• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Tube Phono or Solid State

Thanks for every bodies input I have now got another 3 I'm interested in, anybody see problems with them?
 

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Given the fact that the supposed title of this topic sais somthing about comparing tube with solid state, you probably mean the best of each world and none of these designs here are the best of tube world... We get simillar dicusions every few months and we probably have about 100 topics on phono preamps on diyaudio already so maybe it would be best for you to try reading as much as posible of what was already publihed , otherwise it's just a waste of time...
 
I dont think yore wasting anybodys time,I find it interresting to read this thread.
But I myself find it interresting to read others thread to. :)

He isn't wasting anyone's time. No one is forcing other people to click or read this thread. If they have no interest in the topic and continue to read anyway, they are wasting their own time voluntarily :p
 
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So you tried the cheapest phono preamp outhere and jumped on tube ones...that's what i call an intuitive guy, but i can't blame you cause my second phono preamp was the best and most complex i ever built...just that it took me a full year to read and investigate other's work before even start drawing mine.The first one was a 4 stages with 12ax7, 12au7, 12at7 with tone controll passive design of which i didn't really like the sound, being on the dark side, but very resolute.
 
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May I ask a sincere question about that design?

Why is the plate load on ECC83 T3 (T3A and T3B) only 22k ohms? That's less than half the rp of an ECC83. What is that supposed to do?

There are things that look good in simulation but work terribly in real life, with real devices that have more complex limitations than those in the models. I fear that might be at work here. I don't see how a 12AX7/ECC83 could work well as a clean amplifying stage with a 22k ohm plate load. But hey, the author may know something I don't. Either I'll learn something or I'll have exposed a flaw in the design. So... Which is it?


Well, I have, as carefully as I could, read the article of that Bucci and I cannot find anything in it which is not carefully designed. From that second stage of the RIAA circuit it is possible to increase the gain somewhat more by increasing that 100k resistor R34 after the coupling capacitor because it is shunted by the 50k volume control resistor R23A when the RIAA output is selected by S3A.
But anyway, why should the voltage gain of that gain stage be larger that it is now (about 20dB hand calculated)? In total the gain is enough to amplify the MM cardridge to a sufficient level.
That stage is not meant (I think) to supply max power, if so then yes, its plate resistance R32 must be a lot more.
But I hope that rongon or other participants of this thread, can enlighten my lack of knowledge in this matter. Always glad to learn something. :)
And yes, there are other tubes to do that job producing lesser noise than that ECC83. But it was not the intention of this design to perform top level performance.
 
I cannot find anything in it which is not carefully designed

Careful and competent are not the same thing :)

... From that second stage of the RIAA circuit it is possible to increase the gain somewhat more by increasing that 100k resistor R34 after the coupling capacitor because it is shunted by the 50k volume control resistor R23A when the RIAA output is selected by S3A.

Not with the 22k anode load. The 22k dominates the gain.

Nothing against the guy, but I'd also be curious as to why the 22k and also why the 22uF coupling cap. There are some other odd choices in that circuit but I'm not really interested in dissecting it. It does smell a bit odd...
 
Not questioning anyone, just responding to your remark that you cannot find anything that was not carefully designed.
Perhaps there is a language/translation issue with the word "careful" here, but in the normal meaning of the word, that statement doesn't make sense. No offense. Would you want me to perform brain surgery on a loved one if I'm "careful"? Would you not be more interested if I'm competent?
Regardless, if you examined his design closely and it was done competently in your opinion, perhaps you can explain his choice of the 22k load, 22uF cap and I might have a couple other questions after that :)
 
Op Amps have way less hiss, hum and distortion, let alone precision following EQ networks (RIAA) than any tube available so that´s a no brainer, but hey, it´s me.

Maybe somebody´s objective is none of those but fun, looks, mystery orange glow inside a glass bottle with silver patches, doing things a different way, so it´s a personal choice.

Remember we are talking tens of millivolts signals and NOT directly driving speakers, that has already been taken care of by Tubes.