A question about the Quad 909

[Rickster71]

While doing some searching on Quad amps, I stumbled upon this Quad restoration site: http://quadrevisionspot.blogspot.com/2010/08/improving-new-quad-909.html

The article I've linked shows some testing on a 909 that had noise problems.
It was discovered that at some point in the production cycle, cheaper caps were substituted.
My question is: How can I find out when they started substituting different caps? It sounds like the old versions are a safer bet than the new models.

The article is complete with a post (near the bottom) from Stan Curtis of Quad.

Stan's Post:
I just came across your site; an interesting read although I won't have time to go through your archives. Your results on testing the Quad 909 are quite shocking. When I designed this product I introduced new components throughout with great care and the sound and measured performance were greatly superior to the earlier but almost identical 606. To most listeners it was a different amplifier. Many of the components as specified had to be imported from Europe; inconvenient but necessary.
It seems that the factory no longer bothers and fits generic components. With factories everywhere, not just China, the designer has to keep monitoring the production because the factory will substitute components for convenience; to save money or even to fit a "better" part with the best of intentions.
I adopted the same philosophy as with Rotel; Cambridge Audio and many other companies I designed for where there is no one component or circuit feature that is vital but the overall combination works very well. Change one thing and the balance is lost.
With best wishes to you.
Stan Curtis

 

[TLS Guy]

While doing some searching on Quad amps, I stumbled upon this Quad restoration site: http://quadrevisionspot.blogspot.com/2010/08/improving-new-quad-909.html

The article I've linked shows some testing on a 909 that had noise problems.
It was discovered that at some point in the production cycle, cheaper caps were substituted.
My question is: How can I find out when they started substituting different caps? It sounds like the old versions are a safer bet than the new models.

The article is complete with a post (near the bottom) from Stan Curtis of Quad.

Stan's Post:
I just came across your site; an interesting read although I won't have time to go through your archives. Your results on testing the Quad 909 are quite shocking. When I designed this product I introduced new components throughout with great care and the sound and measured performance were greatly superior to the earlier but almost identical 606. To most listeners it was a different amplifier. Many of the components as specified had to be imported from Europe; inconvenient but necessary.
It seems that the factory no longer bothers and fits generic components. With factories everywhere, not just China, the designer has to keep monitoring the production because the factory will substitute components for convenience; to save money or even to fit a "better" part with the best of intentions.
I adopted the same philosophy as with Rotel; Cambridge Audio and many other companies I designed for where there is no one component or circuit feature that is vital but the overall combination works very well. Change one thing and the balance is lost.
With best wishes to you.
Stan Curtis

All but one of my 909s are older and made in Huntingdon and not China.

I will take a closer look at the Chinese made one next week.

I just wish China would fall off the globe or self destruct. Far Eastern kit has been the ruination of the audio industry.

It would take that crowd to ruin a good thing.

I'm certain we will eventually have to have hefty tariffs, or let wages sink to $2 per hour.

I just see a lot of posturing at present to try and put off he inevitable.

 

[Rickster71]

Thanks Mark,
Quad sounds like the make some nice equipment.
I'd be interested in your findings once you pop the hood.

If and when China cleans up their act, they'll be a huge force to reckoned with.