my apologies if it's rude for me to be questioning the merits of this amp, but how high does ultimate bom myrefc stack up against commercial designs?
comparing my 'FC-ed' unit to a sumo nine+ class A last night, the latter still had more substantial bass, better harmonic rendition and even instrument separation. on other areas myrefc was superior by whole bunch but these deficiencies surprisingly made sumo a more articulate and engaging listen.
one of my test track for example- 'Whooski' by squarepusher, has a double bass rhythm that's laid through the whole track that's much easier to pick out with the sumo. on my myref it's still more of a monotonous thudding.
i still plan on upgrading the myref since it only costs me a cup of coffee but if it doesn't show dramatic improvement over areas that it lost out to sumo last night, i may end up replacing it
comparing my 'FC-ed' unit to a sumo nine+ class A last night, the latter still had more substantial bass, better harmonic rendition and even instrument separation. on other areas myrefc was superior by whole bunch but these deficiencies surprisingly made sumo a more articulate and engaging listen.
one of my test track for example- 'Whooski' by squarepusher, has a double bass rhythm that's laid through the whole track that's much easier to pick out with the sumo. on my myref it's still more of a monotonous thudding.
i still plan on upgrading the myref since it only costs me a cup of coffee but if it doesn't show dramatic improvement over areas that it lost out to sumo last night, i may end up replacing it
comparing my 'FC-ed' unit to a sumo nine+ class A last night, the latter still had more substantial bass, better harmonic rendition and even instrument separation.
...
i still plan on upgrading the myref since it only costs me a cup of coffee but if it doesn't show dramatic improvement over areas that it lost out to sumo last night, i may end up replacing it
It would be nice if you can tell us exactly what parts your MyRef mounts.
A lot of parts have a not small influence in the parameters you find inferior on the MyRef.
Smoothing caps, decoupling caps, filter caps and even resistors makes a difference.
i think it's the twisted pear offering part for part. looking at the picture everything looks exactly the same as mine. Schematic, Parts List, etc - RevC Amplifier - Twisted Pear Audio Supporti bought it from our forum member weskoki and the rest of components are exactly how his was- mundorf supreme dc cap, wbt connectors, oversized toroidal.
from here i replaced c9, c6 to silmic ii, c14 to ucc kmg.
from here i replaced c9, c6 to silmic ii, c14 to ucc kmg.
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Well, if it's so you have a whole world of mods to do...
Please confirm that C3/C8 (the big smothing caps) are Panasonic TS-HA. If so they're good, otherwise they should be changed.
Pull out all PS bypass caps (C17,C18,C19 and C20)
Replace all film filter caps with Wima FKP2 and ceramics with Silver Micas.
Replace C6/C11 with Nichicon KZs 100uF 50V (very tight fit)
Replace C7 with a 10nF FKP2 and C21 with a 22nF FKP2.
Replace R1, R4 with KOA SPR.
These are the most important mods, refer to my BOM for order codes.
I've left out the very important coupling cap but, since I'm investigating other caps, it's still to be confirmed.
As an interim cap you can use a cheap 1uF K73-16 which sounds pretty good, neutral and detailed.
http://www.diyaudio.com/forums/chip-amps/134726-new-my-ref-rev-c-thread-119.html
Here are some photos of the components used (bottom page)
I think Madisonears had compared it with some very expensive High end designs.
Here are some photos of the components used (bottom page)
I think Madisonears had compared it with some very expensive High end designs.
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Let's split your inquiry into two portions. One: is the Ultimate BOM My Ref C better than the one you own now? Undoubtedly. The version you own has many standard components, and probably sounds better than most amps of equal cost. For a few dollars more of better quality parts, you will achieve an amplifier that sounds better than amps that cost five to ten times more.
The recommendations Dario and I have made are all worthwhile improvements. The single biggest improvement, as has been stated here many times, is a better cap at C13. The Mundorf is a decent cap, but there are exceptionally good caps to use instead that don't cost a lot. Sonicap Gen I and Mundorf Zn both give superb results.
I'm not sure what cap you have at C9, but the Black Gate is the best there. Nothing else equals it.
Changing R3 to a Caddock or Mills is also worthwhile.
As Dario wrote, there are many other changes to consider. In addition, better cabling, connectors, and especially the power cord will improve the sound. The sum of all the parts will make the MyRef perform at the same level as multi-thousand dollar amplifiers. I have heard them side by side.
Second part of your question: is the MyRef better than any other amplifier, regardless of cost? Of course not. Your Sumo class A amp probably is a very good amplifier. It is complex and uses (and wastes) obscene amounts of power, and moving it will break your back. The MyRef is simple and runs quite efficiently, and you can hold a complete monoblock in one hand. Do you see where the balance lies here? The MyRef will never be able to produce bass notes with as much authority as a huge discrete amplifier; it simply cannot pass as much current to control those woofers.
But the bass from the MyRef is certainly good enough. I have compared the bass from my MyRef's to that from an Aragon 8008, the "poor man's Krell". Using only my four 8" Peerless woofers, the Aragon does play slightly deeper bass with better control over the lowest frequencies. However, the bass from the MyRef is certainly not a monotonous thudding, and it is far more musical, less mechanical sounding. There is a trade-off there, and I prefer the musical one. Perhaps the Sumo combines both good qualities.
In the mids and highs, I have not yet found an amplifier that surpasses the MyRef Ultimate BOM for detail, realistic tonality, smoothness, separation of instruments, and spatial characteristics. That includes some very expensive amps played through some very nice speakers.
Peace,
Tom E
The recommendations Dario and I have made are all worthwhile improvements. The single biggest improvement, as has been stated here many times, is a better cap at C13. The Mundorf is a decent cap, but there are exceptionally good caps to use instead that don't cost a lot. Sonicap Gen I and Mundorf Zn both give superb results.
I'm not sure what cap you have at C9, but the Black Gate is the best there. Nothing else equals it.
Changing R3 to a Caddock or Mills is also worthwhile.
As Dario wrote, there are many other changes to consider. In addition, better cabling, connectors, and especially the power cord will improve the sound. The sum of all the parts will make the MyRef perform at the same level as multi-thousand dollar amplifiers. I have heard them side by side.
Second part of your question: is the MyRef better than any other amplifier, regardless of cost? Of course not. Your Sumo class A amp probably is a very good amplifier. It is complex and uses (and wastes) obscene amounts of power, and moving it will break your back. The MyRef is simple and runs quite efficiently, and you can hold a complete monoblock in one hand. Do you see where the balance lies here? The MyRef will never be able to produce bass notes with as much authority as a huge discrete amplifier; it simply cannot pass as much current to control those woofers.
But the bass from the MyRef is certainly good enough. I have compared the bass from my MyRef's to that from an Aragon 8008, the "poor man's Krell". Using only my four 8" Peerless woofers, the Aragon does play slightly deeper bass with better control over the lowest frequencies. However, the bass from the MyRef is certainly not a monotonous thudding, and it is far more musical, less mechanical sounding. There is a trade-off there, and I prefer the musical one. Perhaps the Sumo combines both good qualities.
In the mids and highs, I have not yet found an amplifier that surpasses the MyRef Ultimate BOM for detail, realistic tonality, smoothness, separation of instruments, and spatial characteristics. That includes some very expensive amps played through some very nice speakers.
Peace,
Tom E
If you swap the Pannies for CD you'll ear for sure a difference...
It will sound worse...
Wait some days, soon I'll try Mundorf MLPI which could be better... but TS-HA are already very good caps.
He already ordered the BGs...
A big YES for the Caddock but the Mills, IMHO, is too soft, I prefer the cement one.
Tom, what OCC cable are you using?
Hi Tom,
Did the woofer cabinet in your new speaker design change, augment or enhance the overall bottom end when used with the MyRef-C amps?
Regards
when you suggested 100uF 50V KZs for C1/C2, I suppose you also actualy tried them, isn't it?
Do you think that lowering the value didn't had any adverse effect on bass performace of whatever?
BTW I've ordered the BC038s, I'll do the test with them and also 100uF KZs
Yes, I have a pair of Twisted Pear V1.2 boards with the 100uF/50V KZs. I haven't done an A-B comparison, but I haven't noticed any loss of Bass compared to 220uF/50V KZs on another pair of V1.4 boards (at another location) which have similar components, including the 4.7uF/63V Panasonic ECQ input coupling caps.
YMMV, the timbre may differ between the two caps on close comparison. It won't be a disaster, because C1/C2 are in any case just bypasses for the large PSU caps which are 50x-100x the value - the tonal balance, etc. of the large caps will dominate.
Interesting...thanks
Here I must disagree or it can't be explained why timbre changes so much with different capacitors...
The white ceramic-case non-inductive Futaba MPC74 is fine for R3, but any of the MPC7x series should also be reasonable as long as they can handle the power.
For R1/R4, I just received a new alternative - a (Shallcross?) RWR80N 1k/2W mil-spec non-inductive wirewound which I'll try out in the next build. It seems to be magnetic, unlike my current CFRs, so I'm keeping my fingers crossed.
i couldn't ask for more bass from myrefc. doing so would be unrealistic and also it's already perfectly good as it as. but the one area i have gripe about myrefc lacking in comparison to sumo9 is harmonic rendition.
inner resolution, i guess it's called. being able to hear the ripples of oboe, feeling the intimacy of quiet rhythms in the background, and simply how much more intense the harmonics are expressed. if my old SET amp was 10, and my yamaha receiver 0 (modern, the worst kind..), the luxman 6l6 would be 7, sumo 6, and then myref right below it. it was my understanding that a chipamp was capable of much higher score according to web reviews and testimonials.
i'm about to find out soon enough but just wanted to know if i'll also see further improvement on inner resolution. with 3 of the caps changed to silmic ii's, i haven't heard much improvement in that department. perhaps resistors are where the key is?
but the one area i have gripe about myrefc lacking in comparison to sumo9 is harmonic rendition. inner resolution, i guess it's called. being able to hear the ripples of oboe, feeling the intimacy of quiet rhythms in the background, and simply how much more intense the harmonics are expressed. if my old SET amp was 10, and my yamaha receiver 0 (modern, the worst kind..), the luxman 6l6 would be 7, sumo 6, and then myref right below it. it was my understanding that a chipamp was capable of much higher score according to web reviews and testimonials.
i'm about to find out soon enough but just wanted to know if i'll also see further improvement on inner resolution. with 3 of the caps changed to silmic ii's, i haven't heard much improvement in that department. perhaps resistors are where the key is?
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i couldn't ask for more bass from myrefc. doing so would be unrealistic and also it's already perfectly good as it as.
...
i'm about to find out soon enough but just wanted to know if i'll also see further improvement on inner resolution. with 3 of the caps changed to silmic ii's, i haven't heard much improvement in that department. perhaps resistors are where the key is?
After you've changed C13 (all mods are useless if you filter the soul of the music before entering the amp ...), as I've said even a K73-16 is a good starting point.
Install FKP2 where specified in the Ultimate BOM and you'll have a nice surprise...
Ceramics and metallized caps are 'harmonics' killers
Dario, I never tried the Mills at R3. I went from Xicon cement directly to Caddock and never felt the need to try anything else. I thought you had recommended the Mills at one time, so that's why I mentioned it. If someone doesn't want to mess about with a heatsink for Caddock, then the cement part might be next best. I like Mills in a few places in xovers. They really do have low inductance.
I use Neotech OCC solid copper with teflon insulation. I use it everywhere in my system: IC's, speaker wire, chassis wire. I have never noticed the "bathroom" effect. Is that some kind of echo? I swear that my system is more resolving now than ever before. I hear individual instruments within the orchestra that were masked before. I can tell if a singer is making a joke in the lyrics, as if I can HEAR them smiling. A large chorus with female singers does not have that annoying fuzz at the top, but I can hear many different voices within the group. Applause of individuals within an audience, always a good test of resolution though not very entertaining, is very distinct.
Bob, my new speakers are very heavily damped. I would guess system Q is below 0.7. Low bass is very well controlled, perhaps too much for some tastes. I also use a sub, so I don't notice any lack of lowest frequencies. I could easily discern (with sub off) the difference between Aragon and MyRef bass. The Aragon was slightly dry, mechanical sounding. MyRef is fuller but doesn't go quite as low, with just as much detail but an overlying richness and musicality. I was quite surprised that the MyRef seemed to have almost as much power as the Aragon. In addition, the Aragon had an annoying hum (mechanical and electrical), while the MyRef was dead silent. I was happy to return the Aragon to its owner. Now I am biamping, with a Yamaha Class D amp for bass, and it sounds very similar to the MyRef, but MUCH more powerful. I might be missing the very lowest stuff, but the sub picks it up down there.
If you're going to swap resistors, R3 gives good payback. R12 is worthwhile, as the signal passes through it initially. I have tried Shinkoh tantalum, which sweetens the sound but gives up a small amount of detail. Now I have nude Vishay which provides more detail, but I'm not sure yet that I like it more. Also you might change R10. Now that I think about it, perhaps the Shinkoh would be better at R12 with a nude Vishay at R10. Probably anything will sound better than the original Xicons. How much is it worth? If you're looking for that last bit of quality, then every component contributes. PRP's sound good in general, but Dario has made some other specific recommendations. I've now mixed in some carbon films at R13 and R11 and those big KOA at R1 and R4.
The FKP caps are very nice, indeed.
Peace,
Tom E
I use Neotech OCC solid copper with teflon insulation. I use it everywhere in my system: IC's, speaker wire, chassis wire. I have never noticed the "bathroom" effect. Is that some kind of echo? I swear that my system is more resolving now than ever before. I hear individual instruments within the orchestra that were masked before. I can tell if a singer is making a joke in the lyrics, as if I can HEAR them smiling. A large chorus with female singers does not have that annoying fuzz at the top, but I can hear many different voices within the group. Applause of individuals within an audience, always a good test of resolution though not very entertaining, is very distinct.
Bob, my new speakers are very heavily damped. I would guess system Q is below 0.7. Low bass is very well controlled, perhaps too much for some tastes. I also use a sub, so I don't notice any lack of lowest frequencies. I could easily discern (with sub off) the difference between Aragon and MyRef bass. The Aragon was slightly dry, mechanical sounding. MyRef is fuller but doesn't go quite as low, with just as much detail but an overlying richness and musicality. I was quite surprised that the MyRef seemed to have almost as much power as the Aragon. In addition, the Aragon had an annoying hum (mechanical and electrical), while the MyRef was dead silent. I was happy to return the Aragon to its owner. Now I am biamping, with a Yamaha Class D amp for bass, and it sounds very similar to the MyRef, but MUCH more powerful. I might be missing the very lowest stuff, but the sub picks it up down there.
If you're going to swap resistors, R3 gives good payback. R12 is worthwhile, as the signal passes through it initially. I have tried Shinkoh tantalum, which sweetens the sound but gives up a small amount of detail. Now I have nude Vishay which provides more detail, but I'm not sure yet that I like it more. Also you might change R10. Now that I think about it, perhaps the Shinkoh would be better at R12 with a nude Vishay at R10. Probably anything will sound better than the original Xicons. How much is it worth? If you're looking for that last bit of quality, then every component contributes. PRP's sound good in general, but Dario has made some other specific recommendations. I've now mixed in some carbon films at R13 and R11 and those big KOA at R1 and R4.
The FKP caps are very nice, indeed.
Peace,
Tom E
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I've tried the Mills and initially I liked it (they're very sweet) but I've later discovered that they masked some detail, the cement one is probably a bit more 'raw' but better. The Caddock is more detailed and refined.
That's exactly the last lead I've tried! (PartsConnexion?)
I'm using Neotech NS-2440 as speaker cable and NA-012095 for interconnects and both are very good sounding, I didn't noticed any bathroom effect.
But when I've connected that solid core timbre was wrong from the start!
Apart timbre that cable is resolving, detailed and not harsh at all.
But with it a lot of CDs became bad sounding, some harsh...
It gave me the same feelings you were describing when you tried Silmics//MKP2.
Now I'm using an AWG17 OCC aluminum solid core wire and it mantains all the good from the Neotech but with a perfect timbre. Those CDs started to be enjoyable again.
I'm pretty sure that with the first MyRef (which used a plain PVC insulated solid copper wire) I've never heard this effect.
After this experience I've tried again the teflon insulated OCC copper from DIYHifiSupply that I started with and while warmer and less detailed it also give that strange effect (but less).
In the next days I'll try a plain OFC speaker wire to confirm or not this strange behaviour.
I confirm that PRPs, where I suggest metal films, makes a difference: they sounds full and with little or no harshness, pretty similar to industrial carbon films.
I've had another confirmation in the MINI2496 DAC upgrade project.
I've done all the work with SMA0207 metalfilms mixed with no name but good quality carbon films and it sounded very very good.
When I've swapped the SMAs with PRPs sound improved audibly with the same effect I've just described.
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Great to hear bi-amping with the MyRef is working for a discerning listener. I needed a bit of encouragement for my BPA-150 project.
I am very satisfied with the results from the following DIY speakers cables.
TNT tripleT
I would be interested to hear how they compare with items like those mentioned above with these amps. From the info on the link, both the quality of the copper and the actual lay of the wire are surprisingly well suited for audio. I hope someone who already has a variety of cables will give these a try and report back. I built two 8' with cat6 I had on hand. Many pro mixing studios are moving to some configuration of cat-6. Some are using a single strand per channel.
I am very satisfied with the results from the following DIY speakers cables.
TNT tripleT
I would be interested to hear how they compare with items like those mentioned above with these amps. From the info on the link, both the quality of the copper and the actual lay of the wire are surprisingly well suited for audio. I hope someone who already has a variety of cables will give these a try and report back. I built two 8' with cat6 I had on hand. Many pro mixing studios are moving to some configuration of cat-6. Some are using a single strand per channel.
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Well, this is getting pretty far off topic, and I apologize. Someone might find this useful.
Okay, now I finally get it. Dario, you are using Neotech cable. I am using Neotech wire to build my own cables.
Neotech uses PE insulation, not teflon, on the wire inside their cables, and they use a PVC jacket, which I don't like anywhere near a signal.
I buy OCC copper teflon-insulated chassis wire of various gauges, depending on the application, and build my own IC's and speaker cables. These poor quality pics show my balanced IC, a simple, spaced twisted pair with a counter-spiral ground. Each 24ga insulated signal wire is spiraled around opposite sides of a teflon tube. This provides separation to reduce capacitance. The ground is inside a cotton tube, which spaces it farther from the signal wires. When I was running the MyRef's full range, I used this same construction technique in single-ended format (no separate ground). Now these balanced IC's go to the active xover.
The speaker cable is a simple braid, two 18ga conductors for each leg, four wires total, no jacket. It doesn't get any easier.
I have owned and heard some very nice, expensive IC's and speaker cables. Only one IC was very slightly better than these, and no speaker cable was better. I'm sure there are, but I haven't heard them.
Peace,
Tom E
Okay, now I finally get it. Dario, you are using Neotech cable. I am using Neotech wire to build my own cables.
Neotech uses PE insulation, not teflon, on the wire inside their cables, and they use a PVC jacket, which I don't like anywhere near a signal.
I buy OCC copper teflon-insulated chassis wire of various gauges, depending on the application, and build my own IC's and speaker cables. These poor quality pics show my balanced IC, a simple, spaced twisted pair with a counter-spiral ground. Each 24ga insulated signal wire is spiraled around opposite sides of a teflon tube. This provides separation to reduce capacitance. The ground is inside a cotton tube, which spaces it farther from the signal wires. When I was running the MyRef's full range, I used this same construction technique in single-ended format (no separate ground). Now these balanced IC's go to the active xover.
The speaker cable is a simple braid, two 18ga conductors for each leg, four wires total, no jacket. It doesn't get any easier.
I have owned and heard some very nice, expensive IC's and speaker cables. Only one IC was very slightly better than these, and no speaker cable was better. I'm sure there are, but I haven't heard them.
Peace,
Tom E
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Hi Tom,
I'm using Neotech cables outside of the MyRef and I'm satisfied by their performance, no problem with them...
The problem arose when I've tried a Neotech teflon insulated solid core wire (single run) inside the MyRef.
