Allright
Hi,
Finally i complete my "FE", work perfectly. It's play in naked version whit tannoy m20 gold mkii and a very poor cdplayer, the sound is very good but I have some doubt about the bass: Little present. Depend from other device? However for now it is fine so. Next week i begin to build a case for My_ref and start a diy cdplayer from cdrom....
See you late
Ivan
Hi,
Finally i complete my "FE", work perfectly. It's play in naked version whit tannoy m20 gold mkii and a very poor cdplayer, the sound is very good but I have some doubt about the bass: Little present. Depend from other device? However for now it is fine so. Next week i begin to build a case for My_ref and start a diy cdplayer from cdrom....
See you late
Ivan
Attachments
Ivan,
I note that your heat sinks are floating.
they should be connected to PGND, or in your special case even better, HSGND pads on your boards.
Drill a threaded hole in the heatsink, right next where the HSGND pad is. put an 'orecchiette' on the heatsink, and connect it to the pad with a short thick wire.
And twist those transformer wires together, please..
If everything works and you do not note strange noises than it might not change anything, but in any case renders the setup more stable. And who knows, you even might be in for a surprise..
Ciao, George
I note that your heat sinks are floating.
they should be connected to PGND, or in your special case even better, HSGND pads on your boards.
Drill a threaded hole in the heatsink, right next where the HSGND pad is. put an 'orecchiette' on the heatsink, and connect it to the pad with a short thick wire.
And twist those transformer wires together, please..
If everything works and you do not note strange noises than it might not change anything, but in any case renders the setup more stable. And who knows, you even might be in for a surprise..
Ciao, George
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There is a groupbuy for the latest pcb, you can find it here:
http://www.diyaudio.com/forums/group-buys/280283-my_ref-fremen-edition-gb-seventh-run.html
Cheers guys!
http://www.diyaudio.com/forums/group-buys/280283-my_ref-fremen-edition-gb-seventh-run.html
Cheers guys!
Latest runs added a bypass cap for C9, to remediate somewhat the lack of Blackgates at reasonable price.
Recently Joseph K have made a lot of measures and tests giving me a lot of feedback.
Measurements are pretty good but there's room for possible enhancements.
7th run boards will receive some minor upgrades based on that feedback and some parts in BOM will change.
Maybe, in the next months, I'll start a complete PCB redesign and a new beta phase.
In the meanwhile actual boards are a proven and good sounding design.
Dario, what is this red spike on harmonic distortion measurement?
Friend is asking
As already linked:
http://www.diyaudio.com/forums/chip...on-beta-build-fine-tuning-21.html#post3064216
White Caps (Ok, one black one)
I am working on some inexpensive speakers for my niece and was looking for some reasonably priced capacitors for the crossover. I decided that the best way to compare was to order some new caps in 1 uF and try them in the C13 position on my Fremen amp.
The Caps
The black cap is the Mundorf Supreme which is Dario's recommendation for a premium build. This was my reference. All of the other caps were less expensive, so the goal was to get as close as possible to the sound of the Supreme.
Starting from the bottom of the picture, the Vishay Sprague V-735P has been Dario's recommendation for the Budget BOM. Somehow, even with all my playing around, I had never tried them. When I found them in Mouser, I also found that Vishay is going to stop building this series, so although they will probably be available for a long time, they will become harder to find from the primary sellers.
Above that is the Soni-cap Gen 1. This is a cap that I have had for a few years, but wanted to go back and try it again. Soni-Craft has all of it's Gen 1 caps for sale on close-out, so this would be a good deal if they worked. You may notice the little green box cap next to the Soni-cap. In the end, I found that the Soni-cap worked best with a bypass that the green box is a Russian K-71-7 polystyrene at 1 nF.
Above the Mundorf is the Cornell Dubilier 940c. This is an industrial cap suggested by Tony Gee. It has a hybrid construction with both metallized polypropylene and double metallized polyester. It has a similar cost to the V-735P and is new on the market.
The Audyn Cap Plus is also a cap that I have had for a while, but I included it in the evaluation because it is priced competitively. As you may have noticed, it is getting on the big side for the My_Ref FE board. I would call it a squeeze fit.
The cap on top is the Cornell Dubilier 942c. This is another new industrial cap that is designed for very high dV/dt. It also has a hybrid construction with polypropylene film/foil combined with metallized polypropylene. It is definitely big with a length of 52 mm and a diameter of 29 mm. [The cap that was available to me was rated 1000 V. They list a 600 V that is smaller.] The 942c that I bought has a price point that is about 1/2 the Mundorf Supreme and comparable to the Audyn, depending on if the Audyn is on sale.
Weasel Words
The usual cautions apply. Your result may vary. I am evaluating my system with my ears.
I also feel like there is a link between C13 and C9 and they should be considered together. In my system, I am using a Jensen axial cap at C9 and I realize that this isn't the typical choice. For reference, the Jensen is similar in character to the Blackgate PK with a little more detail added. In other words, it has clear sound but has a relatively laid-back treble. For comparison, a Blackgate NX at C9 has more detail and more treble energy (sparkle). Please keep that in mind.
Subjective Sound Comparison
The first two caps I listened to were the Mundorf Supreme and the Audyn Plus. The Supreme remains a well balanced cap, neutral across the frequency spectrum, and has good dynamic range. It also has a very good sound stage and remains an excellent choice at it's price point.
The Audyn Plus makes an good first impression. It has a very good sound stage and lots of detail. That said, the longer I listen to the Plus, the more I notice that the treble is a little too strong. The mids and bass seem to fade a bit into the background. Of course, that could also be due to the rest of my system. I can easily imagine a system where the Plus is a good fit. Just doesn't work in my system.
The word on the Soni-cap Gen 1 is that they sound overly warm and colored and I have to agree with that for the cap on its own. The mids and bass are forward and rounded with the treble recessed. When I find a cap like that, it makes me wonder if a bypass cap is appropriate, so I tried a few with the Gen 1.
My first comment is that this cap doesn't easily mix with bypass caps. I tried a range from Russian telfon (FT-3) to a small PIO with a reputation for being dark. The only cap that fit the Gen 1 was the polystyrene K71-7 in 1 nF. It adds just enough treble energy to tighten up the mids and bass and add some sparkle to the top end. Even with this bypass, I wouldn't say that the Gen1/K71-7 combo is neutral, but it is much better balanced and really quite enjoyable to listen to. Every time I come back to it, I say "This is nice."
The V-735P has a fairly neutral balance and good dynamic range. It has better bass than the Audyn Plus and the clarity is good for the price, although not quite up to the Supreme IMHO. The only draw back for me is a slight amount of harshness in the treble that makes it a touch tiring to listen to for long periods. Again, that may be because of my system.
The 940c is an interesting contrast to the V-735P. I find this a very neutral sounding cap with a good sound stage and detail. Although it is never harsh, it is also doesn't have a very strong dynamic range. When I listen to this cap, everything sound right. It is only when I directly compare it to the Supreme, for example, that I notice the reduced dynamics.
Finally, the 942c most definitely needs some time to settle in. It starts out bright and harsh. But after time, I found it to settle into something very much like the Mundorf Supreme. Sound stage is very good, it is fairly neutral, and has good detail. Dynamic response is on par with the Supreme and clarity is also very good. Swapping back and forth between the 942c and the Supreme, I can only find very minor differences.
Coming out of this evaluation, the 942c stands out as a very interesting choice, but then this is just one man's opinion and I have been wrong before. I hope others will give them a try and report back. And if you are looking for a fun sound, try the Soni-cap Gen 1/K71-7 combo. It's just plain entertaining.
Jac
I am working on some inexpensive speakers for my niece and was looking for some reasonably priced capacitors for the crossover. I decided that the best way to compare was to order some new caps in 1 uF and try them in the C13 position on my Fremen amp.
The Caps
The black cap is the Mundorf Supreme which is Dario's recommendation for a premium build. This was my reference. All of the other caps were less expensive, so the goal was to get as close as possible to the sound of the Supreme.
Starting from the bottom of the picture, the Vishay Sprague V-735P has been Dario's recommendation for the Budget BOM. Somehow, even with all my playing around, I had never tried them. When I found them in Mouser, I also found that Vishay is going to stop building this series, so although they will probably be available for a long time, they will become harder to find from the primary sellers.
Above that is the Soni-cap Gen 1. This is a cap that I have had for a few years, but wanted to go back and try it again. Soni-Craft has all of it's Gen 1 caps for sale on close-out, so this would be a good deal if they worked. You may notice the little green box cap next to the Soni-cap. In the end, I found that the Soni-cap worked best with a bypass that the green box is a Russian K-71-7 polystyrene at 1 nF.
Above the Mundorf is the Cornell Dubilier 940c. This is an industrial cap suggested by Tony Gee. It has a hybrid construction with both metallized polypropylene and double metallized polyester. It has a similar cost to the V-735P and is new on the market.
The Audyn Cap Plus is also a cap that I have had for a while, but I included it in the evaluation because it is priced competitively. As you may have noticed, it is getting on the big side for the My_Ref FE board. I would call it a squeeze fit.
The cap on top is the Cornell Dubilier 942c. This is another new industrial cap that is designed for very high dV/dt. It also has a hybrid construction with polypropylene film/foil combined with metallized polypropylene. It is definitely big with a length of 52 mm and a diameter of 29 mm. [The cap that was available to me was rated 1000 V. They list a 600 V that is smaller.] The 942c that I bought has a price point that is about 1/2 the Mundorf Supreme and comparable to the Audyn, depending on if the Audyn is on sale.
Weasel Words
The usual cautions apply. Your result may vary. I am evaluating my system with my ears.
I also feel like there is a link between C13 and C9 and they should be considered together. In my system, I am using a Jensen axial cap at C9 and I realize that this isn't the typical choice. For reference, the Jensen is similar in character to the Blackgate PK with a little more detail added. In other words, it has clear sound but has a relatively laid-back treble. For comparison, a Blackgate NX at C9 has more detail and more treble energy (sparkle). Please keep that in mind.
Subjective Sound Comparison
The first two caps I listened to were the Mundorf Supreme and the Audyn Plus. The Supreme remains a well balanced cap, neutral across the frequency spectrum, and has good dynamic range. It also has a very good sound stage and remains an excellent choice at it's price point.
The Audyn Plus makes an good first impression. It has a very good sound stage and lots of detail. That said, the longer I listen to the Plus, the more I notice that the treble is a little too strong. The mids and bass seem to fade a bit into the background. Of course, that could also be due to the rest of my system. I can easily imagine a system where the Plus is a good fit. Just doesn't work in my system.
The word on the Soni-cap Gen 1 is that they sound overly warm and colored and I have to agree with that for the cap on its own. The mids and bass are forward and rounded with the treble recessed. When I find a cap like that, it makes me wonder if a bypass cap is appropriate, so I tried a few with the Gen 1.
My first comment is that this cap doesn't easily mix with bypass caps. I tried a range from Russian telfon (FT-3) to a small PIO with a reputation for being dark. The only cap that fit the Gen 1 was the polystyrene K71-7 in 1 nF. It adds just enough treble energy to tighten up the mids and bass and add some sparkle to the top end. Even with this bypass, I wouldn't say that the Gen1/K71-7 combo is neutral, but it is much better balanced and really quite enjoyable to listen to. Every time I come back to it, I say "This is nice."
The V-735P has a fairly neutral balance and good dynamic range. It has better bass than the Audyn Plus and the clarity is good for the price, although not quite up to the Supreme IMHO. The only draw back for me is a slight amount of harshness in the treble that makes it a touch tiring to listen to for long periods. Again, that may be because of my system.
The 940c is an interesting contrast to the V-735P. I find this a very neutral sounding cap with a good sound stage and detail. Although it is never harsh, it is also doesn't have a very strong dynamic range. When I listen to this cap, everything sound right. It is only when I directly compare it to the Supreme, for example, that I notice the reduced dynamics.
Finally, the 942c most definitely needs some time to settle in. It starts out bright and harsh. But after time, I found it to settle into something very much like the Mundorf Supreme. Sound stage is very good, it is fairly neutral, and has good detail. Dynamic response is on par with the Supreme and clarity is also very good. Swapping back and forth between the 942c and the Supreme, I can only find very minor differences.
Coming out of this evaluation, the 942c stands out as a very interesting choice, but then this is just one man's opinion and I have been wrong before. I hope others will give them a try and report back. And if you are looking for a fun sound, try the Soni-cap Gen 1/K71-7 combo. It's just plain entertaining.
Jac
Attachments
Last edited:
I'm very late coming in to this thread. I just got hold of a pair of FE boards through a swap with a friend.
I noticed on the FE builds here, the holes for local caps for the 8pin IC were left unpopulated. Could somebody point me to where Dario posted his rationale for this? What prompted this decision?
I noticed on the FE builds here, the holes for local caps for the 8pin IC were left unpopulated. Could somebody point me to where Dario posted his rationale for this? What prompted this decision?
rough,
Just for clarity, the caps you are referring to are in the middle of the board. If you look close, they are labelled C102 and C202 just outside of the circle for the component. If I have the right caps, then you are correct, they are not used. As I recall, they are power supply caps for the LM318M, however, they were not needed because the amp has been stable without them. My memory is poor, but I think Dario thought that the amp sounded a bit better without them, so leaving them open is recommended.
A few other notes. The BOM is changing a few components for this newest build. If your boards are from an earlier build, make sure you follow an earlier BOM. Also, if they are rev 1.10 - Nov 2014, there was a small flaw in the build. Nothing that affects performance. You will need to add a short jumper. Please see post 2028 of this thread.
I hope you enjoy the amp.
Jac
Just for clarity, the caps you are referring to are in the middle of the board. If you look close, they are labelled C102 and C202 just outside of the circle for the component. If I have the right caps, then you are correct, they are not used. As I recall, they are power supply caps for the LM318M, however, they were not needed because the amp has been stable without them. My memory is poor, but I think Dario thought that the amp sounded a bit better without them, so leaving them open is recommended.
A few other notes. The BOM is changing a few components for this newest build. If your boards are from an earlier build, make sure you follow an earlier BOM. Also, if they are rev 1.10 - Nov 2014, there was a small flaw in the build. Nothing that affects performance. You will need to add a short jumper. Please see post 2028 of this thread.
I hope you enjoy the amp.
Jac
thanks lehman, I'll need to check the BOMs and the version number then.
one last request, I remember reading a thread way back where Dario was documenting his observations after each change. There's a lot of myref threads now. Which thread was it and if you can direct me to post# where I can restart reading Dario's observations , it would be greatly appreciated.
one last request, I remember reading a thread way back where Dario was documenting his observations after each change. There's a lot of myref threads now. Which thread was it and if you can direct me to post# where I can restart reading Dario's observations , it would be greatly appreciated.
rough,
I found the post where Dario commented on C102 and C202 being open. It is in the "my_ref-fremen-edition-rc-build-thread", post #25.
As for Dario's tuning changes, I think the thread you are referring to is:
"My_Ref Fremen Edition - Beta build/Fine tuning"
Unfortunately, there are tuning exercises spread out through many threads, so start there and ask questions here because some things have changed over time. For example, the Audyn Tru-Copper cap was preferred for C13 by several builders at that time but build revisions haven't seen it as popular as it was earlier. Also, Dario has continued to experiment, so it' worth asking questions.
Jac
I found the post where Dario commented on C102 and C202 being open. It is in the "my_ref-fremen-edition-rc-build-thread", post #25.
As for Dario's tuning changes, I think the thread you are referring to is:
"My_Ref Fremen Edition - Beta build/Fine tuning"
Unfortunately, there are tuning exercises spread out through many threads, so start there and ask questions here because some things have changed over time. For example, the Audyn Tru-Copper cap was preferred for C13 by several builders at that time but build revisions haven't seen it as popular as it was earlier. Also, Dario has continued to experiment, so it' worth asking questions.
Jac
Jac, thanks for a thorough review of an interesting variety of economical caps. I realize the amount of time and dedication required, along with a lot of concentrated listening, to properly evaluate parts.
It's not clear which one is your favorite, but perhaps it's better for people to choose their own rather than be influenced by yours.
Have you decided which cap to use in the speakers? What you hear in line level does not always apply to xovers because there are so many other variables. In my own speakers, the tweeter combo I found to work best is Sonicap Gen I with 10% Mundorf SIO in parallel. At line level, I had difficulty bypassing either Sonicap or Mundorf. In the tweeter circuit, the combination seems to work very well.
My current project is building a passive high-pass 2nd order crossover for the FE so I can get rid of the opamps/active xover for the tweeter/mid speakers. Of course this will serve as C13, which means the Audyn TC's will be obsoleted. So now I'll be choosing caps again, and the values are small (33nF and 4.7nF) and must be tightly selected, which really narrows the field of candidates. For my first attempt and to test the basic concept, I chose inexpensive Orange Drops (the 716 series with copper leads) and Wima FKP. The sound was initially horribly bright, but has since smoothed out considerably. It's still not realistic and sounds very hi-fi. Next test will be between Jensen polystyrene/aluminum foil or Relcap teflon/tin foil along with the Amtrans film/foil. Any suggestions are welcome.
I realize this is a pretty specialized application, but it might have some bearing for larger value caps so I'll report my findings for anyone who's interested.
Peace,
Tom E
It's not clear which one is your favorite, but perhaps it's better for people to choose their own rather than be influenced by yours.
Have you decided which cap to use in the speakers? What you hear in line level does not always apply to xovers because there are so many other variables. In my own speakers, the tweeter combo I found to work best is Sonicap Gen I with 10% Mundorf SIO in parallel. At line level, I had difficulty bypassing either Sonicap or Mundorf. In the tweeter circuit, the combination seems to work very well.
My current project is building a passive high-pass 2nd order crossover for the FE so I can get rid of the opamps/active xover for the tweeter/mid speakers. Of course this will serve as C13, which means the Audyn TC's will be obsoleted.
So now I'll be choosing caps again, and the values are small (33nF and 4.7nF) and must be tightly selected, which really narrows the field of candidates. For my first attempt and to test the basic concept, I chose inexpensive Orange Drops (the 716 series with copper leads) and Wima FKP. The sound was initially horribly bright, but has since smoothed out considerably. It's still not realistic and sounds very hi-fi. Next test will be between Jensen polystyrene/aluminum foil or Relcap teflon/tin foil along with the Amtrans film/foil. Any suggestions are welcome.I realize this is a pretty specialized application, but it might have some bearing for larger value caps so I'll report my findings for anyone who's interested.
Peace,
Tom E