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Thread: Vox AC15 (TBX) general Q's

  1. #36
    Don't forget the joker g1's Avatar
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    The latter part of this vid is what I would expect with preamp volume full up.


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  2. #37
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    Hi g1.. yes I saw this clip prior to buying it.

    With my preamp vol up full, the -1st- part of the vid is what I get. It tallies spot-on me with you, that the ammount of OD I'd expect would be like the latter part too. Hence my thread.

    I don't suppose you can ID the latter to be preamp or 'proper amp OD' from this clip-? It does sound a bit 'fizzy/ so-so' suggestive of preamp to me, perhaps. Turning the MV up to ~3/4 to get a similar OD 'saturation', Id expect alot richer tone & sustain.. but it is a poor recording. And I can't do that here. Shame I can't see the dials.

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  3. #38
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    Quote Originally Posted by Sea Chief View Post
    ...So do you recall trying the input volume @ max on them?
    I will have done, if only to check all was ok. If I had encountered to low gain issue you describe, I would have investigated.
    Some amps are like that, the DrZ EZG50 comes to mind as having insufficient preamp gain to get any useful degree of overdrive. But the AC15TB should be able to get a reasonable degree of crunch.

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  4. #39
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    pdf one thing I do notice, is the input placcy jacks 1 & 2.. sound the same level: no typical attenuation drop between them: is this typical for vox amps? I recognise similar 68k/68k and 1M resistors I'm used to seeing on fenders around here on the schematic, so should I expect a similar vol drop between them?

    My thinking is if 1 isn't as loud as it should be, I might be robbed of a bit of OD as a result.

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  5. #40
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    Yes, Input 1 should be 1M input resistance, input 2 134k and 6dB quieter. What input resistance do they measure? ie plug a cable in and measure the resistance between tip and screen.

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  6. #41
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    So measure @ the guitar end of the lead, unplugging gtr?

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  7. #42
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    Quote Originally Posted by pdf64 View Post
    Yes, Input 1 should be 1M input resistance, input 2 134k and 6dB quieter. What input resistance do they measure? ie plug a cable in and measure the resistance between tip and screen.
    Actually 1st is 990k - 1050M, 2nd input 1M120 or so. Odd.

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  8. #43
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    So the shorting contact of the 1 jack is faulty. That will result in the inputs picking up hum when nothing is plugged in, and will prevent the 6dB attenuation of the 2 input.
    So both inputs are equally loud, rather than equally quiet.

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  9. #44
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    Aha understood- damn I thought I might have solved the OD 'problem'!

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