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  1. Isn't there something you could have the...

    Isn't there something you could have the customers sign when they drop off the amp? Before learning amp repair I used to take my amps to a field service repair shop. You would sign for an estimated...
  2. Thread: Tube tester

    by DrGonz78
    Replies
    13
    Views
    258

    Looking at the new picture that wire looks like...

    Looking at the new picture that wire looks like much thinner gauge wire than it did in the original picture. Weird. Is it stranded wire and lots of strands broken off? Yup light bulb 💡 limiter is a...
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    4
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    163

    Is the 5 volts negative or positive voltage? Do...

    Is the 5 volts negative or positive voltage? Do you have a diode setting on your multimeter? Have you checked the part with a meter? Keep the speaker disconnected for now since DC voltage can damage...
  4. Thread: Tube tester

    by DrGonz78
    Replies
    13
    Views
    258

    That white wire appears to be thin but appears to...

    That white wire appears to be thin but appears to be solid core wire. It's not like a tiny strand of wire and is probably pretty strong in actuality. Looks like it is supposed to be soldered into the...
  5. I would measure for AC ripple at C18 and C21 just...

    I would measure for AC ripple at C18 and C21 just to be sure. The preamp section has another 100uf filtering stage on the power supply. If your meter has trouble measuring AC ripple effectively you...
  6. What type of voltmeter are using? Since you know...

    What type of voltmeter are using? Since you know already to check the current (voltage) across those resistors it tells me you have probably checked this before on other amps. So I assume it's...
  7. The output section on this amp looks like a quasi...

    The output section on this amp looks like a quasi complementary type which has two npn transistors instead of a pnp/npn pair. As I recall the DC offset with a quasi complementary output can measure...
  8. Be careful making sure the Gibson night light is...

    Be careful making sure the Gibson night light is authentic or they might come after you!!
  9. Saw this the other day. "Uses real amp...

    Saw this the other day. "Uses real amp materials". I think I like the tube night light better. ...
  10. Replies
    15
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    4,422

    If the manufacturer doesn't supply a board layout...

    If the manufacturer doesn't supply a board layout then I don't think you will find it.
    https://supportloudtech.netx.net/file/asset/1375/original/attachment
  11. Thread: Crate TD-70

    by DrGonz78
    Replies
    18
    Views
    5,669

    The server had a crash a few years back and some...

    The server had a crash a few years back and some files were corrupted, this is one of them. Here is a reupload... Also I wouldn't recommend leaving your email in public forum as you might attract...
  12. Replies
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    224

    Possible that the wire running from the emitter...

    Possible that the wire running from the emitter to the pcb was a fix due to a cracked transistor leg.
  13. Replies
    4
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    163

    The amp schematic shows that the headphones jack...

    The amp schematic shows that the headphones jack is actually in parallel with the speaker output jack connections. So that would make me think that anything you hear out of the speaker then would be...
  14. Replies
    12
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    224

    ERS is a replacement parts company just like ECG...

    ERS is a replacement parts company just like ECG or NTE. Looking at this ebay listing it shows "1 Piece | 2SC2773 Sanken NPN Transistors Equiv: NTE58 ECG58" in the items description. ERS58 should be...
  15. Replies
    63
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    1,166

    None of the legs of the bridge rectifier should...

    None of the legs of the bridge rectifier should have a connection to the metal base. Get out your meter and check to see. Just different heat sink potential.
  16. Replies
    46
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    881

    I am assuming that the circuit board picture was...

    I am assuming that the circuit board picture was before you re-flowed any questionable solder joints.

    Edit: it's sometimes tough to tell in photos but some of those joints look like they need a...
  17. Replies
    17
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    1,527

    Well first things first, mine is actually not a...

    Well first things first, mine is actually not a Marlboro G60R but rather a 560A model. You can see that the Hohner CA-12R model which is pictured early in this thread had different arrangement of...
  18. Replies
    63
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    1,166

    You build a light bulb limiter so it will,...

    You build a light bulb limiter so it will, hopefully, stop blowing fuses. No point powering it up without the light bulb limiter as that will only blow more fuses and possibly keep destroying more...
  19. Replies
    36
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    668

    I have to wonder if this squealing has anything...

    I have to wonder if this squealing has anything to do with the input jacks. Have we cleaned them and ohmed out the contacts to make sure they are closed? When we are inputting the signal is it into...
  20. Replies
    36
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    668

    I believe it is the 1458 by going by the pictures...

    I believe it is the 1458 by going by the pictures he uploaded. I had that same thought about the 1458 being swapped with a 4558.
  21. Replies
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    1,527

    I still have the amp but I need to dig it out of...

    I still have the amp but I need to dig it out of my storage area. This might get me to finally change the speakers (really cracked up cones) and sell the thing. In the next couple of days I will take...
  22. Replies
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    668

    There is one thread on mylespaul website where...

    There is one thread on mylespaul website where someone matched component values and rewrote out the schematic of the original 5005 lead 12 amp. See post #57. Not sure this is any help but just...
  23. Replies
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    1,166

    I am thankful every time someone initiates a...

    I am thankful every time someone initiates a thread that gets the group here troubleshooting. This website represents a wealth of information detailing so many different faults and resolutions to...
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    469

    Well if it is 100hz hum I would check for AC...

    Well if it is 100hz hum I would check for AC ripple, suggesting a leaky mains filter cap. I would think a ground loop would be a 50hz hum. In the US we have different mains voltage so it is 120hz DC...
  25. I went straight to parts is parts website and...

    I went straight to parts is parts website and searched for the jack when I first read your post. Funny thing is that they have the listing for the part as "Vox speaker Jack for NT15H, 530000001452"...
  26. If the circuit boards end in -00, like Soulfetish...

    If the circuit boards end in -00, like Soulfetish thought, then they must be older jcm 2000 models. Probably had 1000's of hours of use and just cooked the connections. The other one that springs to...
  27. Which exact model of jcm 2000 was it? Can you...

    Which exact model of jcm 2000 was it? Can you date the amps?
  28. To me it looks like those burnt up resistors are...

    To me it looks like those burnt up resistors are probably dropping resistors for the lower voltage preamp supply. D10 & D9 appear to burnt up a bit too and it would not surprise me if those diodes...
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