Ricardo finds film caps excellent everywhere in the reg, you preferred lytics for Vref bypass I remember in Buffalo regs. Its a system thing too, but I have Ricardo's experience also in phono.
i changed the layout to have the ccs very tight. it did nothing, not even the gate stopper. then i changed the irf540 to 240 and it worked right away. looks like the 540/9540 is not optimal in the ccs position...at least in my case 🙂
sad because the irf9540/540 is significantly cheaper...still this reg is phenomenal bang for buck.
I have used it only in the shunt position. Try 9610 for TO-220 CCS in some other build in the future also.
Will be interesting to know other opinions in digital reg.
About Vref bypass lytics or films it's a personal taste because if you have an analytic system perhaps you prefer lytic that will give more body but if you have a warm not more analytic system could you prefer films....
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While waiting for an oscope, I decided to kill the hum so I can go on listening to music 🙂
Just replaced the output zobel by a 47u EL and hum disapeared completely. (Now this riaa build is dead silent .... at full power I can not hear anything... no hum... no hiss... nothing at all)
The strangest part is that I initially made this mod only in the left channel, leaving the right one with the zobel and hum was totaly absent. (I only did the same on the right channel to maintain overall timbre !)
I can assure you that the zobel sounds much faster and cleaner with faster transients than the EL on the output.
I did this before I read about bypassing the film cap..... I will keep it as is until I get the scope. Zobel in the output is so much better !!!
Ricardo
Just replaced the output zobel by a 47u EL and hum disapeared completely. (Now this riaa build is dead silent .... at full power I can not hear anything... no hum... no hiss... nothing at all)
The strangest part is that I initially made this mod only in the left channel, leaving the right one with the zobel and hum was totaly absent. (I only did the same on the right channel to maintain overall timbre !)
I can assure you that the zobel sounds much faster and cleaner with faster transients than the EL on the output.
I did this before I read about bypassing the film cap..... I will keep it as is until I get the scope. Zobel in the output is so much better !!!
Ricardo
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IMO using a film for vref might initially seem to have less weight but in the end (after a good burning period), film prevails with outstanding bass weight with much more detail than with EL.
The sonic signature of the vref cap is so heavy that you must use good quality parts... not the average MKP... something more elaborate 🙂
A film in the output does not produce such evident results but in the end lifts detail to another, much higher level.
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How do you guys decouple at the load if you use a zobeld foil C as the main cap? I normally use 100uF elcaps with opamps and between 220-1000uF for discrete circuits.
Since audiophile foils tend to get very big I admit I have problems to ignore potential problems due to long leads and loop area.
Any thoughts?
Rüdiger
Since audiophile foils tend to get very big I admit I have problems to ignore potential problems due to long leads and loop area.
Any thoughts?
Rüdiger
Big audiophile film caps I don't recommend out of hand. I use compact MKT or MKP radial that can also be bypassed in subjective experiments with the likes of Vishay MKP1837, FT-1 etc. I generally go the lowest value without problems on the scope given a certain load circuit. If a film cap + R Zobel proves OK, I avoid the lytic. In that one I showed, the 2 blue boxes are Philips MKT both for Vref and out. The first has a Vishay 10n across, the second has +1//1R series. Gave clean B+ in that application. But I have had with PP Arcotronics 4u7//FT1 22n & Arc4u7+1R per channel in a double mono phono, as well. You can even try with 22-47uF lytic that has some ESR by the way.
Is that reg you made meant for your Jfet dif input phono with several complementary symmetric Jfet buffers and loop servo?
P.S. Most of the circuits I feed with those regs are not strongly locally decoupled on most stages if at all. RC feeds mainly with up to 220uF.
Is that reg you made meant for your Jfet dif input phono with several complementary symmetric Jfet buffers and loop servo?
P.S. Most of the circuits I feed with those regs are not strongly locally decoupled on most stages if at all. RC feeds mainly with up to 220uF.
Salas, thanks for your answer.
I don't use that phono you mentioned anymore. Was nice, but not nice enough. Currently I'm working on a simple-as-possible balanced input phono stage. Fet input, of course. I might use opamps in the subsequent stages or some ugs-modules or something similar.
Rüdiger
I don't use that phono you mentioned anymore. Was nice, but not nice enough. Currently I'm working on a simple-as-possible balanced input phono stage. Fet input, of course. I might use opamps in the subsequent stages or some ugs-modules or something similar.
Rüdiger
Something like Werner's but symmetric? Folded cascode input with op amp 2nd stage and active Riaa?
Not to far away, definitly a variation of the vendetta theme. I have build Werner's and it is beautiful, but my build had it's limitations on complex material (what I hear a lot), and one fet is not quiet enough. I will post it on this forum if I get somewhere with it.
Rüdiger
Rüdiger
Hi Merlin
After heavily shielding power lines I decided to go back to the zobel on the output.
Once again I experimented first on the left channel with a smaller 10u MKP on the output.
Hum was quite low but not absent as in the right channel (with EL on the output) so I decided to bypass the zobel output cap with a K72 .047uF and this proved to be a major success
Now hum is on par with the right channel (lower than normal riaa hiss).
And of course I get the "full film" bass control and overall definition boost
Thank you so much for your idea !
PS: bypassing the lytic on the output is not a good idea as it reduces ESR at the point to make the circuit unstable producing the "dreadfull whistle" ..... Sometime ago, I tryed it on a special test shunt with awfull results.
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Final setup..... 10uF Audyn-cap MKP // .1uF Vishay MKP1837 on the output zobel (both channels).
Outstanding results already audible in the bass and overall detail and attack.
Outstanding results already audible in the bass and overall detail and attack.
Could be killing some ESL of the big cap's winding. I just remind that when bypassing the output Zobel only bypass the cap part. Subjective remarks I leave to the builders.
psu voltages
Now I'm changing the Tx & I have measured incoming voltage to regulators:
One channel 56.1VDC
Other channel 61.3VDC
How can drop the PSU voltages, with a resistor 10W, wich resistance values for each channel?
Now I'm changing the Tx & I have measured incoming voltage to regulators:
One channel 56.1VDC
Other channel 61.3VDC
How can drop the PSU voltages, with a resistor 10W, wich resistance values for each channel?
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