Re: transformers [message #8744 is a reply to message #8742] |
Tue, 25 January 2005 21:24 |
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Wayne Parham
Messages: 18782 Registered: January 2001
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Illuminati (33rd Degree) |
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Hey Akhilesh, You oughta get into the Guinevere project on the Group Build forum. I think you'd really enjoy it. Interested? And by the way, Bill Wassilak announced he's having the next GPAC meeting at his house on the 5th. See you there? Wayne
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transformers [message #8746 is a reply to message #8743] |
Wed, 26 January 2005 02:18 |
akhilesh
Messages: 1275 Registered: May 2009
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Illuminati (3rd Degree) |
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I agree John! trannies are important in all aspects of the tube circuit. I guess my point was (and of course its just my opinion) that the engineering demands on the output trannies of a directly coupled SET are much greater than, say, for the power tranny. This does not mean that a bad power tranny will do. -akhilesh
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OPT Iron [message #8748 is a reply to message #8746] |
Wed, 26 January 2005 04:49 |
PakProtector
Messages: 935 Registered: May 2009
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Illuminati (2nd Degree) |
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Hey-Hey!!!, Sorry, I must disagree with the idea that a good OPT is only going to really benefit a DC SE amp. Not my experirience. I have found that PP requires the same sort of consideration. Even for measured paramenters like leakage L and capacitance. It is not just OPT's, other signal Iron is also very dependant on its construction details for excellent sound. Good sound is easy. Four triodes, two or them low mu power valves like 2A3, a good OPT. With some careful design, and implementation, we can make the leap to excellent. We could just as easily start with EL34, 1619, 807 or 13E1... regards, Douglas
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Re: Why? [message #8753 is a reply to message #8750] |
Wed, 26 January 2005 08:20 |
akhilesh
Messages: 1275 Registered: May 2009
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Illuminati (3rd Degree) |
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HI Douglas, IN the standard transformer coupling, single ended situation, the major disadvantage of the method is the average DC current that flows in the circuit must be supported by the transformer, making the transformer relatively large so that it does not saturate due to the DC only. This is probably the most common output coupling method, as it is relatively simple. At quiescent conditions, the power supply voltage appears on the plate (minus a little loss due to the IR loss in the transformer. During signal conditions, the output swings above and below the supply voltage. akhilesh
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Re: Why? [message #8756 is a reply to message #8754] |
Wed, 26 January 2005 09:28 |
TubeCraft
Messages: 30 Registered: May 2009
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Baron |
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"So in the parafeed you need to replace an expensive transformer with an expensive large choke.." Don't forget it could be a simple resistor, or an itty-bitty CCS... (I like the sound of the resistor-loaded version best. Yeah, they'll both need more HT.) TC
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