Simplistic NJFET RIAA

[nicoch58]

I love The Synchronicity Concert

I had forgotten My sharona , is a simple song ,but rocks with is riff ,like rock the casbah 80s nice time, vinyl time....my time 14s old

 

[Salas]

The Clash are the cream of the crop of the first gen Punk explosion carried bands IMHO. They had multicultural influences that have shown early and culminated in Sandinista. This one was made for an NME flexi that never made it and was included in London Calling without mention on the sleeve. One of my favorites for their more melodic side, along Lost In The Supermarket Charlie Don't Surf, Somebody Got Murdered, Spanish Bombs latin, Ska, Reggae (Rudie Can't Fail, Gun's Of Brixton,Police And Thieves) what to remember or exclude... a pain. Had the opportunity to be in their last live appearance. No ideology in music anymore.

 

[RCruz]

I have a copy of that album.... must heart it again !

I see you like subs... but I wonder why 5 units ?

I have only one and already hear the stereo image sliding towards one side.... I would like to have two, and connect one to each channel... but that´s all.... now 5 units ?

Ricardo

 

[Salas]

There is a way to have perfect, even, deep bass like in a big hall in your living room if scattering many subs differently tuned (some bigger some smaller) also different for level and phase, pioneered by Dr. Earl Geddes. Without resorting to bass traps etc. And without caring much about their quality. You with one sub just excite the room modes, the many ones excite them in an evening out manner through long time averaging measurements and tweaks.

 

[RCruz]

Excuse my ignorance... I should have known better by now

 

[Salas]

Speakers are my long time love, I should have mentioned.

 

[RCruz]

My brother is into speakers... He knows a lot about notch filters and builds the things.

I prefer needles and tonearms.

PS:
I always loved caps.

 

[Salas]

Notch filtering nods to a full range one way man. Is he?

 

[RCruz]

Yes.

after all he loves full range speakers in complex boxes... two meters tall.

 

[Salas]

Oh, he is like Planet 10 and Nelson Pass.

 

[RCruz]

Hi Salas

I did not know about Planet 10... I used this link before : http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=6344 P-L;orb=1

Ricardo

 

[Salas]

P10 is Dave, he is very much into FR speakers.

http://www.planet10-hifi.com/

 

[RCruz]

Rcruz, you will be shocked by the difference!
I measured the obligato and it was 46.5 both of them. I added a 450pF silver mica to get close to 47nF.

Hi vgeorge
Today I got two 47nF obbligato.

Using my china DMM, I read 45.1nF but I did a database of readings with all the caps I have available and am quite sure the DMM reads -5% in this capacitance range.

45.1 + 5% = 47.4n

What difference did you notice by replacing the PIO with this combination ? Where is it more noticeable ?

I am going to do this mod in my actual riaa and as the pcb is very damaged, I need to plan in advance to avoid issues.

Ricardo

 

[vgeorge]

Rcruz,

the difference was most in the sound stage, especially height, and the air around the instruments.
Everything seemed more defined now. Tone is much better. I didn' t expect such a big change.
I expect further improvement when I change the 16nF to some silver micas Ι have ordered.

 

[AndrewT]

............ I did a database of readings with all the caps I have available and am quite sure the DMM reads -5% in this capacitance range.

Hi,
borrow or buy a few 1% or better caps and check your DMM against these "standards".

 

[Salas]

Those 15700pF Russian giant Silver Micas Ricardo has, are very tight for tolerance. He can use those so to have and idea.

 

[RCruz]

Those 15700pF Russian giant Silver Micas Ricardo has, are very tight for tolerance. He can use those so to have and idea.

I already ordered some more of those 15750pF for the new riaa. I will use those as bench.

The problem is that there is not a constant variation. It oscilates depending on the cap value, but the average is -5%.

The graphs give an idea.

 

[Salas]

It can give you an average idea of what to expect non the less. OK, nowhere near a good practice, but better than nothing.

 

[RCruz]

Sucessfull operation !!!

Out came the PIO and in the 47nF obbligato.

Also added some "special reserve " NSF polystyrenes 2700pF on the +28v in the board decoupling to GND.

Imediate results after 1 minute settling down: Lower noise floor... good stereo image ...

After initial loose sound, things are getting tighter. Need to wait some hours to be able to report correctly

Ricardo

PS:
This is getting BIG

 

[Salas]

Remember you said in the start, I need to listen better to my vinyl, but I will never hope I will best my expertly super tweaked Marantz CDP? Never say never.