Simplistic NJFET RIAA

diyAudio Chief Moderator
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Try the *load for the Lyra and your 47K series Riaa resistor in bulk foil Z. That will up refinement and treble purity, along some more reverberation.

*(100R maybe better, but try 100-150-220-330 in handier resistor first, so to nail the Lyra in your system).
 
Making these changes will be very painfull. I will have to stop listening to do it.


Kidding aside, It is presently loaded with 150R carbon comp. (Why CC? because I had one). I am going to take it to 249R Metal Film (Vishay RN60). It is a good in-between. I'll then take it 350R later to see if I like it lower or higher than 249R.

I just finished up on a new alignment that allows me to use the triplanar with the outer-ring stabilizer.
 
diyAudio Chief Moderator
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That's a typical 5 Ohm Rg Lyra? Gerhard was using 330R in his system and the Titan for instance I think, or somewhere around there. Its low Rg guarantees it will work with 100 Ohm even without much signal loss. Maybe 150 Ohm you got now can be best, you never know in different systems. The alignment, the speakers and amps tonality, the TT signature, all combine. Its wise to check out with neutral stuff like RN60, and when best value is hit, go for 4 special order resistors. Merlin was very positive about the Z types in those 4 places. I guess that after your new investments, just 4 best resistors are well justified. Such stuff like small differences in purity etc. will be adjusting with parts tests and load. Also the cart will open up a bit further when run in.
 
Put in the 249R RN60 load resistor. I am not sure if it was the switch from carbon comp to metal film or the change in resistance from 155R to 249R that made the biggest impact. Will have to try a 150R Metal Film during this tuning phase.

The impact however, was immediate and stunning. Detail, depth of sound stage, and instrumental focus became crystal clear. At times while listening to Linda Ronsdtat Sentimental Reasons I had gooseumps and tears in my eyes at the same time. You can hear the attack of the Bass and the harmonics of the string set in. It is very engaging.
I need to listen to this for a while and see how it is perceived over time.
 
nicoch46,
I will try those resistors soon. Once I dial in the range of loading with the RN60's (which I have lots of) I will order the Z foils and Shinko's. Have to figure out where to order them first. I'll get a couple values to try your suggestion of upping the value.

I also want to play with the output caps at some point as well.
 
diyAudio Chief Moderator
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@ Salas, sorry i have no working Digi-Cam at the moment.
Maybe Christmas will help ;-)
Parts i use are Takman resistors, russian Teflon, Obbigado
outputcap, Panasonic FM. Thats it.

Greetings and Thanks to everybody keeping this project
alive

Ulf

Can you post your particular schematic with measured bias voltages written on, so I check it went fully OK?
 
The V1.2R has a slightly different(simpler) sense circuit with a differently tuned Zobel and capacitor on the output. Per those that have built it, it has even better qualities suited for audio. From what I have read so far it seems to be a little more stable to set up as well which is a big plus. The v1.2 is very sensitive to layout, parts and takes a bit of fiddling to get up and running stable. If you skipped the v1.2 and built the v1.2R you are ahead of the game.
 
Tonight I went the other direction in loading. This time I went to 120R. While still early in my evaluation I find the tonal balance to remain about the same. The biggest impact IMHO is in the imaging. The 390R seemed to focus the sound and the image tightly in the center between the speakers with the left / right extremes being more out of focus. Kinda like tunnel vision. The 120R is perceived to do the opposite. Now the image and focus appear to be from the speaker outward. In between the speakers seems more void.

Is this a normal? This is the first time that I have really "dialed" in the load with this kind of precision. The change in perception is not what I expected.
 
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