Hi, I own a first generation Quad 405 amp (s/n 49125) which does not have a voltage selector switch on the back panel as was provisioned on later models. To adapt to different world voltages, wires had to be desoldered and reconfigured. Quad published four diagrams that detailed the different configs for 110V, 120V, 230V and 240V. I'v searched online but can't find this diagram. Does anyone have the diagram that they can share?
Alternatively, can someone post a photo of their 405 transformer in this thread if it is configured for 120V?
Pictured is my current wiring config. There is a RED circle around a soldered connection between GREY and BLACK wires. I'm not sure the primary voltage configuration - it might be 230V or 120V.
Alternatively, can someone post a photo of their 405 transformer in this thread if it is configured for 120V?
Pictured is my current wiring config. There is a RED circle around a soldered connection between GREY and BLACK wires. I'm not sure the primary voltage configuration - it might be 230V or 120V.
Haveing said that, this doesn't match any Quad configuration that I can see. It doesn't look correct. Don't plug it in until you've figured it out.
Ok, thanks for the information. I did search extensively online for the diagram I'm thinking of, but didn't find it. I see loots of references to Quad 405-2 transformer wiring but that wiring is different than the original first generation Quad 405.
Well, my diligence paid off. I located the piece of paper buried in my file cabinet containing the diagram I remember. It was a fax I received from Acoustical Mfg. back in 1992 when I was enquiring. I scanned it and attached it to this posting. Is there a repository for Quad 405 documentation where I should place this PDF? It would be useful for other people and it will get lost in this forum.
Well, my diligence paid off. I located the piece of paper buried in my file cabinet containing the diagram I remember. It was a fax I received from Acoustical Mfg. back in 1992 when I was enquiring. I scanned it and attached it to this posting. Is there a repository for Quad 405 documentation where I should place this PDF? It would be useful for other people and it will get lost in this forum.
Well your photo looks like the 230V configuration from your document, but please don't take anybody's word for it: measure.
If you're in a 110V area you can probably just plug it in and measure the rail voltages, which should be about +-50V. If it's half that, it is 220, 230, or 240, but whatever it is you should change it to the 110V configuration, i.e. don't waste money on a stepup transformer when in reality you already have one.
If you're in a 220-240V area you will need a filament transformer or a signal generator that can output a few volts at 50Hz to test it. Connect it to the two AC points shown and measure the AC voltage across the 0V point and one of the 38V points. Take this output voltage's ratio to 38V and divide the input voltage by that to get the expected AC primary voltage. Bear in mind that the transformer if unloaded will deliver more than its secondary voltage rating.
If you're in the UK, Australia, NZ, etc., I would rewire it to the 240V configuration. When they harmonized the UK to 220V it was only an adjustment on paper: the voltage at the wall is what it always has been.
But whatever you do, consider all the risks first and take the path of least risk, both to the transformer and yourself. No liability expressed or implied.
I've uploaded the document to my Quad stash at https://dadaelectronics.com.au/doc/Audio/Quad.
If you're in a 110V area you can probably just plug it in and measure the rail voltages, which should be about +-50V. If it's half that, it is 220, 230, or 240, but whatever it is you should change it to the 110V configuration, i.e. don't waste money on a stepup transformer when in reality you already have one.
If you're in a 220-240V area you will need a filament transformer or a signal generator that can output a few volts at 50Hz to test it. Connect it to the two AC points shown and measure the AC voltage across the 0V point and one of the 38V points. Take this output voltage's ratio to 38V and divide the input voltage by that to get the expected AC primary voltage. Bear in mind that the transformer if unloaded will deliver more than its secondary voltage rating.
If you're in the UK, Australia, NZ, etc., I would rewire it to the 240V configuration. When they harmonized the UK to 220V it was only an adjustment on paper: the voltage at the wall is what it always has been.
But whatever you do, consider all the risks first and take the path of least risk, both to the transformer and yourself. No liability expressed or implied.
I've uploaded the document to my Quad stash at https://dadaelectronics.com.au/doc/Audio/Quad.
I'm in Toronto, Canada so it's a 120VAC 60Hz country. It was previously rewired for 230VAC ( remember now) because I lived in Norway for a while but moved back to Canada. I have now rewired the transformer to match the diagram for 120VAC.
P.S. I just submitted an order to Dada for a 33 refresh kit and a 405 refresh kit. 🙂
P.S. I just submitted an order to Dada for a 33 refresh kit and a 405 refresh kit. 🙂