Thanks for your suggestions on the tinny cartridge sound. I checked voltages, all good. Then starting checking resistors to find one was the correct 47K load resistor and in the other channel 100ohms. The offending R had been replaced and now the preamp sounds excellent.
I do not need an input cap.
I do not need an input cap.
Hi there,
so today i managed to swop the resistors between cooking dinner and
bringing my baby-son to bed. While reading the bedtime-story i´ve let
the amp run in and after i measured the voltages as follows to ground:
Q7: d - 16,5v, s - 5,95v
Q1/2: d - 5,3v, c - 0,02v
Q3: d - 14,8v, s - 0,12v
Q4: d - 26v, s - 14,8v
So what about those voltages? Well they´ve changed allot - are they
reading better?
Greetings Ulf
so today i managed to swop the resistors between cooking dinner and
bringing my baby-son to bed. While reading the bedtime-story i´ve let
the amp run in and after i measured the voltages as follows to ground:
Q7: d - 16,5v, s - 5,95v
Q1/2: d - 5,3v, c - 0,02v
Q3: d - 14,8v, s - 0,12v
Q4: d - 26v, s - 14,8v
So what about those voltages? Well they´ve changed allot - are they
reading better?
Greetings Ulf
Ah, thats fine to read....thanks Salas.
I´m just listening to some well known records. Sound is nor much
different, maybe just a bit more open and fluent.
One thing i again recognized is that the russian teflon is really micro-
phonic. When touching on the parts with my fingers i can´t hear any-
thing, except the teflon ones. I can hear the touching through my
speakers. Another thing is that i think my njfet listens somehow kind
of through the curtain. You understand what i mean? Maybe the teflons
need way more burning in. What are your sonic descriptions of the "sound"
of the teflons? I miss some neutral analytic bit of a sound.
Greetings Ulf
I´m just listening to some well known records. Sound is nor much
different, maybe just a bit more open and fluent.
One thing i again recognized is that the russian teflon is really micro-
phonic. When touching on the parts with my fingers i can´t hear any-
thing, except the teflon ones. I can hear the touching through my
speakers. Another thing is that i think my njfet listens somehow kind
of through the curtain. You understand what i mean? Maybe the teflons
need way more burning in. What are your sonic descriptions of the "sound"
of the teflons? I miss some neutral analytic bit of a sound.
Greetings Ulf
FT2-3 I find grainless, transparent, tonally even. Could be batches and batches out there though. Don't know, try Mundorf Silver & Oil Supreme 0.1uF there maybe. It could be closer to what you are after. Also try to up your load resistor and/or change types. Loading can do the veil thing if heavy.
P.S. What is the now value of your circa 15nF HF Riaa capacitor?
P.S. What is the now value of your circa 15nF HF Riaa capacitor?
I have used the low Volt version for size enough times. The thicker higher Volt can be a bit 'tamer' in HF but very close. My gut feeling is that your HF Riaa cap value can be overcooked for your system tonality already, and also the loading resistor value can be tuned further. See how it goes with a straight 15nF value for C3 first of all. Regs can be different for some things like dynamics, analysis, etc. but I suspect a more fundamental tuning need in the filter or loading.
Hi Salas,
great (concering the teflon). In RIAA position i use 15,16nF Wima FKP1
as i have very good experience with those in valve PhonoPres. Much
better than mica in that position.
Loading resistor is 100R naked z-foil for my lyra dorian. Ahh and to men-
tion...as output coupling cap i use 4,7uF Wima mkp4. Tinfoil (that i hat in
that place before) was worse, and i just had 4,7 uF at hand, so they went
in.
Greetings Ulf
P.S. and thanks for all your helpness
great (concering the teflon). In RIAA position i use 15,16nF Wima FKP1
as i have very good experience with those in valve PhonoPres. Much
better than mica in that position.
Loading resistor is 100R naked z-foil for my lyra dorian. Ahh and to men-
tion...as output coupling cap i use 4,7uF Wima mkp4. Tinfoil (that i hat in
that place before) was worse, and i just had 4,7 uF at hand, so they went
in.
Greetings Ulf
P.S. and thanks for all your helpness
I did not have good impressions with FKP1, MKP4, MKP10, in some tests I did using a DCB1 with double RCA outputs, by listening to DC one time and then to different coupling capacitors the next time between outputs. One thing that helped was bypassing all those MKP caps with Teflon. Maybe you can try that on your output capacitors and see if it helps. Use up to 2.2uF if possible. Can be passing enough sub LF now. Even 1uF if you got 100K line input. One of the best combinations for output cap was the big green paper & MKT K-75 Soviet cap, bypassed with FT. Of course such things are not based on controlled listening and can be just system compatibility with my speakers, my preferences etc. Take them with a pinch of salt. Although Tin Foil I have found worse in those tests too. If you have 15n Riaa cap samples, I would prefer them than 15.16n also. Is your Dorian doing OK with 100R in other phono stages too? Is that a standard load that you found tonally even before, in other words?
Well Salas, what was it that you did not like about Wimas?
Yes, you´re right, it all depends on the system. A friend of mine who has
a really good diy system, all valve uses wima mkp4. and i know his system
for a long time and mostly twice a year i go to him with the new so called best
cap....but always this f...... red cap wins - even better than those expensive
mundorf oil thingies. Okay my setup is quite different and i´ll try your sugges-tions. What brand do you like in RIAA network?
I use 100r because you put it in the circuit. But i left it in sockets on the pcb
so i can change the load res.
I have 220r and 470r around and will stick them in at the weekend.
Did you ever played with capacitive load on MC Systems?
Greetings Ulf
Yes, you´re right, it all depends on the system. A friend of mine who has
a really good diy system, all valve uses wima mkp4. and i know his system
for a long time and mostly twice a year i go to him with the new so called best
cap....but always this f...... red cap wins - even better than those expensive
mundorf oil thingies. Okay my setup is quite different and i´ll try your sugges-tions. What brand do you like in RIAA network?
I use 100r because you put it in the circuit. But i left it in sockets on the pcb
so i can change the load res.
I have 220r and 470r around and will stick them in at the weekend.
Did you ever played with capacitive load on MC Systems?
Greetings Ulf
I found them distinctly veiled and artificial. Pinched without punch and flat. SCR simple grade was better enough, Tin Foil worse of all, really dark. Auricap and Mundorf much better. Teflon only best, reminding DC coupling. K40-Y and K75 very good, great when Teflon bypassed. Vishay MKP 1837 I find good for Riaa and NOS Polysterene too. Dorian gives 10R source impedance so 100R is typically OK, but we would not know if 220R or 470R can fair better in real life without a test. I have found extra load capacitance rounding off MC carts non naturally sometimes that I have tried. There are models like those from EMT that require it I have read though.
Hi Salas,
well thats really funny to read because my sense while listening was
opposite to yours concerning the sound of wimas (well my experience
with cap-comparison where at my friends system). Wimas where
allways the ones with open more fluent and detailed sound. I never
thought that there must be so much of synergy within the system.....
By the way, what are your system components you compared the caps
with? My friend system is Audioplan contrast (heavily moddified), LA-
audio pushpull 6550, and LA audio pre-clone with e83cc. DAC is PSaudio.
Greetings Ulf
well thats really funny to read because my sense while listening was
opposite to yours concerning the sound of wimas (well my experience
with cap-comparison where at my friends system). Wimas where
allways the ones with open more fluent and detailed sound. I never
thought that there must be so much of synergy within the system.....
By the way, what are your system components you compared the caps
with? My friend system is Audioplan contrast (heavily moddified), LA-
audio pushpull 6550, and LA audio pre-clone with e83cc. DAC is PSaudio.
Greetings Ulf
Hi Ulf
After you experiment with cart load and reduce the 15n cap (IMO micas are fine here), you can further tune your system definition bypassing C2 (100u) on the shunt Vref. This cap is determinant in overall tone also.
Do Not bypass the shunt output cap because you will probably make it unstable.
Regards
After you experiment with cart load and reduce the 15n cap (IMO micas are fine here), you can further tune your system definition bypassing C2 (100u) on the shunt Vref. This cap is determinant in overall tone also.
Do Not bypass the shunt output cap because you will probably make it unstable.
Regards
I suspect that Ulf doesn't use the Salas Shunt Low Voltage regulator, because he answered linking the Salas NJFET Phono RIAA schematic used by him.
I believe this is the schematic: http://www.diyaudio.com/forums/analogue-source/129126-simplistic-njfet-riaa-415.html#post2242075
The reg you are using is very good.... Just experiment bypassing 100u vref cap (C2) or use a BG there.... You will be amazed.
But first you should try Salas indications regarding lowering 15n on the riaa (a slight change here makes enormous difference) and than tune cart load.
Depending on your findings, you could upgrade to Salas V12r shunt that provides more detail. (In this case you will be using film caps on vref)
But first you should try Salas indications regarding lowering 15n on the riaa (a slight change here makes enormous difference) and than tune cart load.
Depending on your findings, you could upgrade to Salas V12r shunt that provides more detail. (In this case you will be using film caps on vref)
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The optimal reg. is the same posted by Salas togheter his Phono NJFET RIAA that you are using, did you do the regulator also?
If you don't do it, do like RCruz advice, do the reg. Salas V1.2R it's simply the best.
Cheers
Felipe
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