Should I power this thing up?(I HAVE NO VARIAC)

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  • hardwareguy
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    Originally posted by goontron
    The Marantz 2325 is going for $1,175.00, i don't get why. These fuckers are deaf! They can't pick up a 1 watt FM transmitter next to the bloody antenna! Yet a yamaha CR640 has no problem picking it up from across the room! Marantz garbage!
    While I will say prices have gone INSANE with these, the particular unit you have seems to need a tuner alignment very badly. The tuners in these are quite sensitive if they're operating properly.

    I'd also recap that voltage regulator board and adjust its output. The tuner won't work for crap if it's out of whack.

    Leave a comment:


  • TechGeek
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    Volume is dirty and one of the switches is dirty. Going to clean it soon. Right now, the signal strength meter is frozen.

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  • stj
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    does it work? if yes then just change the caps for now.

    later you can check switchs & pots for crackle and any backlights in meters etc.

    Leave a comment:


  • TechGeek
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    hello??????

    Leave a comment:


  • TechGeek
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    hello?

    Leave a comment:


  • TechGeek
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    what to do now? is there anything else that needs replaced?

    Leave a comment:


  • TechGeek
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    power cable: yup.
    fuses: most are soldered in, main fuse holder needs juuuuust a little work.
    update: fixed main fuse holder
    Last edited by TechGeek; 08-04-2016, 08:58 AM. Reason: update

    Leave a comment:


  • stj
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    my experience with old stuff,

    check the power cable - is it still flexible & smooth - not stiff or cracked?
    take all the fuses out (one at a time) - are all the clips still tight and springy?

    Leave a comment:


  • TechGeek
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    Got a list of caps to replace:
    List of caps to replace

    Now, is there anything else to replace? And have I gotten all of the caps to replace? I got the caps from the amp, the prot. board, and the tone board. Thank you.
    Attached Files

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  • kaboom
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    Originally posted by TechGeek
    do what do I do with all the diodes? and thermistors?
    Once again, you don't have thermistors in that power amp!
    Just STV-3s, bias diodes, which will be fine if undisturbed. They're mounted to the heatsink.

    If you're confused as to what they are, look at the schematic. The STV-3s have diode symbols, don't they? If you don't have the sch, I''ve attached it.

    The only thermistors in this unit are the ones on the prot relay PCB, for temperature compensation, so the trip point is (mostly) the same over varying ambient temperatures.
    Attached Files

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  • TechGeek
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    do what do I do with all the diodes? and thermistors?

    Leave a comment:


  • rhomanski
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    Those are thermistors, not varistors.

    Too little sleep. I've always used 1n4148 diodes because a guy in Kansas city tested several kinds and found they have the closest thermal reaction to the original STV-3's and 4's. Some Sansui's use a dual diode that I replace with two 1n4148's solder them together side by side and heat shrink over them. They work just fine that way.

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  • ReeceyBurger123
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    Originally posted by TechGeek
    Couldn't I put some electrical insulation material below the transistor/rectifier to avoid electrical shorts against the heatsink?

    Also, got the screw out.
    Use thermal insulation pads for that size transistor and screws with nylon washers on to help stop it shorting to the heatsink.

    Leave a comment:


  • TechGeek
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    Originally posted by kaboom
    SNIP
    The other ones are STV-3s. Just use 3 1N4004s in series, but be careful mounting them! Shorts to the heatsink are bad. As in "blow the amp up" bad. SNIP
    Couldn't I put some electrical insulation material below the transistor/rectifier to avoid electrical shorts against the heatsink?

    Also, got the screw out.
    Last edited by TechGeek; 08-03-2016, 02:21 PM. Reason: screw removed

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  • stj
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    get an iron with T2 tips.
    blackjack solderwerkz, circuit specialists (CSI), chinese - it's not important as long as it's got T12 tips.

    Leave a comment:


  • diif
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    Originally posted by TechGeek
    conflicting information all over the place... help?
    Help us to help you by providing some detail on the what you're finding conflicting.

    Have you got the stripped screw out yet ?

    Leave a comment:


  • TechGeek
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    conflicting information all over the place... help?

    Leave a comment:


  • momaka
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    Originally posted by kaboom
    AVOID AOYOUE like the plague.
    It's not just AOYUE. Every cheap China-made station has poor built quality. That said, some of them do perform quite well. This is one of them, IMO:
    https://www.circuitspecialists.com/l...l-display.html
    I've had mine (the CSI 2900) for close to 5 years now.
    It's based on the Aoyue 2900 and uses the T12 / T15 style tips that have a heating element inside each tip. Thus, you get excellent thermal response from the tips. Nothing at all like the super-cheap stations that use crappy 900M clone tips that can't even melt leaded solder properly. Heck, even the Weller Magnastat tips don't come close to the performance of the T12 / T15 tips. I have used mine to remove an entire thru-hole VGA connector from a motherboard simply by flooding all of its pins with solder. No wick or desolder pump nonsense for that part. Got the connector out in under 30 seconds. All with lead-free solder too.

    Now, I am not going to claim that this station is built well (it isn't). But it works, it's not a fire hazard as far as I've checked it, and is very well priced for what it does.

    As for the amplifier in this topic...
    I say first learn to solder well. Perhaps on some less important stuff. Maybe even grab a few cheap blank PCBs and try building some easy projects first. Then move to the amp. Also, if you mess up the amp, it's NOT the end of the world. Don't get frustrated and smash it or throw it away. Simply just stash it away and come back to it another time (even if that is a few years from now). I've done that with many projects back in the day, and I am glad I did that.

    Originally posted by kaboom
    TG, do not attempt to use those cheep irons with only a setscrew holding the tip. Those awful 40W things with poor tip thermal coupling. They hit 1000+ degrees, but the tip cools off the moment you try to "solder." Nothing better for ripping off traces...
    Actually, even those are better than the cheap "stations" that use cheap 900M series tips.

    Originally posted by kaboom
    A 25W Weller "Marksman" (the orange ones) from Home Depot is a dream by comparison.
    They also have these two, which are quite respectable IMO:
    http://www.homedepot.com/p/Hakko-40-...-1-P/204215977
    http://www.homedepot.com/p/Weller-40...NKUS/204195330
    Back in high school some many years ago, I think we had an older version of those 40-Watt Weller irons. They worked great.
    Last edited by momaka; 08-02-2016, 10:52 PM.

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  • kaboom
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    Originally posted by dmill89
    If your going to spend $80 on a Weller W60P, you might as well spend the extra $15 for a Hakko FX-888:
    https://www.amazon.com/Hakko-FX888D-...s=hakko+fx-888

    or Pick up a used Hakko 936 on eBay for around $50-$75.
    Also good.


    TG, do not attempt to use those cheep irons with only a setscrew holding the tip. Those awful 40W things with poor tip thermal coupling. They hit 1000+ degrees, but the tip cools off the moment you try to "solder." Nothing better for ripping off traces...

    A 25W Weller "Marksman" (the orange ones) from Home Depot is a dream by comparison.

    Leave a comment:


  • dmill89
    replied
    Re: Should I power this thing up?(I HAVE NO VARIAC)

    Originally posted by kaboom
    That right there is ~$80 to budget, for a W60P. You'll also need a bigger tip than what comes with it. Something like a 700 degree, 3/32 "screwdriver" tip. Or closer to ~$180-200 for a "station."
    If your going to spend $80 on a Weller W60P, you might as well spend the extra $15 for a Hakko FX-888:
    https://www.amazon.com/Hakko-FX888D-...s=hakko+fx-888

    or Pick up a used Hakko 936 on eBay for around $50-$75.

    Leave a comment:

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