The price is otraugeous, IMHO... 🙁
IMHO, yes.
Cerafines have a much more balanced timbre, though they're no as 'silky' as Silmics.
When you say "Removed" do you mean omited-did not populate or do you mean Jumpered-completed the circuit with wire ?
Also, what is the best part (for FE) for C1-C2 from Parts Connexion ?
DANGER!!!
bypasses must be removed not shorted!!! 😱
The corresponding positions must be left void, unpopulated.
If you have FMs keep them until you find a good sorce for RJHs....
Hey Dario,
Out of curiosity, how much, if any of the changes discussed here are you incorporating into the Freeman edition. I know you are dealing with different boards but it seems there is the possibility of some overlap. Can you clarify?
Out of curiosity, how much, if any of the changes discussed here are you incorporating into the Freeman edition. I know you are dealing with different boards but it seems there is the possibility of some overlap. Can you clarify?
The Fremen Edition initial BOM will be exaclty the same as per version 1.5 with the exception of different circuits (like LM318 PS) and bigger TH resistors (1/2 watt).
In the beta test this BOM will be tailored to the new amp.
hehe. still, $10 a blackgate might seem bargain to some. they were $55 a bag when I bought them, though. http://www.ebay.com/itm/28075948834...NX:IT&_trksid=p3984.m1439.l2649#ht_500wt_1413
these would make an excellent bypass caps for c4,7 btw.
4X K40Y-9 NEW OLD STOCK 0.1uf 400V RUSSIAN PAPER IN OIL CAPACITOR PIO .1 | eBay
i'll be ordering them along with 1uf value of the same cap, possibly putting my mundorf supreme caps out of commission.
I just love that oil sound 😉
The difference between a bypassed RJH and blackgate standard (for C9) isn't worth ten times the cost...IMHO
I've bought them too but I didn't tried them, yet.
But those are not PS bypass caps... a bypass to be effective should have very short leads...
so you reckon RJHs are better than silmic ii? still bypassed with fpk2? I wouldn't mind trying them for other applications in place of where i was wishing i could put blackgates 🙂
Say what you will about shorter leads but all I know is that the improvement was most wholesome when I swapped the wimas out with mundorfs in c4,7. timbre, extension, you name it- it was an improvement in every spectrum.
I'm confident enough to bet that it would be the case for the k40y also. 🙂
i suppose you could solder them directly to the legs of c1/2 c6/11 to cut down on the lead length. knowing the size of k40y, it's probably a neat fit, too.
Say what you will about shorter leads but all I know is that the improvement was most wholesome when I swapped the wimas out with mundorfs in c4,7. timbre, extension, you name it- it was an improvement in every spectrum.
I'm confident enough to bet that it would be the case for the k40y also. 🙂
i suppose you could solder them directly to the legs of c1/2 c6/11 to cut down on the lead length. knowing the size of k40y, it's probably a neat fit, too.
My RJH test in C9 has been brief, so I could be wrong, but IMHO sounded better, both bypassed with FKP2s.
But not in C6/C11, in that positions Cerafines are better (fuller).
I don't doubt you heard an improvement but what you're hearing is sound of the cap.
It's effectiveness as a bypass that filters high frequency noise from PS lines is much (much) lower though....
It seems even though caps of similar value, size is still a critical factor for wide frequency range performance.😀
Sometimes components make differences for reasons unknown. I like to get to the bottom of things because there is a reason, and there are tradeoffs. Generally, components that seem to provide a lively sound also sacrifices. If we know exactly why something provides the wrong sound, it makes things easier to fine the right solution.
Size matters, for sure... but for decoupling smaller is better. 😉
In fact for decoupling, sometimes, small ceramics, even X7R, works better than film caps...
Try the KOAs... you'll be delightetd 😉
If the problem is in a specific frequency range, then probably a variety of smaller capacitors are better. This is also why snubbers work the way they do, one thing I have on my other amp that I have not used here. I know people have mentioned snubbers do not work in this circuit, but with the sound of the original kit, I can understand why.
No particular problem I'm aware of... simply decoupling.
Can you elaborate?
If you have coupling problem in a specific frequency range, then that is a problem.
The original MyRef Kit had a sound that was much colored. It sounded dynamic under many circumstances which attracts attention. This coloration is in the design of the circuit which is at a level that dominates overall performance so putting in devices like snubbers is not going to help. Only when the circuit is tuned for less sonic coloration, then other improvements can accumulate improvement on the overall amplifier. I don't know if anyone had tried R7 and gm changes. If anyone has, would appreciate reporting.
After further measurements, with gm=1, R7=6K seems to provide the best damping, just slightly better than the standard MyRef. I am going to try changing gm when I get the resistors in.
It seems that C32 might be reducing damping at high frequency, has anyone actually ran into stability problems without it?
It seems that C32 might be reducing damping at high frequency, has anyone actually ran into stability problems without it?
Siva simulations shown stability problems from 100pF downward, if I remember correctly.
In the Rev A that cap doesn't exists but neither C10... it was introduced with Rev B, different compensations...
For LTSpice simulations, I'm using the LM1875 model. However, C32 is a crucial compensation element in Rev C and later - I'm certain that both stability and sonics will be compromised if it's removed.