Add standby switch?

[sharpshooter]

On my Ampeg Gemini 1, while it's opened up, for a cap job, I'am thinking of a standby switch. Would like to replace the off/on switch with a 3 position switch, for off/standby/on. What kind of switch should I use, and how should I wire it?

[hasserl]

I think Dave West of West Labs has Off, On, On switches available for this, so you can switch it progressively from Off to Power On/Standby ON to Power On/Standby Off. But I think this is needless and I wouldn't waste my time or resources doing it, you'll only gain a little convenience of being able to silence the amp for guitar changes or breaks or something, but that's what Volume controls are for.

If you think you'll gain tube life by using a Standby switch, I hate to disappoint you, but you won't.

[SatelliteAmps]

You need a DPDT On-Off-On 125v 15A. One side of the switch will get the center tap off the B+ (middle lug) and a connection to ground (bottom lug). The other side will have the AC line from the fuse (middle lug), and then the transformer tap goes to both the bottom and top lugs (use a jumper wire).

[dodgeone]

Hi! I know that i'm a little late in posting to this thread....But, I did just what you are trying to accomplish on my 67' Ampeg Reverberocket 2 model. Here is what i did....Whilst performing a complete Cap job {filters} and replacing some plate resistors, i thought why not a stand-by circuit?

So, not wanting to drill holes or anything too radical, i removed the fuse holder from the face-plate and relocated it to the bottom of the amp chasis where a convienent hole already existed!! Wired into the line cord circuit as appropriate....and installed a 3 prong grounded cord too. Adios "death cap" also. Also at this time , i replaced the original Selenium rectifier diodes with modern high quality Silcon diode replacements. This is a highly recommended reliability mod to make.

Now, where the fuse holder was located, i installed a high quality on/off switch {SP/ST} that i wired between the output of the rectifier and the first filter cap. The switch is on the LOW side of the circuit....that is to say that it opens or closes the Grounded side of the rectifier output to the first filter stage. This is the way that Ampeg did it back in the 60's on there amps that had a stand-by switch.

These improvements were done by me about 6 years ago and i have had ZERO reliability problems with this amp.

I could argue that going with the stand-by switch is a very good idea on these amps.....notably because the original 7591 output tubes that these amps employ are amongst the rarest NOS tubes to be found, and quite expensive in matched pairs when available. I have hoarded a lifetime supply for this amp along with the 6U10 tubes also. I like that these tubes are getting there filaments warmed up prior to the B+ application. I allways give all my amps equipped with tubes a 10 minute warm-up prior to coming out of stand-by.....but that's just me.

By the way, my Ampeg is an incredible amp. Best reverb of all my amps and whisper quiet even when CRANKED between passages.

Regards and best of luck with your project.