"gobsmacked" ....yea, I never could find the exact right word 😀😀 I like it.
BTW: I'm going to try the Jantzen Silver caps. What has been used/tested - 1uF only?
Also, where is the best place to buy the K-71s?
BTW: I'm going to try the Jantzen Silver caps. What has been used/tested - 1uF only?
Also, where is the best place to buy the K-71s?
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Hi Bob
Yes those silvers look interesting and I have them on the list for when the DIY coffers recover a little.
I’ve also read good things about these
Rike Audio S-cap paper in oil aluminium capacitors homepage
So they will be next on the list just for a bit of contrast.
Yes those silvers look interesting and I have them on the list for when the DIY coffers recover a little.
I’ve also read good things about these
Rike Audio S-cap paper in oil aluminium capacitors homepage
So they will be next on the list just for a bit of contrast.
Bob, I am using the 1uf version....and I am still very happy. As for the k71s I got them on ebay I will try to dig up the seller.
Thanks Will. I have the k71 links from eBay, just wanted to check for the possibility of a U.S. source. I'll go ahead and order. If someone in the States wants to piggyback on the order to lower shipping costs PM me by Monday. USPS reship transfers domestically will probably be only ~ $2-$3 if not less.
I finished the MyRef FE about 4 months ago and all I can say is that it's a REAL reference amplifier. I compared it with a few expensive hi-end power amps (both linear and class d) and to my ears it plays definitely in the same league.
Considering its cost this is the absolute winner.
Unfortunately the original MyRef C is no longer with me and I almost completely changed my setup since then, so I cannot compare the two.
A big thanks to Mauro and Dario 🙂
Marco
Considering its cost this is the absolute winner.
Unfortunately the original MyRef C is no longer with me and I almost completely changed my setup since then, so I cannot compare the two.
A big thanks to Mauro and Dario 🙂
Marco
Bob,
You already have tried the K71. Those were the gold color Russian polystyrene that I loaned to you. The ones that you sent on to Tom E, but he never tried. I still like them. If you are still looking for a source, I have purchased 4 times from bay seller valtek_2005. His stuff has always been exactly what he said and he stands behind it well.
Jac
Jac, Must be one of those "Senior Moments" 
😱
Actually, based on all the positive reviews it appears I didn't devote enough time for a thorough investigation. I know I didn't try the bypass technique you like - so I must take a second shot at the Ks 🙂
😱Actually, based on all the positive reviews it appears I didn't devote enough time for a thorough investigation. I know I didn't try the bypass technique you like - so I must take a second shot at the Ks 🙂
Russian Confusion
Bob,
A note of clarification.
The K71-4 are gold colored polystyrene that I loaned you. They are also the recommended budget C13 on Dario's BOM. They are typically not used with a bypass cap as they have very good imaging and sparkle on their own. The only downside of the K71-4 is that some find them a little cool sounding or slightly lacking in harmonic warmth. I found them to be a lot like the Audyn Plus caps, but I slightly prefer the K71-4 over the plus. That difference is small and easily varies with system differences.
The other K cap, the one that I recommend with a bypass, is the K75-10 (typically green in 1 uF size). It is a hybrid paper/mylar in oil cap that, at 52 mm length, is a little too long to fit "on board" on an FE board. This cap is very warm but lacks sparkle and soundstage, which is why I suggest a small polypropylene cap as a bypass. A 1 nF AMTRANS works great as a bypass cap. The combined cap remains my favorite, even compared to the TC that you lent me. Also, this cap takes a little longer to settle in compared to the K71-4.
Both are cheap from suppliers in Eastern Europe. If you are curious, why not buy a pair of each and give them a try.
Jac
Bob,
A note of clarification.
The K71-4 are gold colored polystyrene that I loaned you. They are also the recommended budget C13 on Dario's BOM. They are typically not used with a bypass cap as they have very good imaging and sparkle on their own. The only downside of the K71-4 is that some find them a little cool sounding or slightly lacking in harmonic warmth. I found them to be a lot like the Audyn Plus caps, but I slightly prefer the K71-4 over the plus. That difference is small and easily varies with system differences.
The other K cap, the one that I recommend with a bypass, is the K75-10 (typically green in 1 uF size). It is a hybrid paper/mylar in oil cap that, at 52 mm length, is a little too long to fit "on board" on an FE board. This cap is very warm but lacks sparkle and soundstage, which is why I suggest a small polypropylene cap as a bypass. A 1 nF AMTRANS works great as a bypass cap. The combined cap remains my favorite, even compared to the TC that you lent me. Also, this cap takes a little longer to settle in compared to the K71-4.
Both are cheap from suppliers in Eastern Europe. If you are curious, why not buy a pair of each and give them a try.
Jac
Today I finally soldered up my pcb's and checked them for voltages and offsets.Three checked out ok with all p/s voltages as they should be and dc offsets of 2mv;18.5mv and 57mv although this one started at 130mv and dropped slowly over 20 mins.Hopefully this will drop further with use although none have played music yet;should get time to try them in the next couple of days.The fourth one on the other hand has -3.8V on its output and 1.2V on the input pins.C102 pads read 8.58V with C202 pads reading -0.9V both resistor on the outside of the regulated supply area have 1.25V across them as shown on the pcb.
Any pointers would be much appreciated;thanks.
Any pointers would be much appreciated;thanks.
Thanks Dario I will post pics as soon as I can get hold of a camera.A quick question ;when I fired the amp up yesterday I realised🙁 that had not installed R11 the 1R resistor.Would this have caused my problem.
Yes as soon as I realised I switched off and soldered one in.The readings are all taken afterwards.
Yes the jumper is soldered in.I forgot to mention that the relay clicks on and off but with no set sequence.
I am happy to say that the other three modules all play music😀 They were left on for 30/40mins with no problems Its time to sort a chassis and buy the proper size transformers.
I am happy to say that the other three modules all play music😀 They were left on for 30/40mins with no problems Its time to sort a chassis and buy the proper size transformers.
Jantzen Silver Z are here.
First impression is (really) positive, maybe they sound a (tiny) bit less full than DC-coupling.
They seem to have full detail and pretty neutral balance but a bit less involving, maybe, than the more colored Supremes.
I'll let them burn in a bit more before final opinion.
2nd build
So I have almost completed my 2nd pair of amps but to my dismay I ended up not ordering the extra 8- .25" terminals. So close but yet so far.
Also I noticed that there are two different types of On Semi transistors in the BOM:
bc639g tight terminal spacing.
bc639-16zl1g proper terminal spacing.
Im not sure what the difference is but if they are the same the 16zl1g is easier to install.
So I have almost completed my 2nd pair of amps but to my dismay I ended up not ordering the extra 8- .25" terminals. So close but yet so far.
Also I noticed that there are two different types of On Semi transistors in the BOM:
bc639g tight terminal spacing.
bc639-16zl1g proper terminal spacing.
Im not sure what the difference is but if they are the same the 16zl1g is easier to install.
Attachments
BC639G is for DC protection circuitry
BC639-16 is for the shunt regulator.
Probably the ZL1G suffix is for bent leads version so BC639G with bent leads became BC639ZL1G