12K hours at 85C.
Hi, actually I am think about the accuracy of LTSpice simulation result.
The second is the high side driver, I am worry that the driver can survive at the voltage level.
For comparator, I think it will survive. I saw lots of Class AB, with that arrangement at that voltage level. Is class AB input stage work harder than class D?
For Sovadk, the charging time start stop at -rail+12V I think no worry about diode stress. Our concern is to charge the cap fastly. Not like your totem-pole BJT, this driver need more power to charge and hold the gate driver. That is the reason that we need big cap and fast charger.
For zener at gate mosfet, yes, is used for protection, work as standby, do nothing.
The non inverting input, originally this amp is balanced input. I will keep that.
OK, R19 C14 C15 is used for passive current limiter. Safety reason too. I will consider later.
So, I am worry two thing: 1) LTSpice accuracy, 2) High side driver reliability
Thanks for all suggestions,
Regards,
Kartino
The second is the high side driver, I am worry that the driver can survive at the voltage level.
For comparator, I think it will survive. I saw lots of Class AB, with that arrangement at that voltage level. Is class AB input stage work harder than class D?
For Sovadk, the charging time start stop at -rail+12V I think no worry about diode stress. Our concern is to charge the cap fastly. Not like your totem-pole BJT, this driver need more power to charge and hold the gate driver. That is the reason that we need big cap and fast charger.
For zener at gate mosfet, yes, is used for protection, work as standby, do nothing.
The non inverting input, originally this amp is balanced input. I will keep that.
OK, R19 C14 C15 is used for passive current limiter. Safety reason too. I will consider later.
So, I am worry two thing: 1) LTSpice accuracy, 2) High side driver reliability
Thanks for all suggestions,
Regards,
Kartino
Classd4sure - well mostly it will boost sales to promise very high output - doing the opposite and lower output to half is no good marketing strategie - and I think they are well aware of that - actually they seem honest and write output in 8 ohm load - so I think there will be other reasons
tinitus said:
Hi.
I disagree.
In audio it seems rather common for products that want to be considered as "quality" to under-rate the power capability... I'm sure you won't have to search very hard to find a reviewer who's highly impressed by just such a thing, and I dont' even read reviews, unless they're for some reason the source of some discussion, but I"ve seen that time and again.
However I'm fairly confident that's not the case here. I may be mistaken but I vaguely recall the builder of that amp explaining the reason behind the low power output before as being ... it's cheaper. Lower voltage parts are much cheaper, and so he could ... very losely quoted from memory "better afford to make it higher quality". Lower voltage parts cost much less, so he was saying he could then afford to get better quality parts..also there's more of a selection to pick from at lower voltage.
You can see an internal pic of it on their website, look at the power supply caps, not very big now are they? I'm pretty sure it wouldn't be under-rated. I don't know sort of parts he's actually using though... quality wise, anyone's guess.
Over-rating on the other hand is a BS tactic by people who only have junk to sell... PMPO and all that jazz.
How many times have you seen a "1200W" amp sticker on the box and when you look more closely you see it's 20W RMS X6.
I don't think any serious amp builder wants to be associated with that sort of gimmick so commonly used for commercial crap.
Regards,
Chris
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