Simplistic NJFET RIAA

Hi.

I thought about these regarding Q4, Q5 and Q6.

Q4 = 8,51mA
Q5 = 8,62mA
Q6 = 9,35mA

These are about the lowest and highest I got from Alawi in Israel. I bought 12 matched pairs but I have a feeling that some might do better in the Mezmerize. So I have 9 other values to play with - they are all between the above figures.

Caveat: I haven't checked them by myself yet - the xmas work :up:

Regards
Or should I let Q4 be a little higher than Q5?

I better go back in the thread and read if there was anything said about these...
 
Dear Salas,

1. So, for the load...
I used 47k first and went down to 220R (do not have 100R yet). No significant differences beside loudness. No clipping or distortion. It ran smoothly with nice stage presentation. I amazed by very life-like sound with nice bass, mid and highs.
My problem is still relevant and I do not know what load to use. Please advice based on your vast expiration.

2. For the gain...
It is a bit more loud than my CD on the same volume of pre-amp and I think I need to lower the gain a bit.
Per manual, I used 2.2k for R13 and 8.2R for R2 (Q1=13.57/6).
Should I try to increase R13 (manual suggests from 2.2k to 5.6k) or should I increase both R2 ( from 8.2R till 68R) and R13? Please advise.

Thank you.

P.S. I'm going to drop it into my enclosure during Christmas. Should be fun again! :D

You made exceptional Phono-Pre unit. The best so far that I used!!!!!!!!!
Do not what to compare it to BHL (different budget, different class of components), but it is like Soviet made piano sound vs. Steinway...! My congratulations to you and all who got it here.
 
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Dear Salas,

1. So, for the load...
I used 47k first and went down to 220R (do not have 100R yet). No significant differences beside loudness. No clipping or distortion. It ran smoothly with nice stage presentation. I amazed by very life-like sound with nice bass, mid and highs.
My problem is still relevant and I do not know what load to use. Please advice.

2. For the gain...
It is a bit more loud than my CD on the same volume of pre-amp and I think I need to lower the gain a bit. Per manual, I used 2.2k for R13 and 8.2R for R2 (Q1=13.57/6).
Should I try to increase R13 (manual suggests from 2.2k to 5.6k) or should I increase both R2 ( from 8.2R till 68R) and R13? Please advise.

Thank you.

P.S. I'm going to drop it info my enclosure during Christmas. Should be fun again! :D

I'm about to dig into my Pioneer (PDZ9 or something), does it all exept WIFI... This one sounds very good - exept on Phono. I have to raise the volume from 30 to over 40 (I guess it's linear from 0 to 99) to get the same output.

Something ain't as it should be with the amp. Is there a technical manual out there or do I need to buy one?

Probably as I said the amp input, I will, when able, feed it into LINE from the simplistic.

Regards
 
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@alex

1. Its a 25R internal impedance cart the manufacturer tells us. So I don't know if it will be productive at all to load below 220R.

2. Is the gain still louder than CD when the load is 220R?

Hi Salas,

OK, I'll set it to 1K for now.
Yes, it is a bit louder....
I use 35-40% of my volume scale for CD player and I have same loudness on phono on 20-25%.
 
diyAudio Chief Moderator
Joined 2002
Paid Member
OK, we will only boost that R2 value, then you will re-bias so we will shave off 4dB or so. You will need some good resistor again, like Dale CMF55, TT RCY55, PRP etc. You will keep the older value PRP so if you will feel it was better in any way vs. the new milder gain result, it can be reversible. Although chances are it should relax to the better for detail and hiss.
 
diyAudio Chief Moderator
Joined 2002
Paid Member
You made exceptional Phono-Pre unit. The best so far that I used!!!!!!!!!
Do not what to compare it to BHL (different budget, different class of components), but it is like Soviet made piano sound vs. Steinway...! My congratulations to you and all who got it here.

Its due to I managed to sit the Soviet pianist on an American piano.:D
 
Rsource run DC current so their excess noise characteristic can surface. Good wirewound types are counter-inductive wound also.
In our case the Rs values are small plus dropping in the tens of mV only so thin film resistors are good also. R13 should be more susceptible.
It runs both JFETS bias current on the highest Vdrop found in this circuit. Putting a KIWAME there would be much worse theoretically than putting a brown MR Mills for instance.

"The lowest noise level is observed in resistors with bulk metal resistive elements: foil and wirewound"
Selecting resistors for preamp, amplifier and other high-end audio applications | EE Times

Thanks, Salas. :)

Andy
 
Its due to I managed to sit the Soviet pianist on an American piano.:D

All my family members, beside me and my dad, are former professional piano performers and piano teachers. We all used Soviet instruments back then (I'm made in USSR) and I remenber my mom's and my wife's eyes when they tried to play Bluthner or Stanway pianos first time at the end of 80th...:D
 
Hi Turbon,

I'm not sure if I got what you're saying...
Does your volume is still constant when you increase or decrease it on Pioneer when Phono is use?
It's like this - if I change from CD to phono it decreases a lot - but this hasn't anything to do with the simplistic... More than it hopefully gives the punch when connected to line in... Im in the believe no one uses the phono in on this amp :) more than me...

Well, something is bad with the phono in on this one - for sure.

Regards
 
It's like this - if I change from CD to phono it decreases a lot - but this hasn't anything to do with the simplistic... More than it hopefully gives the punch when connected to line in... Im in the believe no one uses the phono in on this amp :) more than me...

Well, something is bad with the phono in on this one - for sure.

Regards

Still do not get it why do you use Phono IN for Folded. Phono IN is typical MM (or some has MC and MM) phono pre-amp. You should connect Folded to Line IN, the same type of input as you connects your CD player.