A tale of two Quads

[MarginWalker]

I have now received the second of two Quad 306s i have bought recently so thought i would open them both up to see if there were any differences inside. Sure enough the one with the slightly shabbier case and new binding posts has had new caps fitted, whereas the much tidier example looks to be all original. My intention is to have a listen to both to see if i prefer one or the other . If the upgraded version sounds better, as i imagine it will, then i will probably cannibalise the minty case for use on that one. It will certainly be interesting to be able to hear the two of them side by side once the preamp arrives!

http://i.imgur.com/lA5t57Bh.jpg (https://imgur.com/lA5t57B)

http://i.imgur.com/MfeQOZJh.jpg (https://imgur.com/MfeQOZJ)

http://i.imgur.com/iM1PgyTh.jpg (https://imgur.com/iM1PgyT)

http://i.imgur.com/vqu42Dkh.jpg (https://imgur.com/vqu42Dk)

http://i.imgur.com/DBw1YySh.jpg (https://imgur.com/DBw1YyS)

[walpurgis]

I'm betting you'll struggle to hear anything between them

The upgraded speaker terminals may look good, but the only real thing wrong with the originals is that they can become looser fitting over time, they can be crimped tight again easily.

[Shovel_Knight]

Personally, I wouldn't consider Nover capacitors an upgrade... Call me a snob, but I believe in quality components, like the original BHC caps :confused:

[MarginWalker]

Hmmm, interesting. If there is no audible difference maybe I should just hold on to the original then. The new speaker posts aren't anything fancy and the original caps do sem in very good nick, no signs of bulging

[Firebottle]

The second one has also had the feed forward bridge balance adjusted, as I did it.

[MarginWalker]

The second one has also had the feed forward bridge balance adjusted, as I did it.

Hi Alan,

Im afraid I have no idea what this means. Could you explain for the technically illiterate?

Phil

[Firebottle]

As it is a current dumping amplifier there is a set of four components that forms a bridge (4 components connected in a square) that balances the driver and output stage.
As built it is felt that this bridge is out of balance, hence the advice on a couple of sites to change one of the resistor values.

[Light Dependant Resistor]

I have now received the second of two Quad 306s i have bought recently so thought i would open them both up to see if there were any differences inside. Sure enough the one with the slightly shabbier case and new binding posts has had new caps fitted, whereas the much tidier example looks to be all original. My intention is to have a listen to both to see if i prefer one or the other . If the upgraded version sounds better, as i imagine it will, then i will probably cannibalise the minty case for use on that one. It will certainly be interesting to be able to hear the two of them side by side once the preamp arrives!

http://i.imgur.com/lA5t57Bh.jpg (https://imgur.com/lA5t57B)

http://i.imgur.com/MfeQOZJh.jpg (https://imgur.com/MfeQOZJ)

http://i.imgur.com/iM1PgyTh.jpg (https://imgur.com/iM1PgyT)

http://i.imgur.com/vqu42Dkh.jpg (https://imgur.com/vqu42Dk)

http://i.imgur.com/DBw1YySh.jpg (https://imgur.com/DBw1YyS)

As you have 2 , use one amp per channel, per speaker - meaning one channel is unconnected on each amp - the benefit of connecting that way will be immediately apparent.

[bosa]

I had two Arcam Alpha 9 power amps and used one for stereo bass and one for stereo treble. Is the one amp for each channel better? I was very impressed with the Arcam setup.

[Light Dependant Resistor]

I had two Arcam Alpha 9 power amps and used one for stereo bass and one for stereo treble. Is the one amp for each channel better? I was very impressed with the Arcam setup.

Involving frequency division as you suggest, requires either a set of speakers providing separate binding posts for each section- or ability to divide the crossover with separate binding posts
and Yes will work well, usually without too much trouble.

Where though we use a active crossover, this enables much greater refinement and audio result, some guidance here with a project involving electrostatic panels shows what is involved:
https://robmid42.wixsite.com/diyaudiokits/er-audio-esl-speaker-kit

The idea though of a Quad 306 using one channel of each amp per speaker is far more simple, easy if you have a spare amplifier to implement , and provides easy to hear benefit, over one amp in a normal stereo set up.