303 inside pic.

[southall-1998]

303 owners,

Check this Quad 303, it has one blue and 3 silver caps. Is this a good/bad thing?

http://i602.photobucket.com/albums/tt104/TDL-STUDIO/IMG_8837.jpg

[Rare Bird]

They basically need changing & uprating in value anyway..

[spendorman]

The three big ones look like they are original and fairly early production, blue one is probably a replacement.

Those very early production caps can last a long time, I have a very early production 303 and it's caps are still OK. I have other, newer 303's where caps have leaked.

But, in that amp with one odd (probably newer) cap, think I would have replaced all.

[kenworthy100]

Early 303 (bridge rectifier is the earlier style), the three silver caps are probably original (2000uf@100v) and the odd cap is probably an ITT cap (2200UF@100V) as fitted to the later production 303's.

I have restored a number of these and at that age you would normally replace all four caps with modern equivalents and replace the 3 smaller ones on the driver boards. For good measure you would additionally replace the trimmers and reset voltages and bias.

Unless you are going to get this serviced I wouldn't personally touch it

[spendorman]

Early 303 (bridge rectifier is the earlier style), the three silver caps are probably original (2000uf@100v) and the odd cap is probably an ITT cap (2200UF@100V) as fitted to the later production 303's.

I have restored a number of these and at that age you would normally replace all four caps with modern equivalents and replace the 3 smaller ones on the driver boards. For good measure you would additionally replace the trimmers and reset voltages and bias.

Unless you are going to get this serviced I wouldn't personally touch it

I was going to mention the rectifiers, but could see it properly. My very early 303 has the four separate rectifiers and has different biassing arrangement to later models.

http://farm9.staticflickr.com/8485/8166924794_4edfb36674.jpg (http://www.flickr.com/photos/41679262@N02/8166924794/)
photo 3-Very early 303 original caps (http://www.flickr.com/photos/41679262@N02/8166924794/) by A60man (http://www.flickr.com/people/41679262@N02/), on Flickr

[DSJR]

Shane knows how much many of us 303 owners love ours, but the one pictured needs a favour done to it by replacing those four caps. The earlier upside down ones could leak onto the boards underneath so checking every few years is a great idea on these vintage units. In this case, the blue cap looks to be a replacement done by an engineer from the times when these things weren't supposed to matter much and I've seen odd value cap-pairs quite often, done in some 1970's repairs - the engineer fitted what would work with no thought for anything else. may not sound any different, but since we have much higher values available now, and on the 303 it makes a positive difference, I'd change all four.

Shane, the dada website is sensible, the "replacement" boards in keeping with the original design (just updated with good modern parts) and the parts they supply are good ones - no bodging around in this firm in my experience. Have a look on there for a cap kit - I know you're familiar with them because you post on the Yahoo Quad group !

[dantheman91]

Soon as we are on the 303.

I would like to ask if my pre and power are early or later ones

33 serial Number
28285

303 Number
28689

[spendorman]

Soon as we are on the 303.

I would like to ask if my pre and power are early or later ones

33 serial Number
28285

303 Number
28689

I can't remember the serial numbers at changes, but the instruction manual will guide. For example, in the 303 booklet there are two circuit diags. and it tells of the serial number change.

Can't lay my hands on the booklets at the moment.

Suspect your 303 is the later type ckt. diag.

[southall-1998]

Shane knows how much many of us 303 owners love ours, but the one pictured needs a favour done to it by replacing those four caps. The earlier upside down ones could leak onto the boards underneath so checking every few years is a great idea on these vintage units. In this case, the blue cap looks to be a replacement done by an engineer from the times when these things weren't supposed to matter much and I've seen odd value cap-pairs quite often, done in some 1970's repairs - the engineer fitted what would work with no thought for anything else. may not sound any different, but since we have much higher values available now, and on the 303 it makes a positive difference, I'd change all four.

Shane, the dada website is sensible, the "replacement" boards in keeping with the original design (just updated with good modern parts) and the parts they supply are good ones - no bodging around in this firm in my experience. Have a look on there for a cap kit - I know you're familiar with them because you post on the Yahoo Quad group !

Dave,

Does Quad in Huntingdon still service the 303?

Cheers.

[spendorman]

Dave,

Does Quad in Huntingdon still service the 303?

Cheers.

I know that they do, the main man there is a friend's friend.

[southall-1998]

I know that they do, the main man there is a friend's friend.

Well, I hope they do a decent job servicing the 303.

[spendorman]

Well, I hope they do a decent job servicing the 303.

He's a great bloke, been there decades, recently fixed the friends very rare valuable amplifier.

[southall-1998]

Thanks, Spendorman.

[spendorman]

Thanks, Spendorman.

303 needs to be incredibly well protected for transit, I think I mentioned of what happened to one of mine, bust heatsink and bent chassis, and it was reasonably packed.

[southall-1998]

Yes, you told me this in the past. Was your 303 packed in it's original box and packaging at the time?

[spendorman]

Yes, you told me this in the past. Was your 303 packed in it's original box and packaging at the time?


Yes

+extra

[southall-1998]

Good grief! Sounds like your 303 was delivered by taz mania :)

[spendorman]

Good grief! Sounds like your 303 was delivered by taz mania :)

There was a claim!