Hello
My Ref_C works and play fine. It was very easy to built, thanks again Peter and Uriah for his hard work.
For C13 i have testet my MKP Q4 from IT and the Rifas PHE426. In my ears the Q4 sounds better than the Rifas.
The Rifas sounds a little bit flat, the room is closer and the highs sounds a bit harsh.
For C21 i use a Wima MKS2 100nf. C17,C18,C19,C20 i leave free.
Also for C4 and C5 i use a Wima MKS4 100nf.
The encloser is not finally ready, the front becomes a VA-Plate and the top 3mm Aluminium sheet.
Here some pics from my Amp.
@Uriah
Have you solved your buzzing problem ? At first test i have a buzz problem too. When i touch the pot i hear some scratching and buzz becomes louder. Then i grounded the pot to signalground and the buzz is gone. I think the pot actet as a antenna that pic up some hf-noise.
Udo
My Ref_C works and play fine. It was very easy to built, thanks again Peter and Uriah for his hard work.
For C13 i have testet my MKP Q4 from IT and the Rifas PHE426. In my ears the Q4 sounds better than the Rifas.
The Rifas sounds a little bit flat, the room is closer and the highs sounds a bit harsh.
For C21 i use a Wima MKS2 100nf. C17,C18,C19,C20 i leave free.
Also for C4 and C5 i use a Wima MKS4 100nf.
The encloser is not finally ready, the front becomes a VA-Plate and the top 3mm Aluminium sheet.
Here some pics from my Amp.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
@Uriah
Have you solved your buzzing problem ? At first test i have a buzz problem too. When i touch the pot i hear some scratching and buzz becomes louder. Then i grounded the pot to signalground and the buzz is gone. I think the pot actet as a antenna that pic up some hf-noise.
Udo
ClaveFremen said:
40 hours of additional burn-in time passed since my quoted post and things changed:
PHE426: tone is neutral but soundstage deepness is restricted (you're right Udo) and it lacks a bit of transparency
MCap: tone is almost neutral but soundstage wideness is restricted, bass a bit boosted and it lacks a bit of transparency
MCap Zn: tone is almost neutral and soundtage is there,it lacks that last bit of transparency and a bit of bass
MKP10: tone is slightly warm (very musical), soundstage is quite here and it lacks a bit of transparency
I've tried also bypassing PHE426, MCap and MCap Zn with MKP1837 and FKP2 (both 10nF): FKP2 is much more neutral than MKP1837 that lacks a bit of bass.
So caps bypassed by FKP2:
PHE426: tone is neutral and soundstage is quite here, it lacks a bit of transparency and soundstage deepness (much better than alone)
MCap: tone is neutral and soundstage is here, it becomes 97% of MCap Zn alone (you were right Uriah)
MCap Zn: tone is neutral and soundtage is there,it lacks that last bit of clarity but much less than alone, it gains that last bit of bass it was lacking too
Nichicons Fine Gold and KZs burned-in also 40 hours and I must say that I still prefer Silmics in C9, C6, C11 positions: Nichicons sounds good but channel separation and soundstage are not as good as with Silmics or FMs, regarding bass though they're better than FMs (but not than Silmics).
In C1, C2 positions Fine Gold seems better than FMs but channel separation suffers a bit. I'm still evaluating here...
Thanks for the updates and hard work Dario.
I have a little listening impression.
I removed C19 and C20.
Music is effortless. Separation of instruments is better. Clarity is better than just C13 being removed, which it is.. Diamonds on the Soles of Her Shoes when the African guys are singing "cha nah na nah na" over and over you can tell their voices apart. Its neat. So to me its a big change for the positive but there are two drawbacks and they dont make sense. The soundstage has not collapsed but it is now relegated to living between the speakers. Before it was out past the speakers about an hour on the clock face each way. Voices seem less aggressive, more subdued. Basically its like I turned the volume down on the sounds that happen in the very middle of the soundstage. Weird. Hard time deciding if I like it better cuz the pros are definitely better than before and I like detail and I have it in spades.
Uriah
I have a little listening impression.
I removed C19 and C20.
Music is effortless. Separation of instruments is better. Clarity is better than just C13 being removed, which it is.. Diamonds on the Soles of Her Shoes when the African guys are singing "cha nah na nah na" over and over you can tell their voices apart. Its neat. So to me its a big change for the positive but there are two drawbacks and they dont make sense. The soundstage has not collapsed but it is now relegated to living between the speakers. Before it was out past the speakers about an hour on the clock face each way. Voices seem less aggressive, more subdued. Basically its like I turned the volume down on the sounds that happen in the very middle of the soundstage. Weird. Hard time deciding if I like it better cuz the pros are definitely better than before and I like detail and I have it in spades.
Uriah
I've been enjoying my myref quite a bit and have been reading this thread and following the cap tweaks to see what people are trying.
I replaced the BOM C13 caps with WIMA MPK10 1uF and I really like those there. I've kept all the FMs because I've always liked those. I've been using a .22uF russian k42y-2 for c21 from the start and I tried changing that for a .1 uF ERO-Roederstein mkp1837 for a while but I went back to the russians there. I really like the warmth that the russian caps give.
I replaced the BOM C13 caps with WIMA MPK10 1uF and I really like those there. I've kept all the FMs because I've always liked those. I've been using a .22uF russian k42y-2 for c21 from the start and I tried changing that for a .1 uF ERO-Roederstein mkp1837 for a while but I went back to the russians there. I really like the warmth that the russian caps give.
udailey said:
Uriah, to me seems the description of BQs sound...
I suspect that what you hear, now that sound is no more masked by C19 and C20, is the signature of the cap in C7, I have a 220nF Wima MKS2 in that position.
This night I'll try C19, C20 again.
Coreyk78 said:
I agree, they're slightly warm and involving, very musical but they're also a bit coloured compared to DC coupling.
Well, the problem is that something was LOST and all I did was remove those two. Now, dont get me wrong, the result has its improvements as well and I like the improvements but I dont understand why the soundstage would get smaller here. They are bypass caps so they are there to filter noise out but would the addition of a little noise collapse some of my soundstage? Thats what is weird about this change.
Uriah
It is great to see other's comments on the component selction and resulting sound of their My Ref amps. Thanks to everyone who contributes their experiments and impressions.
We begin to see how much a factor each of these components plays in the final sound of the amps. I am not done experimenting yet, and I will continue to provide updates. It appears that selection of C13 depends a lot on personal tastes. The important fact is that the stock part is not the best suited there. I recommend using the best cap you can afford. All of these other mods are secondary to that.
Uriah, you are hearing the same coloration of voices and some other midrange elements that I have reported previously. Removal of C19 and C20 yielded only improvements, and probably have nothing to do with it. I noticed the effect after replacing C9 with Elna Silmic II, but it may have been there from the outset with the Panny FM's and I just didn't notice it. It did not change at all after I recently removed C19 and C20, so I'm certain that's not the cause. The coloration is very subtle until you notice it, and then it's there all the time, although audible only with certain material, notably female vocals at the center of the soundstage. I can detect it now with other instruments such as guitar, horns, and, just the other night, harpsichord! It is some kind of phasey effect. It produces not only a loss of some tones, but also an augmentation of other tones, almost like a nasal resonance. I believe it might be caused by the interaction of C9 and its C21 bypass, but I'm not certain. Dario reports it is reduced by lowering the value of C21 with different selections of C9. Maybe that's because, as C21 gets smaller, it has less effect in the circuit. I certainly hope it is not a basic tonal characteristic of this amplifier design, as that would certainly be a deal breaker for me.
Dario, you are our primary detective for tracking down these problems, so get to work! Your test set-up is very cool. You reported that 0.02uF at C21 gave the least effect. Is that because of the value, or because you are using an FKP2, which is a stacked film and foil cap instead of metallized poly? That value is so very small compared to the typical recommended bypass value. I wonder if the cap is really doing anything at all? Too bad we can't get a FKP or similar film and foil cap in value greater than 0.02uF that would fit there. I guess that's what CoreyK is doing and mounting it somewhere other than its regular position. Got a pic or other description, Corey?
What happened to that other poster with the complex cap testing rig? Any news?
Peace,
Tom E
We begin to see how much a factor each of these components plays in the final sound of the amps. I am not done experimenting yet, and I will continue to provide updates. It appears that selection of C13 depends a lot on personal tastes. The important fact is that the stock part is not the best suited there. I recommend using the best cap you can afford. All of these other mods are secondary to that.
Uriah, you are hearing the same coloration of voices and some other midrange elements that I have reported previously. Removal of C19 and C20 yielded only improvements, and probably have nothing to do with it. I noticed the effect after replacing C9 with Elna Silmic II, but it may have been there from the outset with the Panny FM's and I just didn't notice it. It did not change at all after I recently removed C19 and C20, so I'm certain that's not the cause. The coloration is very subtle until you notice it, and then it's there all the time, although audible only with certain material, notably female vocals at the center of the soundstage. I can detect it now with other instruments such as guitar, horns, and, just the other night, harpsichord! It is some kind of phasey effect. It produces not only a loss of some tones, but also an augmentation of other tones, almost like a nasal resonance. I believe it might be caused by the interaction of C9 and its C21 bypass, but I'm not certain. Dario reports it is reduced by lowering the value of C21 with different selections of C9. Maybe that's because, as C21 gets smaller, it has less effect in the circuit. I certainly hope it is not a basic tonal characteristic of this amplifier design, as that would certainly be a deal breaker for me.
Dario, you are our primary detective for tracking down these problems, so get to work! Your test set-up is very cool. You reported that 0.02uF at C21 gave the least effect. Is that because of the value, or because you are using an FKP2, which is a stacked film and foil cap instead of metallized poly? That value is so very small compared to the typical recommended bypass value. I wonder if the cap is really doing anything at all? Too bad we can't get a FKP or similar film and foil cap in value greater than 0.02uF that would fit there. I guess that's what CoreyK is doing and mounting it somewhere other than its regular position. Got a pic or other description, Corey?
What happened to that other poster with the complex cap testing rig? Any news?
Peace,
Tom E
VictoriaGuy is still testing away I believe.
I wonder if Dario's use of 22nf is in fact better than removing the cap for this reason: If its a bypass cap it removes some noise right? What if the noise we need removed is a tiny hiss atop of the rest of the signal and with that hiss things just sound wrong? What if having 220nf is large enough to really mess with other frequencies, but 22nf just takes care of the problem that was supposed to be bypassed anyway?
Dario, can you hear the soundstage shrink with the removal of these two caps? Can you hear it attenuated a little in the middle? Weird I know. If so, does 22nf restore the soundstage?
Uriah
I wonder if Dario's use of 22nf is in fact better than removing the cap for this reason: If its a bypass cap it removes some noise right? What if the noise we need removed is a tiny hiss atop of the rest of the signal and with that hiss things just sound wrong? What if having 220nf is large enough to really mess with other frequencies, but 22nf just takes care of the problem that was supposed to be bypassed anyway?
Dario, can you hear the soundstage shrink with the removal of these two caps? Can you hear it attenuated a little in the middle? Weird I know. If so, does 22nf restore the soundstage?
Uriah
madisonears said:
Tom-
I'm still listening and flipping switches here.....
My main conclusion, so far, is that if I want to get really significant changes, I should hit the workshop and work on speaker boxes and a variety of amps.
I have actually been quite busy and have only spent an hour or two in concentrated listening tests, and with a reasonably limited mix of caps. If anybody would like to send me some 'proven' good caps, I'd be happy to include them in the mix!
I do believe that my memory for sound quality is quite flawed and unreliable, and that without an 'instant' method of comparing components I can't make meaningful decisions.
I have a friend or two with better ears and I'm trying to get them to drop around to the house to play with the switcher.
I'll report back with any definitive conclusions I/we reach.
Cheers
John
PS- I did put a 'straight wire' in as one of the 'cap options' as suggested.
Yeah, John, it's easy to get "flipped out" comparing caps. I listen to my two monoblocks with a different C13 in each and I think that one sounds good with some kinds of music, but the other sounds better with other kinds of music. I've changed my mind about a dozen times in the last few days. It'll drive ya nuts! It's much easier when one cap is bad bad bad and the other is decent or better. At a certain level of performance, it really comes down to personal taste and system/speaker interface. Now I know why the many cap reviews cannot declare a clear winner. Generally, their conclusions group certain caps as better than other groups of caps. Within those groups, it's up to the user, not the reviewer. Right now, I'm stuck in one of those groups.
Please persevere.
Peace,
Tom E
Please persevere.
Peace,
Tom E
udailey said:
udailey said:
Uriah, I've just tried again BQs in C19 and C20 and to my ears, like last time, there's no match
With BQs in soundstage wideness is pretty much the same but the deepness collapse and a big part of reverbs and tiny details simply disappear. The result is that voices and instruments seems to have more body because they 'eat' resolution and deepness becoming 'bigger' but IMHO they are simply ticker and fine detail is lost.
This sort of thing happens with all caps I've tried in all positions: if you have detail and reverbs voices and instruments seems thinner, initially.
Have you ever noticed how different sounds your voice in the bathroom, where there's a LOT of reverb...
I'm still thinking that also C7 has a role here because also in C21 position BQs has the same 'simplifying' effect I've described, MKS2 (that is my C7) has much more detail, reverbs and better soundstage.
I think that C21 has no effect here.
madisonears said:
Yeah Tom, I think too that is great that others are starting to experiment, it's stimulating and useful.
I don't think that what Uriah reported is exactly the coloration you reported, if I have understood well.
What I have heard searching your coloration is a change of the position of voices in the soundstage and their focus and this is fixed, IMHO, with 22nF C21, I think Uriah said that he lost something he was used to and he liked (that 'thickness' I've described), he likes the new sound but he miss the 'body'...
Regarding C21 I've first used FKP2 to determine the value using first 10nF (that simplified music), after 33nF (that added something) and last 22nF (that seemed right)
I had too the suspect that this value could be related to FKP2s so Ive repeated the test with MKS2s starting with 100nF going down to 10nF with the very same results.
In both cases the 22nF bypass sounded 'right', highs are better, bass too and voices are correctly placed and focused (better than Silmics alone)
Uh, yeah, FKP2s are much better than MKS2s
udailey said:
I think that the problem handled by the C21 bypass is different from a normal PS bypass. The goal, IMHO, is to obtain a 'custom' capacitor that has the high value of the elco and the speed and clarity of a tiny film cap. The incredible thing is that this tiny bypass has effect also on bass (for instance a FKP2 bypass restores the right bass that MCap Zn lacks...
)