aerius Posted May 12, 2007 Report Share Posted May 12, 2007 Thanks to a person on DIYaudio.com who had a blown MOSFET on this PH12, we now have this wonderful schematic so we can all clone "the best amp in the world that's ever been built", that is if you believe dretardwells. Quote Link to comment Share on other sites More sharing options...
ojnihs Posted May 12, 2007 Report Share Posted May 12, 2007 cool Quote Link to comment Share on other sites More sharing options...
Nanoha Posted May 12, 2007 Report Share Posted May 12, 2007 I thought schematics had been floating around. At least I remember a few people were trying to clone it last year. And it's not just arthurwells. Quote Link to comment Share on other sites More sharing options...
cotdt Posted May 13, 2007 Report Share Posted May 13, 2007 maybe not the best, but it should be a pretty good amp based on what i've been told. if you make a clone, you have access to better parts so it should sound better than stock. i've also got the schematics to the Doge 6210, and also my "improved" circuit, which uses the booster triode trick and removes global feedback. Quote Link to comment Share on other sites More sharing options...
aerius Posted May 13, 2007 Author Report Share Posted May 13, 2007 maybe not the best, but it should be a pretty good amp based on what i've been told. if you make a clone, you have access to better parts so it should sound better than stock. I've heard it, it's decent and performs at its pricepoint. The big problem is the electrolytic capacitor on the output which will mess up the sound, along with the 10k plate resistors on the 6SN7's in the cascode which are too low and will lead to excess distortion. Ideally, the plate resistors should be about 5-10 times the resistance of the tube's plate impedance, the Rp of a 6SN7 is about 7.7k. I'm guessing that the Chinese ripped off a 6DJ8 circuit and swapped in 6SN7's without bothering to fix the circuit. i've also got the schematics to the Doge 6210, and also my "improved" circuit, which uses the booster triode trick and removes global feedback. Interesting, want to post the improved circuit? There's a surplus shop in my area and I should be able to find the parts to build it. Quote Link to comment Share on other sites More sharing options...
n_maher Posted May 13, 2007 Report Share Posted May 13, 2007 maybe not the best, but it should be a pretty good amp based on what i've been told. if you make a clone, you have access to better parts so it should sound better than stock. i've also got the schematics to the Doge 6210, and also my "improved" circuit, which uses the booster triode trick and removes global feedback. Just so you're aware, the good Dr. is ripping you a new asshole on Head-Fi. Quote Link to comment Share on other sites More sharing options...
deepak Posted May 13, 2007 Report Share Posted May 13, 2007 Woah... I would be afraid for the good doc, cotdt could always threaten to kill him like he did half his high school class Quote Link to comment Share on other sites More sharing options...
cotdt Posted May 13, 2007 Report Share Posted May 13, 2007 drauthurwells is going nuts on the Doge thread on head-fi. It's a good read, and very entertaining. I stopped replying because his claims are so out of this world. The story is that Mr. Wells contacted Earl by PM, to sell him a Doge amp. Earl agreed to buy it based on the good previous experience with the EL84 tube. Well, Earl said the amp did not work and the knobs were completely loose and falling apart. He returned the amp for another one from Mr. Wells, and that one didn't work either. It arched Earl's NOS tubes, in fact. This time, Mr. Wells refused to allow the return, claiming that Earl's agenda was to damage his reputation to help Singlepower. This ignores the fact that it was Mr. Wells who was the one who contacted Earl to sell him the amp, not the other way around. After much argument with Earl, Mr. Wells offered to give a HALF refund for return of the amp, but this offer is not acceptable to any sane person. So Earl and I was talking about it and Earl wondered if I can fix it, and I said "yeah, i have a working version of this amp, so i should be able to do it." So he sent me his broken amp and the build quality was horrible. The tube sockets were loose, and the chassis itself was twisted and would not sit on all four legs. In contrast, my Doge from Pacific Valve was very well-built. I did not even test Earl's amp since I was sure it would destroy my nice Russian 6P14P tubes. I proceeded to rebuild the entire amp from stratch with premium parts and it now works wonderfully. The stock amp used Pin 1 as a binding post, so NOS 6BQ5s did not work with the amp unless you snipped off Pin 1. This and the loose parts could have been the problem with Earl's amp(s). 6BQ5 and EL84 are not the same tube, because the 6BQ5 uses Pin 1 internally, but they are otherwise swappable. Mr. Wells is still accusing me about lying that anything was wrong with Earl's amp. He still claims the amps were working perfectly, and that Earl should have returned it to him, forgetting the fact that Mr. Wells refused the full return money. Quote Link to comment Share on other sites More sharing options...
cotdt Posted May 13, 2007 Report Share Posted May 13, 2007 Interesting, want to post the improved circuit? There's a surplus shop in my area and I should be able to find the parts to build it. Sure, but I need to find a way to draw the schematics on my computer. right now i have to draw schematics by hand and take a picture, which doesn't come out so clear. Quote Link to comment Share on other sites More sharing options...
Nanoha Posted May 13, 2007 Report Share Posted May 13, 2007 arthurwells is hilarious as always. Quote Link to comment Share on other sites More sharing options...
tkam Posted May 13, 2007 Report Share Posted May 13, 2007 arthurwells is possibly the stupidest person on the planet Quote Link to comment Share on other sites More sharing options...
cotdt Posted May 13, 2007 Report Share Posted May 13, 2007 Here is my improved circuit for the Doge 6210. Let me know if you find any improvements. Seems to sound better without capacitors in the cathode bias, which the Doge originally used. I know it's a strange circuit. Quote Link to comment Share on other sites More sharing options...
ojnihs Posted May 13, 2007 Report Share Posted May 13, 2007 dear god i'm so sick of drarthurwells Quote Link to comment Share on other sites More sharing options...
cotdt Posted May 13, 2007 Report Share Posted May 13, 2007 I made a mistake on the booster triode on Post #11, on where the resistor goes. The 10R resistor is already part of the schematics, so it should be clear, anyway. Here is the correct version: Quote Link to comment Share on other sites More sharing options...
recstar24 Posted May 13, 2007 Report Share Posted May 13, 2007 arthurwells is possibly the stupidest person on the planet Nah, Welly Wu is totally off the mark, and he is unstable. Doc is just overtly biased to the point of being irrational. Quote Link to comment Share on other sites More sharing options...
cotdt Posted May 13, 2007 Report Share Posted May 13, 2007 Welly Wu seems okay to me. drarthurwells is definately the worst IMHO. After this bizzare incident, I sincerely hope he does not become a member of this forum, or we will soon have another head-fi on our hands. Quote Link to comment Share on other sites More sharing options...
cotdt Posted May 13, 2007 Report Share Posted May 13, 2007 he joined, but didn't stay. he found out quickly that his particular brand of bullshit wouldn't go uncontested. aha excellent! i'm loving this forum more and more! Quote Link to comment Share on other sites More sharing options...
Dusty Chalk Posted May 13, 2007 Report Share Posted May 13, 2007 arthurwells is hilarious as always. It's not even remotely amusing if you look at it from the perspective of someone like me, who doesn't know enough about the internals or behind-the-scenes to see through his bullshit, and then subtract the enlightening aspect of this forum (e.g., a newb on head-fi). Quote Link to comment Share on other sites More sharing options...
cotdt Posted May 13, 2007 Report Share Posted May 13, 2007 It's not even remotely amusing if you look at it from the perspective of someone like me, who doesn't know enough about the internals or behind-the-scenes to see through his bullshit, and then subtract the enlightening aspect of this forum (e.g., a newb on head-fi). it's not difficult to see his tricks. he "loans" people his amps for the full price, and then doesn't want it back. he even says he is not a member of the trade but just an ordinary consumer like the rest of us, but seems to have sold very many amps to people via PMing anyone that shows some interest in the amps he sells, and I remember seeing him advertise his 20,000 or so tubes. i forget the exact number, but it's on head-fi somewhere. he's been aggressively advertising the amps he sells on head-fi, and reveiwing them. thing is, later i found out how inaccurate his reviews were. i bought some tubes from him, but later on after price-matching I found that I've been ripped off. This was back when I was still new to tube amps. His tubes were also very microphonic and hummed. The tubes he recommended for the Doge amp were average at best, and nowhere near as good as NOS tubes that I later tried. don't get me wrong, the Doge 6210 is my favorite amp, but not for the reasons Mr. Wells states. BTW, I don't think he's a doctor. Mr. Wells kept sending me unsolicited PMs, telling me how I don't understand soundstage, how I listened to music too loud and damaged my hearing (huh?), how I don't listen attentively to inner details, and all this stuff about how my listening habits were bad, even though he has never met me in person. This was all in reaction to a post about how my speakers can do certain things well that no headphone I've heard has acheived. Apparently he disagrees with this. Quote Link to comment Share on other sites More sharing options...
n_maher Posted May 13, 2007 Report Share Posted May 13, 2007 drarthurwells is definately the worst IMHO. After this bizzare incident, I sincerely hope he does not become a member of this forum, or we will soon have another head-fi on our hands.You know, I'm trying to give you a second chance here outside of Head-Fi but comments like this aren't giving me much hope. Your appraisal of Dr. Wells is pretty close to mine of you. On Head-Fi you come across as judgmental, overly critical and like your opinion is the only one that matters. Take the following quote for example: the bass boost in the M^3 is poorly implemented. it makes the sound muddy. What makes this comment odd is that it was in a thread asking about the M3 vs. the PPA and their bass boost, which just so happens is implemented in exactly the same way. Now luckily enough amb came into the thread and corrected you but this isn't the first (or even second) time that I've seen you post something in a way that makes it read as if you know what you're talking about when you don't. I guess what I'm trying to say (as I've said on Head-Fi) is that you should choose your words a little more carefully if you don't want to become the second Dr. Just my 2c, probably not worth that much. Nate Quote Link to comment Share on other sites More sharing options...
cotdt Posted May 13, 2007 Report Share Posted May 13, 2007 you are correct. i do try to make things interesting my giving my opinions and being judgemental, but I do not talk about stuff i know nothing about, which you say. I have heard the M^3 and played with its bass boost, but not heard the PPA's and made no comment about that. The bass boost on the M^3 sounded boomy and muddy to me, and that is my subjective opinion. You know... words like "muddy" are by definition subjective. If it were a factual word, then you can use figures to show that I am wrong. But a person's opinion is not up for debate. My speculation as to why the M^3's bass boost is muddy is because the wrong frequencies are boosted. Personally, I built a Linkwitz Transform circuit boosting around 3dB from 80Hz and under. It gives bass impact without being muddy. The male vocal range begins at around 120Hz and above, so these frequencies need to be untouched. Bass boost is something I've researched on, and yes have discussed with amb in PMs. I don't see how Ti Kan or Mike refuted anything I've said. I don't even see how it's possible to refute a person's personal opinion. Quote Link to comment Share on other sites More sharing options...
n_maher Posted May 13, 2007 Report Share Posted May 13, 2007 I guess my point was, in a thread asking for a comparison between two amps it might be helpful if you said that you hadn't heard the ppa or that knowing that the two bass boost circuits are identical that your experience had been negative with the M3. You comment reads as if the M3 is the worse of the two. FWIW, I agree with your opinion of the bass boost, I didn't care for it in either amp. And I retract my statement saying that you speak about things that you don't know about, I have no idea what your knowledge level is. Quote Link to comment Share on other sites More sharing options...
cotdt Posted May 13, 2007 Report Share Posted May 13, 2007 Yes, perhaps I should have mentioned that I have not heard the PPA's version of the bass boost, but now we know they are the same. BTW, my above post about the bass boost is incorrect, but I've since found the real reason why the bass boost doesn't sound good and updated the head-fi thread. Quote Link to comment Share on other sites More sharing options...
aerius Posted May 13, 2007 Author Report Share Posted May 13, 2007 I'm trying to make sense of the Doge circuit, but either it's too early in the morning or something's really weird. It looks like a cathode-follower input to a common-cathode gain stage which then feeds the trioded output tube. Other than dropping gain, I can't figure out a reason for a cathode-follower input, and the 330k resistor puzzles me as well. It's just not making sense to me, I don't know if it's some brilliant concept which is way over my head or an amateur hackjob. Quote Link to comment Share on other sites More sharing options...
Nanoha Posted May 13, 2007 Report Share Posted May 13, 2007 he joined, but didn't stay. he found out quickly that his particular brand of bullshit wouldn't go uncontested. You wouldn't believe the PM conversations we had here when he first arrived. It was wonderful. Oh wait, or have you been peeking in my PM boxes? Quote Link to comment Share on other sites More sharing options...
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