Simplistic NJFET RIAA - Page 491

Salas · 15th September 2010, 09:27 AM

Reminder, each version and idss has slightly different needs-initial value. Plus its a system, preference, capacitor measurement, capacitor tone, capacitor tolerance, thing.

RCruz · 15th September 2010, 10:05 AM

Yes, I know that but I would like to see if there are similarities between several builds.

Salas · 15th September 2010, 10:41 AM

Those are different versions with different initial values, not just different builds.

merlin el mago · 11:28 AM

Amphom 0.1uF 630VDC for interstage arrived today, size is the same that russian FT-3 teflon, photo:

merlin el mago · 15th September 2010, 11:27 AM

Quote:

Originally Posted by SGregory

The issue I am having, and have had even before v1.2 was that the bass is not a strong as I would like. Given response of riaa I will look towards TT as culprit. I even pulle he TT stand out and away from speaker thinking it was being effected but no diff.

If you can afford 35$00 USD for RIAA mid-bass try metallized teflon film SCR Solen 0.047uF 1000VDC are 5%, I bought matched pairs here:

Teflon Tin Foil 0.047uF 1000V | Diy HiFi Supply

Photo:

SGregory · 15th September 2010, 10:47 PM

Merlin, I may look into those at some point. How close to the stated value were they when you recieved them?

SGregory · 11:12 PM

Had a little time to play. Started off the evening listening to it as I had left it last night. My opinion was still the same so I deceided to add the 250pF cap accross C3. The first measurement shows represents what the impact was. I could not really see a change, but I listened to it. I noted a small reduction in the extreme high end, it was a little better. I gave it a couple of sides of albums and decided to kick it up another notch. THis time I replaced the 15nF polystyrene cap with a 15.1nF poystyrene cap. so basically in total I have added 350pF or so to C3. The measurment is the second plot. Again not a huge change in the measurement. I have been listening to it ever since. At this point I don't want to change it again for another couple of days as the cap breaks in. Went back over some of the same albums and my initial perception is that the mids are more pronounced. Still great detail and stage.

In a nutshell, I can't measure the change, but it has changed perceptively. It will be interesting to see if my impression stays the same tomorrow. I wonder how much is me wanting a change.

For somereason I can't upload the graphs right now. will try later.

I saved them ib bmp format. Here is the last in jpg format.

Salas · 15th September 2010, 11:29 PM

In simulation it would give a 0.1-0.2dB overall trend above 1kHz. There it shows. With pink noise and cards its difficult. I see easier such differences if I watch with 1/96 oct. but there will be no lows to see, they shrink bandwidth with such an octave resolution. Now its subjectively tamer maybe you can feel the lower notes progressing better.

P.S. Textbook Riaa at 50Hz=16.95dB, 40Hz=17.79dB, 30Hz=18.59dB, 20Hz=-19.27dB, 5kHz=-8.21dB, 10kHz=-13.73dB, 20kHz=-19.63dB. I.e. your graph looks good I think.

SGregory · 15th September 2010, 11:36 PM

Audio Tester uses a sweep not pink noise. But you are correct it is hard to see.
I will give it a couple of days before I final judge. Too easy to convince myself anything I want this early.

Salas · 15th September 2010, 11:43 PM

Sinusoidal sweep can be better. Depends on how it connects the gaps. But your sweep looks great VS theory.

15th September 2010, 11:14 AM	#4904
merlin el mago diyAudio Member Join Date: Sep 2009 Location: Catalonia new Europe state	Amphom 0.1uF 630VDC for interstage arrived today, size is the same that russian FT-3 teflon, photo: Last edited by merlin el mago; 15th September 2010 at 11:28 AM.

15th September 2010, 10:47 PM	#4906
SGregory diyAudio Member Join Date: Apr 2003 Location: Southern Tier NY	Merlin, I may look into those at some point. How close to the stated value were they when you recieved them? __________________ Living Life Doing the Waltz in 4/4 meter.

15th September 2010, 11:36 PM	#4909
SGregory diyAudio Member Join Date: Apr 2003 Location: Southern Tier NY	Audio Tester uses a sweep not pink noise. But you are correct it is hard to see. I will give it a couple of days before I final judge. Too easy to convince myself anything I want this early. __________________ Living Life Doing the Waltz in 4/4 meter.

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15th September 2010, 09:27 AM	#4901
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	Reminder, each version and idss has slightly different needs-initial value. Plus its a system, preference, capacitor measurement, capacitor tone, capacitor tolerance, thing.

15th September 2010, 10:05 AM	#4902
RCruz diyAudio Member Join Date: Sep 2006 Location: Saxon Blog Entries: 1	Yes, I know that but I would like to see if there are similarities between several builds.

15th September 2010, 10:41 AM	#4903
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	Those are different versions with different initial values, not just different builds.

15th September 2010, 11:43 PM	#4910
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	Sinusoidal sweep can be better. Depends on how it connects the gaps. But your sweep looks great VS theory.