Well..... I am runing it at 12 oclock now but with the tremendous improvement in dynamics, I believe I can push it much higher without stress..... For now I am just listening ... openning nicely.. still some harshness in the highs.... (Mundorfs probably)... nevertheless, as is it is already a superb Riaa.
Ricardo
Ricardo
Not sure before it will burn for about 50 hours, but your big brown cap can get a further 300pF mica in parallel if you will still feel that your sound is a bit stronger in between 10kHz-20kHz.
Edit: You can also bypass the Mundorf with a 47nF K-40 if some harshness proves to be related to that capacitor.
Edit: You can also bypass the Mundorf with a 47nF K-40 if some harshness proves to be related to that capacitor.
nicoch46 said:HI kent my suggestion is to order two optvol if you want tray the lightspeed, fom me better use the series element as normal resistor ,and play with brand for fine tweak ...
you can tray for we?
Hi nicoh46-
I have already ordered matched LDR's from a chap offering them on the thread. I liked the shunt-series ldr approach. Also, maximus on that thread has a chip based controller (with IR remote capability) design and will be producing boards for sale.
Cheers- Kent
Hi Salas
Now the sound of the Riaa is really impressive.
Comparing it with the stock MM Riaa in the 101, the timbre of the instruments and the subjective frequency response seem very similar (meaning that I lost nothing).
But the comparison stops there.... Your design is faster, much more detailed and a lot more dynamic.
The distortion is lower and the schunt + Riaa is very silent in comparison.
All this after 48 hours and based on some low quality components. Now I will fine tune starting with the resistors, case, cabling and connectors.
Regarding the cable, The last pics you posted (dual mono psu) has a nice red coax... where can I get it ?
I found some silver plated copper screened wire:
Two types available. 7/0.2 - signal wire is 7 strands of 0.2mm dia. amd 19/0.2 - signal wire is 19 strands of 0.15mm dia. Overall diameter for 7/0.2 is 2.3mm and for the 19/0.15 is 2.7mm
What should I choose ???
Thank you for the wonderfull design and unconditional support.
Ricardo
Now the sound of the Riaa is really impressive.
Comparing it with the stock MM Riaa in the 101, the timbre of the instruments and the subjective frequency response seem very similar (meaning that I lost nothing).
But the comparison stops there.... Your design is faster, much more detailed and a lot more dynamic.
The distortion is lower and the schunt + Riaa is very silent in comparison.
All this after 48 hours and based on some low quality components. Now I will fine tune starting with the resistors, case, cabling and connectors.
Regarding the cable, The last pics you posted (dual mono psu) has a nice red coax... where can I get it ?
I found some silver plated copper screened wire:
Two types available. 7/0.2 - signal wire is 7 strands of 0.2mm dia. amd 19/0.2 - signal wire is 19 strands of 0.15mm dia. Overall diameter for 7/0.2 is 2.3mm and for the 19/0.15 is 2.7mm
What should I choose ???
Thank you for the wonderfull design and unconditional support.
Ricardo
Valve itch
I am also thinking of ideas about a new valve phono to make. Trying to do better than the Bench one, bcs the Simplistic NJFET overachieved it. So I made a preliminary design based on 2 mu followers in cascade like in phono dude. I have E283CC and 6CG7 which are low noise, better 12AX7 with funny pin out, and noval 6SN7. This one can do 44dB, good for down to 2mV high MC. Must share low valves and high valves between channels, with the high valves heaters lifted at 100V. It can do 38dB if first valve is 6SL7 and the first stage 47k must be substituted for 33k. No problem with real MM or X10 step up. Nice full octal variant if second valve will be 6SN7. There is a good stash of flavors with many people. I guess that I will try it at a point. No definitive plans yet.
I am also thinking of ideas about a new valve phono to make. Trying to do better than the Bench one, bcs the Simplistic NJFET overachieved it. So I made a preliminary design based on 2 mu followers in cascade like in phono dude. I have E283CC and 6CG7 which are low noise, better 12AX7 with funny pin out, and noval 6SN7. This one can do 44dB, good for down to 2mV high MC. Must share low valves and high valves between channels, with the high valves heaters lifted at 100V. It can do 38dB if first valve is 6SL7 and the first stage 47k must be substituted for 33k. No problem with real MM or X10 step up. Nice full octal variant if second valve will be 6SN7. There is a good stash of flavors with many people. I guess that I will try it at a point. No definitive plans yet.
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salas said:
Hi Salas!
I have an original La Maison de L'Audiophile schematics (1990) which is slightly different:
R9 = 2 kohms
No R11 for Jfet with Idss=2 mA (reccomended) but a 47ohms resistors may be added if you find only Jfet with Idss > 2mA
No R10
C5 = 1uF
Jfet was 1/2 2SK240GR
As far as tubes are concernd, I won't use an 12AX7 (not even a rare version) as I consider its sound not the very best.
Why not try other hi mu tubes such as ECC8010 or the much less expensive EC86? Or even a triode connected D3a.