Quad 405 preamp question

Ok so I have been out of the audio loop for a few years now as I now focus on networking for my work. I recently aquired a Quad 405 amp from a friend and wanted to know if I can connect my older Sony STR AV770
receiver (80W) as a preamp to the Quad. I know there are a set of RCA u-plugs on the back of the Sony apparantly to be used for an equilizer in series if desired. I was wondering if iremove the jumper plugs and redirect the audio out from the Sony to the Quad if this will work? I dont want to over drive the Quad though. I just had the gear at home and cant afford a Quad 44 preamp even if i mod it for 120VAC line voltage. The Quad needs a power circuit cap replacement and possibly some other upgrades. The final speakers are Bose 501 II's

Any advice? Can I use the Sony or should I look for another pre-amp solution.

Matt

 

You can use the Sony, but the QUAD 405 has a 500mV input sensitivity, so depending on what the Sony outputs, you may find that the volume control is all at the bottom.

Incidentally, do make sure that the Ulinks come after the volume control. If they are intended for an equaliser, they may be before the volume control, in which case the QUAD will be driven flat out.

S

 

If/when you get this done, that is the time to also get the Quad 405's input sensitivity reduced down by a factor of three to 1500mV - a fairly standard mod, that makes it play nicely with other gear.

Actually, if you're up for it, it's a relatively easy D-I-Y mod:
http://www.dadaelectronics.eu/shop/quad-upgrade-kits/quad-405-upgrade-and-revision-kit

 

One of the oddities with the 405 and 306 power amps and possibly later ones, is that their 500mV sensitivity doesn't even match their own preamps. The Quad 34 has an attenuator on its output to reduce the 'real' output from 1.5v to 0.5v. The Quad 44 has alternative outputs, 1.5v is standard. So I can only assume that the 405's sensitivity was set to match the 303's, for backwards compatibility, and then the newer preamps continued that, and then when the 306 came out, it then had to match the preamps........ I think it would have been rather better to have the 405 etc with settable sensitivity, perhaps moving a pair of links or a DIL switch.