Turtlerock Forum

Hey All you Techies
can you advise me on which replacemnets to use for recapping my Quad Eight desk? The existing caps are the blue ones (16v 100uf). The desk is 70's vintage & I'm interested in recapping a couple of channels to hear the difference.Could you also advise me as to where I could purchase said caps? thanks jb

Nitai Bi-polars for the audio path...keeping it simple!
get them from Farnell

[quote="blackfoot"]Hey All you Techies
can you advise me on which replacemnets to use for recapping my Quad Eight desk? The existing caps are the blue ones (16v 100uf). The desk is 70's vintage & I'm interested in recapping a couple of channels to hear the difference.Could you also advise me as to where I could purchase said caps? thanks jb[/quote]

Hi,

You're really best off making sure the new caps that you choose fit properly ie swap radials for radials, axials for axials. If your caps are axials, then your choice for replacements is a little more limited.

Keep the capacitance the same, but increase the voltage one notch (ie instead of 16V, get 25V, they usually fit no problems as older caps were larger). Also only ever get 105 degree, throw the 85 degree caps in the bin. capacitor technology has come a long way since your desk was designed, so pretty much anything you put in will be better than the originals.

For DC blocking, low leakage is preferred. For everything else, low ESR(equivalent series resistance) is best. The best caps around were the Panasonic HFS but I think they've stopped making them. Panasonic FC or HC caps are good, as are nichicon and everything else that isn't too cheap.

Farnell is the best resource for caps, get the catalogue or go online.

http://www.farnell.com

they're in sydney, if you order in the morning you get in the afternoon.

[quote="rob"]Nitai Bi-polars for the audio path...keeping it simple!
get them from Farnell[/quote]

hmm, i'd avoid bi-polars. really, they're just two caps tied together and aren't particularly great.

but rob knows a hell of a lot more than me.

is there any reason you'd use bipolars in the audio path? i would have thought it would be better to use two caps tied together with their positives on the +V rail - I've done it before and have read that this is the best (but most cumbersome) way to use caps for audio because they like to be biased.

Chris

The method using two caps with a pull-up between them is what SSL use in the 4000 series.

I've just recapped a 72 ch neve vrsp using 100uF bipolar caps instead of polars, and the sound is appreciably better than the original.

I'd go the non polars for the Quad Eight as Rob suggested.

regards,

Otto

just out of interest otto... how long did that neve take to recap? the sheer terrifying number of caps in those things was one of the reasons we didn't get a neve V-series.

[quote="wez"]just out of interest otto... how long did that neve take to recap? the sheer terrifying number of caps in those things was one of the reasons we didn't get a neve V-series.[/quote]

It took 1 man day per channel, plus there were a lot of other cards (monitor section, VRSP section). About 13,000 caps or so. We only did the audio signal caps, though both PSUs have now been fully recapped as well.

regards,

Otto

sounds about right! I'm currently refurbishing two Neve 51 consoles. Having knocked over the first 8 channels, they are averaging about a day a piece. doo dee doo