So when you say it was poorly reviewed its ok to believe the reviews but when its the other way its not?? You crack me up. And I am an electro-mechanical engineer of 45 years with a masters degree in mechanical engineering. if you want to toss credentials around.
No I came here wondering why the volume stayed the same. Nothing more. You guys are worse than a bunch of old women.???"
Obviously you came here for confirmation, expecting to elicit "oooh"s and "aaah"s about your $500 MC preamp ... and you got honest opinion instead.
No likey.
As of
, that means a preamp built around a couple triodes, period, probably with transformer input to match ultra low MC impedance to high tube impedance.
probably 20 parts in total.
Something like:
or
^^^^ this is what wiseoldtch is talking about.
From what I see in that overstuffed PCB, ICs (Op Amps?) do the main work, say 90% of it, tubes may do something or nothing at all.
Either tubes or Op Amps are redundant, pick one.
Yes, almost certainly the tubes are simple output buffers (with paralleled sections).
Since the cathode follower gain is inherently about 0dB, it won't change noticeably with tube type.
But the tubes are being operated on rather low DC supply voltage (probably 24VDC for series filaments),
so it isn't really optimal for them.
Since the cathode follower gain is inherently about 0dB, it won't change noticeably with tube type.
But the tubes are being operated on rather low DC supply voltage (probably 24VDC for series filaments),
so it isn't really optimal for them.
I have that preamp and it's an excellent choice for the price. There is nothing with that sound quality , for both MC and MM , they far surpass other pure SS .
To overcome it you have to put at least double the coin.
Output tubes (whether buffered or not) change the sound by tube rolling.
I tried with Mullard NOS -borrowed- and yes, there is another sound, Pro Ject doesn't lie there, although there are other issues that I don't see as a drawback, I just like to put my hand to improve some minor issues.
To overcome it you have to put at least double the coin.
Output tubes (whether buffered or not) change the sound by tube rolling.
I tried with Mullard NOS -borrowed- and yes, there is another sound, Pro Ject doesn't lie there, although there are other issues that I don't see as a drawback, I just like to put my hand to improve some minor issues.
The dip switches are a bit hard to read and have changed on some models, but you do have gain (Db) on the front panel and impedance (Ohms) and sensitivity to adjust to the cartridge on the base. Study it with time
You won't get any schematics, not even writing to Pro ject .
But if the pre works, you won't need it.
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Heyyy jwags
The loading adjustments in your picture are only for low output MC.
If you don´t have the dip-switches in the bottom, you should at least have a switch on the back panel for MM/MC.
Since you cartridge is a high output, the setting needs to be for MM.
Sometimes I wonder, what´s wrong with people. 26 posts, and no one has mentioned this yet exept for Mona in post #12.
Anyway, you need to find the MM/MC selector and put it in the proper position (MM 47Kohm) 🙂
I had one too years ago (just for fun). The best sound from tube rolling I got with a pair of Sylvanias NOS 12AY7. Not night and day difference,
but enough to be called an improvement 🙂
In my case, I answered according to post 1, the OP made the confusion, he talks about one model and publishes the photo of another.
I've got credentials and certificates too.
But I've no need to prove anything to anyone.
And besides, mechanical engineering is nothing like hands-on audio for 45 years, and servicing tens of thousands of consumer and commercial equipment on a day-to-day basis.
Give it up already.
I tend to block/ignore hard-heads with insistant attitudes.
Does it still work if you take the tubes out?
I don’t see enough big resistors for it to be configured properly. The main reason the gain won’t change is because the tubes are a cathode follower.
I agree that 12au7 should not be used, as that it is designed for a 12ax7. Not an ideal tribe for a cathode follower, but it’s what they put in.
I don’t see enough big resistors for it to be configured properly. The main reason the gain won’t change is because the tubes are a cathode follower.
I agree that 12au7 should not be used, as that it is designed for a 12ax7. Not an ideal tribe for a cathode follower, but it’s what they put in.
I did a quick schematic with LTSPICE and with same components and 12ax7 and 12au7 come out very similar, gain 16 to 18.
However I don't know how much I trust the LTSPICE models.
However I don't know how much I trust the LTSPICE models.
Owners manual.
INSTRUCTIONS FOR USE
Pro-Ject Tube Box S2
https://www.hifihuone.fi/wp-content/uploads/2018/04/manual_tubeboxs2.pdf
Runs off 18V DC.
INSTRUCTIONS FOR USE
Pro-Ject Tube Box S2
https://www.hifihuone.fi/wp-content/uploads/2018/04/manual_tubeboxs2.pdf
Runs off 18V DC.
It's not the OP's, it's Project Tube Box SE, (MM) then there's version II, which apparently incorporated MC, (I can't be sure) The official page of Pro Ject had all the models that it manufactured, but in a quick search I did not find it.... Here is to recreate the view and be entertained ............
https://www.google.com/search?rlz=1C1ALOY_esAR969AR969&sxsrf=ALiCzsZ_ap8C21RFkvElQfGCooQ3yzndSQ:1656889788098&source=univ&tbm=isch&q=Project+Tube+Tube+phono+SE&fir=crVg7DBihhqlIM%2C2OZrzdGGJeVGSM%2C_%3ByYo1TDOAMDf-cM%2Cr37cNxOnGLJ5XM%2C_%3B13oasxxC1V4F1M%2Cr37cNxOnGLJ5XM%2C_%3Br61MwdqEAzg70M%2CuvOMcy0o8jbonM%2C_%3BecusOpt5ZnQp_M%2CGbh-e6eBi8VKhM%2C_%3BFhBLxTvSMcJWxM%2CWZI3WL_SZXm1YM%2C_%3BMuvLtLVYUAAdBM%2CDrftA2FSo7ogXM%2C_%3BoiN3839YKT6CtM%2CyUyMhyrrZWQLRM%2C_%3BYVWBW1RfBe6wvM%2CwAukwowuNcLcJM%2C_%3BNlKqMcp46qC9uM%2CAjlnnepYZEjqtM%2C_&usg=AI4_-kQfILQfxqTvhzJc4atz_Tetm-HyNw&sa=X&ved=2ahUKEwiil4G66934AhULu5UCH
Here is a simple review that helped me decide with the S2, I also read the most technical-with measurements -which is the one that corresponds to the photo of the OP, from the ASR forum
That model surely doesn't have cathode follower valves.....judging by the dimensions and heat sinks....
Find how to search all models manufactured by Pro Ject. On the main page, https://www.project-audio.com/en/archive/ at the bottom, / downloads/ archive.
The nomenclature provided by the OP is incorrect, Tube Box SE does not exist, there is S or SE II.
Diagrams, ha, don't even dream about it.....
Find how to search all models manufactured by Pro Ject. On the main page, https://www.project-audio.com/en/archive/ at the bottom, / downloads/ archive.
The nomenclature provided by the OP is incorrect, Tube Box SE does not exist, there is S or SE II.
Diagrams, ha, don't even dream about it.....