Simplistic NJFET RIAA

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I played it quite abit last night, but not today, I will later when I rturn again. It is not bad sounding. Initially I was not impressed and almost wished that I left the WIMAs in. It had no bass at first, but that changed as the night went on.

I let it run with strong pink noise signal for the last couple of hours. I will let you know tonight.

Channels are close in timbre to each other.
 
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Attached is the freq response of the measuring system with the voltage divider load on it. Output (with load) into the input. Looking at the high side if the divider.


Verdict still out on the sound. I can say that I won't pull the new caps out anytime soon. Nor do I want to tweek it for a little while unless something is obvious wrong. RIAA curve looked identical to yours
 

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Thanks Merlin.
I will look for the opportunity to experiment in a short period. Your insight and experience here regarding cap type is well regarded.

In it current configuration, I find the overall system detail to have gone up a notch or two. Sound stage is solid and depth is very good. These caps imho are better than the original WIMA. My kids and family agree. I certainly can listen to it for an extended period of time.
 
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Did the tone come back to neutral with those as well? Some arms will not produce the same hf energy with some mc. VTA play, and last resort tweaking of the hf Riaa cap's value isn't out of the plan. But the cart has to break in before final VTF/VTA also.

P.S. I have made a mini subjective comparative survey rather recently, mainly to examine C0Gs for the Riaa filter. I had used a DCB1 with 2 outputs. One I kept DC, the other I was connecting several caps, MKP10 and FKP1 amongst them. Also PIOs (Jensen copper foil, K40, K75 mylar&paper in oil), PP,TF Solen, Auricap, Cog 33nx3//, and a few others, also some bypassing tests with FT-1 22n.
I was listening to DC vs capacitors forth and back. The DCB1 has this trait that is not aggressive at all but has bags of detail, so those caps did not have to balance out tone to be picked as more suitable. I was just looking for nearest to DC. The Wima seemed as the most synthetic to me. FT-3 was very neutral and nearest to DC for detail and size. The K70 120n Polystyrene was great, it only loses size and projection. The C0G/NP0 was like good silver Mica, but a bit cleaner.
 
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I will wait before I give comment. The RIAA has been living in pink noise all night through this moning.
Based on last nights listening, I will say that the system is different in a good way. Poorly recorded cymbals are poor, kinda hashy and irritating. However, the Sheffield Drum record sounded incredible. What was striking to me was the difference in the bass. If it is present on the recording it plays it. A bass drum for example has definition and is more realistic. I also find that the drum is now firmly placed in the soundstage. Before it was a thuuuuuuuumpppp, now it is a proper thump in a good way. Synthetic low notes i.e. Pat Metheny As Fall Witchita so Falls Witchita Falls will rattle the fillings out of your teeth.

All in all the move was a good thing. I am curious to play it a little later with more time for the caps to reform.

You had mentioned the C0G/NP0 caps before, I have not located any, could you post a link to one?
 
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One of the general traits I have heard steadily in this CCT&reg combination is that it does not present a fixed character. Playing an alto sax track all light and projected can sound very nimble, making no fat of its own, and then an ECM production with some big thuds and reverberating space captured, and comes across like a Mack Truck.

CAP 50V 100PF AXIAL CERAMIC C0G - A101J15C0GF5TAA
 
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I concur with that observation.

P.S. I think I may have found out my problem with the noise floor. I believe it lies in my measurement technique.

With a 1kHz signal, I was boosting the input gain on the soundcard to bring it to 0dB while maintaining the RIAA input at .3mV. In doing that I was raising the noise floor with it. Should I make another correction file that offset the 20dB so that 1kHz= 0dB at .3mV input?
 
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Will do. I have lost it and had a little temper tantrum regarding my current measurement system So I am off to the store to get a monitor for my new system to finish it up. I was always fighting ground loops and strange crap with the old. I wasn't kidding when I said I could wave my hand and change things.

No I didn't throw or break it, I just let out a few explatives.
 
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Think we are on to something here. New set-up on dummy load. I can talk, sceam, wave my hand, dance and in general anything I want except start up my tesla coil and I get a stable measurement. No more crazy ground loops either.

Attached is the corrected response from 5 to 45kHz, and a 1kHz FFT 0dB = 1Vrms input. I have the output of the mAudio card throttled back quite a bit to get 1Vrms so I will build a simple attenuator to regain some digital resolution of the wave.
The FFT shows with and without signal applied.

P.S. Now to measure the simplistic again
 

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diyAudio Chief Moderator
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Improvement indeed. I think that you better use it at 48k 24bit. Still not low enough in the highs.

P.S. Just took two loop screens for 1V and 0.1V (ref0dB 1VRMS) for EMU Tracker on USB power from battery laptop. 48k 24bit FFT65536 Blackman both axis Log.
 

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diyAudio Chief Moderator
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Also here's the guy doing white noise. You can see the lift towards 20kHz, in case you wondered why I don't press it -40dB sharp when I take the Riaa curve. Would be wrong, coming across dull if I tweaked the RIAA for hitting textbook HF visuals through this measuring loop.
 

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Your curves are not as easy to hit as you make it sound. This is the best I have been able to do sound card in to sound card out. 48k sample rate 1Vrms 0dB Blackman. 65536 pts.

Now I have sidebands on the fundamental however. Also attached is zoomed in freq range around fundamental. Any Idea?
 

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