Grannyring, Looks like the Wima DC Link caps I am trying in my power supply and the ClarityCap TC600 you are using are both Metallized Polypropylene. Looks like we are on the same path. Regards-Jet
Building the Audio Note Kit 1 SET amp...
Hi, Folks,
If anyone's interested, I've started a blog with lots of photos, documenting my ongoing build of the Audio Note Kit 1 300B SET amp. If you've ever thought of building any kit before and want to get a feel for what it's like, you're welcome to have a look!
If anyone's interested, I've started a blog with lots of photos, documenting my ongoing build of the Audio Note Kit 1 300B SET amp. If you've ever thought of building any kit before and want to get a feel for what it's like, you're welcome to have a look!
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Well, I re-soldered all the joints between the valve base tabs and the pads on the Driver Board PCB but whatever's going on wasn't fixed because I'm still getting a distorted signal on bass-heavy material on the amp. Just got an email from Pete (Digital Pete) Fulton in Florida that my finished driver board is shipping 2-day post tomorrow. So, I should be up and running over the weekend! I hope by comparing the two boards to at least figure out what the problem is/was with my Driver Board! |
Okay: I received my new Driver PCB from Digital Pete in Florida, ANK's designated builder for prebuilt ANK kits. It arrived on Friday. As you'd expect, the workmanship is first-rate. I've managed to remove my driver board from the amp and hope to get Pete's board installed completely by Monday. I'll report back when I do. |
Roxy, I chuckled at the likely typo "God luck"--if it was my soldering skills involved vs those of Rebbi's, I'm quite certain the divine assistance would be most necessary 😄! I too am anxious to learn if the new board solves the issues with the amp, and pass on my best wishes to Rebbi for success as well. Randy |
I will say a Mi Sheberakh prayer of healing for the amp tonight. |
Hi, Guys, Well, no joy yet. I replaced the driver board with the one that Pete sent me but it doesn't resolve the distortion issues. So I have packed up the amp and will ship it out to Pete in Florida tomorrow. He promises to get to the bottom of this. I should mention that both Pete and Brian say they've never seen an amp behave this way. Usually it either works brilliantly or it fails miserably due to a build issue, as in "terrible noise in one channel," "really bad hum," "no sound at all" or "bursts into flames." This whole "sort of works" thing is just bizarre. I'm sad not to have ironed this out on my own but it may just require someone with the required debugging expertise being able to get their hands on the amp in person. Pete should be that guy. I'll update you when I know something. |
Hi Reb, Pete is just the nicest man around; really talented, and humble as well. I know he will do it for you. As a sidebar, I have to say that on my efficient horn speakers, this amp is quieter than 3 other SS amps I tried. That was a really nice surprise, as we all know that noise obscures detail, as well as causing long term listener fatigue. When I stand with my ear to the drivers, it is really silent. Just a great amp. |
Hmm, well let's be real and not exaggerate. Any good quality amp delivering just a few watts will clip and distort sooner than one of similar good quality with more watts, all else aside. Its just a matter of when and how. I don't think this point is debatable even really. In this case specifically though, the experts are saying that there is something wrong and it should not be clipping and distorting as soon as it is. That makes it harder to resolve perhaps in that the issue is not as severe as many it would seem, but I don't think it accurate to say that an amp that delivers only a few watts clipping is "rare". If one applies an underpowered amp to a task in general it might be harder than normal in practice to determine if things are working properly or not as this case would seem to support, in that clipping WILL occur sooner than in other cases. |
Rebbi had the amp tested by a qualified tech who confirmed markedly decreased power output.The amp struggled with a Tekton speaker that was then easily driven by a 3 watt 2A3 SET. brownsfan has very successfully driven the De Capo with 2 different 8 watt amplifiers. Rebbi has a malfunctioning amplifier. Here's what I find remarkable about this situation. A decfective(below specified power rating) amp driving 86-87 db speakers sounding better than the former higher powered amplifier with the same speaker. When this amplifier is fixed, look out! |
Well, let's not jump to conclusions. I hope that's the case, but time will tell. There are many reasons why one thing may sound better than another case by case. No doubt sending the amp to an expert with the right knowledge and tools to get to the heart of the matter is the best thing at this point. |
Rebbi has been emphatic regarding the new sonic discoveries heard with the amp with familiar music(three listening session notes on his blog). There's no logical reason not to expect a properly functioning amp to sound better than one that's defective.He's getting better music reproduction than he ever had with his prior Manley. His future is bright with the AN Kit amplifier. With the one exception he has pointed out(synthesized bass reproduction)all else was an improvement. Quite telling and very encouraging. Rebbi built a better amp than what he had. |
I could be shocked, of course, but I would be very surprised if this isn't some problem with the amplifier itself and not merely a matter of inadequate wattage. You may remember earlier in this endless thread that when the local technician attempted to fix the amp, he sent pictures of his scope readings to Brian at Audio Note Kits. Brian said that the scope readings looked "squashed." Something really didn't look right. I would also be surprised if there isn't a legitimate problem with this amplifier because it's such a classic and time-tested design and the parts quality is so outstanding, from the gargantuan transformers to the beautiful, Audio Note silver speaker binding posts. Anyway, we shall see |
Sounds like digital Pete is the right guy to sort through it all. Then we will know. I am rooting for a happy ending. Once the amp is certified to be doing its thing perfectly as it should, you'll know if it is able to fit the bill with the Decapos to your satisfaction. I think there is a reasonable chance of that occurring and am rooting for it, but only time will tell. Its not a match made in heaven, so anything is possible. Might still be even if it were. |
"Here's what I find remarkable about this situation. A decfective(below specified power rating) amp driving 86-87 db speakers sounding better than the former higher powered amplifier with the same speaker. When this amplifier is fixed, look out!" Charles, your statement above is the crux of this seeming paradox. I am TRULY hopeful that Digital Pete gets down to the bottom of this perplexing issue and that in the end the Decapo and Audio Note work together, maybe not perfectly, what does....but then again to a point that really doesn't matter if there is magic to Rebbi. We're all rooting for him and hoping all works out with what he has on hand without the need to change speakers which at this point seems the next logical step. |
Rebbi, I got my Stereophile mag today and Herb Reichert does a review of the Tekton Enzo XL. He basically raves about them. They cost $2,200 and play with the big boys according to him. LF down to low 30, can do it with 3 watts of 2A3. I just picked up my brother's 3A DeCapos to compare against the M-Lore and Lore in my system at my place. Give me a week or so and I will report back. My gut tells me you'll soon get to the bottom of problem and the AN Kit is going to be more than superb with the deCapo. Best |
Rebbi, Yes, our family has always had great audiophile stuff. Both brothers currently. Sister no. Father and uncle, many big name pieces in a bygone era, KLH Electrostatic 9s, Marantz 7, 8b, Big MacIntost, Bozaks, Garrard 301, Thorens, JBL, plus many more...thousands of records. Wish I had all this stuff today. My first serious listening was with Quad 57 speakers, tube set-up, getting schooled on big-band Jazz of the 40s. |
Yes, Pete did send me a fully built up driver board, but replacing my board with his didn't fix the issues. So the amp is on its way to him. (Brian sent me the replacement board free of charge.) Yes, shipping a 50 pound amp to Florida (and insuring it) wasn't cheap, but I think it's the only way to get to the bottom of this, so it's worth it to me. IÂm confident, too, that Pete will figure it out. |
Well, for all of you (all 2 of you?) who have been on pins and needles to learn what was going on with my amp, here's what we know at last. My build was on target - nothing wrong there. Furthermore, Brian and Pete WERE able to replicate the distortion issue. This relieved my worst worry that they wouldn't be able to even reproduce the problem and we'd be back to square one. The problem, it turns out, was with the output transformers. Brian and Pete have NEVER seen this issue in all the years they've been shipping and assembling these kits, but somehow or other these transformers had become magnetized and as a result weren't putting out full power. How this happened is even more of a mystery since these trannies are all very high quality and thoroughly tested before they ship! Brian is going to get these trannies back to go over them with his transformer manufacturer/designer to determine what happened to cause this very odd result. In the meantime, Brian is shipping two new transformers to Pete to install in the amp. So bottom line is that I should have a perfectly working Kit 1 in a week or so. Let me again emphasize that Brian and Pete have provided superb support. And if the amp sounded great before, it should be really amazing with this issue sorted out. Whew! |
Wow! Congratulations, Rebbi, and kudos to Brian and Pete. I've never heard or read of anything like that happening, but you might find the second from the last page of this paper to be worth reading, and possibly suggestive of something that might have led to the problem. It was written by Bill Whitlock of Jensen Transformers, who is a renowned expert on audio transformers. Also, as you are most probably aware, a tube amplifier having output transformers should not be operated without speakers or equivalent resistive loads being connected (assuming the tubes are installed, that is). If perchance you operated the amp at any point without loads being connected (following the initial voltage checks that were performed sans tubes), I'm not sure that it could result in magnetization of the output transformers, but it seems to me to be a conceivable possibility so I thought I'd mention it to be sure. Best regards, -- Al |
I'm very happy for you Rebbi that you have finally resolved the problem. We are ALL still on pins and needles, hoping that the amp will work with the Decapos but the fact that you did everything on your part correctly must give you some relief and satisfaction that it at least wasn't you which I'm sure was somewhere in the back of your mind, kudos to you and please keep us updated. |
Tubegroover, As I said, my greatest worry was that Brian and Pete wouldnÂt be able to reproduce the problem - like those times I've brought my car in to the shop with a funny noise and the mechanic couldn't reproduce it. As soon as they confirmed that there was a real issue, I was relieved because I knew they'd take care of it. Brian said, "I'll make sure you're happy." Almarg: such an interesting article, thanks. Seikosha and Mikirob: Thanks for the good wishes. And Rob, really sorry my Stereophile sub lapsed. I'd like to read that Tekton Enzo review and may have to pick up a news stand copy. |
Rebbi, By-the-way, the Enzo Reviewer (Reichert) favorably compared the Enzo to the DeVore Orangutang O/96. As I've previously mentioned on this thread I am currently comparing my brother's DeCapo Ref 3A against the M-Lore using the Coincident Dynamo 34SE 8 watt amp in my room and set-up. I will make one comment at this juncture. The bass on the M-Lore is much, much better in quantity and quality. YMMV. Best. |
Good news, Reb. Can't wait to "hear" your impressions of the amp w the new trannies in place. FWIW, I used a Wavac 300b with some much older "Ref 3a" monitors several years ago and never ran into clipping, although I don't usually listen to full range orchestral music and volume is typically quite moderate. I put Ref 3a in quotes because they are labeled Innovac; a predecessor company to Ref 3a. Built in Switzerland, same designer/owner (before Tash took it over), same basic technology w/o the BE tweeter. I'll have to drag them up from the basement and see how they sound w the Lady Day+ 300bs monos I am now running. |
I too was on pins and needles and checking the "My Forum Threads" link (which used to be on the left column but is now buried in the "Community" tab) at least twice a day hoping for updates and good news. Rebbi, so glad to hear that they were able to quickly find the issue and I look forward to hearing your listening impressions. And after switching to an SET amp with my Merlin VSMs, and then following your story, I was actually inspired to break out a soldering iron (for the first time in decades), take the crossovers out of my speakers and send them in to Bobby at Merlin for an upgrade to the current Black Magic edition. So thanks for posting and blogging about your experience and keeping us all engrossed in your suspense thriller! |
Excellent news Rebbi! Mikirob, I am looking forward to more detail on the M Lore (that just sounds too much like Data's evil twin) vs DeCappo evaluation. I find it kind of funny with the DeCappos. They can deliver the goods reasonably well with transients, like tympani, but they do seem to struggle a bit with walking bass on baroque music. Just seems a little soft and lacking definition. |
I share everyone 's excitement and enthusiasm for the outcome and for Rebbi's generous sharing of his journey. Regarding Almarg's comment above, is there an important takeaway for operating tube amps? I've known that tube amps don't like to be operated with a load, but think I've violated that warning a time or two. How common is this magnetization problem? |
