Quad 303 - Interesting mod :scratch:

[DSJR]

Dave:
Stop messing about gut the 303 & stuff it with With NET Audio clobber.This is what i'm upto anyway

This one's been rebuilt almost from the ground up but using the original boards, which have good gauge track on 'em. I was hoping it would have been well fugged at the price I paid, but it quite the opposite.

I also like the Dada upgrades.

Alex, I agree about playing with older gear. I think it was the preamps on some of these things that strangled the sound back then, together with less good source setup and bell-wire for speaker cables. I love the 33/303 once the component shackles are removed and the 33 has been a revelation, it's so much better now

[Rare Bird]

The original boards want more than just rebuilding Dave..

[DSJR]

I think we're agreed that it's a fine old vintage amp though, into the right speakers.

[Martyn Miles]

I think we're agreed that it's a fine old vintage amp though, into the right speakers.

I own a 303 which is used to power my little Harbeth P3ESRs along with a Quad 34 Preamp. The 303 has been repaired and checked, as was the 34 which required some component replacement. At my age I'm not going to rush into trying different amplifiers...

[worrasf]

Dave:
Stop messing about gut the 303 & stuff it with With NET Audio clobber.

+1

My 303 and 33 have had the full NetAudio treatment - the 303 is in 303SE spec and the 33 has new PSU, amplifier, tape and disc boards.
I refitted the disc adapter board from scratch

[zanash]

ok so no one appears to answered your original question ..why the bypass caps ....................this was a very late 80's thing ...the hypothesis was that it made the caps react quicker [deliver there charge] for high freq signals and transients...as small cap react quicker than large ones ...theres a paper some where on the interweb by colin wonfor published in common ground or audio conversions magazine that explains it all

[Colin Wonfor]

ok so no one appears to answered your original question ..why the bypass caps ....................this was a very late 80's thing ...the hypothesis was that it made the caps react quicker [deliver there charge] for high freq signals and transients...as small cap react quicker than large ones ...theres a paper some where on the interweb by colin wonfor published in common ground or audio conversions magazine that explains it all

Hi, there is but I cant find it sorry,also Martin Column,s and I in the early 1980,s did some work on split foil capacitors which proved to be crap at high frequency as the impedances went up.
Some were used by DNM and other and audio improvement were reported but under extreme examination the caps were very bad for power supplies.
So the choice of caps will and does depend on the load, be it dynamic or static loading and the speed and reaction of the dynamic loading will determine type, ESR, ESL,and current rating all these affect the sound. So be careful what your choice is ! it will normally be a compromise on COST, CURRENT, ESR, VALUE to give you the desired sound you like. NOTE your likes, me I like deep bass, rich warm sound but with speed and dynamic, so the caps I select would have very low esr, huge value high ripple current and cost a small fortune.
Poo, and diodes this is another nightmare area, again depending on the PSU and for another time.

OH Happy New Year all and to Steve who thought I had past on to A Class Hell sorry mate I am still here just he he

[The Barbarian]

+1

My 303 and 33 have had the full NetAudio treatment - the 303 is in 303SE spec and the 33 has new PSU, amplifier, tape and disc boards.
I refitted the disc adapter board from scratch

Steve:
I know this thread is a bit old now but looking at that Q33 Board you stuffed. I Recognise the Takman carbon films cos i rebuilt my Ferrograph amp with them..What make are the Polystyrene caps you used? i managed to get hold of some NOS Suflex jobbies..