I was looking at this last night I really like the sound 6DJ8 give out, and seeing I have a el34 6dj8 amplifier i built already. this one will make the list of choices, thanks
The first one would seem to increase input capacitance. The third has gotten some decent reviews but I think it would be worth splitting up the EQ network and adding another stage of amplification since it is a few dB shy on gain.The middle one also does the passive EQ in one step and also would benefit from a follower at the output.
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...
Ok thanks I don't want to waste your or anybody elves time, please how do I delete this thread??
Another to look at is Patrick Turners website (RIP) he was very generous with information. You can learn allot from there. You can just flat copy and build or read, and read and learn.
I am going to build his phono and compare it to Allen Wrights.
I am going to build his phono and compare it to Allen Wrights.
For solid state I would use a OPA637 opamp. But only buy those from real distributors like digikey or mouser.
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 😛
I brought a cheap JayCar solid state phono preamp has a LM833N Dual Low Noise Op-Amp Linear IC. it lacks low end and to much of high end. I know it was cheap but thought tube phono might give me the lift I was looking for.
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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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.
Careful and competent are not the same thing 🙂
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...
"Careful and competent are not the same thing"
Are you questioning the author or me?
Are you questioning the author or me?
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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 🙂
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.
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.
I tend to prefer the passive RIAA designs, where the RIAA shaping components are placed between an input and an output amplifier, rather than in a feedback loop. Just personal preference. Both can work equally well, accuracy wise.