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Hoffman Amps Forum image Author Topic: Any audible impact on tone from shielded grid wires?  (Read 2457 times)

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Offline Mike_J

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Any audible impact on tone from shielded grid wires?
« on: February 26, 2021, 10:40:51 am »
The attached picture shows how I envision the jacks and wires would fit. Spent enough time on the shielded wire to hope the capacitance of the cable does not have an audible impact on the signal coming through the cable.


The cable lengths including an allowance for 3/4” for the lead length to the 68K resistors for V1a and V1b is 4” and 3-1/2”, respectively with a corresponding capacitance of 17 and 15pF respectively.


If it is not noticeable I will install them and think about them no more. However, if it would make an even one percent impact the wires are probably short enough and isolated enough to get away with straight wire. Then I would test the amp for soundness with the cables installed then change to straight wire as probably my first test.

Offline thetragichero

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Re: Any audible impact on tone from shielded grid wires?
« Reply #1 on: February 26, 2021, 10:47:06 am »
just put em in. only ground one end of the shielding (end at the input jack seems convenient enough)

Offline Mike_J

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Re: Any audible impact on tone from shielded grid wires?
« Reply #2 on: February 26, 2021, 11:43:48 am »
just put em in. only ground one end of the shielding (end at the input jack seems convenient enough)
Thanks. Already grounded on the input jacks end.

Offline PRR

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Re: Any audible impact on tone from shielded grid wires?
« Reply #3 on: February 26, 2021, 02:43:31 pm »
How long is the shield cable from guitar to amplifier?

Offline Mike_J

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Re: Any audible impact on tone from shielded grid wires?
« Reply #4 on: February 26, 2021, 07:03:57 pm »
How long is the shield cable from guitar to amplifier?
Twenty feet and a lot more pF than in those short shielded grid cables if that is where you are pointing me towards.


Thanks
Mike


Made it pretty easy to understand.

Offline pdf64

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Re: Any audible impact on tone from shielded grid wires?
« Reply #5 on: February 27, 2021, 03:19:25 am »
In that scenario, my particular OCD allows me to feel content with the 68k resistors moved to the valve socket, rather than being mounted at the jack.
From the photo I couldn’t make out if that’s how you’ve already done it.
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Offline Mike_J

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Re: Any audible impact on tone from shielded grid wires?
« Reply #6 on: March 03, 2021, 03:01:40 pm »
In that scenario, my particular OCD allows me to feel content with the 68k resistors moved to the valve socket, rather than being mounted at the jack.
From the photo I couldn’t make out if that’s how you’ve already done it.
They will be wired to the socket. Can't do it until near the end of the build because there wouldn't be room to remove and replace the board over and over again.

 


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