It sets the SNR. Without adequate SNR there is no original signal. The other stages can only handle it to liking or neutral standards. But they are the duct while the input is the well if the signal is the water. With a dirty well you may fancy color the poisoned water later in the duct. It will never be natural water, still. So, first things first.
Hi,
Thank you.
I cannot tell, without knowing the scale.
Anyhow, the higher harmonics are quite prominent, relative to the second.
At what output level the measurement was taken? How much down are the second, fifth and seventh harmonics referenced to the first?
What topology/architecture is it?
The noise is -80dB referenced to what?
Thank you.
I cannot tell, without knowing the scale.
Anyhow, the higher harmonics are quite prominent, relative to the second.
At what output level the measurement was taken? How much down are the second, fifth and seventh harmonics referenced to the first?
What topology/architecture is it?
The noise is -80dB referenced to what?
I haven't enough time.
Hungarian proverb: Twenty-four hours a day... plus the night.
Designing and building components is my late night project.
This phono (highly modified Audio Innovations 200) is very good for me, just as my turntable (Roksan Xerxes, SME IV tonearm, Supex 900S pickup, EAR MC3 SUT).
C3g phono was the challenge (designing and building in two weeks to Hungarian Triode Fest).
I fail to get the point of designing and building and then not listening to.
2nd harmonic at -50dbV
5th at -55dbV
7th at -60dbV
But this is with 4 triodes in the MM stage.
The noise is referenced to 0dbV.
But the design does not has all the specs you ask for. The triodes have al between 2 and 3mA plate currents, this is much to low to sound good according to you.
5th at -55dbV
7th at -60dbV
But this is with 4 triodes in the MM stage.
The noise is referenced to 0dbV.
But the design does not has all the specs you ask for. The triodes have al between 2 and 3mA plate currents, this is much to low to sound good according to you.
Last edited:
It sets the SNR. Without adequate SNR there is no original signal. The other stages can only handle it to liking or neutral standards. But they are the duct while the input is the well if the signal is the water. With a dirty well you may fancy color the poisoned water later in the duct. It will never be natural water, still. So, first things first.
Indeed, SNR is crucial to any phono stage.
Yet, SNR alone isn't the only factor affecting the sound quality.
In your folded simplistic (as well as in any other amp), choosing different resistors and capacitors will affect the sound, while it probably wouldn't be seen in any measurements.
So, once again, adequate SNR is crucial, yet it isn't the only parameter that counts, that affects the overall sound quality.
Let's assume, for the sake of the present discussion, that JFET's have the edge on tubes concerning noise, while tubes have the edge on JFET's concerning linearity. In such a case, it may make sense, under certain circumstance, to prefer noise over linearity for the first MC stage – and on the following stages to prefer linearity over noise – with the end result being a certain compromise between noise and linearity.
This is the breadboard prototype (see one channel).
There are too much hum and noise (from PSU). Separated PSU (and maybe Salas SSHV regulator) and metal box are necessary.
Attachments
Hi,
Thank you.
Referenced to what output level?
The fifth being 5dB and the seventh being 10dB below the second is a no go for me.
How does it look in the all tubes MC/MM phono stage that you referred to above?
This is the least of my concerns at this stage.
Right now, more important are the noise and the higher harmonics figures for the entire MC all tubes phono stage.
BTW, how does it sound to you and compared to what other(s) phono stage(s)?
Thank you.
Referenced to what output level?
The fifth being 5dB and the seventh being 10dB below the second is a no go for me.
How does it look in the all tubes MC/MM phono stage that you referred to above?
This is the least of my concerns at this stage.
Right now, more important are the noise and the higher harmonics figures for the entire MC all tubes phono stage.
BTW, how does it sound to you and compared to what other(s) phono stage(s)?
Before you'll put it in a proper housing and before you'll sort out the noise problem, neither you nor me can possibly know how it may sound – both in itself and compared to other phono stage(s).
Measurements alone don't say how certain amp sounds.
I'd like to build a phono stage in order to enjoy listening to music through it – not in order to only measure it.
Also, without comparing, you don't know what may sound better – tube rectifier with LCLCRC filtering, or the Salas SSHV, or another shunt regulator, possibly tubes based.
Output level was 2Vrms
I use 6 triodes in the complete MC/MM stage.
I have also Project tube box 2 se, phonedude and several opamp based phono preamps.
For me it sounds like a tubeamp, wider soundstage and fluid sound, a complete other sound as the opamp based preamps. No noise no humm. Just look the thread below. There are enought great designs in the analoge source section.
http://www.diyaudio.com/forums/analogue-source/242855-mini-me-phono-preamp.html
I use 6 triodes in the complete MC/MM stage.
I have also Project tube box 2 se, phonedude and several opamp based phono preamps.
For me it sounds like a tubeamp, wider soundstage and fluid sound, a complete other sound as the opamp based preamps. No noise no humm. Just look the thread below. There are enought great designs in the analoge source section.
http://www.diyaudio.com/forums/analogue-source/242855-mini-me-phono-preamp.html
A couple of quick points, Joshua .
D3a triode is a good option , I've run a phono with D3a/RIAA/D3a for many years , D3a's at about 13mA . The input capacitance through a 10x step-up does not seem to have any problems sound-wise, despite warnings ...
The cathode by-pass cap does need to be the best you can get, however . Black Gate NX is the 'daddy' but unfortunately you'll be lucky to find a real one now !
I'll put in a word for a small amount of residual 2nd harmonic .
Having built a jFet/triode cascode front-end for my phono ( to avoid step-ups ) recently, I tested various operating points for the jFet , and at the same time a friend of mine was testing the exact same set-ups ( ie. complete cascode ) on precision test gear ( Agilent ) . We found that the lowest-distortion set-up had practically nothing measurable , at the signal levels involved . This also sounded somewhat clinical and lacking tone . The best set-up found by ear had a small residual of 2nd-harmonic at 70dB down from the main signal, for 5mV input. This set-up had a substantially more natural sound with more tone in the midrange.
D3a triode is a good option , I've run a phono with D3a/RIAA/D3a for many years , D3a's at about 13mA . The input capacitance through a 10x step-up does not seem to have any problems sound-wise, despite warnings ...
The cathode by-pass cap does need to be the best you can get, however . Black Gate NX is the 'daddy' but unfortunately you'll be lucky to find a real one now !
I'll put in a word for a small amount of residual 2nd harmonic .
Having built a jFet/triode cascode front-end for my phono ( to avoid step-ups ) recently, I tested various operating points for the jFet , and at the same time a friend of mine was testing the exact same set-ups ( ie. complete cascode ) on precision test gear ( Agilent ) . We found that the lowest-distortion set-up had practically nothing measurable , at the signal levels involved . This also sounded somewhat clinical and lacking tone . The best set-up found by ear had a small residual of 2nd-harmonic at 70dB down from the main signal, for 5mV input. This set-up had a substantially more natural sound with more tone in the midrange.
The swings in input stage are diminutive so linearity is largely irrelevant there. You rightly say that linearity is a job further on.
But I am not talking silicon or vacuum in particular, I am talking gain stages. That's just architectural.
Folded Simplistic being just a study on economical circuitry and DIY ease of build has no belts and braces and the main parts are few so they tend to stick out more in the face of negative feedback loop absence.
Still we get down on those after we set the base adequately well on input.
Just trying to be a successful DIY build for many, not a high spec build for few. A cheerful compromise.
My breadboard has no noise and humm, i think this you need to solve this first.
Without metal housing there also should be no noise and humm.
Attachments
Hi,
Thank you very much.
What you wrote makes a lot of sense to me.
I stated few times that I don't care at all about relatively small amount of second harmonic, I care much more about the proportion of the higher harmonics, especially to odd ones, to the second.
In the D3a/RIAA/D3a, was it passive RIAA?
In the JFET/triode cascode front-end, which JFET and which triode did you use?
How would you compare the JFET/triode cascode front-end to a good SUT (sound-wise)?
Hi Salas,
Thank you.
It's good to see that we agree here, on this point.
So?
Sorry, I fail to see the point you were trying to make here.
Dear Salas,
I'm well aware of your motivations and considerations behind the various DIY projects you present here. I have very high respect and appreciation for your motivations, considerations and the amount of time you dedicate in guiding and assisting others.
In the present project, I come out from a different stand. I'm looking for the best possible sound quality I may attain, with my limited budget.
In the end, whether the folded simplistic, or all tubes + SUT, or hybrid phono stage will sound best – only listening comparison will tell. In order to make that comparison, I'll have to build all 3 options.
Thank you.
It's good to see that we agree here, on this point.
So?
Sorry, I fail to see the point you were trying to make here.
Folded Simplistic being just a study on economical circuitry and DIY ease of build has no belts and braces and the main parts are few so they tend to stick out more in the face of negative feedback loop absence.
Still we get down on those after we set the base adequately well on input.
Just trying to be a successful DIY build for many, not a high spec build for few. A cheerful compromise.
Dear Salas,
I'm well aware of your motivations and considerations behind the various DIY projects you present here. I have very high respect and appreciation for your motivations, considerations and the amount of time you dedicate in guiding and assisting others.
In the present project, I come out from a different stand. I'm looking for the best possible sound quality I may attain, with my limited budget.
In the end, whether the folded simplistic, or all tubes + SUT, or hybrid phono stage will sound best – only listening comparison will tell. In order to make that comparison, I'll have to build all 3 options.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.