Correction - To get my bearings back, I listened to the base files with some good earphones. The trumpet licks are stage right but the separation and definition still are not the best.
Great Work!
Bob,
Thanks for doing all this. I know I wouldn't have had the time and I know about listening fatigue. Thanks for working so hard to make the comparison real.
By the way, did you ever take your F.E. to the high end stereo store like you were planning? If so, any results?
Jac
Bob,
Thanks for doing all this. I know I wouldn't have had the time and I know about listening fatigue. Thanks for working so hard to make the comparison real.
By the way, did you ever take your F.E. to the high end stereo store like you were planning? If so, any results?
Jac
Glad to do it 🙂
Please see this post.http://www.diyaudio.com/forums/chip...f-vs-simple-lm3886-circuit-4.html#post3029108
Please see this post.http://www.diyaudio.com/forums/chip...f-vs-simple-lm3886-circuit-4.html#post3029108
Suburra raised :
- ClaveFremen x 2 (IT)
- Suburra x2 (IT)
- SoIL4x4 (US)
- Bmcbob (US)
- Randytsuch (US)
- alex70ita (IT)
- b.veneri (IT)
- StefanoSan73 (IT)
- diymax62 (IT)
- billo44 (UK/JP?)
- TjongKristian (ID)
- arthur x 2 (N/A)
- PMeade (US)
- Badrisuper (IN)
- lehmanhill x2 (US)
- ?
Looking Good! Just finished burning the rest of the caps and will start testing later this morning.
I guess I should comment on some mistakes I made. Somewhere in my messing around in the past few days I attached non-paired leads (secondaries) to the power tabs on one amp. The fuse blew with no damage to any component. Yesterday, at the end of the swapping session, I left C30 out of both amps. When I powered up again all manner of lights, clicks and hisses scared the heck out of me. Putting them back in and using the dim bulb, all came back to normal operation. Don't know what could have happened but those two screw ups demonstrate to me good stability and protection in this design.
I guess I should comment on some mistakes I made. Somewhere in my messing around in the past few days I attached non-paired leads (secondaries) to the power tabs on one amp. The fuse blew with no damage to any component. Yesterday, at the end of the swapping session, I left C30 out of both amps. When I powered up again all manner of lights, clicks and hisses scared the heck out of me. Putting them back in and using the dim bulb, all came back to normal operation. Don't know what could have happened but those two screw ups demonstrate to me good stability and protection in this design.
Huh, C30 is pretty much the main compensation capacitor (in fact, the real deal is R37, C30 just blocks DC and audio frequencies). If omitted you get a perfect oscillator. 🙂
I'm having a long conversation with my MK132s and, maybe, we'll not divorce anymore... 😉
At least in R13, in R104/R204 it's more complicated.
Starting my little dance here also.
Test #4 - C30 - Wima FKC2 1nF. The orientation effects the width of stage just slightly.
I then went back to the Euro KP1830 and can confirm the Euro is cloudy and dispersed - more difficult to pick out individual voices/instruments. I them went all the way back to the stock Wima FKS2 from the BOM. I would call that the most musical with the FKC having a slight edege in clarity/shine. I would not special order the FKC as opposed to some other parts. Not a whole lot of significant change here, other than a thumbs down on the Euro.
Next up C32
Test #4 - C30 - Wima FKC2 1nF. The orientation effects the width of stage just slightly.
I then went back to the Euro KP1830 and can confirm the Euro is cloudy and dispersed - more difficult to pick out individual voices/instruments. I them went all the way back to the stock Wima FKS2 from the BOM. I would call that the most musical with the FKC having a slight edege in clarity/shine. I would not special order the FKC as opposed to some other parts. Not a whole lot of significant change here, other than a thumbs down on the Euro.
Next up C32
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n-th +1... I've just broken another socket... 😀
An interesting note on R2.
R2? But isn't it the muting resistor?
Yes, R2...
Some time ago I swapped the BOM one (CMA0204) with KOA RK73H but at that time I didn't noticed much since I was playing with all the others RK73Hs (discarded).
I've just restored the original CMA0204s and noticed a big difference in bass response and overall balance... those little carbon film MELFs are little gems...
They sound full and pleasant with no harsness...
But the real surprise is that R2 affects, unexpectedly, sound so much.
Also for the My_Ref this resistor should be carbon film, IMHO.
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Quick test #5 - Euro KP1834 150 pF
A definite keeper. First impression was depth of stage improvement - that ambiance extension. Very musical and clean image. Great detail and separation. The trumpets have a real nice bite without sounding piercing.
Unfortunately, I believe these are among the group of no longer manufactured caps and are hard to find. If you see some and the price is right - grab them.
C7 next.......
A definite keeper. First impression was depth of stage improvement - that ambiance extension. Very musical and clean image. Great detail and separation. The trumpets have a real nice bite without sounding piercing.
Unfortunately, I believe these are among the group of no longer manufactured caps and are hard to find. If you see some and the price is right - grab them.
C7 next.......
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Quick test #6 - C7 - Wima FKC2 10 nF Poly-carbonate film/foil.
Now we're getting into the good stuff. This one has that "lifted a thin veil" effect. It retains the musicality and bumps up the "realistic" image. Can't quite tell if the front to back is better but it certainly didn't take anything away. For orientation - there is slightly more punch and bass (including control) with the writing facing away from the LM3886 chip. This one actually made me smile.🙂
Now we're getting into the good stuff. This one has that "lifted a thin veil" effect. It retains the musicality and bumps up the "realistic" image. Can't quite tell if the front to back is better but it certainly didn't take anything away. For orientation - there is slightly more punch and bass (including control) with the writing facing away from the LM3886 chip. This one actually made me smile.🙂
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Quick test #7 - C7 - Ero MKP1837 10 nF Polypropylene metallized foil.
Probably the warmest cap tested, but to me sounds compressed. The clarity is there but it makes me feel life I'm listening to a good amp - not sitting in the concert venue. Not much difference with twirling the orientation. To my ears, the Wima FKC2 10 nF is my preference.
That should be a wrap. What I've learned is it might be well worth a builder buying a few sockets in order to be able to "Tune" the amps to personal preference in a few key spots. I'm going to go back over my reports and try to make a key list as I also double check my findings.
I will also state that all of this truly did enhance the performance of the Fremen Edition, but builders using the stock Mouser BOM already have ~ 90% of what I could squeeze out of the amps. These upgrades are truly "frosting on the cake" for an already great effort from Dario.
later.........
Probably the warmest cap tested, but to me sounds compressed. The clarity is there but it makes me feel life I'm listening to a good amp - not sitting in the concert venue. Not much difference with twirling the orientation. To my ears, the Wima FKC2 10 nF is my preference.
That should be a wrap. What I've learned is it might be well worth a builder buying a few sockets in order to be able to "Tune" the amps to personal preference in a few key spots. I'm going to go back over my reports and try to make a key list as I also double check my findings.
I will also state that all of this truly did enhance the performance of the Fremen Edition, but builders using the stock Mouser BOM already have ~ 90% of what I could squeeze out of the amps. These upgrades are truly "frosting on the cake" for an already great effort from Dario.
later.........
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