Probably not for C4 - you need at least a 100V DC-rated cap there. For C4, almost any MKP film cap should be better than a non-polar BG.
C5 is across the AC rails from the trafo, and it is not that critical - any MKP or MKT will work fine. The core hysteresis of the trafo is far more non-linear than almost any film cap. I use either a Wima MKS-3 or Roederstein MKT1818 0.1/250V box-type cap there. The voltage rating of 250V is recommended to maintain a margin of safety from AC spikes, etc.
Thanks linuxguru. I'll try to find some mkp wimas then...
Yesterday i found on ebay some russian polystyrene caps at 1uf and i am tempted to try them in C13. The problem is they are pretty big - would that pose a problem ? ( length of leads etc)
1uF 250V 10% Hi-End Polystyrene capacitors K71-4 Lot 4 | eBay
No, they should be pretty good, I've buyed them too but didn't find the time to try them...
I've tried the Russian K71 caps at C13, and they're very good and detailed. Maybe only the Russian Paper-in-Oils and Teflons are better, but those are huge in size for 1 uF.
You will have to bend the leads outward to make it fit - I'll try to post a pic later. It helps if C9 is 4V Black Gate PK or 6.3V Cerafine or similar low-profile cap, in which case C13 can be mounted with sufficient clearance above C9.
I’m having another “Oh My Gosh” moment with the MyRef amps. Several weeks ago I reported on the upgrade to Mundorf AG caps in C3 & C8. At that time I said they were well worth the cost but not as dramatic as the C9 & C13 changes. Mids and bass were tighter and better defined, but I felt there was just a slight reduction of the output on the low-mids and bottom.
In preparation for installing Siva’a LF01 and Dario’s Rev E mods, (I found a loose heat sink screw that was triggering small intermittent signal losses) I checked and reheated a few solder points and, as I’m in the middle of building a new chassis, used just my modded PlayStation CD to Uriah’s Lightspeed to the MyRefs.
From the information I had gathered, I was under the impression there wasn’t much of a “Burn-in” required for the AGs. My first review was after about eight hours of listening. I’ve been using the amps (Siva’s V1.3 + BG + Sonicaps) but not doing any serious listening. Yesterday with 35 -40 hours on the caps I heard a whole new amp. The full spectrum from the top of the mid-range all the way down to the lowest lows sounded so much better it was almost scary. It wasn’t just the quality of the sound but a higher SPL was available to the point I might just stop trying to add a buffer/pre to the build.
Some results:
Deutsche Grammophone – “Scheherazade op.35” - There are several passages when the dynamics go from almost silent to super kinetic in a flash. There were no hints of fatigue or latency and made me feel I had actually gained some head room. Again, notes started and stopped with definition without a hint of carryover or muddiness.
WBros - Quest Recording “Back on the Block” Q Jones - A bit over-recorded but a CD that contains all the elements of pop music from 30’s big band Jazz, Acapella, Rock and even a bit of Rap. The electric basses sounded full and correctly dynamic. The Mid-harmonics in the percussion (Toms, blocks, bells and such) came through with authority and added warmth. On this CD I got the impression I had moved several rows closer to the stage.
Verve – “Accentuate the Positive” Al Jarreau - Another CD where the recording engineers turned things up a tad but the artist uses a lot of vocal instrument sounds as well as pristine notes in his songs. That “he’s in the room” presence was augmented noticeably with the new “fermented “caps. There are a few passages where the kick drum and bass interplay made me smile at the improved accuracy and punch. Everything, particularly the baritone center of the singer’s voice, just sounded “filled in”.
So now, IMHO, the Mundorf AG caps (with continued usage) have indeed made an improvement about as significant as Tom’s BlackGate and Sonicap mod suggestion. In my usual car racing analogy – It's sounds like someone put a little “Mundorf Pure Alcohol Booster” in the fuel mix.
Great call Dario!
Hope to complete the LF01 and comp mods this weekend.
Happy Holidays to All -
In preparation for installing Siva’a LF01 and Dario’s Rev E mods, (I found a loose heat sink screw that was triggering small intermittent signal losses) I checked and reheated a few solder points and, as I’m in the middle of building a new chassis, used just my modded PlayStation CD to Uriah’s Lightspeed to the MyRefs.
From the information I had gathered, I was under the impression there wasn’t much of a “Burn-in” required for the AGs. My first review was after about eight hours of listening. I’ve been using the amps (Siva’s V1.3 + BG + Sonicaps) but not doing any serious listening. Yesterday with 35 -40 hours on the caps I heard a whole new amp. The full spectrum from the top of the mid-range all the way down to the lowest lows sounded so much better it was almost scary. It wasn’t just the quality of the sound but a higher SPL was available to the point I might just stop trying to add a buffer/pre to the build.
Some results:
Deutsche Grammophone – “Scheherazade op.35” - There are several passages when the dynamics go from almost silent to super kinetic in a flash. There were no hints of fatigue or latency and made me feel I had actually gained some head room. Again, notes started and stopped with definition without a hint of carryover or muddiness.
WBros - Quest Recording “Back on the Block” Q Jones - A bit over-recorded but a CD that contains all the elements of pop music from 30’s big band Jazz, Acapella, Rock and even a bit of Rap. The electric basses sounded full and correctly dynamic. The Mid-harmonics in the percussion (Toms, blocks, bells and such) came through with authority and added warmth. On this CD I got the impression I had moved several rows closer to the stage.
Verve – “Accentuate the Positive” Al Jarreau - Another CD where the recording engineers turned things up a tad but the artist uses a lot of vocal instrument sounds as well as pristine notes in his songs. That “he’s in the room” presence was augmented noticeably with the new “fermented “caps. There are a few passages where the kick drum and bass interplay made me smile at the improved accuracy and punch. Everything, particularly the baritone center of the singer’s voice, just sounded “filled in”.
So now, IMHO, the Mundorf AG caps (with continued usage) have indeed made an improvement about as significant as Tom’s BlackGate and Sonicap mod suggestion. In my usual car racing analogy – It's sounds like someone put a little “Mundorf Pure Alcohol Booster” in the fuel mix.
Great call Dario!
Hope to complete the LF01 and comp mods this weekend.
Happy Holidays to All -
Something I neglected to mention in the last post that is a noticeable improvement. I think the Audiophiles call it "Butt Sonics" 🙄
I'm talking about those vibrations the come through the floor, up you legs and to wherever. That tactile element can add so much to listening pleasure and I have to say with these caps, is much improved without seeming unbalanced or artificial. It's that thing many seek by adding a sub. With only my two speakers (The Sunflowers) it's all there with the Mundorf AG caps!
I'm talking about those vibrations the come through the floor, up you legs and to wherever. That tactile element can add so much to listening pleasure and I have to say with these caps, is much improved without seeming unbalanced or artificial. It's that thing many seek by adding a sub. With only my two speakers (The Sunflowers) it's all there with the Mundorf AG caps!
You're welcome 😉
Here in continental Europe is already Christmas...
So merry Christmas to everyone from Nice (France) 🙂
Here in continental Europe is already Christmas...
So merry Christmas to everyone from Nice (France) 🙂
Merry Christmass everybody! 
Thanks to everybody for your suggestions.....but i have more questions so bare with me 😀
I've read somewhere in earlier posts (cant find the post now) about a resistor position where the quality of the resistor is critical to the sound q. What do you guys think about using a caddock TF020 in that place?. Also, i have some MUR860's at hand- is there a reason not to use them and choose MUR820 instead?
Thanks to everybody for your suggestions.....but i have more questions so bare with me 😀
I've read somewhere in earlier posts (cant find the post now) about a resistor position where the quality of the resistor is critical to the sound q. What do you guys think about using a caddock TF020 in that place?. Also, i have some MUR860's at hand- is there a reason not to use them and choose MUR820 instead?
skouliki, I think it's R10 and R12. Oh, and the big Caddock at R3
bcmbob, I’m also in the middle of building a new chassis. The pic shows where I am so far. In your usual car racing analogy - I'm getting sideways.
I want to build Uriah’s LDR and an thinking about getting these, ptsoundlab's idea.
L298N Dual Stepper Motor Driver Controller Board Module 5V $6.69usd
L298N Dual Stepper Motor Driver Controller Board Module 5V For Robot Smart Car | eBay
Infrared Remote Decoder Module Power/Volume with remote handset $14.00usd
Infrared Remote Decoder Modul + Small 7-key Controller | eBay
ALPS Blue Velvet - STEREO Conductive Plastic Potentiometer, 100K, Motorized, audio/log taper volume control for LDR users $34.95
http://www.partsconnexion.com/product7383.html
so I can have remote volume. Not as good as the Hynes boards but it's got to be better than a PGA2311 kit.
Happy Holidays to ya'all, may all your babies be born nekid. Merry Christmas Mauro Penasa.
bcmbob, I’m also in the middle of building a new chassis. The pic shows where I am so far. In your usual car racing analogy - I'm getting sideways.
I want to build Uriah’s LDR and an thinking about getting these, ptsoundlab's idea.
L298N Dual Stepper Motor Driver Controller Board Module 5V $6.69usd
L298N Dual Stepper Motor Driver Controller Board Module 5V For Robot Smart Car | eBay
Infrared Remote Decoder Module Power/Volume with remote handset $14.00usd
Infrared Remote Decoder Modul + Small 7-key Controller | eBay
ALPS Blue Velvet - STEREO Conductive Plastic Potentiometer, 100K, Motorized, audio/log taper volume control for LDR users $34.95
http://www.partsconnexion.com/product7383.html
so I can have remote volume. Not as good as the Hynes boards but it's got to be better than a PGA2311 kit.
Happy Holidays to ya'all, may all your babies be born nekid. Merry Christmas Mauro Penasa.
Attachments
squalor,
Please send Uriah a pm as he has been working on a few remote controlled devices. Don't know how far along he is but I bet he has a good track on combining RC, LDR attenuators and the MyRef.
Your build looks very clean and promising. Keep us up to date.
Please send Uriah a pm as he has been working on a few remote controlled devices. Don't know how far along he is but I bet he has a good track on combining RC, LDR attenuators and the MyRef.
Your build looks very clean and promising. Keep us up to date.
Last edited:
skouliki, Parts Connexion want's $7.95usd + S&H for those. Guess that's why most builders go for the 15W part. See if they have the heatsinks for them too.
MUR860s are fine, instead of MUR820s. Earlier, there was a higher probability of counterfeit 860s as compared to the slightly less expensive 820s, but now there's no difficulty in finding authentic On Semi 860s at competitive prices.
The authentic ones have plated copper tabs and are heavier than the counterfeits.
On semi recent production has thin tabs...
I've genuine Onsemi lm78xx with thin tabs.
MUR860 are good, 820 are better since they're soft-recovery.
I've genuine Onsemi lm78xx with thin tabs.
MUR860 are good, 820 are better since they're soft-recovery.
I am going to remove the C4 and C7 caps to see how things change. Still have the alternate compensation in one channel because there are some positive aspects in the sound.
Last edited:
why not using Schottky barrier rectifiers instead, which does not suffer from reverse-recovery at all?