RCruz said:Hi Salas
Just replaced R6 by a jfet and the sound is much more sweet without loosing any detail.
I am hearing chet baker and his trumpet is much more lifelike now. Also his voice is crearer and with more "grunt".
I believe it is a fundamental mod to this shunt.
PS: I still have some hissing and spiting noises after power up... I must review the shunt to Riaa wiring...
Ricardo
Thanks for your report, maybe it manifests even more in your case due to sensitive cascode first stage. I agree it gets somewhat softer but not that much in my non cascoded 1st stage case and others.
Also see to change your last JFET, the buffer one. Maybe with all those soldering cycles it got too hot at a point, and simple source follower buffers are not the best for DC thermal stability especially after some strain. Since over 15 phono like yours have been made, counting those here and those between me and local friends, and no such noises have been reported, I am challenged for expert suggestions accounting more than seek and destroy plans.
P.S. I am talking about your phono stage last JFET to the right.
At a point soon, I will gather the MM, HighMC, NormalMC, schematics, along their respective suggested shunts including R6 mod, and a few words about parts that work together well so to have a resume post for those who need to know fast, because the thread as live as it is and as long as it got, will be challenging for new comers to know what is best to build.
At a point soon, I will gather the MM, HighMC, NormalMC, schematics, along their respective suggested shunts including R6 mod, and a few words about parts that work together well so to have a resume post for those who need to know fast, because the thread as live as it is and as long as it got, will be challenging for new comers to know what is best to build.
The sound is really improving now... after one hour burning, there are no more noises. Nevertheless I search for bad solder in the psu lines (Noises appeared after their replacement) If it does not solve it, I will replace the buffer jfets.
I do not mean the sound became softer, just less edgy. It sounds quieter so the noise floor if lower and the micro detail is really enhanced.
The fingers touching the bass strings are very evident with speed, detail and attack.... Outstanding.
Ricardo
I do not mean the sound became softer, just less edgy. It sounds quieter so the noise floor if lower and the micro detail is really enhanced.
The fingers touching the bass strings are very evident with speed, detail and attack.... Outstanding.
Ricardo
In my case, I have heard less edge, more open tone in low and high treble, so in brief I said ''softer''. Wider mids a bit also. A better feeling of coherency for the whole. But it was not dramatic, just positive. The details seemed better to me, just presented easier. But we differ in cartridge, and first stage. Did you feel better plasticity in the bass? I guess I got some more too. My friend Michael with double shunts, felt all those even less, also vgeorge with double shunts said better but he did not mention dramatic. I am happy it positively works for all even if in different scale. So it will be suggested as standard from now on.
What is evident in the course of this thread and we did not talk about, is how impressive it is that some circuit changes or parts substitutions are described in the same subjective lines from different people with different systems across the world using the same phono circuits. Maybe hearing isn't that individual after all.
salas said:
That will be much appreciated, i think i already lost track
Will modify the one i build at a later time, right now all my gear is stuffed away in a storage room, as i'm in the process of moving. My son will get the one i made, so he can enjoy too.
When i finally get another apartment, it would be nice to refresh the memory with the help of a summary
All the best
Ebbe
Hmm. OK! Though haven't some other folks laid out a shunt pcb??
Oddly enough, I will stick w/ my breadboard for a while, as modding can be done so much easier.
haven't played with my RIAA in a while- need to try different R's (tants and kiwame) and C's (teflon) as well as that JFET mod to the shunt. Might even try a balanced buffer to get rid of output C. So much to do!
Still up in the air on Rload- as I tried 40-80k PRP's and liked the treble smoothness (alas much more laid back and less life). Possibly what it was doing was masking harshness, so by using tants around 1k for Rload, my Glider LO might be be smoother...
Presently focused on building an LDR attenuator so I can listen to vinyl w/o the neighbors complaining...
Oddly enough, I will stick w/ my breadboard for a while, as modding can be done so much easier.
haven't played with my RIAA in a while- need to try different R's (tants and kiwame) and C's (teflon) as well as that JFET mod to the shunt. Might even try a balanced buffer to get rid of output C. So much to do!
Still up in the air on Rload- as I tried 40-80k PRP's and liked the treble smoothness (alas much more laid back and less life). Possibly what it was doing was masking harshness, so by using tants around 1k for Rload, my Glider LO might be be smoother...
Presently focused on building an LDR attenuator so I can listen to vinyl w/o the neighbors complaining...
Iko has done, es44 never presented his final, but I guess if there is a pairing, must have the same aesthetic and layout seal. If you may of course. If you make, don't forget R6 mod. Here is what must be made into a pcb
The FT3 you will appreciate, the Shinkoh Rload you will appreciate too (got some PRP's and tested...typical. I prefer TAKMAN or DALE better).
Also the shunt R6 mod will lead you better to decide.
Also good news from solid state forum, member jwb made a breadboard shunt and runs tests. His findings till now that I took from his posts:
''Here's my 9V version of the design by salas. I think it's brilliant.
...
It doesn't oscillate at all, and whatever noise there may be is well below the ability of my scope to measure (also well below the noise from the bench supply input.)
I like it!''
''I had a chance to play around more with this simple shunt this morning. The output impedance is flat from 10Hz to 20kHz at 30milliOhms. Not bad''
''Transient performance isn't bad either. The top trace is the load signal into a 62R load (about a 25mA load step), and the bottom trace is the regulator output.''
The FT3 you will appreciate, the Shinkoh Rload you will appreciate too (got some PRP's and tested...typical. I prefer TAKMAN or DALE better).
Also the shunt R6 mod will lead you better to decide.
Also good news from solid state forum, member jwb made a breadboard shunt and runs tests. His findings till now that I took from his posts:
''Here's my 9V version of the design by salas. I think it's brilliant.
...
It doesn't oscillate at all, and whatever noise there may be is well below the ability of my scope to measure (also well below the noise from the bench supply input.)
I like it!''
''I had a chance to play around more with this simple shunt this morning. The output impedance is flat from 10Hz to 20kHz at 30milliOhms. Not bad
''''Transient performance isn't bad either. The top trace is the load signal into a 62R load (about a 25mA load step), and the bottom trace is the regulator output.''
Attachments
I must admit, that my layout didn't really finish. I ended up with using the ones i made, and made a "few" jumpers where i made some errors, that's why i didn't publish them 
The last 1 and a half month have been busy packing all my stuff, incredible how much one can collect, hehe.
Best regards
Ebbe
The last 1 and a half month have been busy packing all my stuff, incredible how much one can collect, hehe.
Best regards
Ebbe
jam said:
Hi Jam, thanks for your appreciation. Those tests have been run by jwb. I don't have any IC controlled regulator of any kind to run tests on. I did some shunts under a concept of simplicity so to integrate with the phonos and voice them together. My goal was just to sound OK and be easy to make. My engineering wits are simply DIY level and my regs lack any true technical performance. I would describe them as just adequate to my circuits. Jung, EB, Pass, Janneman, syn08 etc, are the real engineering people that teach us and we struggle to understand just a little. If it wouldn't be for their kind contributions in publications and forums, I would know what AC/DC is just a Rock band. Really.
es44 said:I must admit, that my layout didn't really finish. I ended up with using the ones i made, and made a "few" jumpers where i made some errors, that's why i didn't publish them
The last 1 and a half month have been busy packing all my stuff, incredible how much one can collect, hehe.
Best regards
Ebbe
No worries! I just mentioned all the PCBs (BTW where are Lee's finals ?
) that I could remember, bcs in due time we have to put what this thread is about in some order through a little summary.
salas said:
Hi Salas
Today I placed the 4.7u 630v obligato caps on the output.
I cleaned the pcb gnd plate around input and output tracks and settling time is now under 15 minutes...
The caps are burning ok and sound is becoming more coherent... I notice bigger soundstage and more low level detail but bass is a little shy right now. (Hope it opens up in the end).
BTW, can you point Kent´s board for me ?
Ricardo
Attachments
Well, I still have to wait until the output offset stops oscilating after power on... It oscilates from 20 to -4 mv until it rests near zero.... 15 minutes spitting and puffing... after that, total silence.
It is channel dependent (one stops faster than the other) so the problem is not in the shunt.
Now the caps are opening... quite good so far.
Now the pic with the new GND arrangement (This gave a great improvement in focus and coherency so I believe it is very important)
It is channel dependent (one stops faster than the other) so the problem is not in the shunt.
Now the caps are opening... quite good so far.
Now the pic with the new GND arrangement (This gave a great improvement in focus and coherency so I believe it is very important)
