Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: isaac_teller on July 07, 2022, 07:29:36 am

Title: diodes/rectifier switch
Post by: isaac_teller on July 07, 2022, 07:29:36 am
Hello. I'm building a AA1164 Princeton and the user wants the option of switching from diodes to rectifier tube. Unfortunately he informed me of this after I had already installed a non center-tapped power transformer. I drew up a possible solution. Does anyone see a problem with this?
Title: Re: diodes/rectifier switch
Post by: jordan86 on July 07, 2022, 07:47:26 am
I don’t know enough to say how a non center tapped PT would affect this, but I’d tell that fella you snooze you lose, and then have him buy one of these  :laugh:

https://tubedepot.com/products/solid-state-rectifier?utm_source=google&utm_medium=cpc&adpos=&scid=scplpSSR&sc_intid=SSR&gclid=EAIaIQobChMIwLWHlefm-AIVMhXUAR0l9gwXEAQYAiABEgJiUvD_BwE
Title: Re: diodes/rectifier switch
Post by: isaac_teller on July 07, 2022, 08:03:27 am
I thought of doing that but if the above solution is feasible it's not that much of an effort to add one switch and 4 diodes.
Title: Re: diodes/rectifier switch
Post by: joesatch on July 07, 2022, 08:16:36 am
switchable rectifier sounds good on paper. i think it's alotta work for little reward. you have to have some resistor switching in it to get the same bias because that will be off (orr you have to find a bias middle ground). Also, could be bad for the filter caps going from gradual current to rushes of current?
Title: Re: diodes/rectifier switch
Post by: mresistor on July 07, 2022, 08:24:07 am
Is your build a SS recto? I'm just curious as to why you would build an AA1164 PR with a non center-tapped PT?
Title: Re: diodes/rectifier switch
Post by: sluckey on July 07, 2022, 08:30:59 am
I drew up a possible solution. Does anyone see a problem with this?
Works on paper. How will you connect the bias supply? Can we see a complete schematic for your non-standard PR?
Title: Re: diodes/rectifier switch
Post by: isaac_teller on July 07, 2022, 08:45:50 am
The original requirement was for a full wave bridge only. This is the current bias supply. Other than full wave bridge, standard AA1164.
https://robrobinette.com/images/Guitar/Bassman/High_Voltage_Bias_Tap_Bridge_Rectifier.png

Title: Re: diodes/rectifier switch
Post by: tubeswell on July 07, 2022, 12:00:47 pm
Yes, See hybrid bridge rectifier in this link http://www.valvewizard.co.uk/bridge.html (http://www.valvewizard.co.uk/bridge.html)

(You also need a filament winding for the tube)
Title: Re: diodes/rectifier switch
Post by: isaac_teller on July 07, 2022, 12:32:40 pm
I have a small 5 volt, 3 amp filament transformer that I added to the chassis.