http://www.coasterreview.com/phono/?mode=album&album=phono&dispsize=725&start=0
Anyone able to identify the two silver caps on that board?
Anyone able to identify the two silver caps on that board?
Capacitor type.
If you mean what type they are : - they were called styroflex capacitors over here. I never knew why it was called that.
One doesn't find them nowadays in this market.
If you mean values , you might have to rotate them around. The value is usually mentioned quite clearly . I have several of these types ( old stock !).
Cheers.
If you mean what type they are : - they were called styroflex capacitors over here. I never knew why it was called that.
One doesn't find them nowadays in this market.
If you mean values , you might have to rotate them around. The value is usually mentioned quite clearly . I have several of these types ( old stock !).
Cheers.
Forgot some details.
These are metal film caps unlike the metallised foil that is very popular today. Basically I think they are made with two metal foils and a plastic film rolled up into a roll. I have no idea how good it is compared to modern day film caps. But I have seen 2.5% types and so they must be pretty good I think.
I have seen values from 100pF to just over 0.01uF.
If the circuit is a phono preamp, you could check the resistor values and calculate the cap values . It looks like a standard phono feedback circuit.
Cheers.
These are metal film caps unlike the metallised foil that is very popular today. Basically I think they are made with two metal foils and a plastic film rolled up into a roll. I have no idea how good it is compared to modern day film caps. But I have seen 2.5% types and so they must be pretty good I think.
I have seen values from 100pF to just over 0.01uF.
If the circuit is a phono preamp, you could check the resistor values and calculate the cap values . It looks like a standard phono feedback circuit.
Cheers.
It seems like you already have the values on the attached schematic. Here's the equasions which you can use to check if the values are correct.
This is a pretty nice album and the phono stage looks very nice too (the way it's put together). You can use any quality caps and the better ones will improve performance. As to coupling caps, they look indeed like Solens, and again, you can use better ones here.
Do you have any more albums like that?
Edit: 270 and 75 should be followed by " = " which is missing in a drawing.
This is a pretty nice album and the phono stage looks very nice too (the way it's put together). You can use any quality caps and the better ones will improve performance. As to coupling caps, they look indeed like Solens, and again, you can use better ones here.
Do you have any more albums like that?
Edit: 270 and 75 should be followed by " = " which is missing in a drawing.
Attachments
And still available from Partsconnexion: http://www.partsconnexion.com/catalog/capacitors.html
Dig that crazy glue.....Man....
I don't believe polystyrene caps are made much anymore due to there poor resistance to many solvents. I also heard that the only remaining vendor of good PS film has stopped manufacturing it. They are foil and film and I don't believe you can metalize the PS dielectric. They are my favorite type cap and I have seen them up to about a uF for audiophile type caps. Have yet to find a Silver Mica sound better than a good PS in anything I have modified. For small values the old Siemens Styroflex were some of the best. For those who still think they are commonly available go try to buy a bunch of new (not surplus) 4700 pF PS caps.
I believe 0.0027uF (2700 pF) and 27K ohms is what comes close to the 75 uS time constant. The exact value would be 2778pF for the precision people and could be a selected 2700 pF cap or selected 27K resistor picked to match the cap value.
I don't believe polystyrene caps are made much anymore due to there poor resistance to many solvents. I also heard that the only remaining vendor of good PS film has stopped manufacturing it. They are foil and film and I don't believe you can metalize the PS dielectric. They are my favorite type cap and I have seen them up to about a uF for audiophile type caps. Have yet to find a Silver Mica sound better than a good PS in anything I have modified. For small values the old Siemens Styroflex were some of the best. For those who still think they are commonly available go try to buy a bunch of new (not surplus) 4700 pF PS caps.
I believe 0.0027uF (2700 pF) and 27K ohms is what comes close to the 75 uS time constant. The exact value would be 2778pF for the precision people and could be a selected 2700 pF cap or selected 27K resistor picked to match the cap value.
>Simplicity at it's best.<
From a production engineering standpoint, I don't think so. When I don't want any worksmanship to be involved, I use an automated pcb assembly facility (pick-and-place machines, cream solder, ovens, wave soldering), and pcbs designed for the task. Eliminating the possibility of human error usually helps reliablity, and the outcome will look a lot neater and nicer than the photos that were posted.
And when I want to use human worksmanship, I want it done well, with a craftsmans' sense of pride in the quality of the results.
regards, jonathan carr
From a production engineering standpoint, I don't think so. When I don't want any worksmanship to be involved, I use an automated pcb assembly facility (pick-and-place machines, cream solder, ovens, wave soldering), and pcbs designed for the task. Eliminating the possibility of human error usually helps reliablity, and the outcome will look a lot neater and nicer than the photos that were posted.
And when I want to use human worksmanship, I want it done well, with a craftsmans' sense of pride in the quality of the results.
regards, jonathan carr
Re: Dig that crazy glue.....Man....
Fred
Polystyrene capacitors, in values up to 10nF, are still being made by LCR and are readily available here in the UK, in small or large quantities, at the likes of CPC, RS Components and Farnell.
They also appear to be available in the US, see:
http://www.lcr-inc.com/capacitors_electronics.htm
Geoff
Fred Dieckmann said:
Fred
Polystyrene capacitors, in values up to 10nF, are still being made by LCR and are readily available here in the UK, in small or large quantities, at the likes of CPC, RS Components and Farnell.
They also appear to be available in the US, see:
http://www.lcr-inc.com/capacitors_electronics.htm
Geoff
Hi Jonathan,
I'm still far away from having access to such facilities, so my main interest is not in PCBs, but in the ways to put things together nicely, without using much effort.
The Grado unit strikes me as such. Having the wood block milled out to a required shape, and then painted inside to eliminate RF interference, makes it a nice starting point for a chassis. It's probably better than metal chassis, as wood affects electrical circuits less than metal (sonically, or at least in a different way). If the type of wood is chosen properly, it can even make a nice contribution to the final sound.
I also suspect that it's not coincidence that the board is not attached to the wood by screws and usual standoffs but it's done by using hot glue (I suspect). Also the output coupling caps make a nice coupling point to the wooden box (although this may cause picking the vibrations from the box).
Additionally the bottom metal cover, adds some mass and stability. I am still impressed by the engineering choices made in constraction of this little wonder, and I definitely use some of them to inspire my future projects (the cheap ones at least).
Any idea how it performs?
I'm still far away from having access to such facilities, so my main interest is not in PCBs, but in the ways to put things together nicely, without using much effort.
The Grado unit strikes me as such. Having the wood block milled out to a required shape, and then painted inside to eliminate RF interference, makes it a nice starting point for a chassis. It's probably better than metal chassis, as wood affects electrical circuits less than metal (sonically, or at least in a different way). If the type of wood is chosen properly, it can even make a nice contribution to the final sound.
I also suspect that it's not coincidence that the board is not attached to the wood by screws and usual standoffs but it's done by using hot glue (I suspect). Also the output coupling caps make a nice coupling point to the wooden box (although this may cause picking the vibrations from the box).
Additionally the bottom metal cover, adds some mass and stability. I am still impressed by the engineering choices made in constraction of this little wonder, and I definitely use some of them to inspire my future projects (the cheap ones at least
).Any idea how it performs?
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