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Old 21st Aug 2019, 4:04 pm   #1
Jeremy39
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Default Quad 405, 44 and FM4 reinstating

I bought my Quad 405, 44 and FM4 back in 1985. They gave excellent service until I moved house in 2007 since when they have been stored in their original packaging in a cool dry room. I want to reinstall the system but am concerned that the capacitors may have deteriorated as they have been uncharged for so long. Should I get the 405 professionally tested beforehand, and is there any risks with the pre Amp and Tuner?
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Old 21st Aug 2019, 5:21 pm   #2
fetteler
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Default Re: Quad 405, 44 and FM4 reinstating

Yes, after such a long time you should check it all over before re powering and use - there's less risk of anything expensive happening with the preamp and tuner but after nearly 35 years it's time for a service, they'll sound fantastic afterwards!
As I see it you have three options dependent on your own level of electronics skill

1) Get the excellent refurb kits for each piece from DaDa electronics and install them yourself. These kits are excellent and will upgrade as well as refurbish.
http://www.dadaelectronics.eu/shop/quad-upgrade-kits

2) Have DaDa upgrade and refurbish them for you
http://www.dadaelectronics.eu/prices

3) Quad still service these great amps and tuners - send it all to them in Huntingdon
http://quad-hifi.co.uk/our-story.php?id=19

I hope this helps.

Cheers,
Steve.
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Old 21st Aug 2019, 5:40 pm   #3
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Default Re: Quad 405, 44 and FM4 reinstating

I back up what Steve has said. I have managed to repair two 405's, one very recently and my main concern being blown thick film circuits was sorted by a visit to Huntington where replacements were available. You need things like a Variac so you can apply power slowly while looking for bad offset voltages on the output and of course struggling electrolytics.
Make sure you replace R7 and R8, 3.3k between the 50V rails and the 15V zeners D1 and D2. The resistors have a nasty habit of going open circuit and this causes no end of problems. Not entirely the resistors fault as in the 405 they are being subject to over dissipation so you need to replace with 1W types.
I am also lucky in having high power 8 Ohm non inductive loads and a distortion measuring test set, very rarely used but a nice to have when dealing with something like the Quad 405.

Here are the notes I took which may be useful to anyone working on a 405.
http://www.g4cnh.com/public/Another_Quad_405_repair.pdf
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Old 21st Aug 2019, 8:49 pm   #4
KeithsTV
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Default Re: Quad 405, 44 and FM4 reinstating

R7 and R8 should be uprated to 1W parts. I've had both channels of my 405 fail, one due to R7 and one due to R8. Fortunately the crowbar on the output saved the speakers.

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Old 21st Aug 2019, 9:23 pm   #5
Ted Kendall
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Default Re: Quad 405, 44 and FM4 reinstating

You might have trouble with the FM4 - the backup battery can leak and the processor fail. Quad offer a replacement processor kit which has more presets and obviates the need for the battery.
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Old 22nd Aug 2019, 9:03 am   #6
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Default Re: Quad 405, 44 and FM4 reinstating

The other thing is the RIFA caps in both the FM4 and 44
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Old 23rd Aug 2019, 4:07 pm   #7
Jeremy39
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Default Re: Quad 405, 44 and FM4 reinstating

Thank you to all who proffered help and advice. As I donít have the necessary variable power supply and the mods are probably beyond my capabilities Iíll be utilising Quadís service. For info, they are charging £55 per unit plus parts and VAT for a factory service to full working spec.
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Old 24th Aug 2019, 4:42 am   #8
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Default Re: Quad 405, 44 and FM4 reinstating

Crikey, that's a bargain!

Can you please come back and give us the final cost? I'll bet there's a lot of people reading this forum who are a bit scared of going back to Quad, but they've been doing a great job for decades so they must be value for money.
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Old 25th Aug 2019, 1:05 am   #9
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Default Re: Quad 405, 44 and FM4 reinstating

Quote:
Originally Posted by Jeremy39 View Post
Thank you to all who proffered help and advice. As I donít have the necessary variable power supply and the mods are probably beyond my capabilities Iíll be utilising Quadís service. For info, they are charging £55 per unit plus parts and VAT for a factory service to full working spec.
You have made the right decision. Money well spent

Cheers,
Steve.
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Old 26th Aug 2019, 3:43 pm   #10
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Default Re: Quad 405, 44 and FM4 reinstating

Geez, £55! That's what I spent on parts. As it is a hobby thing here I did not charge any labour else it would have come to something like £200+.
Has to be a good option plus you get a guarantee with the work.
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Old 26th Aug 2019, 5:27 pm   #11
Jeremy39
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Default Re: Quad 405, 44 and FM4 reinstating

I have queried whether they routinely change the components you have all suggested (only just sent email so hopefully should have response this week) and expect the final bill to be significantly bigger than £55+VAT per unit. Not going up to QUAD until second week of September so will let you know the final score sometime later.
All I need to do now is to refurbish the homemade deck (simple Connoisseur BD1 turntable and Mayware F4 arm mounted in Perspex on microsorper feet), hope that the homemade speakers havenít deteriorated and Iím back listening to vinyl again! On the latter, I attach a photo of the drive unit control board. Not sure if I need to test this to check the components beforehand.
Built the deck and speakers c.40 years ago when I thought I knew what I was doing. Seem to have forgotten most of the basics over these years so am grateful for all the help that has been offered.
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Old 26th Aug 2019, 6:03 pm   #12
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Default Re: Quad 405, 44 and FM4 reinstating

Those black capacitors on the crossover boards are non-polarised electrolytics. They might have deteriorated over the years. If they were mine I'd replace them with Polypropylene film types, provided I could find some way to fit them in the available space.

They might be OK, so I don't recommend you change them regardless if you don't have the necessary skills. But if the speakers don't sound quite right, or there is a noticeable difference between them which can't be blamed on the drive units, they would be the prime suspects.
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