Hello again guys!
So I've been using the 303 with the the 33 and FM3 and it has been a pleasure.
I've been getting a loud crackling sound from now and then though. It sounds like a scratching needle with some loud pops. It lasts about 5-10s and then goes away. Turning the power off once it starts doesn't cut it, it goes on the same as with power, 5-10s.
It has to be the 303 right? I can't test it solo as I don't have the connector.
So I've been using the 303 with the the 33 and FM3 and it has been a pleasure.
I've been getting a loud crackling sound from now and then though. It sounds like a scratching needle with some loud pops. It lasts about 5-10s and then goes away. Turning the power off once it starts doesn't cut it, it goes on the same as with power, 5-10s.
It has to be the 303 right? I can't test it solo as I don't have the connector.
Not enough to come to any conclusions really.
One or both channels affected?
Does the volume control on the 33 change the level of the cracks?
Does altering any of the tone controls change anything?
Is it on any input?
One or both channels affected?
Does the volume control on the 33 change the level of the cracks?
Does altering any of the tone controls change anything?
Is it on any input?
Yes, I know... I should just buy a connector so I can test the 303 solo.
Since I power everything off and it still goes on it has to be the 303 right?
I will try to replicate it, power it off while removing the connection to the 33. That way I will make sure it is the 303.
both
no
not tested
at least in two
Since I power everything off and it still goes on it has to be the 303 right?
I will try to replicate it, power it off while removing the connection to the 33. That way I will make sure it is the 303.
I really wouldn't like to say. The 303 will run for a while as the reservoir caps discharge but killing the power you would think would at least change the fault if it were in the regulator section. It can't really be a power amp issue because both boards/channels are affected.
Clicks and cracks mean rapid changes in voltage and I don't the supply going up and down wouldn't do that, it just couldn't change that quickly.
Is there any possibility this could be external to the amp like an arcing thermostat or similar?
If it happens a lot then try running the 303 with the 33 removed and the power amp inputs shorted.
Clicks and cracks mean rapid changes in voltage and I don't the supply going up and down wouldn't do that, it just couldn't change that quickly.
Is there any possibility this could be external to the amp like an arcing thermostat or similar?
If it happens a lot then try running the 303 with the 33 removed and the power amp inputs shorted.
I had a similar problem and it was the 33. Single sided board with lots of solder joints. It could have been on this forum I talked about this. The conclusion was to reflow all the solder joints on the 33 main board.
That sorted it.
Of course that might not be the poster's problem
That sorted it.
Of course that might not be the poster's problem
Intermittent fault possibility. When I hear that kind of thing... A quick way to locate/ eliminate intermittency: Make sure everything is on and audible, 'Wiggle the interconnect cables' routine. Then with the equipment open, gently wiggle all internal cables/ wires or anything that can be connected or disconnected, clean and electro lube it. Then tap tap components on the circuit board. Make sure to use a non conductive instrument, like thin wood or plastic.
Dry solder joints can be deceptive. A 10 x magnifier eye piece and a very strong lamp will be useful.
Dry solder joints can be deceptive. A 10 x magnifier eye piece and a very strong lamp will be useful.
I don't quite get the question, do you mean HVAC/similar? I don't have any of that.
Earths, I will make a careful inspection as that might be the problem.
So yesterday I left it on for a few hours and no problemo. Today when I turned it up I got the noise so I disconnected the 33 with everything on.
The noise continued and seemed to get worse. Turn the 303 off and then on again (with 33 disconnected), now the noise is much louder, scary loud.
But with some power ups it got "normal" again and with the 33 connected it stabilized.
I don't know how it didn't occur to me to power up the 303 with nothing connected. Why should I short the inputs Mooly?
This is what I found. Do you mean connect 1-2 and 3-2 ?
Anything that could arc like HVAC or fridge, freezer etc. They would be more on off noises though.
Don't rule out anything like fuse holders in the amp or in the mains plug etc. Mains switch arcing ?
Sort of good practice really as it stops stray pickup of noise. You would short pins 1, 2 and 3 in your diagram.
The on/off switch on my 33 burnt out, because the contact snubber had failed. That produced all sorts of untoward squeaks and crackle noises. I tried replacing it with a new one from Quad, but the channel matching was lousy. The old Neanderthal one was almost perfectly matched.
So I bought a NOS 1Meg single gang pot for peanuts from eBay, but had an identical switch to the failed one. So I removed the burnt out switch, and put the NOS one from the sacrificial 1Meg. Then put on a new snubber.
Problem solved.
So I bought a NOS 1Meg single gang pot for peanuts from eBay, but had an identical switch to the failed one. So I removed the burnt out switch, and put the NOS one from the sacrificial 1Meg. Then put on a new snubber.
Problem solved.
It seems to be fixed 🙂
It was a dry solder joint as Earths suggested. Going through all components I replaced and wires that I add to remove, I found a condenser that made the faintest click when pressed down. I made a new weld and no more noise!
Thank you again guys 🙏
The 303 is really a joy to work with, we have access to everything by just removing 4 screws! And all in a very compact design. Do any of you know who was the industrial designer that worked in this? It could be very well be made today, slick design.
It was a dry solder joint as Earths suggested. Going through all components I replaced and wires that I add to remove, I found a condenser that made the faintest click when pressed down. I made a new weld and no more noise!
Thank you again guys 🙏
The 303 is really a joy to work with, we have access to everything by just removing 4 screws! And all in a very compact design. Do any of you know who was the industrial designer that worked in this? It could be very well be made today, slick design.
Well that's excellent news 👍 well done.
RIFA caps and snubbers are the ones that always crop up. They are horrendous as they age and often fail with clouds of dense smoke.
Just search the web for 'RIFA caps'.
It is a new product in Quad's stable https://quad-hifi.co.uk/products/quad-303 as is a new 33 https://quad-hifi.co.uk/products/quad-33
I meant the case design, color palette, etc
In my opinion it even beats Dieter Rams designs. Maybe I'm biased but aren't they the most beautiful looking things? In this style nothing beats it.
I have the 3 lined up, the only thing that is missing is the second 303 hehehe
I know sawyers, that is a testament to the design.
What do you guys think?
Cabinet was made by me. Not from the scratch but from what I had access too. Base is from a bench and the stainless steel top was from a kitchen hehehe
I used a tensioned steel cable for central support, an idea from an older project.
Really happy with the results, It is a joy to look at everyday.