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| Romy the Cat's
personal site dedicated to advanced audio and evolved music reproduction
techniques
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It is impossible to make two amp with the same quality with such big difference in output tubes , the transformer design are vastly different, a 10Kohm transformer would never have a good bandwidth as a 600ohm transformer. I just have to experime...
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I just finished the GM70SE amplifier. It is built on the same size chassis as the 6C33C (with few extra holes) but 1/2 in higher to accommodate quite a few extra parts.
The GM70SE is built with quite interesting feature similar to 6C33CSE :- Double...
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Paul,
I tried this tube in few other amps and also on a phono amp and I like the sound of this tubes, perhaps it matched with the speakers/amp combination better than other, still there are lots of other tube out there that I would like to tr...
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Paul,I used both halves of 6C33C this time, I planned to use two 6C33C and uses each half for more power, but that would shortened the life of 6C33C if run one triode at max power dissipation. I used the C3G as driver, since I dont use negative feedb...
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Amp at close to clipping level 20.4W, I am surprised that sine wave looked pretty symmetrical. Still has couple chassis left for the Melquiades, the problem is the 400V supplies which required extra power supplies. This interstage amp is so much simp...
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Just finished one mono block 6C33C SE amp.To keep things simple (power supply only need 220V), I used a single driver tube (the second tube is there for backup if not going as planned) through an interstage transformer...
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[quote user="Romy the Cat"]There are no good ready to go transformer for 6C33C. Tangos are garbage. The 20 years back Tangos were OK for small tubes but Tango is long gone and whatever crap they label by Tango in fact Chinese transformers agglomerat...
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Ok, I just read your "Melquides Remote biasing". This technic can not be duplicate in my amp due to DC coupling, the C3G (I dont use 6E5P) driver stage basically adjust the 6C33C current in the output stage. Just for curiosity, I will build a mono bl...
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Romy,I looked at your Melq schematic : http://www.goodsoundclub.com/PDF/Melquiades_SET.pdf regarding the 6E5P bias. Would it be simpler to use two alkaline battery in place of R5 to provide 3V , or 3 Rechargeable for 3.6V in place of R5 ? Did you tr...
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Romy, in the contrary, it is very unfair to compare my 845 amp with the 6C33C. The main reason is the 845 amp used the best output/interstage transformer available, while the 6C33C's output xformer is pretty good but far from being best for the 6C33C...
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Ok, I will try to lower the primary impedance like you suggested, but it will be on the new 6C33C mono block amplifier that I am building. The custom made chassis will be finished by next week and I have the better components waiting to get installle...
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I am not too worried about the 6C33C bass, since I have other alternative. Even if lower loading will improve it, the problem is to get more power out of the 6C33C to a 40W (PSE perhaps) level to be able to drive the 12in or 15in woofer, even then th...
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Forgot to elaborate the Quad system.It is actually a tri-amp Quad system, below 100Hz is the Supravox 15in Field coil in open baffle, then it's a Stacked Quad ,and about 5Khz there were 5 RTR ESL cell. I did try the 6C33C amp in a single pair Quad by...
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The reason that I built the 6C33C preamp was to explore the 6C33C true musical potential like I did with the 845. Not only did I compare the sound of these tubes in power amp, but also in preamp. The reason is that with power amp you might hit some l...
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Wow! I did not realized that almost 4 months have passed since I wrote last.
Quite a few things have happened the last 4 months that I have played with the 6C33Camp/preamp combo. I have tried at least 3 different vendors on the Ulyanovsk type, the ...
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I used those VPI magic brick sitting on top of the transformer, my audio analyzer tell me that these bricks helped the noise by about 1db, may be the 6 lbs or so weight does damp the xformer vibration, so I leave them on, just trying everything to ke...
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One last thing I can do is buy some Mu metal sheet on Ebay and lined up the transformer can and potted with wax as you said, but that's too much work and probably do not work as well as on a separate chassis, so for now I will listen the way it is an...
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It's 60Hz hum, caused by both mechanical and magnetic field coupling to the output transformer. I used a toroidal transformer and thought it would not caused this problem but it did. When using an external power supply for both ...
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After spending considerable amount on the hum problem, one way to fix it is tho remove transformer and place it in a different chassis, the noise level will improve more than 15 db to -74db. But that cause too much hassle, so I got it improved to 62d...
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[quote user="Romy the Cat"]From what you describe I can conclude that your DAC is not good. You said you use DIY wireless DAC with tube output. I do not know what wireless mean in this context, but it is not important. I also know do not like any tub...
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Romy,
No, the DAC was not set at maximum level (for best sound) while Cyrille listening to the system. It was set at normal volume for the whole system. When Cyrille dropped by, I was showing him the Field Coil open baffle speaker system which con...
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Romy,I added the fuse recently just for protection for the output transformer since these 6C33C tubes plate current can get very high and might damaged them. Also DC coupling on this high gm tube can cause plate current to go max if something failed....
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Last weekend, just for fun, I brought the amp and preamp to the 2011 Burning Amp in San Francisco. On the first speakers, the Audio Kinesis, I let the heater warmup for about 15 min, and then switched on the power, the amp was fine, we played...
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Romy,The normal bias for the Golden Grid tube for 200V Plate at 200ma is about 70V-80V for the good tubes, the bad tube read 0ma at this bias, when drop to -30V it start reading some current, but can't get to 150-200ma current for the SE amplifier.Th...
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After burn-in the heater for 24 hrs, I tested all 3 Golden grid tubes on a bench power supply , 2 of the tubes worked fines, 1 tubes does not have current. The tube seller gladly refund for the non functional tube.I talked to a 6C33C OTL amp manufact...
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Just in time. After about 5 hrs of music on the preamp , I received today the 3 golden grid tube. Looking with a magnifying glass, I could not determined if it is gold wire. Anyway, I am burning the heater and will try out tomorrow. Here are some pic...
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The transformer in this preamp was given from a friend who want to learn how to wind transformer. If I remember correctly it started out as UBT, they were bought (when UBT was operating in the Silicon Valley) at the company swap meet. They were rejec...
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The preamp has the classic tube regulated power supply using 5R4, 6AS7, 6SJ7. It is transformer coupled output and has no capacitor in the signal chain, the gain is about 8db, so it is not a buffer. For convenience, it does has a remote control. It i...
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Romy,Nah, I just want to careful with what I have left, dont want to have an amp without tube for now. The gold grid tube probably take a while to get them. From what I remember from a tube dealer who said that these 6C33C need to have the heater bur...
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Shame on you Romy, you took them all without leaving some for others!I am waiting for the shipment of these tubes, I only bought 3 to try it out in my amp. In the meantime, I am running my amp with the rest of these unknown qualities from Asia with f...
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