I believe the photo in post #9 and #12 is not Pro-ject Tube Box S2, it is Pro-ject Phono Box S2.
The Pro-ject Tube Box S2 doesn't has gain setting on the bottom, the gain setting is on the front.
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Then what can I see through the windows on the front panel?? Also ventilation mesh on top...
How do you know ? that photo would seem to confirm that there is a need for heat dissipation that would not be justified in a phono preamplifier.
Which would seem to indicate that there is amplification with tubes at the output. ( gain)
Try to find this model in the PJ file. I couldn't, which makes me think that it was one of the first models and was discontinued without remaining at the pinnacle of audiophile favorites.
Which would seem to indicate that there is amplification with tubes at the output. ( gain)
Try to find this model in the PJ file. I couldn't, which makes me think that it was one of the first models and was discontinued without remaining at the pinnacle of audiophile favorites.
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The heat is from the heaters regardless of the use of the tube. even a cathode follower is going to get hot.
Same answer, such dissipation for a dedicated RIAA amplifier, it's not even a preamplifier? I do not understand that.
I thought about putting this together, but I didn't want to complicate myself, buying from a reliable brand gives me peace of mind.
https://diyaudioprojects.com/Tubes/RIAA-Phono-Preamp/
It is a preamplifier, just the gain is from solid state, the tubes are cathode followers. If the tubes were part the the gain circuitry, changing the amplification factor of the tubes would have changed the gain and it didn't.
Marketing, plain and simple...
Related thread:
https://www.diyaudio.com/community/...-says-it-is-digital-but-has-tubes-wtf.387840/
Seem to remember a Nobosound preamp discussed (maybe here) w/ same topography
Related thread:
https://www.diyaudio.com/community/...-says-it-is-digital-but-has-tubes-wtf.387840/
Seem to remember a Nobosound preamp discussed (maybe here) w/ same topography
If the heaters on a tube are powered up, the tube is going to put off some heat, even if nothing else is connected to it. That is why they are called "heaters"...
Seems that with those delicate and sensitive styrene caps, you'd want as cool an environment as feasible.
I'd use whatever method I could to achieve this including heat sinks. To quote 6A3 Summer " just my opinion, ymmv"
I'd use whatever method I could to achieve this including heat sinks. To quote 6A3 Summer " just my opinion, ymmv"
Ok, thanks for clearing up my ignorance on this.
And then what is that of the load line, please explain to me.... 🤔
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The tubes can handle 0's and 1's, just make it lead or not lead. Thus an analog signal is reconstructed by digital decoding.
There are Dac's with tubes, you have no idea how good they sound, I've had the experience, look for a store where you can have the experience and take your favorite CDA.
https://www.primaluna-usa.com/reviews-evo-100-dac
You seem to discard every relevant or well founded input from everyone in here, and contradict them with "I think"/"photo seems to show"?
Did it ever occur to you, that the enclosure was just available for a competitive price at the time, and actually had nothing
to do with dissipating heat??
This was Project´s first "tubed" phono stage, and it didn´t last long, thus being replaced with same electrical construction in far cheaper
enclosures. Why?? Because the heatsinks weren´t neccesary.
The curve traces you show in another post are irrelevant, since there´s no amplification in the tubes. The sole heat dissipation
from the tubes comes from the heaters alone.
As said before..... All Project´s tube Phono´s are SS amplification with cathode followers, who´s sole purpose are to lower
the output impedance and act as a marketing stunt. Could have been done with one trasistor in Class-A pr. channel instead......... period. 🙂
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Yeah...... really a bright statement. Dac´s with tubes don´t use the tubes in the digital signal path. It´s all analogue, so your comments about,
how tubes handle 0´s and 1´s are ?????????🤣🤣🤣
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Uh...
you missed the point-
It's not that tubes CANT be used for these purposes,,, but that they ARENT in these examples-
Jim
The use of vacuum tubes in an audiophile quality DAC is fundamentally in their application as a clock. And they are not ANY TUBE.
There is a substantial SQ improvement compared to SS technology for the same function.
And the conventional tubes used in the output of the phono pre, also influence the quality of the signal that will then be amplified throughout the chain until it reaches the speakers. Whether you like it or not is another matter. But it seems pointless to me to say that it's all "smoke and marketing", as some here say, if you're one of them, all good, it's your taste and/or opinion, but keep in mind that many people
they gladly spend their money to add tubes (see Lampizator web) to their CD players and report excellent results.
Call it cathode follower, gain 1, buffer, whatever you want. The audio signal goes through that tube. But no reputable brand would risk misleading buyers by claiming they can tube roll if it wasn't true. There is a thing called JUDICIAL DEMAND, you know?
https://www.primaluna-usa.com/primaluna-evo-100-tube-dac
https://www.mav-audio.com/base/product/tube_magic_d1
https://www.stereonet.com/forums/topic/337084-the-valvedac/
There is a substantial SQ improvement compared to SS technology for the same function.
And the conventional tubes used in the output of the phono pre, also influence the quality of the signal that will then be amplified throughout the chain until it reaches the speakers. Whether you like it or not is another matter. But it seems pointless to me to say that it's all "smoke and marketing", as some here say, if you're one of them, all good, it's your taste and/or opinion, but keep in mind that many people
they gladly spend their money to add tubes (see Lampizator web) to their CD players and report excellent results.
Call it cathode follower, gain 1, buffer, whatever you want. The audio signal goes through that tube. But no reputable brand would risk misleading buyers by claiming they can tube roll if it wasn't true. There is a thing called JUDICIAL DEMAND, you know?
https://www.primaluna-usa.com/primaluna-evo-100-tube-dac
https://www.mav-audio.com/base/product/tube_magic_d1
https://www.stereonet.com/forums/topic/337084-the-valvedac/
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A {working!} cathode follower has dissipation similar to a voltage "gain" stage.
Perhaps 1.9 Watts heater and 0.6 Watts through plate-cathode and resistors. So "mostly heater". But the plate circuit dissipation is non-negligible.