Nice !
Pro Ject Tube Box S2 :
It is that with only a series of holes around the socket of each tube they would have prevented the heat from being trapped .....
To imagine that you don't need so much I+D.
It is curious, among the criticisms of the readers, I found only one occasion to mention excessive heat.
PS: The capacitors came away from the tubes as seen in the photo in the factory, that means something ......
Pro Ject Tube Box S2 :
It is that with only a series of holes around the socket of each tube they would have prevented the heat from being trapped .....
To imagine that you don't need so much I+D.
It is curious, among the criticisms of the readers, I found only one occasion to mention excessive heat.
PS: The capacitors came away from the tubes as seen in the photo in the factory, that means something ......
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I would have to look for a job as a reviewer .....🙂😉
Tipos de Capacitores
"Polystyrene Capacitors Polystyrene Capacitor
Polystyrene capacitors are capacitors that have a dielectric made up of polystyrene.
They come only in low values, usually 10pF to 47nF. Normally their tolerance is 5% to 10%, but high precision polystyrene capacitors are also available with tolerances of 1% and 2%. The working voltages for the polystyrene capacitors are from 30V to 630V. Polystyrene capacitors are advantageous because they have high insulation resistance, making them good for use in docking and storage applications. Precision types are suitable for timing, tuning, and filter circuits.
One of their disadvantages is that they are built as a coil on the inside, so they are not suitable for high frequency applications. (This is because the coils create inductance, and the inductance blocks the passage of high-frequency signals.) Another disadvantage is that polystyrene capacitors exhibit a permanent change in value if they are ever exposed to temperatures well above 70 ° C; they do not return to their previous value when cooled. "
Tipos de Capacitores
"Polystyrene Capacitors Polystyrene Capacitor
Polystyrene capacitors are capacitors that have a dielectric made up of polystyrene.
They come only in low values, usually 10pF to 47nF. Normally their tolerance is 5% to 10%, but high precision polystyrene capacitors are also available with tolerances of 1% and 2%. The working voltages for the polystyrene capacitors are from 30V to 630V. Polystyrene capacitors are advantageous because they have high insulation resistance, making them good for use in docking and storage applications. Precision types are suitable for timing, tuning, and filter circuits.
One of their disadvantages is that they are built as a coil on the inside, so they are not suitable for high frequency applications. (This is because the coils create inductance, and the inductance blocks the passage of high-frequency signals.) Another disadvantage is that polystyrene capacitors exhibit a permanent change in value if they are ever exposed to temperatures well above 70 ° C; they do not return to their previous value when cooled. "
I have done a rework on the PJTBS2 box, you can see it here:
https://www.diyaudio.com/community/...ubes-project-tube-box-s2.383291/#post-6946817
https://www.diyaudio.com/community/...ubes-project-tube-box-s2.383291/#post-6946817
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Thanks! , in something you have to entertain yourself...... I should have taken the temperature before and after with the multimeter sensor ....
Just a thought...
Are there gaps/vents in the lower part of the enclosure through which cool air can enter?
For effective cooling, a convection current must be able to form where warm air rising through your holes can pull cool air into the lower part of the enclosure.
Are there gaps/vents in the lower part of the enclosure through which cool air can enter?
For effective cooling, a convection current must be able to form where warm air rising through your holes can pull cool air into the lower part of the enclosure.
I originally wrote "Are there gaps/vents at pc board level...", but changed it.
The vents would have to be on the sides of the upper removable section of the enclosure, just above the top surface of the pc board.
Just my thoughts - you may be correct in thinking that it's not necessary. 😎
The vents would have to be on the sides of the upper removable section of the enclosure, just above the top surface of the pc board.
Just my thoughts - you may be correct in thinking that it's not necessary. 😎
Wouldn't it be better to put the valve bases on standoffs so that all of the valve was above the top surface of the case?
Methinks all this discussion concerning heat is overthinking it.
A ring of holes through top cover around each tube, and a line of similar holes lower down on either side of the cabinet cover. = sufficient convection cooling flow.
These are small tubes, not 6V6's for jeez sakes.
A ring of holes through top cover around each tube, and a line of similar holes lower down on either side of the cabinet cover. = sufficient convection cooling flow.
These are small tubes, not 6V6's for jeez sakes.
Galu, ralphfcooke, wiseoldtech :
Thanks for the suggestions but I need to clarify something.
The reason for the rework is explained in post 102. It is not to extend the life of the valves but to protect the interior of the cabinet from a slight excess of temperature.
The photo you can see was taken from the web, obviously it is not my unit since mine is silver and that one is black. But you can see two capacitors indicated with arrows, they are the ones that I wanted to protect especially.
Avoid overheating beyond 70 degrees Celsius. In fact, the factory unit does not have any ventilation, beyond the necessary holes to house the tubes, so I decided to make the modification.
But I can't make holes on the sides (the idea is a good one, I had already thought about it, thanks anyway) because I would need a professional bench drilling machine that allows the carcass to be placed vertically. I'm not going to buy it, nor annoy friends, nor invest neither time nor money sending the work to a metal-mechanic specialist.
As soon as I have some free time, I'll measure the case temperature - after a few hours of operation - with the multimeter sensor and let you know.
Thanks for the suggestions but I need to clarify something.
The reason for the rework is explained in post 102. It is not to extend the life of the valves but to protect the interior of the cabinet from a slight excess of temperature.
The photo you can see was taken from the web, obviously it is not my unit since mine is silver and that one is black. But you can see two capacitors indicated with arrows, they are the ones that I wanted to protect especially.
Avoid overheating beyond 70 degrees Celsius. In fact, the factory unit does not have any ventilation, beyond the necessary holes to house the tubes, so I decided to make the modification.
But I can't make holes on the sides (the idea is a good one, I had already thought about it, thanks anyway) because I would need a professional bench drilling machine that allows the carcass to be placed vertically. I'm not going to buy it, nor annoy friends, nor invest neither time nor money sending the work to a metal-mechanic specialist.
As soon as I have some free time, I'll measure the case temperature - after a few hours of operation - with the multimeter sensor and let you know.
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A simple 12AX7 preamp for $500, built with poor design?
I'd haul that thing back and get something well thought out and $ensible.
Pro-ject has lots of issues with their turntables as well..
Google for details.
I'd haul that thing back and get something well thought out and $ensible.
Pro-ject has lots of issues with their turntables as well..
Google for details.
Trying to read 6moons is like being at a poetry slam where everyones having a stroke
Here are the promised photos. After a few hours of loud music (more than I normally listen to) this little but great Project Tube Box S2 hybrid preamplifier, - suitable for MM, MC cartridges, precise RIAA equalization, selection of impedances, capacitances, gain and subsonic filter - 😊 , step from 40 ° to 42 ° , with an ambient temperature of 26 ° .
So very happy, thanks for stopping by. 👍
So very happy, thanks for stopping by. 👍
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