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  1. I guess this might be the thread for this question on repurposing an amp. Images included

    Had a very old home made amp dropped off and he wants to know if the power supply and one output transformers can be used to build a guitar amp. Well the cabinet is home made and looks like rats nest...
  2. Thread: 67 Super Reverb

    by J Luth
    Replies
    6
    Views
    249

    Thanks Enzo I get it now. Or were you just...

    Thanks Enzo I get it now.

    Or were you just concerned since the readings LOOKED funny?

    Yes wasn't sure if I was measuring the voltage correctly. Across the wires it measures 5.4.

    Not sure...
  3. Thread: 67 Super Reverb

    by J Luth
    Replies
    6
    Views
    249

    "They pulled the rectifier tube and put diodes in...

    "They pulled the rectifier tube and put diodes in its place. They moved the 5v wires so if someone stuck a rectifier tube inther it wouldn't do anything. Putting them on unused pins was just a way of...
  4. Thread: 67 Super Reverb

    by J Luth
    Replies
    6
    Views
    249

    Had a feeling it might be the center tap for the...

    Had a feeling it might be the center tap for the 6.3V. They have cut it off from it's ground point and added 2 100r resistors from the pilot light to ground.

    On the 5V winding, I measured each...
  5. Thread: 67 Super Reverb

    by J Luth
    Replies
    6
    Views
    249

    67 Super Reverb

    New question time.

    A friend just picked one up and brought it by, nice amp itís been recapped and a few resistors changed. I found a few things more it needs but there are a couple of things that...
  6. Thread: Danelectro DM25

    by J Luth
    Replies
    16
    Views
    362

    Helmholtz Just realized I put the voltages for...

    Helmholtz

    Just realized I put the voltages for the 2nd 12AX7's on the wrong plate on the attachment. 169 should 125, the 133 should be 169.

    Have to stop doing it late at night.
  7. Thread: Danelectro DM25

    by J Luth
    Replies
    16
    Views
    362

    xtian Yes I did

    xtian

    Yes I did
  8. Thread: Danelectro DM25

    by J Luth
    Replies
    16
    Views
    362

    Rechecked everything today and with the exception...

    Rechecked everything today and with the exception of the voltages listed above all others are the same as shown on the attachment.

    I did find two caps on both tone stacks that had there leads...
  9. Thread: Danelectro DM25

    by J Luth
    Replies
    16
    Views
    362

    Helmholtz My mistake on the 7189 plates I'll...

    Helmholtz

    My mistake on the 7189 plates I'll admit to it, I read the wrong pin DOH. It was late.

    Using a Fluke 117 meter

    After full warm up

    7189 plates 334 and 335
  10. Thread: Danelectro DM25

    by J Luth
    Replies
    16
    Views
    362

    Did some voltage checks and most are within + -...

    Did some voltage checks and most are within + - 10 to 20 volts except the first 2, 12AX7's. Plate voltage is high on all plates.

    Voltage shown on this schematic.

    56369
  11. Thread: Danelectro DM25

    by J Luth
    Replies
    16
    Views
    362

    Chuck H First checked on the scope with a 1k...

    Chuck H

    First checked on the scope with a 1k 100mV signal, scope set to 2v PD wave form peek to peek a bit over 5 div's. The peeks did start to flatten out just before it reached max volume and...
  12. Thread: Danelectro DM25

    by J Luth
    Replies
    16
    Views
    362

    Oops should have been more specific. I have...

    Oops should have been more specific.

    I have the schematic, I'll recheck voltages.

    The Dude
    Yes it is clean with the volume all the way up, no breakup.

    g1
    No crunch sounds wimpy
  13. Thread: Danelectro DM25

    by J Luth
    Replies
    16
    Views
    362

    Danelectro DM25

    Recent purchase, his complaint appears to have low output, not much gain and a bit of hum.

    Looks like it spent a lot of time in a dirty damp basement. Faceplate has a lot of surface rust, reverb...
  14. Replies
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    Thanks Chuck H Now the fun begins.

    Thanks Chuck H

    Now the fun begins.
  15. Replies
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    675

    Thanks Chuck Told him to leave the stock...

    Thanks Chuck

    Told him to leave the stock presence If he still wants to change it I'll show him the the options you show but to leave it up to him

    Finding a few things on this amp that are...
  16. Replies
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    675

    Thanks Enzo. Probably going to leave the...

    Thanks Enzo.

    Probably going to leave the stock presence control, it's up to him.

    The amp is here now it turns out to be a reissue amp that has had the circuit boards removed, a hand wired...
  17. Replies
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    675

    Getting ready to try the mod but have one more...

    Getting ready to try the mod but have one more question. Enzo stated that the there should be a 4.7K resistor installed once the persence pot is removed and the circuit installed. I am not quite sure...
  18. Replies
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    675

    Thanks Chuck H I'll talk to the owner and see...

    Thanks Chuck H

    I'll talk to the owner and see which way he wants to do it.
  19. Replies
    16
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    675

    Enzo If I did remove the pot and put in a 5K...

    Enzo

    If I did remove the pot and put in a 5K resistor, could I then use the 50K pot and resistor to vary the feedback voltage?
  20. Replies
    16
    Views
    675

    Enzo My mistake, there was supposed to be a...

    Enzo

    My mistake, there was supposed to be a question mark in the text as to the value of R1 which is labeled as 1500R.

    The question on the resistor, R1, was when removing the 5K presence pot...
  21. Replies
    16
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    675

    Would this circuit work

    I have a guy that wants to remove the presence control on his Bassman 5F6-A and replace it with an adjustable negative feeback circuit. I drew up a circuit but not sure if it will work.

    56117
  22. Replies
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    653

    Mick You are correct

    Mick
    You are correct
  23. Replies
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    653

    Thanks Enzo

    Thanks Enzo
  24. Replies
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    653

    Wondering if this would work. ...

    Wondering if this would work.
    ...
  25. Replies
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    653

    G1 It is used to set the meter in the center...

    G1

    It is used to set the meter in the center of it's range. Appears to be in the area of most use.
    When turning it to set the meter the needle starts to move up but before it is centered the pot...
  26. Replies
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    653

    Superior TV-11 Tube Tester

    I was just given a Superior TV-11 tube tester. It needs a little work that will not be to bad.
    The main problem is the meter adjustment is not working correctly. I opened it up and found that a...
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    962

    Mick Appears you may have been correct about a...

    Mick

    Appears you may have been correct about a flaky resistor.

    Tried tapping everything in the PI circuit very lightly until I found what was the loudest. The 510K resistor was very loud when...
  28. Replies
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    962

    Where I'm at today. Still does it but when I...

    Where I'm at today.

    Still does it but when I push hard on the board in the area of the 2, 20uf radial caps it stops. The board does not flex or move a lot just slightly. All solder joints are...
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