Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Bieworm on October 25, 2023, 02:21:13 am
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Hi guys
I've been wrapping my head around this. A 2 channel amp (5F6A) with an input for each channel on which I want to put a bridging switch. I also want to be able to use each channel individually by putting the cord into the individual input.
The culprit is the fact that only one input will be jacked by the guitar cord. So in a regular input wiring where the switch of the hot lead is connected to switch of the ground lead, the unused input will be grounded and there will be no bridging going on.. but grounding both inputs hot lead.
I eventually came up with this. Is it a good approach, or am I way overthinking this?
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That works. But why two input jacks? I use a simpler (to me) single jack and special three position switch that allows me to select either channel or both (bridged). Like this...
http://sluckeyamps.com/phoenix/phoenix.pdf
http://sluckeyamps.com/supro/supro.pdf
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That works. But why two input jacks? I use a simpler (to me) single jack and special three position switch that allows me to select either channel or both (bridged). Like this...
http://sluckeyamps.com/phoenix/phoenix.pdf
http://sluckeyamps.com/supro/supro.pdf
Thanks Steve.. your idea was originally my suggestion too. But my buddy insists on having 2 inputs for some inexplicable reason
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… A 2 channel amp (5F6A) with an input for each channel on which I want to put a bridging switch. I also want to be able to use each channel individually by putting the cord into the individual input. …
There’s no need for a separate switch, just use the ones built into the sockets, one of which needs to be stereo. See https://music-electronics-forum.com/forum/amplification/guitar-amps/31380-4-hole-functionality-from-2-holes-almost
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… A 2 channel amp (5F6A) with an input for each channel on which I want to put a bridging switch. I also want to be able to use each channel individually by putting the cord into the individual input. …
There’s no need for a separate switch, just use the ones built into the sockets, one of which needs to be stereo. See https://music-electronics-forum.com/forum/amplification/guitar-amps/31380-4-hole-functionality-from-2-holes-almost
Nice engineering job, Pete👍
I like to have a switch to bridge both triodes though. Maybe I’m not reading your thread correctly to get the options as intended
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… A 2 channel amp (5F6A) with an input for each channel on which I want to put a bridging switch. I also want to be able to use each channel individually by putting the cord into the individual input. …
There’s no need for a separate switch, just use the ones built into the sockets, one of which needs to be stereo. See https://music-electronics-forum.com/forum/amplification/guitar-amps/31380-4-hole-functionality-from-2-holes-almost (https://music-electronics-forum.com/forum/amplification/guitar-amps/31380-4-hole-functionality-from-2-holes-almost)
I am interested in this jack switching arrangement, makes a lot of sense towards tidying up the control panel.
I read the linked thread but I am not quite clear on how the options function.
"I worked out an arrangement so that with 1 regular/mono and 1 stereo switching jack sockets, I could achieve all the above, such that -
Input A (Normal / Link) - plug into this ONLY to use both channels.
Input B (Lead) - plug into this to use 'Lead' channel; doing so disables the 'link' function, allowing the channels to be used independently."
Maybe it is the included "ONLY" in the second sentence that is confusing.
But I am reading that:
Plugging into channel A feeds both A & B (you turn down channel B to use A exclusively)
Plugging into channel B feeds B only (it disconnects the built-in jumper)
Is there meant to be another way to use channel A exclusively that I am not seeing?
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Thanks Steve.. your idea was originally my suggestion too. But my buddy insists on having 2 inputs for some inexplicable reason
Meant to add above, that while the switch is cleaner, having two jacks would facilitate being able to use an ABY box for switching on the fly.
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Thanks Steve.. your idea was originally my suggestion too. But my buddy insists on having 2 inputs for some inexplicable reason
Meant to add above, that while the switch is cleaner, having two jacks would facilitate being able to use an ABY box for switching on the fly.
Yep. No need to do anything to the amp. :icon_biggrin:
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Thanks Steve.. your idea was originally my suggestion too. But my buddy insists on having 2 inputs for some inexplicable reason
Meant to add above, that while the switch is cleaner, having two jacks would facilitate being able to use an ABY box for switching on the fly.
Yep. No need to do anything to the amp. :icon_biggrin:
Nah…ABY.. another cable/device on the floor makes me go crazy. This amp is not intended to be switched on the fly. I have built one for myself where i can switch off the normal channel by grounding the signal before the mixing resistor. The normal channel can be switched in to add some beef, and the level of it with the volume pot. (The Brutus, another thread)
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(https://i.ibb.co/KhX43VW/IMG-3015.png)
Plug into the upper ‘A / Mix’ input and the signal is routed to both grids.
That’s nice for noodling and twiddling around at home.
Plug into the B input to access the B channel only; that will mute the A channel.
Plugging into both the A and B inputs routes the A input to the A channel, the B input to the B channel. That’s handy for use with an external A B (Y) switch, which I like in a band scenario.
Note that I voice the channels for ‘lead’ and ‘rhythm’, rather than ‘normal’ and ‘bright’.
The difference being that I find the latter generally need to be mixed together to get a full tone, whereas the former can both be voiced for a full tone when used independently or together.
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Or a simple switchable single/parallel input (one jack is single, the other jack is both V1 stages in parallel) and where plugging in both inputs at the same time gives a 'stereo' input for guitar players who like to mix up different A/B switching on their stereo pedal boards
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Or a simple switchable single/parallel input (one jack is single, the other jack is both V1 stages in parallel) and where plugging in both inputs at the same time gives a 'stereo' input for guitar players who like to mix up different A/B switching on their stereo pedal boards
Marshall 1974 18 watt normal channel.