| cowanrg |
ok, finally, the cases are almost complete... the faceplates should be complete today or tomorrow. im just waiting for the call from the powdercoater. (they are being coated in clear matte powder). here are some pics.
the details are (each chassis):
2x UCD400AD's
modified onboard caps, upgraded to panasonics
modified output cap
shared power supply (forgot cap size)
dual bridge rectifiers
shared single 1.7KVA transformer
the case gets pretty warm when listening at full volume. just kidding. its always ice cold. |
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| cowanrg |
another:
(they are 8" tall, 17" wide, and around 16" deep. each chassis weighs in at 65 pounds) |
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| KeithC |
| Impressive heatsinks - they'll take some dusting though. |
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| cowanrg |
well, yeah, they will get dusty. it wasnt my prime concern when i built them though...
i was more concerned with the "mine is bigger than yours" phenomenon. |
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| v-bro |
whoa!!:bigeyes: :bigeyes:
Yours is bigger than mine!
Could be because I concentrate more on building it smaller... |
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| Tekko |
| Unnecessarily big heatsinks, a shame to waste them for a class d. |
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| KeithC |
Good for defacing Readers Digests though.
And they ain't likely to get knicked. |
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| v-bro |
| At least you get the 'Aleph" look...:D |
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| cowanrg |
| quote: | Originally posted by Tekko
Unnecessarily big heatsinks, a shame to waste them for a class d. |
thanks for the support :D
they aren't wasted. some of us just get to do what we want and dont care what other people think. |
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| cowanrg |
| i just got the unnecessarily large faceplates back from the powder-coated and put one of them on. the meters still need to go in though. |
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| cowanrg |
| they are a bit darker in real life, the flash just makes them look very light. |
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| KeithC |
| quote: | Originally posted by Tekko
Unnecessarily big heatsinks, a shame to waste them for a class d. |
Why waste? No more than any other casing - me, the closest I've come to encasing a class D is a Tea Tray.
Besides which, they probably make good aerials for tx'ing any rfi. |
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| -_nando-_ |
| This heatsink is a waste. |
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| Daveis |
cowanrg, where are you getting your metalwork done? where'd you get those monster cases?
I'd be inclined to put a multichannel mini-aleph into those myself. |
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| ssmith |
| quote: | Originally posted by -_nando-_
This heatsink is a waste. |
Does form have to follow function? :whazzat:
I think they are very decorative -- powder coat finish is nice too.
Is that a Peranders DC filter and softstart? And any chance of sharing the PSU schematic??? |
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| cowanrg |
| quote: | Originally posted by -_nando-_
This heatsink is a waste. |
haha, thanks for the constructive criticism. lets see something you've built so we can talk bad about it... |
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| cowanrg |
| quote: | Originally posted by ssmith
Does form have to follow function? :whazzat:
I think they are very decorative -- powder coat finish is nice too.
Is that a Peranders DC filter and softstart? And any chance of sharing the PSU schematic??? |
thanks!
i didnt build these to impress anyone or to make anyone else happy. i built them because i wanted to, and when i go into my listening room and look at them, it makes me happy. i have some fine looking cases. i could have just done a stamped steel case with a plain faceplate, but i didnt.
yes, thats perander's dc filter and soft-start. the PSU schematic is simple enough, nothing fancy, just some caps, bridge rectifiers, and thats about it. |
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| -_nando-_ |
| quote: | Originally posted by cowanrg
haha, thanks for the constructive criticism. lets see something you've built so we can talk bad about it... |
;)
You can talk bad about anything that I build, since is your true opinion and is based in something solid.
Example, why a class A heatsink on a class D amp?
I'm not fighting against you, relax man... :cool: |
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| novec |
| quote: | Originally posted by -_nando-_
Example, why a class A heatsink on a class D amp?
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Because it looks cool, and nothing else ;) |
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| maxlorenz |
| quote: | | Because it looks cool, and nothing else |
Yeah!...very well done cowanrg :)
Appart the MACHO look, the thieves will think twice before pulling it up :D |
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| novec |
| quote: | Originally posted by maxlorenz
Yeah!...very well done cowanrg :)
Appart the MACHO look, the thieves will think twice before pulling it up :D |
... and with 65 pounds a piece; once more when they try! |
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| AR2 |
Great work Cowanrg,
Good looking case is always a great asset. You could easily switch from Class D to Class A at your will. Honestly how much work is to build a great looking case? A lot, so than if you decide to change what is inside doesn't necceserly mean that you have to change the case. With that toroid size, and big caps housed any other amp will do.
For people that are not in the know, as far as I remember these heatsinks and face plates were part of Cowanrg's mega Aleph project. It is great that you have been able to reuse faceplate and heatsinks. That much great work that you have put in and exceptional results would be really bad not to put in use.
Any reason that you chose powercoating instead of anodizing?
Stay well
AR2 |
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| Daveis |
| quote: | Originally posted by AR2
Great work Cowanrg,
For people that are not in the know, as far as I remember these heatsinks and face plates were part of Cowanrg's mega Aleph project.
AR2 |
I'm always interested in which amp designs people have chosen as their reference. I just sold my Aleph30 to make way for more UCD. I'm afraid that none of the low power Aleph's have the bass control that the UCD gives me. In the end I decided that the UCD's were better amps than the Aleph series. (Haven't listened to the AlephJ or F3 which might be better). |
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| AR2 |
| I never had opportunity to hear UCD amp, but I am trilled with my Aleph30 for the top end where I am using it in my 3 way active set up with Aurus Cantum ribbons. For the mids I have Cary Audio vacuum tube 2A3 amps with PHL mids. Bottom is driven by various AB amps. I did a lots of changes and come to conclusion that is hard to ask one amp to do everything. Also there is a taste issue, so certain caracteristics of an amp could be deciding factor. There is nothing like tube fot the mid range, and not even Aleph could compite with that, altough it comes close. I see many people are building UCD amps - it must be good. |
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| harryeng |
| quote: | Originally posted by maxlorenz
Yeah!...very well done cowanrg :)
Appart the MACHO look, the thieves will think twice before pulling it up :D |
You sure about Mauricio? They will think they are lifting an XA-100 from Pass-Labs! :D
Greetings, Harry
P.S., I even have heatsinks on my power center. But that is just so it stays put when I plug power connectors. |
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| maxlorenz |
Hi Harry :)
How do you do?
| quote: | | You sure about Mauricio? They will think they are lifting an XA-100 from Pass-Labs! |
Well, if they recognise it, they deserve it! :clown:
Cheers,
M
PS: superDAC still on the "electronic ICU". Too much projects, so little time...:( |
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| cowanrg |
well, im working on finishing up the meters right now. they are nothing special, just a dc meter that measures voltage at the outputs (has a small rectifier on it for ac/dc), nothing special and can be switched in and out of circuit).
but the cases are actually kinda interesting (i think so). the case is more of a chassis in that it can accommodate anything. there is only one (1) hole in the entire case that isnt for actually holding the case together. that one hole is for the transformer. everything else is mounted on the rails that attach to the heatsink screws. so, if i want to swap out the guts, the case wouldnt have any extra holes or anything. it has dual 12v triggers on the back (one in and one out) which also accommodate mini toggle switches. there is already one mini toggle switch on there already. so, the case could have a 12v trigger plus, 2 mini toggles, 3 mini toggles, etc. and the guts can be changed just by sliding out the rails and putting new ones in.
it took me awhile to plan out, because i didnt want to drill a ton of holes all over the case to mount stuff. i know how DIY is, i might want a new amp as soon as im finished with this one, and i didnt want to have a case that looked like swiss cheese. |
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| JoshK |
I think you did a damn good job....to heck with the naysayers. :D
You were wise to plan for the future and you can do what you want with the case. I wish I had such mechanical aptitude. |
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| cowanrg |
| quote: | Originally posted by JoshK
I think you did a damn good job....to heck with the naysayers. :D
You were wise to plan for the future and you can do what you want with the case. I wish I had such mechanical aptitude. |
thanks!
i was sort of suprised to see so many negative comments. i knew it would happen when i switched to class D. however, most people havent even heard class D stuff to form an accurate opinion. but thats how it goes.
i would get emails all the time from people asking about the progress on the amps. when i finally post them here, it took almost a day to get a comment. strange. people really are THAT opposed to class D. |
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| Daveis |
Cowanrq,
Shared single 1.7KVA transformer? You dont mention a softstart circuit. Are you using one? |
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| cowanrg |
yes, a single 1.7kva per chassis, so its shared for two amps. but there are two individual supplies (dual rectifiers, two sets of caps, etc).
the soft-start is from peranders. the top "layer" has a soft-start and dc hum blocker thing from peranders. |
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| cowanrg |
| im actually looking into making a simpler soft-start circuit (not necessarily for these amps, but just in general). people keep asking for them and always have problems finding a good one. there are some out there, but ~$40-$50 is too much in my opinion for such a simple circuit. im working with a friend of mine to make a really simple one that can be made cheap and be flexible. |
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| maxlorenz |
| quote: | | im actually looking into making a simpler soft-start circuit |
Mine costs US$3 but is ugly and non-elegant from an intelectual point of view. Doesn't matter, I keep the PS "ON" all the time. ;)
Two power rails in parallel, each one with its own interruptor. One has a resistor and the other has not ;)
I do the smart counting... :D |
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| cowanrg |
| quote: | Originally posted by maxlorenz
Mine costs US$3 but is ugly and non-elegant from an intelectual point of view. Doesn't matter, I keep the PS "ON" all the time. ;)
Two power rails in parallel, each one with its own interruptor. One has a resistor and the other has not ;)
I do the smart counting... :D |
i actually keep my amp on all the time too. the modules themselves have a 12v trigger signal from the processor to turn them on and off, but the power supply always remains on. however, i like to have it just because its a better design.
so, you have two sets of rails, one with a resistor (for "soft-start" and one without? do you use a DPDT switch or something to switch between them or something? |
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| maxlorenz |
| quote: | | so, you have two sets of rails, one with a resistor (for "soft-start" and one without? do you use a DPDT switch or something to switch between them or something? |
He, he...I'm too primitive for that :D just my finger to do the switch (you know, like airplanes check out).
When I was considering some electronic switch i realized that it had to be capable of high current...instead of searching I opted for sturdy conventional switch.
Lazyness always win :xeye: |
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| novec |
| Wouldn't it be possible to use a 220V (or 110V if you're on the other side of the pond) relay for that switching, and just connect the relay coil to the transformer primaries? That way, the power resistor would let the primary voltage rise slowly, and as it comes to ~200V, the relay kicks in and switches to "direct drive". A little resistor on the relay coil might be necessary for tuning the kick-in voltage, though. |
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| lucpes |
| quote: | Originally posted by maxlorenz
Mine costs US$3 but is ugly and non-elegant from an intelectual point of view. Doesn't matter, I keep the PS "ON" all the time. ;)
Two power rails in parallel, each one with its own interruptor. One has a resistor and the other has not ;)
I do the smart counting... :D |
I assume you mean two mains input :) a power rail would imply DC :) |
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| maxlorenz |
Hi Lucpes,
Yes, you're right. My mistake. |
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| maxlorenz |
Hi Novec,| quote: | | Wouldn't it be possible to use a 220V (or 110V if you're on the other side of the pond) relay for that switching, and just connect the relay coil to the transformer primaries? That way, the power resistor would let the primary voltage rise slowly, and as it comes to ~200V, the relay kicks in and switches to "direct drive". |
A guess, as I know nothing about electric stuff, is that power R limits max current but I believe V will rise fast anyway, tiggering the relay.
(I'll measure it)
Any comments welcome.
Some mechanical or electronic counter could trigger the switch to select direct mains path instead of
R-path.
M |
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| novec |
| I'm no expert when it comes to caps and transformers either, but limiting current generally means you're cutting voltage too, because V=RxI. What I do know is that the voltage across a capacitor increases slowly when it's charged through a limiting resistor, but I don't know about transformers. |
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| cowanrg |
| yeah, but after it turns on, you take the resistor out of the circuit... |
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| novec |
That's the whole point of the relay :) It switches between charging through the softstart resistor and going straight to AC, like in any other softstart circuit. The only difference is that this relay has a 220V AC coil connected directly after the resistor, so it'll switch over as soon as the amp gets close to working voltage.
I haven't checked if this actually works, I just think it should ;) |
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| cowanrg |
| thats what im thinking. a relay that switches from a resistor in line with the mains, to nothing in line with the mains, after a delay. i dont yet know the best way to delay the turnon of the relays though. |
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| novec |
| The "best" way would probably be using some timer electronics and/or a current sensor, but that's just so much work... I already have an LC Audio softstart, but I think it might be too wimpy for 2x 1300 VA and 180000 uF. Any comments on that? If it is too small, I'll try my direct relay. |
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| v-bro |
Add an extra supply, and place a heavy duty relais switched by the softstart....
I'm afraid the 8A relais will fry quickly if you don't.... |
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| novec |
| Yup, I think I'll end up putting the LC soft start on my sub and go for a 30A relay and a couple of 100W resistors I have for the main amp. |
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| sx881663 |
You guys are on the right track with a resistor in the line bypassed with a good relay. The first thing to do is to find one of the power supply inrush limiters that is suitable to substitute for a fixed value resistor. They should be available from any of the larger suppliers.
To trip the relay just use the rail voltage dropped with a suitable resistor. Putting an electrolytic across the relay coil allows adjustment of the delay to what ever you think is best.
Great looking amps! I do appreciate how much work all the metal cutting took.
Roger |
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| cowanrg |
| quote: | Originally posted by sx881663
You guys are on the right track with a resistor in the line bypassed with a good relay. The first thing to do is to find one of the power supply inrush limiters that is suitable to substitute for a fixed value resistor. They should be available from any of the larger suppliers.
To trip the relay just use the rail voltage dropped with a suitable resistor. Putting an electrolytic across the relay coil allows adjustment of the delay to what ever you think is best.
Great looking amps! I do appreciate how much work all the metal cutting took.
Roger |
yep, thats what im kinda thinking. i want to keep it as simple as possible. i would love to offer a group buy for it that wouldnt cost a lot. it just sucks that you can buy a hypex module for about twice what a softstart costs. it doesnt make a whole lot of sense.
ill be starting a thread some day for a cheap softstart. maybe we can develop something flexible and cheap. something that could even be hand-wired on a PCB board too.
thanks for the compliments on the amp. they are breaking in now and are sounding SO much better. im very impressed. |
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| Baldin |
cowanrg
Just wanted to say that I think your build quality is super cool :cool:
Don't care whether you need the heat sinks or not ... it's cool.
I once did a big amp case with a black granite face plate ..... not necessary .... but quite cool ;) |
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