Fuse bypass?
Dear Fred:
While we are on the subject of regulators and power supplies, on a previous occasion, I recall you mentioning that bypassing the fuse-holder on the primary side of an AC mains transformer with a small-value capacitor could have a beneficial effect on the sonics of an amplifier. Since you have hands-on experience in this area, and I do not, could you offer your thoughts on the following questions?
What sort of voltage rating would you suggest for the cap - for use with 100V AC lines, 117V AC lines, and 230V AC lines, respectively?
What is the largest capacitance value that you could safely recommend, and by the same token, what is the smallest capacitance value that you think would still provide some sonic benefit?
Do you feel that the capacitor dielectric (electrolytic vs. film, and within film, polyester vs. film etc,) and construction (stacked vs, non-inductive wound vs. inductive wound) will affect the sonics? If you tried a variety of different capacitor types, what sort of trend did you observe regarding the relationship between the capacitor type and the sonics?
Do you feel that the sonic benefit is due to the bypassing of the fuse, or the fuse holder? If, for example, the fuse were soldered in place rather than captured in a spring-loaded holder, do you think that there would still be a good chance of a clearly perceptible sonic improvement?
Subjective impressions and speculative opinions are both welcome.
Thank you in advance, jonathan carr
Dear Fred:
While we are on the subject of regulators and power supplies, on a previous occasion, I recall you mentioning that bypassing the fuse-holder on the primary side of an AC mains transformer with a small-value capacitor could have a beneficial effect on the sonics of an amplifier. Since you have hands-on experience in this area, and I do not, could you offer your thoughts on the following questions?
What sort of voltage rating would you suggest for the cap - for use with 100V AC lines, 117V AC lines, and 230V AC lines, respectively?
What is the largest capacitance value that you could safely recommend, and by the same token, what is the smallest capacitance value that you think would still provide some sonic benefit?
Do you feel that the capacitor dielectric (electrolytic vs. film, and within film, polyester vs. film etc,) and construction (stacked vs, non-inductive wound vs. inductive wound) will affect the sonics? If you tried a variety of different capacitor types, what sort of trend did you observe regarding the relationship between the capacitor type and the sonics?
Do you feel that the sonic benefit is due to the bypassing of the fuse, or the fuse holder? If, for example, the fuse were soldered in place rather than captured in a spring-loaded holder, do you think that there would still be a good chance of a clearly perceptible sonic improvement?
Subjective impressions and speculative opinions are both welcome.
Thank you in advance, jonathan carr
Re: Fuse bypass?
This can be checked by wrapping copper tape around the fuse and reinserting it in a holder.
I'm also interested in that issue but didn't try it yet.
jcarr said:
This can be checked by wrapping copper tape around the fuse and reinserting it in a holder.
I'm also interested in that issue but didn't try it yet.
Peter Daniel
I don't think this is what jcarr is asking. The issue of the fuse holder as a sonic detriment is the less obvious one. The method you suggest will bypass the fuse but not the fuse holder effect on sonics.
I don't think this is what jcarr is asking. The issue of the fuse holder as a sonic detriment is the less obvious one. The method you suggest will bypass the fuse but not the fuse holder effect on sonics.
FWIW
Hi,
I did some experiments with soldering the fuse to its holder and found it brought a small improvement.
Many years ago you could get upgrades to mains plugs and fuses
(gold plated prongs and gold plated endcaps respectively) from RATA in the U.K.
I never thought of bypassing the fuse/holder with a cap so I can't comment on that.
Or you could jumper the lot with a piece of wire as an experiment..hoping nothing is going to blow while you're at it.😱
Cheers,😉
Hi,
I did some experiments with soldering the fuse to its holder and found it brought a small improvement.
Many years ago you could get upgrades to mains plugs and fuses
(gold plated prongs and gold plated endcaps respectively) from RATA in the U.K.
I never thought of bypassing the fuse/holder with a cap so I can't comment on that.
Or you could jumper the lot with a piece of wire as an experiment..hoping nothing is going to blow while you're at it.😱
Cheers,😉
By using copper tape around fuse you eliminate fuse but can still here the effect of a folder. Shorting the holder under the board, eliminates whole thing. I've heard about rather expensive type of magnetic circuit breaker that sounds pretty good, but again, didn't try them.
Peter Daniel
Well, I guess you'll hear no greater than half the effect that way since the effect will now be in parallel with the copper tape.
Dear Peter:
>This can be checked by wrapping copper tape around the fuse and reinserting it in a holder.<
This isn't what I meant. Rather, my question was whether using the capacitor bypass on a fuse that had been soldered in position would be sonically benefical, or if the capacitor bypass was beneficial primarily for fuses in fuse holders.
You see, on some of my products, I am already using a silver-plated beryllium copper fuse holder that has a much stronger clamping force than any brass fuse-holder that I have ever encountered. And on some smaller products that draw comparatively little power, the fuse is soldered in place.
Now, if the sonic benefit of the capacitor bypass was primarily due to its effect on the fuse holder rather than the fuse, I would most likely get much less of a sonic improvement than someone who was using a normal brass fuse holder.
Does this make sense?
regards, jonathan carr
>This can be checked by wrapping copper tape around the fuse and reinserting it in a holder.<
This isn't what I meant. Rather, my question was whether using the capacitor bypass on a fuse that had been soldered in position would be sonically benefical, or if the capacitor bypass was beneficial primarily for fuses in fuse holders.
You see, on some of my products, I am already using a silver-plated beryllium copper fuse holder that has a much stronger clamping force than any brass fuse-holder that I have ever encountered. And on some smaller products that draw comparatively little power, the fuse is soldered in place.
Now, if the sonic benefit of the capacitor bypass was primarily due to its effect on the fuse holder rather than the fuse, I would most likely get much less of a sonic improvement than someone who was using a normal brass fuse holder.
Does this make sense?
regards, jonathan carr
WHILE ON THE SUBJECT...
Hi,
Not all fuses are alike either...some are just crap others are high quality, sound better and are far more reliable.
Some fuses are so bad they take the fuseholder with them or carbonising them in the process.
I refer to the panelmounting types.
I only tried a few of those and yes they were better but about ten times the price of a regular one.
I think the brandname was Cirkit but I'm not 100% sure about this.
Cheers,😉
Hi,
Not all fuses are alike either...some are just crap others are high quality, sound better and are far more reliable.
Some fuses are so bad they take the fuseholder with them or carbonising them in the process.
I refer to the panelmounting types.
I only tried a few of those and yes they were better but about ten times the price of a regular one.
I think the brandname was Cirkit but I'm not 100% sure about this.
Cheers,😉
Re: Fuse bypass?
-----------------------------------------------------------
I am the nice Fred and I have some experience on fuses, though not bypassing with a cap.
Replacing delay fuses which seem to be prevalent in north american electronics with fast blos of much lower resistance (around 2-4 times rating ) makes a great difference. More clarity etc.
Doing away with mains fuses in the uk where there is already a fuse inside the unit is similarly beneficial.
There are fast blo fuses and fast blo fuses, and I try to locate those with the lowest impedance from a batch or brand.
I have had good experience with electrononic fuses, some of which are low impedance.
As for bypassing, I would recommend using x2 and if I remeber correctly the notation y2 polypropylenes, if only for safety reasons as the ones to try first. I may try this with 100o p going on to 4700p.
jcarr said:
-----------------------------------------------------------
I am the nice Fred and I have some experience on fuses, though not bypassing with a cap.
Replacing delay fuses which seem to be prevalent in north american electronics with fast blos of much lower resistance (around 2-4 times rating ) makes a great difference. More clarity etc.
Doing away with mains fuses in the uk where there is already a fuse inside the unit is similarly beneficial.
There are fast blo fuses and fast blo fuses, and I try to locate those with the lowest impedance from a batch or brand.
I have had good experience with electrononic fuses, some of which are low impedance.
As for bypassing, I would recommend using x2 and if I remeber correctly the notation y2 polypropylenes, if only for safety reasons as the ones to try first. I may try this with 100o p going on to 4700p.
Jonathan
Very thought-provoking.
The deleterious effects of fuses are a real pain, so this is worthy of some investigation. I would have thought from a safety perspective the cap would have to be a minimum of an X type, maybe a Y as it in effect bypasses the safety device.
For that reason too, too large a value could partially negate the safety aspects of the fiuse, so a Y type (which are generally of a lower value) may be best.
I'm gonna have a rummage through my parts bin, and try something today, if I have anything suitable. The benefits are I guess at HF, and particularly with some time-lag fuses being of a coiled construction this may help with reducing an inductive impedance rise within the fuse, and help with any HF contact issues within the fuseholder.
Off to play....
Andy
Very thought-provoking.
The deleterious effects of fuses are a real pain, so this is worthy of some investigation. I would have thought from a safety perspective the cap would have to be a minimum of an X type, maybe a Y as it in effect bypasses the safety device.
For that reason too, too large a value could partially negate the safety aspects of the fiuse, so a Y type (which are generally of a lower value) may be best.
I'm gonna have a rummage through my parts bin, and try something today, if I have anything suitable. The benefits are I guess at HF, and particularly with some time-lag fuses being of a coiled construction this may help with reducing an inductive impedance rise within the fuse, and help with any HF contact issues within the fuseholder.
Off to play....
Andy
Re: WHILE ON THE SUBJECT...Fuses
Yes Frank, right, not all fuses are alike:
http://db.audioasylum.com/cgi/m.pl?forum=tweaks&n=35148&highlight=elso+fuse&r=&session=
😉
fdegrove said:
Yes Frank, right, not all fuses are alike:
http://db.audioasylum.com/cgi/m.pl?forum=tweaks&n=35148&highlight=elso+fuse&r=&session=
😉
BREEK ME DE BEK NIET OPEN...
Hi Elso,
Car type fuses in your Klipschorns?
Are you sure those are needed at all?
I made my own KHs at the age of 14 and never had any trouble with the speakers without the fuses.
Other than that, what's your prefered type? other than those 3A cartype things...
Cheers,😉
Hi Elso,
Car type fuses in your Klipschorns?
Are you sure those are needed at all?
I made my own KHs at the age of 14 and never had any trouble with the speakers without the fuses.
Other than that, what's your prefered type? other than those 3A cartype things...
Cheers,😉
Jonathan,
I use about .22 mf at about 250v on a 120v line across the fuse. This trick also works across speaker relay contacts and fuses. I have to agree with Frank and Elso that it does not work as well across better fuses. It is pretty easy to experiment with.
As to why it works we can only speculate maybe the capacitor compensates for non-linearities in the fuse or diode junction effects in the relay contacts.
Regards,
Jam
I use about .22 mf at about 250v on a 120v line across the fuse. This trick also works across speaker relay contacts and fuses. I have to agree with Frank and Elso that it does not work as well across better fuses. It is pretty easy to experiment with.
As to why it works we can only speculate maybe the capacitor compensates for non-linearities in the fuse or diode junction effects in the relay contacts.
Regards,
Jam
Fred,
I don't know if you noticed, but the driver in your avatar started moving faster recently.😉
I don't know if you noticed, but the driver in your avatar started moving faster recently.😉
Hi,
Probably his pulse's gone up a bit.😉
Oh, and I'm a conFUSED as to why Fred replied offline to Jonathan...after all it would be nice for us to know what that cap achieves across the fuse.
Ciao,😉
Probably his pulse's gone up a bit.😉
Oh, and I'm a conFUSED as to why Fred replied offline to Jonathan...after all it would be nice for us to know what that cap achieves across the fuse.
Ciao,😉
fdegrove said:
I guess, it's one of the last few mysteries remaining in High End audio. And Fred likes to be mysterious, sometimes:😉
The audible change from getting the fuses out of the circuit will be rather significant unless your amplifier manufacturer/designer has taken measures to reduce the audibility of the fuses. This is possible. A few amp manufacturers know how to do it, but most don’t. Those who do know how to do it consider it one of their proprietary design features. Since I learned how to do it from one of these few amp manufacturers, I am not at liberty to reveal the technique(s), unfortunately.
Again.... see picture under previous post.
'Oh, and I'm a conFUSED as to why Fred replied offline to Jonathan...after all it would be nice for us to know what that cap achieves across the fuse."
Someone will come along and explain it better than I can, honest. Am I the only guy with an opion worth posting? I am starting to feel like the Dear Abby of the DIY audio community. I think most people are a bit tired of listening to me this week. I really don't blame them either. Besides, even God took a day off after a particularly busy week. You have to wonder what he did with his free time though. Mr. Carr directed the question at me and I directed the answer to him, that all there is to it really......
'Oh, and I'm a conFUSED as to why Fred replied offline to Jonathan...after all it would be nice for us to know what that cap achieves across the fuse."
Someone will come along and explain it better than I can, honest. Am I the only guy with an opion worth posting? I am starting to feel like the Dear Abby of the DIY audio community. I think most people are a bit tired of listening to me this week. I really don't blame them either. Besides, even God took a day off after a particularly busy week. You have to wonder what he did with his free time though. Mr. Carr directed the question at me and I directed the answer to him, that all there is to it really......
SO...
Hi,
So, I hope there's no objection then for us to start a new thread while the gods are playing with Eve?
Cheers,😉
P.S. Peter, since this is for DIY purposes and to the best of my knowledge we wouldn't be infringing on anything, shall I start a new thread on this?
Hi,
So, I hope there's no objection then for us to start a new thread while the gods are playing with Eve?
Cheers,😉
P.S. Peter, since this is for DIY purposes and to the best of my knowledge we wouldn't be infringing on anything, shall I start a new thread on this?
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