madisonears said:
I soldered up a pair of boards last weekend and everything went fine. The excellent components labelling along with the detailed printing on the boards made it pretty tough to get anything wrong.
Within a few hours they were playing and sounding good. No hum.
Once I get them in a proper case, I'll post a pic. Right now they are on a breadboard aka 2x6 chunk.
Thanks again to Peter and Uriah.
Cheers
John
Let me preface these observations by suggesting that anyone who is tired of my ramblings and ruminations on this topic is welcome to skip this post and advise me that I'm going on too long about nothing of importance. However, I feel this information is vital to anyone seeking, as I am, ultimate performance from this unique and elegant design, and I enjoy writing about my experience and impressions.
Additionally, let me say that I am not an inveterate tweaker. I have never popped the top of any component and grabbed my iron to start disemboweling some perfectly functioning piece of equipment. I built the original Dynakits back in the 70's with modest success, but, since then, my only forays into the world of DIY involved building cables (very worthwhile, by the way), speakers, and a couple of truly crappy LM1875 amp kits.
I have now made the following mods to both of my monoblocks: substituted AudioCap Theta's for C13; substituted WIMA MKP's for C21; and substituted ELNA Silmic II's for C9. So far, the amps have changed from very average solid state to superb solid state. I have heard lots of very good to excellent SS and tube amps in my system, and these are now close to being the best SS I have ever heard, rivals to the BAT VK-60 monoblocks I once had here. (I sold those because they were impractical beasts, consuming gobs of electricity and converting most of it into unbearable heat and some of it into sublime sound. I tired of fiddling with tubes and not being able to listen to music when the ambient temperature exceeded 80 degrees because my non-air conditioned living room became an oven.)
With this latest modification of C9 and C21, these amps now produce substantial and musical bass, extending very low, with almost the same control as my ARC 100.2. The mids are clearer and more musical, with beautiful tonality and depth. The highs are open and smooth, with plenty of air, extension, and detail and no harshness whatsoever. Images float freely but firmly in real space.
I will write here what some readers might feel is heresy: Mauro was wrong about one thing. In one of his earlier posts on the original MyRef thread, I believe he stated that this amplifier design was not sensitive to quality of components. If that is what he wrote or meant, he was absolutely wrong on that count. He never did divulge what type of components he used to build his own amps. I can state unequivocally that the components supplied in this current round of kits, at least at these critical points, is below the quality required to achieve ultimate performance. Peter and Uriah did an excellent job, and I will always be grateful for their considerable efforts to make this amp available again and do such a thorough job of organizing the kits. However, I believe their goal of holding to a price point by selecting inexpensive and merely adequate parts, while admirable, was somewhat misguided. They probably felt, as Mauro himself stated, that any parts within spec would be suitable. I'm sure they felt that anyone who wanted to could upgrade parts, and my point is that everyone who bought these kits should not hesitate to do just that. These are $65 amplifiers as supplied, but they gain in value completely out of proportion to the cost of a few simple improvements.
Today I received my Mundorf caps (they cost as much as the kits!) and PRP resistors (cheap), so steel yourselves for more preaching after these parts are incorporated into my amps.
Peace,
Tom E
Additionally, let me say that I am not an inveterate tweaker. I have never popped the top of any component and grabbed my iron to start disemboweling some perfectly functioning piece of equipment. I built the original Dynakits back in the 70's with modest success, but, since then, my only forays into the world of DIY involved building cables (very worthwhile, by the way), speakers, and a couple of truly crappy LM1875 amp kits.
I have now made the following mods to both of my monoblocks: substituted AudioCap Theta's for C13; substituted WIMA MKP's for C21; and substituted ELNA Silmic II's for C9. So far, the amps have changed from very average solid state to superb solid state. I have heard lots of very good to excellent SS and tube amps in my system, and these are now close to being the best SS I have ever heard, rivals to the BAT VK-60 monoblocks I once had here. (I sold those because they were impractical beasts, consuming gobs of electricity and converting most of it into unbearable heat and some of it into sublime sound. I tired of fiddling with tubes and not being able to listen to music when the ambient temperature exceeded 80 degrees because my non-air conditioned living room became an oven.)
With this latest modification of C9 and C21, these amps now produce substantial and musical bass, extending very low, with almost the same control as my ARC 100.2. The mids are clearer and more musical, with beautiful tonality and depth. The highs are open and smooth, with plenty of air, extension, and detail and no harshness whatsoever. Images float freely but firmly in real space.
I will write here what some readers might feel is heresy: Mauro was wrong about one thing. In one of his earlier posts on the original MyRef thread, I believe he stated that this amplifier design was not sensitive to quality of components. If that is what he wrote or meant, he was absolutely wrong on that count. He never did divulge what type of components he used to build his own amps. I can state unequivocally that the components supplied in this current round of kits, at least at these critical points, is below the quality required to achieve ultimate performance. Peter and Uriah did an excellent job, and I will always be grateful for their considerable efforts to make this amp available again and do such a thorough job of organizing the kits. However, I believe their goal of holding to a price point by selecting inexpensive and merely adequate parts, while admirable, was somewhat misguided. They probably felt, as Mauro himself stated, that any parts within spec would be suitable. I'm sure they felt that anyone who wanted to could upgrade parts, and my point is that everyone who bought these kits should not hesitate to do just that. These are $65 amplifiers as supplied, but they gain in value completely out of proportion to the cost of a few simple improvements.
Today I received my Mundorf caps (they cost as much as the kits!) and PRP resistors (cheap), so steel yourselves for more preaching after these parts are incorporated into my amps.
Peace,
Tom E
I'm sure they felt that anyone who wanted to could upgrade parts,
Less to control costs and more to do this.
We stuck with the BOM and let it be affordable to all. A 50 cent cap makes it affordable to all and an AudioCap Theta by itself would probably have taken away the affordability.
I bought some BlackGates yesterday by the way. I know caps count
Uriah
Less to control costs and more to do this.
We stuck with the BOM and let it be affordable to all. A 50 cent cap makes it affordable to all and an AudioCap Theta by itself would probably have taken away the affordability.
I bought some BlackGates yesterday by the way. I know caps count
Uriah
madisonears said:
I couldn't agree more
Tonight I did a listening session with my brother (he's a musician and he knows well how music should sound) swapping components and apart confirming what both Tom and I think about C9/C21 he confirmed also some additional findings:
- C17,C18 must be pulled out: soundstage becomes wider and deeper (tryed both AVXs and Wimas)
- C19,C20 must be pulled out too: with both AVXs and Wimas (Wimas are better) sound is somewhat compressed, without there's a lot more air and sound is 'free'
- C6,C11: swapped with Silmics II 100uF 35V (they fit perfectly) another veil disappear and bass gains authority, is even deeper and more articulated.
Mauro's original design doesn't have C17,C18,C19,C20.
At first Silmics in C6,C11 are horrible they must burn-in for 20-40 hours.
For C6, C11 positions I've ordered Nichicon KZ and Nichicon FG for C1,C2 for the next caps tryout.
udailey said:We stuck with the BOM and let it be affordable to all. A 50 cent cap makes it affordable to all and an AudioCap Theta by itself would probably have taken away the affordability.
I bought some BlackGates yesterday by the way. I know caps count
And you both did a great job!
Uriah, if you want bass authority you must try Silmics in C9,C6,C11!!!
premium parts
I think it's terrific that people experiment with these components and report it here. I for one am listening and trying to keep track before spending some extra money to try some of these out with a second kit (for honest to goodness blind comparison).
One thing that would be fun (not sure how to accomplish this) is to come up with a couple of upgrade recommendation lists. People posting personal impressions here is a valuable start, but it would be nice if we could somehow keep a running account of this. I am wary of people later being told "hey, there is this 1000 posts thread and you can find the info in there"...
What I am asking is this. Is there a way (maybe we can use the wiki?) to keep a running "count" of suggested modifications based on budget. If the sky is the limit you can do crazy things and clearly asymptotically it will be meaningless. Engineering design is all about: "If I have 1$ more to spend where should I spend it?"
So, with that in mind. Let's say: if I had 10$ to spend additional where should I spend them? What about 20$ (or 50$)? What about 100$ extra? (Beyond that I'll probably pass and consider other designs...)
peter
I think it's terrific that people experiment with these components and report it here. I for one am listening and trying to keep track before spending some extra money to try some of these out with a second kit (for honest to goodness blind comparison).
One thing that would be fun (not sure how to accomplish this) is to come up with a couple of upgrade recommendation lists. People posting personal impressions here is a valuable start, but it would be nice if we could somehow keep a running account of this. I am wary of people later being told "hey, there is this 1000 posts thread and you can find the info in there"...
What I am asking is this. Is there a way (maybe we can use the wiki?) to keep a running "count" of suggested modifications based on budget. If the sky is the limit you can do crazy things and clearly asymptotically it will be meaningless. Engineering design is all about: "If I have 1$ more to spend where should I spend it?"
So, with that in mind. Let's say: if I had 10$ to spend additional where should I spend them? What about 20$ (or 50$)? What about 100$ extra? (Beyond that I'll probably pass and consider other designs...)
peter
udailey said:
I never soldered them, I was skeptical about Low ESR caps bypassing.
An externally hosted image should be here but it was not working when we last tested it.
Next I've mounted some sockets so I could try them.
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.
The comparison so was made without caps and with caps fitted in the sockets.
Don't short them!!! (shorting V+ and V- to ground
it's not a great idea )thanks!
anyway... finally completed mono-blocs- and they work. I took time- and have (both) working w/out 'heat-sinks' ... on the 3886 chips. I don't listen loud, and could 'feel' ... the music on my thumb and (it does get hot)... but not so hot that I can't keep a finger on that 'chip'. I'll put a heatsink on it eventually- This is just to test it. I've got a 22 volt transformer- dual secondaries- no ground on this toroid transformer, but info about 'transformer hook-ups' ... helped me out. I see why the first cap into this amp can make a big difference... but am in no hurry to change anything- (until tomorrow).... thanks to all! - I encourage everyone to get it up and running just the way it is... then go for the (many) possible modifications/tweeks. thanks-
anyway... finally completed mono-blocs- and they work. I took time- and have (both) working w/out 'heat-sinks' ... on the 3886 chips. I don't listen loud, and could 'feel' ... the music on my thumb and (it does get hot)... but not so hot that I can't keep a finger on that 'chip'. I'll put a heatsink on it eventually- This is just to test it. I've got a 22 volt transformer- dual secondaries- no ground on this toroid transformer, but info about 'transformer hook-ups' ... helped me out. I see why the first cap into this amp can make a big difference... but am in no hurry to change anything- (until tomorrow).... thanks to all! - I encourage everyone to get it up and running just the way it is... then go for the (many) possible modifications/tweeks. thanks-
WHOA! I would not suggest to anyone to run these amps without a heatsink for any reason. The risk is simply too great, and the reward is zero.
Uriah and Peter, I did not mean to criticize your efforts in any way, but only to put the stock kits in relation to a modest outlay for some upgrades. Please accept my apolgy if you took offense.
Yes, I believe the original MyRef did not have bypass caps. There was quite a lot of debate and uncertainty about which version sounded better, and what values of bypass to use. This may come down to a personal preference. There are benefits to bypassing, but you may find it better without. The space is on the board because someone (Russ) thought it sounded better with the bypass caps. At least that mod is free.
I'm happy to see others reporting success! We all want to learn about your various experiments with parts selection and enclosures.
The mods or substitutions I described are not ambiguously beneficial. Cost is always a factor, but why take the time and trouble to build a compromise when a truly incremental increase in cost yields disproportionate benefits? Dario and I are willing to experiment and describe the results so all of you don't have to go through the same learning curve, unless you're eager to learn for yourselves. You can rest assured that the changes we describe are for the better, and some are not at all subtle.
Yikes, do we already need another MyRef thread to document the cost/benefit ratios?
Peace,
Tom E
Uriah and Peter, I did not mean to criticize your efforts in any way, but only to put the stock kits in relation to a modest outlay for some upgrades. Please accept my apolgy if you took offense.
Yes, I believe the original MyRef did not have bypass caps. There was quite a lot of debate and uncertainty about which version sounded better, and what values of bypass to use. This may come down to a personal preference. There are benefits to bypassing, but you may find it better without. The space is on the board because someone (Russ) thought it sounded better with the bypass caps. At least that mod is free.
I'm happy to see others reporting success! We all want to learn about your various experiments with parts selection and enclosures.
The mods or substitutions I described are not ambiguously beneficial. Cost is always a factor, but why take the time and trouble to build a compromise when a truly incremental increase in cost yields disproportionate benefits? Dario and I are willing to experiment and describe the results so all of you don't have to go through the same learning curve, unless you're eager to learn for yourselves. You can rest assured that the changes we describe are for the better, and some are not at all subtle.
Yikes, do we already need another MyRef thread to document the cost/benefit ratios?
Peace,
Tom E
No offense taken.madisonears said:
The way I see how we put it together was to get it in at the lowest price point possible while staying true to a tested and appreciated kit: the TP version. This puts the kit in as many hands as possible and makes for a base to experiment!
If it had been far more expensive there may not have been as many takers... This way in the long run many more may well experiment with high end versions.Peter
so... how to spend extra $$$s
Ok. I realized that I volunteered myself to collate the experiences...
Anyone who has some thoughts on how to spend extra dollars to make for a better amp (by suggesting some certain components be replaced), drop me a note and I will collate. If you can (and it makes sense) make two levels of recommendations: the definite, "this is the most improvement for the dollar" components to swap and then the "if you really want to get the last drop, do this" components.
Just PM me. I will collate and report back.
peter
Ok. I realized that I volunteered myself to collate the experiences...
Anyone who has some thoughts on how to spend extra dollars to make for a better amp (by suggesting some certain components be replaced), drop me a note and I will collate. If you can (and it makes sense) make two levels of recommendations: the definite, "this is the most improvement for the dollar" components to swap and then the "if you really want to get the last drop, do this" components.
Just PM me. I will collate and report back.
peter
If you want to know why bypass caps are always a good idea, take a 200 mHz scope, set the input to low voltage AC and monitor your power supply rails. You will discover a fine hash of garbage from sources well beyond your control. Bypass caps are there to block that crapoli from infecting your music.
OpAmps themselves are often sources of noise that without the bypass caps, will put that noise on the power supply rails to infect other active devices. Always remember that the power supply is part of your signal path. Bypass caps are akin to the charcoal filter in your acquarium. And we all know what happens when that is removed!
OpAmps themselves are often sources of noise that without the bypass caps, will put that noise on the power supply rails to infect other active devices. Always remember that the power supply is part of your signal path. Bypass caps are akin to the charcoal filter in your acquarium. And we all know what happens when that is removed!
udailey said:
Carl_Huff said:
Carl_Huff said:
PS filtering is already done by C4 and C7.
From Mauro Penasa's Technical Documentation (translated from Italian):
"A limited but useful function of noise containment for the power supply section of the operational amplifiers (LM318 and LM3886) is guaranteed by the 100nF capacitors inserted between the lines +Vcc and -Vcc. Usually, in audio circuits, there are batteries of twins capacitors always inserted between PS rails and ground. These techniques serve to increase the efficiency of the "virtual ground" which represents the reference voltage to the circuit. From the point of view of immunity to PS noise of a typical OPAMP these networks are useless. OPAMPs, as a matter of fact, use references associated exclusively to + Vcc and-Vcc, which are sensitive to noise "uncommon" among rails. Capacitors inserted directly (locally) between PS rails provide greater immunity to this problem."
That translation of Mauro's text from Italian to English seems confusing and unclear to me.
#1) Local bypass caps between the voltage rails and ground are about shunting noise to ground.
#2) Caps placed between the rails and not ground are about canceling noise that is common to both rails but 180 degrees out of phase.
#1) Local bypass caps between the voltage rails and ground are about shunting noise to ground.
#2) Caps placed between the rails and not ground are about canceling noise that is common to both rails but 180 degrees out of phase.
