Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Boone on September 26, 2013, 05:20:07 pm

Title: How to install a stand by switch on 5F2-A?
Post by: Boone on September 26, 2013, 05:20:07 pm

The on/off switch will be activated via the tone knob( I have a tone pot with switch in pot). The original on/ off will be used for stand by switch. Here's my question: what type of switch do I buy and how to wire it in. Any ideas? Thanks

Title: Re: How to install a stand by switch on 5F2-A?
Post by: labb on September 26, 2013, 06:23:22 pm

FWIW, when I have tried to use a switch in one of the pots as the on/off switch I have picked up hum from it.

Title: Re: How to install a stand by switch on 5F2-A?
Post by: TubeRube on September 26, 2013, 07:47:53 pm

Many just use the 5F2-A's On-Off switch hole to mount a 'progressive' Off-Standby-On switch (in HoffmanAmp's web store, the last  SPDT Carling toggle under "Power, Standby, Ground" section of 'Switches'), but it doesn't have the short baton lever like 5F2-A's original On-Off. However, I'm pretty sure I've seen a Carling short bat DPDT Center Off switch (Mouser? AES?) that can be wired to do the same thing...   only the 'progression' will be Standby-Off-On (center position always 'power Off'...   'Standby' or 'On' toggled to either side...  your wiring choice). Seems I've seen threads w/exactly this topic here...   a quick search will probably turn up wiring diagram schemo's, etc. for what you want to do...

Title: Re: How to install a stand by switch on 5F2-A?
Post by: tubeswell on September 26, 2013, 08:11:48 pm

A carling type SPST switch rated at 250V 10A or similar will do just fine. Makes sure the switch bushing is going to fit through the chassis hole.

Title: Re: How to install a stand by switch on 5F2-A?
Post by: SleepLess on October 07, 2013, 03:53:34 pm

Hi.
Have you thought about a OFF/Stdby/ON switch? I succesfully installed one in a 5F11 and it works great. Plus it doesn't take more space on the chassis! I got it from this guy, it says it's for a Blues Junior but you can obviously use it for many more amps:
http://billmaudio.com/wp/?page_id=327 (http://billmaudio.com/wp/?page_id=327)

Title: Re: How to install a stand by switch on 5F2-A?
Post by: TubeRube on October 08, 2013, 05:32:40 pm

Boone...   didn't mean to diverge from your initial intention of having an earlier-model's 5D2,5E2,or 5F2 type tone pot w/on-off switch replacement part in addition to the more 'modern' on-off toggle switch in your 5F2-A. Was scheming for all switching from one switch position...   Tubeswell's solution perfectly answers the question you asked...   plus, a 'standard' Carling SPST toggle (as he suggested) w/short baton lever that 'matches' the original 5F2-A on-off switch is readily available (at this site & elsewhere).