Hi,
Have a look at the picture of the power supply section of the Creek 5350. It looks like the fuse is located is located before the bridge rectifier which is a normal 6A diode (?) .
The fuse will be subject to the in rush current everytime the unit is switched on. This will cause it to slowly weaken and break one day even without an overload.
Wouldn't you think so ?
Have a look at the picture of the power supply section of the Creek 5350. It looks like the fuse is located is located before the bridge rectifier which is a normal 6A diode (?) .
The fuse will be subject to the in rush current everytime the unit is switched on. This will cause it to slowly weaken and break one day even without an overload.
Wouldn't you think so ?
Attachments
"Wouldn't you think so ?"
Probably not. The fuse must be on the primary of the power transformer if it is to protect the entire amplifier.
The diodes may be rated at 6 amps but they are on the secondary of the transformer. The primary current will probably be somewhat lower.
I wouldn't worry.
Probably not. The fuse must be on the primary of the power transformer if it is to protect the entire amplifier.
The diodes may be rated at 6 amps but they are on the secondary of the transformer. The primary current will probably be somewhat lower.
I wouldn't worry.
Hmmmm..............................
Hi Frank,
I would have thought that the primary currents would be a scaled down version of the secondary currents. Fuse ratings would also be lower. Switch on surge current would be quite high even though the duration is very short.
True that it would protect the whole amp, being located on the primary side.
Hmm.......... I guess with proper choice it should be OK.
Cheers.
Hi Frank,
I would have thought that the primary currents would be a scaled down version of the secondary currents. Fuse ratings would also be lower. Switch on surge current would be quite high even though the duration is very short.
True that it would protect the whole amp, being located on the primary side.
Hmm.......... I guess with proper choice it should be OK.
Cheers.
ashok said:
I thought it would be right for me to answer as I've designed this amplifier
. Fuses are indeed of a "slow blow" variety, and I didn't heard even of one case when they blew from the inrush current. They positioned as described - between the secondary of the transformer and the bridge rectifier. On top of that there is a usual mains fuse on the primary side - inside the mains socket.Regards
x-pro
Fuses are "lazy", and will open when you amplifier turn damaged
In normal conditions, they are slow to burn, this way, inrush, as a slow time current will be ignored.
Of course if well calculated fuse, wrong value will blow easy when inrush happens.....and if the wrong value, was higher than the correct one....hehe, will burn after other part already burned.
The main reason, is to protect the board and circuits against heavy shorts, to avoid fire in the circuit boards, because transistor is fast to burn, and to call some others to burn with it too!... a sequence of shorts... each one makes the current drain increase....in microseconds all them goes to "heaven"...or "hell" if you prefer....in miliseconds the fuse will burn to avoid flame.
I do not think fuse can protect parts....it is too slow....either the fast ones, i thing it is usefull to tell you that something is going wrong.
This way, when a correct fuse blows, something may be wrong in the circuit, at least the bias moved to a higher value of current, and many reasons can make that, as some example:
temperature drift, rust in bias adjustment trimpot or mechanical vibration.
Avoid fire!, that's the work really done.
Maybe this is obvious to you, but there are young boys that do not know that, if not usefull to you, can be good for them.
I am sorry if you are one expert and i am telling those simple things to you, in the reality, i never write to only one, always i am thinking the young guys problems, those, without experience, will be happy.
In Army, my Sargeant, Ottmar Albert Furrer, helped me a lot; now it's my time to pay my bill to mankind.
regards,
Carlos
In normal conditions, they are slow to burn, this way, inrush, as a slow time current will be ignored.
Of course if well calculated fuse, wrong value will blow easy when inrush happens.....and if the wrong value, was higher than the correct one....hehe, will burn after other part already burned.
The main reason, is to protect the board and circuits against heavy shorts, to avoid fire in the circuit boards, because transistor is fast to burn, and to call some others to burn with it too!... a sequence of shorts... each one makes the current drain increase....in microseconds all them goes to "heaven"...or "hell" if you prefer....in miliseconds the fuse will burn to avoid flame.
I do not think fuse can protect parts....it is too slow....either the fast ones, i thing it is usefull to tell you that something is going wrong.
This way, when a correct fuse blows, something may be wrong in the circuit, at least the bias moved to a higher value of current, and many reasons can make that, as some example:
temperature drift, rust in bias adjustment trimpot or mechanical vibration.
Avoid fire!, that's the work really done.
Maybe this is obvious to you, but there are young boys that do not know that, if not usefull to you, can be good for them.
I am sorry if you are one expert and i am telling those simple things to you, in the reality, i never write to only one, always i am thinking the young guys problems, those, without experience, will be happy.
In Army, my Sargeant, Ottmar Albert Furrer, helped me a lot; now it's my time to pay my bill to mankind.
regards,
Carlos
Hi X-pro and Carlos,
Thanks for your posts.
X-pro ,
The amp looks very nice too ! I like the surface finish which looks like silver satin anodising in the picture.
I have a question. I notice that the inputs are selected by a motorised switch with long signal traces between input and the switch. Would DIP relays at the rear have turned out to be far more expensive ? Would it have detracted from the sound ?
Thanks.
Carlos,
You should keep up your long informative posts. It will help lots of budding DIY guys and refresh the memories of some of the older guys.
Great to see you are having a wonderful time on this forum.
Cheers,
Ashok.
Thanks for your posts.
X-pro ,
The amp looks very nice too ! I like the surface finish which looks like silver satin anodising in the picture.
I have a question. I notice that the inputs are selected by a motorised switch with long signal traces between input and the switch. Would DIP relays at the rear have turned out to be far more expensive ? Would it have detracted from the sound ?
Thanks.
Carlos,
You should keep up your long informative posts. It will help lots of budding DIY guys and refresh the memories of some of the older guys.
Great to see you are having a wonderful time on this forum.
Cheers,
Ashok.
ashok said:
Relays would not be more expencive and I suppose same soundwise, but a motorised switch has an important advantage - you could change the inputs both from remote and from the front panel in a usual manner plus it stays where you put it when the power is off
- without additional complications, like non-volatile memory etc. x-pro
Hi x-pro,
LOL
I was going to answer in a similar way that you did. I do the Creek warranty in Canada for Europroducts. I wonder if we've met?? I was at the Sept show in 2004 and the product meeting as well.
Hi ashok,
I've only replaced one fuse in the field, the customer "did something silly" (they didn't admit what that was). They also blew a 6 A rectifier, first I've seen. Outputs were okay on that one. These seem to be very reliable amplifiers. But a pain to take apart and service.
-Chris
LOL
I was going to answer in a similar way that you did. I do the Creek warranty in Canada for Europroducts. I wonder if we've met?? I was at the Sept show in 2004 and the product meeting as well.
Hi ashok,
I've only replaced one fuse in the field, the customer "did something silly" (they didn't admit what that was). They also blew a 6 A rectifier, first I've seen. Outputs were okay on that one. These seem to be very reliable amplifiers. But a pain to take apart and service.
-Chris
anatech said:
I left Creek Audio in November 2002, so we haven't met
. However 5350 is my original design, based (as all Creek amps from 4240) on the N-channel output design idea I've developed in 1992-93.Hi ashok,
I've only replaced one fuse in the field, the customer "did something silly" (they didn't admit what that was). They also blew a 6 A rectifier, first I've seen. Outputs were okay on that one. These seem to be very reliable amplifiers. But a pain to take apart and service.
-Chris
Shall I give you few hints on taking them apart?
Cheers
Alex (x-pro)
anatech said:Hi Alex,
Sure, as long as it doesn't involve dropping the unit until it's apart.
BTW, a pleasure to "meet" you.
Right now I remove the knobs, front panel, rear screws and heatsink and try to lift it out. Clearing any incidental wires etc...
Where are you working now?
-Chris
I work now in industrial electronics, making analogue and digital circuits for very high sensitivity light and x-ray detectors with applications in medicine, biology, science and security scanners. Generally having a lot of fun, thought may be not as much as I did working in the audio field... . My pet home project -"ANT Audio" is essentially on hold at the moment as I don't have much time to spend on it.
Re. taking apart 5350: it is much easier to remove the PCB without detaching the heatsink - just unsrew it at the bottom and when removed, you can put the whole thing upright on the heatsink - it is quite steady. For 5350SE you'll need to unscrew the transformer to move it out of the way.
Cheers
Alex (x-pro)
Hi Alex,
Yes, I unscrew the heatsink from the chassis. Sorry I didn't make myself clear on that point. I like the old days when you could remove the bottom panel to expose the pcb on the other side, I'm (carbon) dating myself I suppose. It's then easier to run the amplifier for testing.
So you followed the money. Wise choice. Audio is my love and was my profession but it will not pay the bills. I work in telecommunications now full time.
I just about to start a Mission 772. Are you laughing yet?
-Chris
Yes, I unscrew the heatsink from the chassis. Sorry I didn't make myself clear on that point. I like the old days when you could remove the bottom panel to expose the pcb on the other side, I'm (carbon) dating myself I suppose. It's then easier to run the amplifier for testing.
So you followed the money. Wise choice. Audio is my love and was my profession but it will not pay the bills. I work in telecommunications now full time.
I just about to start a Mission 772. Are you laughing yet?
-Chris
Hi x-pro.
Sorry. YES Creek 5350.
I need to know topology of the 5350. Is Fully symmetrical?.
My doubt is: ...N channel mosfet Driven by a P channel mosfet phase splitter and double diff votage amplifier with symmetrical class a DRIVER.
I like the Creek 4330. My intention is redesign the 4330, but with 120-150 W and 8ohm.
What is your opinion?
Thanks.
GEirin
Sorry. YES Creek 5350.
I need to know topology of the 5350. Is Fully symmetrical?.
My doubt is: ...N channel mosfet Driven by a P channel mosfet phase splitter and double diff votage amplifier with symmetrical class a DRIVER.
I like the Creek 4330. My intention is redesign the 4330, but with 120-150 W and 8ohm.
What is your opinion?
Thanks.
GEirin
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