leo
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Post by leo on Mar 28, 2008 13:43:22 GMT
Hi Leo Thanks so much. Are the caps that come stock with the amp in this spot of poor enough quality to justify upgrading? If so, which brand and value should I swap in? Also, did you put 10,000uF Dubilier's in at the recommended spot, or did you use something different? From your picture, it's clear you put in something bigger than the stock caps, but I can't tell what. Thanks for all your help. Chris Hi Chris, That wasn't one of my pics, just one I found in the thread, it was just to give you an idea where the FB caps are. All the standard supplied caps are cheap, most are Jamicon . When I was playing with one of these amps I built a regulated PSU to help improve PSRR, the layout in the Canamp isn't too great because of the long track and inadequate decoupling for the op-amp. Most capacitors classed as audiograde tend to be physically larger than the standard ones in the same value. For the feedback any low 10uf (could try higher) leakage types should be ok, where are you buying the 10,000uf ones for the PSU? reason I ask is because they should also have other suitable types for the fb so you can buy from the same place
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Post by aang on Mar 29, 2008 0:21:41 GMT
Hi Leo Thanks again! I was thinking of Allied Electronics if I buy the Dubilier's, but several people seem to have used Panasonic TS-HA instead, which I would buy through Newark. Which of these two caps do you think would be better for the large smoothing caps? Based on that, then I guess I can see what that particular supplier sells as far as the smaller values. I had though to use either Nichocon golds or Rubycon, since these are both supposed to be pretty good and are not especially expensive, but neither Newark nor Allied sells either of these brands, so I'd have to pay separate shipping to use them... One other question; to upgrade the diodes, can I use the custom ones made by Mike at Rock Grotto for the X-CANS? They appear to be the same, but with some kind of cap bypass to make them better. Thanks so much for all your help Chris
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leo
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Post by leo on Mar 29, 2008 0:47:47 GMT
Hi Chris, TBH any of those caps you mention should be fine and better than the Jamicons. Thing to remember is measure up first to make sure they physically fit. If you PM Mike and ask him nicely he may be able to sell you the caps and diodes too Snubber caps across some types of diodes can help filtering
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Post by aang on May 19, 2008 16:22:55 GMT
Hi Does anyone out there have a schematic for the CanAmp that they would be willing to share? Thanks Chris
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leo
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Post by leo on May 19, 2008 19:46:24 GMT
If you have the Canamp its dead simple to work out the circuit, one of the easiest I've seen ;D
I know the circuit but I'm afraid I won't draw it out and post it on a public forum without Heeds permission as its not really fair
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Post by aang on May 19, 2008 23:38:22 GMT
Hi Leo That's certainly reasonable; I hadn't even thought about that Sorry. I just wanted to show a friend who has some experience with electronics to see what he thought would provide the most bang for the buck as far as mods go. Since he's overseas, I can't show him my amp in person. Chris
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leo
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Post by leo on May 20, 2008 0:38:13 GMT
I only said I wouldn't post it on a public forum A quick browse found this, click on the pdf at the bottom of the first post, its about correct www.htg2.net/index.php?topic=20103.msg217216The PSU is just raw DC non regulated with a few filter caps
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Post by aang on May 20, 2008 1:07:38 GMT
Wow; thanks Leo! Chris
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Post by dc on Jun 5, 2008 0:42:46 GMT
just got an email from the dude i sold my canamp to
apparently the funky angle mounted trannie CRACKED!
this is the 30VA one mike sent me =\
any ideas what could have caused it?
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Post by dc on Jun 8, 2008 3:14:28 GMT
Check out the goo oozing out from that crack in the tranny! I'm sure that that can't be healthy: Could it be replaced with a toroidal transformer as long as the specs were the same? Could the heat have been the cause for this "melt down?" Canamp in Class-A did run hot...
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Post by Deleted on Jun 8, 2008 3:22:28 GMT
dc It's hard to tell with a photo, but is there enough room in there for a suitable toroidal ? What were the ratings of the OEM transformer ? Alex
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Post by dc on Jun 8, 2008 3:32:56 GMT
stock is 230v primaries, 2 x 9v secondaries @ 6VA each
the one i fitted is same but 30VA total, so 15VA each
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Post by Deleted on Jun 8, 2008 3:52:11 GMT
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Post by dc on Jun 8, 2008 4:17:39 GMT
thanks alex.
i've long since sold the canamp, but the buyer has contacted me just recently with this problem
i figure since i modded the living crap out of it, the right think to do would be to help him fix it
however, i've never seen a leaking transformer... i mean that just looks nasty!
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leo
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Post by leo on Jun 8, 2008 9:54:24 GMT
Nasty! transformers don't usually do that so I'd say theres a problem.
There may have been an overloading for that little transformer, could be some instability causing it to ring and overheat, one of the bridge rectifier diodes might have blown. Also the value of those capacitors is huge for such a small transformer
If your going to fit a new transformer I'd first try fitting resistors on the secondary and check to see if its being overloaded
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leo
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Post by leo on Jun 8, 2008 10:29:33 GMT
That brown goo looks like melted enamel off the copper windings, it must have got bloody VERY hot to do that
Of course it may have just been something as simple as an internal short in the transformer, notice how it leaked out from just one of the winding sides? the other looks to be ok
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Post by dc on Jun 8, 2008 12:33:39 GMT
Thanks Leo
I wouldn't suspect the transformer to have become too hot in normal operation. What kind of heat can a transformer take? Would the ambient temperatures inside the amp from other components been enough to cook it?
If so that would be a flaw with the design as my amp actually ran a little cooler than stock and the canamp has barely any ventilation. Somehow I think other canamp owners would have similar issues if this were the case.
After modding the thing I left it running for days on end and what got hot were the big power resistors and the transistors toward the front of the amp.
The transformer as I recall, was always cool to touch.
At this point it seems that the transformer would definitely need replacing. How do you tell if a diode is dead? They're cheap as so I guess that's an inexpensive component to replace any way.
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leo
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Post by leo on Jun 8, 2008 14:00:27 GMT
I doubt very much heat from other components would have caused that tbh, transformers can get over warm to the touch but its going to take something like huge overload to cause it to melt like that.
If you imagine the inside of a traffo, basically long lengths of enamel copper wire wrapped around a core, for the secondarys you get different thickness etc depending on the transformers load current capability , with something like 6 or 12vA its going to be fairly thin, if theres a short or too heavy load on its output it goes like a heating element getting hotter and hotter, this is normally why they have internal thermal fuses in case theres a problem, I'm surprised it didn't trip before getting to this state tbh.
Also that little transformer has a huge amount of inrush current from cold, I still feel the pair of 10,000uf caps is overkill for it, its also possible the charge may have taken out the rectifier diodes if they are only low current types. You can try measuring across them for short circuits but some types of diodes can give some meters strange readings, maybe best just to replace them anyway
Other things to check, make sure no wiring or connections have shorted out to either the metal tray, together or any grounds.
It could be an easy repair (hopefully) but please be warned it could prove to be a headache
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Post by miki on May 20, 2009 20:57:02 GMT
Hello everyone! I'm just abut to build a CanAmp for a k701. During the parts collecting phase, I've encountered some problems: ---(1)--- Film Capacitors: basically the problem is, that I don't know their specifications. I 've found that almost everyone uses different types from all 470nF 250V RIFA to carefully selected but irrelevant sized ones. original - all polyethylene 3x 1uf 63V or 0.001 uF 63V? Arcotronics R82 series (package code is 1J63 sometimes 1K63 at random) 2x 10nF 100V or 100nF 100V? Arcotronics R82 series (package code is 10nJ100) 2x 470nf 63V Arcotronics R82 series (package code is 47k63) planning to buy - paper dielectric 3x 1uF Vishay Rodersein 63V bypassed with 1nF WIMA paper (just to be sure, they are enough) 2x 470nF EVOX RIFA paper high voltage 2x 100nF WIMA paper high voltage ---(2)--- ELCO: the question would be here, that if my smaller capacitors are lower in voltage as the original ones than can it cause a design flow? Or those Jamicons are only higher in voltage to compensate their weaker quality for no extra cost? original 2X 4700uF Jamicon 16V 2x 100uf Jamicon 35V 2x 10uf Jamicon 50V planning to buy 2x 6800uF Panasonic 25V audio grade 2x 100uF SANYO 20V audio grade, low ESR 2x 10uF SANYO 25V audio grade, low ESR ---(3)--- Transformer: The higher VA transformer overloads the other components, or only the voltage rating matters, and an extra power does nothig bad (even running cooler). original Avisor 230V >>> 2X9V 2x6VA power (12VA) planning to buy Multicomp 230V >>> 2x9V 2x7.5VApower (15VA) toroidal, or Multicomp 2x9V 2x15VApower (30VA) toroidal if higher VA is better ---(4)--- Resistors: I really have no idea, what values they have, what type they are... original there are 10 of them blue, and one brown planning to buy ... ---(5)--- Schematics: It's schematics are practiculary unaccessible. If any of you has a high-res picture of the PCB's back side I would be really glad to have it! Any help will be much appreciated! Thx, -Miki-
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Post by PinkFloyd on May 20, 2009 21:19:40 GMT
Hello everyone! I'm just abut to build a CanAmp for a k701. During the parts collecting phase, I've encountered some problems: ---(1)--- Film Capacitors: basically the problem is, that I don't know their specifications. I 've found that almost everyone uses different types from all 470nF 250V RIFA to carefully selected but irrelevant sized ones. original - all polyethylene 3x 1uf 63V or 0.001 uF 63V? Arcotronics R82 series (package code is 1J63 sometimes 1K63 at random) 2x 10nF 100V or 100nF 100V? Arcotronics R82 series (package code is 10nJ100) 2x 470nf 63V Arcotronics R82 series (package code is 47k63) planning to buy - paper dielectric 3x 1uF Vishay Rodersein 63V bypassed with 1nF WIMA paper (just to be sure, they are enough) 2x 470nF EVOX RIFA paper high voltage 2x 100nF WIMA paper high voltage ---(2)--- ELCO: the question would be here, that if my smaller capacitors are lower in voltage as the original ones than can it cause a design flow? Or those Jamicons are only higher in voltage to compensate their weaker quality for no extra cost? original 2X 4700uF Jamicon 16V 2x 100uf Jamicon 35V 2x 10uf Jamicon 50V planning to buy 2x 6800uF Panasonic 25V audio grade 2x 100uF SANYO 20V audio grade, low ESR 2x 10uF SANYO 25V audio grade, low ESR ---(3)--- Transformer: The higher VA transformer overloads the other components, or only the voltage rating matters, and an extra power does nothig bad (even running cooler). original Avisor 230V >>> 2X9V 2x6VA power (12VA) planning to buy Multicomp 230V >>> 2x9V 2x7.5VApower (15VA) toroidal, or Multicomp 2x9V 2x15VApower (30VA) toroidal if higher VA is better ---(4)--- Resistors: I really have no idea, what values they have, what type they are... original there are 10 of them blue, and one brown planning to buy ... ---(5)--- Schematics: It's schematics are practiculary unaccessible. If any of you has a high-res picture of the PCB's back side I would be really glad to have it! Any help will be much appreciated! Thx, -Miki- What do you mean you are just about to "build" a HEED Canamp? I think you meant to say "I am just about to BUY a HEED Canamp"...... If you were about to "build" one you would be working for HEED and wouldn't be asking stupid questions so, go and sober up and tomorrow resume your position as chief builder for HEED It'll all make sense when the alcohol gets out of your system
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Post by miki on May 20, 2009 22:36:27 GMT
First of all, thanks for your quick reply! Well, yes... BUYING was the original plan. I have even found an used one for about 200$, but due to mixed reasons (most of them quite sad) seems like I have to decrease the budget to about 100$. Since Canamps don't die, I could't find any used one in that price range. Yesterday I tried to contact Alpár or Zsolt from HeeD via e-mail. The best sollution would be if I could buy the PCB from them. (I live in Hungary) And because I'm not a potential customer of a whole Canamp (450$ in my country is EXTREMLY much, more than a half salary - what I won't get in my next 4 years) it might be even possible that they sell the PCB to me. I understand however if you say that no money-no Canamp. You are right, because there are plenty of free shematics around the web (starving student projects are my favourite). Still, I decided to try to bring this whole thing together. Planning is almost as much fun as doing it. Well, I could explain my strange sentences with my foreign language, but the fact is that it will really require some time 'till the alcohol leaves my system. ;D -Miki-
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Post by Deleted on May 21, 2009 21:56:49 GMT
Is anyone who owns a Heed, or has a schematic, able to assist Miki with the resistor values, and their location? SandyK
N.B.
I am NOT endorsing cloning of a manufacturer's product, as the schematic may be Copyrighted,and the design is the designer's intellectual property. Cloning of a product denies the original designer a fair reward for his time and effort. There are numerous free designs posted in various forums that would perform equally well. SandyK
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Post by miki on May 22, 2009 8:37:08 GMT
Hmm... It' good to see that this forum lives! to: SandyKI'm working hard to make this thing more or less legal. Canamp itself is not patented, but the basic inellectual-product rights prohibit it's copying like you said. I really hope they will write me back from HeeD about the PCB. Otherwise, I will probably wait untill I can get a used one cheap. I still have a k-271 to bargain from the better times! to: mrarroyoThank you! Those pictures would help me a lot, even if I have a PCB I won't be able to assemble it without the right resistor values. Anyway, thank you for your time. -miki-
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robertkd
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Post by robertkd on May 22, 2009 10:28:14 GMT
Hmm... It' good to see that this forum lives! to: SandyKI'm working hard to make this thing more or less legal. Canamp itself is not patented, but the basic inellectual-product rights prohibit it's copying like you said. I really hope they will write me back from HeeD about the PCB. Otherwise, I will probably wait untill I can get a used one cheap. I still have a k-271 to bargain from the better times! to: mrarroyoThank you! Those pictures would help me a lot, even if I have a PCB I won't be able to assemble it without the right resistor values. Anyway, thank you for your time. -miki- and there are alternatives which may even offer way better preformance rockgrotto.proboards.com/index.cgi?board=chitchat&action=display&thread=3622&page=7#48215Seriously if heed cared to frk the resistor off and put a constant current circuit in place of it, I would almost look at them no I wouldn't it over priced for what it is, mind you they speak the speak don't they Robert
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Post by miki on May 22, 2009 12:00:03 GMT
Thanks Robert! To be honest, I'm not soure if I could handle this circuit and SMD soldering... I think I have to remain under 50 parts! Another interesting Canamp mod found on the internet. ( forum.lowyat.net/topic/343375/+1040 ) He has attacked the poor Avisor transformator quite properly. And look at the audiophile condensators glued on the heat sinks... They ARE big. Something happened to the diodes too. -miki-
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