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Thread: Soundcraftsmen, same as the Hafler?

  1. #16
    Alex Lancaster
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    Terry:

    Looks like pretty soon You´ll be putting Nitrous Oxide and a turbo in them; Anyway put in a higher Amp rating bridge, don´t go too crazy, cause then You´ll be overdriving the transformers; Well You have extras, so You could parallel them, and then change the output section, etc., etc.

  2. #17
    RIP 2011 Zilch's Avatar
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    Inrush current:

    Big bass transients draw lots of current; having larger storage capacity there doesn't give "better bass response," per se, rather, it merely provides more "headroom" for the amp to deal with them. Ultimately, it's the power transformer's ability to replenish the energy in time, and the amplifier's ability to deliver it to the speakers, that determines the performance. You can't make a bigger amp by merely upping the capacitance of the filters. The most you can hope for is that it will be a little ballsier, with less distortion, in the heaviest bass transients.

    As you see, though, there's major $$$ in those capacitors, and it's one area where the designer (or the purchasing agent) may have resisted the temptation to overbuild the product. So, there's little risk in taking advantage of those advances in technology I alluded to above and raise the capacity if you have room to do so. Yuri might have some comments to add here, but he doesn't seem to be reading this thread, alas. I note that he recently mentioned increasing the supply filter capacitance on one of his amps.

    Raising the storage capacity of the power supply filter capacitors will increase the duration of the inrush current through the bridge rectifier at turnon. The magnitude of the current itself is limited by the impedance of the power transformer, and the bridge is rated for overcurrent and duration. Again, it depends upon how much safety margin the designer built into the power supply components used.

    I'd confidently guess that using 12K in lieu of 11K would be no problem, and 15K, a 36% increase, would probably be OK, as well. You've had experience with replacing bridge rectifiers already, if there's a problem. As Alex suggests, if it quits on you, you can move up to a beefier one. Check the rating on the one that's in there. Even the physical look of it can be telling: is it similar to the ones in the Haflers, or an apparent wimpy-weenie alternate?

    Also, do we yet know from the schematic or elsewhere what the actual DC supply voltage is supposed to be on those capacitors or what value capacitance the designer originally specified? Which one you choose will depend upon whether or not you feel you need to move up to a higher rated working voltage. It may be part of the reason the present ones failed. Also, for all we know, some previous owner (or their hotshot tech) may have thought they were "hot rodding" the amp but did not pay attention to the WV spec there....
    Last edited by Zilch; 10-08-2004 at 12:28 PM.

  3. #18
    Senior Member still4given's Avatar
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    Thanks both of you.

    He, he, I guess I am starting to sound like Tim Taylor.

    The only reason I've been thinking about it is that, at least with the Panasonics, the cans that fit physically, are 15000uF and 100 VDC. I still haven't found a supplier for them but Panasonic still makes them so someone must sell them.

    I haven't seen the schematic yet so I'm not sure what it is rated for and the bridge must be built into the PC board because I was looking for it today but couldn't find it. It isn't anything like the Hafler.

    This amp has two PCB's. One that is bolted to the top of the power supply cans and another the lays under the MOSFET's and their heatsinks. They made pretty good use of space.

    Thanks again, Terry

    PS I'll try to take a couple of pictures so this will be easier for you guys.

    Blessings

  4. #19
    RIP 2011 Zilch's Avatar
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    Originally posted by still4given
    I still haven't found a supplier for them but Panasonic still makes them so someone must sell them.
    They're not showing up in their inventory search there. You can try to order them through one of the distributors, but I'd call the rep first. They'll be able to find out if they ever made them (they're an OEM product,) and if so, where some are....

  5. #20
    Senior Member still4given's Avatar
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    Originally posted by Zilch
    They're not showing up in their inventory search there. You can try to order them through one of the distributors, but I'd call the rep first. They'll be able to find out if they ever made them (they're an OEM product,) and if so, where some are....
    That sounds like a great idea. How do I get the phone number of the rep?

    Oh yeah, here's some pics.













    Blessings, Terry

  6. #21
    RIP 2011 Zilch's Avatar
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    To find the rep:

    Originally posted by still4given
    How do I get the phone number of the rep?
    There's a "Sales Reps/Distributors" link in the left column of the Panasonic page.

    Pick United States, then under "OEM Passive and Electomechanical," pick "Capacitors."

    Put CA in there at the bottom and "Submit," and the list comes up.

    Reps are after distributors there....
    Last edited by Zilch; 10-08-2004 at 11:56 PM.

  7. #22
    RIP 2011 Zilch's Avatar
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    A Clue:

    The term "Phase Control Regulation" is a clue as to why the voltage is so high on the caps:

    A predecessor of today's switching regulator power supplies, phase control was used to modulate the AC at the transformer to maintain a constant voltage at the power supply DC output. Since the filter capacitors are not working, it thinks the DC is too low, and turns full on in an attempt to bring it up to the regulation voltage.

    Alternatively, the phase regulation circuitry is itself not working, and that overstressed the capacitors. We'll know more once you get the schematic and the capacitors. You should still be able to follow the transformer output leads to the bridge rectifier if the phase control is being done on the transformer primary.

    The board on top of the capacitors looks to be the power supply phase regulation circuitry. I don't see anything smoked there. I'm surprised there is not some failsafe circuitry in there to shut it down in such a case as this unit is experiencing.

    Don't be pokin' around with it plugged in, needless to say....
    Last edited by Zilch; 10-09-2004 at 12:29 AM.

  8. #23
    Senior Member andresohc's Avatar
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    Interesting site, Hafler "pull outs" with the values you are looking for. Dont know how much better someone elses used caps are but they are cheap enough. No affiliation

    http://www.musicaldesign.com/moving_sale.htm

    jhillig@musicalconcepts.com

  9. #24
    PSS AUDIO
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    I was asked to review this thread and I am honoured of such a request being considered, as a little guru witch is nothing compared being little Buddha!

    From my experience power supply capacitors makes half the sound quality and depending of the schematic of the power amplifier you use the design and use of such or such brands will change and there is no brand leading in this area.

    I used very well known brands and they sounded fine but never as I wished.

    That is why I changed and modified a lot my amplifier schematic to improve the sound quality but never satisfied. And I kept working and working.

    For no reason I changed those so-called excellent power supply capacitors for others I had in stock for months and I was surprised how nice the amplifier sounded.

    I bought several caps from several brands and I finally, after choosing, heard what I was looking for.

    I spent months and years on the power amp while in one-month time I solved what I was looking for by using the right power supply caps.

    Brands and numbers have no meaning in the audio land, I now use Jamicon caps (who heard about them) and I can say that they sound great for me.

    I even changed Nippon Chemicon caps for those Jamicon caps in my Teac CD player (P2/D2) and suddenly it sounded even better!

    Value, ripple current, ESR and other number has NO meaning, listening is the only solution.

    That is why changing an 11000MF cap for a 10000 or 15000MF one is not the matter.

    It will of course work.

    Will it sound good, this is an other story…

  10. #25
    Senior Member still4given's Avatar
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    Re: A Clue:

    Originally posted by Zilch
    The term "Phase Control Regulation" is a clue as to why the voltage is so high on the caps:

    A predecessor of today's switching regulator power supplies, phase control was used to modulate the AC at the transformer to maintain a constant voltage at the power supply DC output. Since the filter capacitors are not working, it thinks the DC is too low, and turns full on in an attempt to bring it up to the regulation voltage.

    Alternatively, the phase regulation circuitry is itself not working, and that overstressed the capacitors. We'll know more once you get the schematic and the capacitors. You should still be able to follow the transformer output leads to the bridge rectifier if the phase control is being done on the transformer primary.

    The board on top of the capacitors looks to be the power supply phase regulation circuitry. I don't see anything smoked there. I'm surprised there is not some failsafe circuitry in there to shut it down in such a case as this unit is experiencing.

    Don't be pokin' around with it plugged in, needless to say....
    Thanks Zilch

    That makes a lot of sense. I am looking forward to receiving the schematic. Hopefully that will shed some light on things before I go spending a lot of money on things I may not need. I know I will need new caps but I would prefer to buy the best values rather than guessing.

    As to the "pull outs" while the price is tempting, I'm a little wary of buying used caps since that is what failed in my Haflers and the amps he pulled them from haven't been manufactured in a long time, meaning those caps are fairly old, at best.


    PSS Audio,

    Thanks for reading this thread and giving you time to help. What you say makes a lot of sense, but I am having a lot of trouble finding a cap with 11000MDF value. I'm very new to this whole thing and so my knowledge of where to source parts is very small. I am very thankful to all those who have taken the time to help me in this endeavor. I will check out the Jamicon caps. Who knows, maybe they carry what I need.

    Thanks again, Terry

  11. #26
    PSS AUDIO
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    Re: Re: A Clue:

    Originally posted by still4given
    ... PSS Audio,... but I am having a lot of trouble finding a cap with 11000MDF value...

    Thanks again, Terry
    In a while I must send an amplifier to Scott. I can add 2 Jamicon 10000MF100V thus he can send them for your personal attention. Those caps are PCB caps; it means that you will have to solder them with wires to the PCB.

    As I had excellent feedback with those power supply capacitors you can even try them with your Haffler amplifier and compare them to the caps you have, I think you will enjoy them!

  12. #27
    Senior Member still4given's Avatar
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    Re: Re: Re: A Clue:

    Originally posted by PSS AUDIO
    In a while I must send an amplifier to Scott. I can add 2 Jamicon 10000MF100V thus he can send them for your personal attention. Those caps are PCB caps; it means that you will have to solder them with wires to the PCB.

    As I had excellent feedback with those power supply capacitors you can even try them with your Haffler amplifier and compare them to the caps you have, I think you will enjoy them!
    AWESOME!

    I am waiting with baited breath!

    Blessings, Terry

  13. #28
    Senior Member still4given's Avatar
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    The new caps came today for my Haflers. They fixed them by the way. Be fore I put the set in the second hafler I tried them in the Soundcraftsmen. WOW! I was pleasantly surprized. This Soundcraftsmen sounds really really good. Put my Haflers to shame IMO. I still need to get some new caps. The ones in the Hafler are too tall.

    I'm going to keep my eyes open for these Soundcraftsmen amps. I see them for pretty good prices on ebay sometimes. I'm a happy camper right now.

    Thanks for all the help.

    Blessings, Terry

  14. #29
    Ski
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    I haven't sent the schematics yet. Do you still need them? I also just snagged a copy of the owner's manual off of ebay. It wasn't very impressive but it's nice to have.

  15. #30
    RIP 2011 Zilch's Avatar
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    Originally posted by still4given
    The new caps came today for my Haflers. They fixed them by the way.
    Of course, I am very pleased they solved the problem(s)!



    It'd be good if you posted here what value capacitors you finally obtained for the Haflers, where you got them, and how much they cost.

    Others with the same or similar problems may stumble on this thread,

    OR be wantin' to send their amps to you for repair!

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