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Old 29th February 2012, 01:40 PM   #281
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In my opinion, these voltages are applied to a smaller laying(noise). I did the heat stabilized in another scheme. simply on the ground the output stabilaser is connect with voltage(-150). Do not connect this pointe with common ground .
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Old 2nd March 2012, 12:58 PM   #282
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Hi Dimitry,

What do you mean by:
In my opinion, these voltages are applied to a smaller laying(noise)
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Old 2nd March 2012, 06:13 PM   #283
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Sorry for my english . I cannot find right translation. I mean this additional voltage for shift heat lamp just for subtruction noise from power supplise (syn 50 hz). It should special term for this noise but I cannot finde this word for translation from Russian . sorry
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Old 2nd March 2012, 06:14 PM   #284
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I understand, thanks.
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Old 27th December 2012, 10:21 AM   #285
rudrud is offline rudrud  Finland
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I want to put instead C8-C11 one C = 2200-250V, as discussed in the NN51-54. What resistance should be put in place of R23-R26?
Thank you!

Merry Christmas and Happy New Year!

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Old 27th December 2012, 06:34 PM   #286
djn is offline djn  United States
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I am glad you brought this thread back up Rudolf. I now have time to work on my projects and I am making two chassis for this amp. One for the power supply and one for the signal side.

I have the room and like the looks of aluminum oil can caps. Does anyone know if the 6800uf caps can be found in oil cans??? I just like the looks of those sticking up out of the chassis.
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Old 8th February 2013, 09:06 PM   #287
gionag is offline gionag  Italy
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I also would like to begin to build this beautiful project of Tim ... maybe updated with 4 tubes per channel.

I was doing some calculations on the fly, and I think, just like that, the power transformers are slightly undersized. I have pretty much a given (if i am not wrong) that the power supply is common to both channels. Especially in the section of the heaters of 6C33C.

What do you think about that?

Thank you,
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Old 5th May 2013, 10:59 AM   #288
koldby is offline koldby  Denmark
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Originally Posted by trondareo View Post
Has any body tried Tims design with Magnepan speakers=4ohm? Im really tempted to try out the design, but my main speakers are the Maggies. (only ones the gold wife will have in the livingroom)
How about these speakers, would that be somethig your wife could accept?
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Old 22nd May 2013, 02:54 PM   #289
nafunga is offline nafunga  United Kingdom
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I have built 2 amps using the Tim mellow design. One using 6C33c's and the other 6C41's, both written up on this site. Both have woked excellently for the past 3 years with no problems - until now! I,m writing this as my experience may be of some use to others should their Amp. have similar problems in the future. The symptom was that one of the 6C41's would overheat - glowing red, obviously drawing too much current - this had the effect of severely loading the positive 150v rail, reducing it to around 45v. The negative rail rose to around 255v. First thoughts were that the glowing valve was the cause of the fault, but it proved not to be. The problem with fault finding on this design is that because it uses direct coupling between stages, normal methods are difficult to use due to only having a short time to measure votages before damage occurs (or fuses blow!) Isolating a suspected stage is therefore difficult. After carefully 'cold' checking all likely (high value resistances) and finding nothing wrong, the EF86 driver's were changed - this, thankfully, cured the problem. Sometimes a substitution pay's off!


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Old 23rd May 2013, 07:45 AM   #290
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Hello, I have same problem as Nafunga... maybe i have to change ef86's as well. Is there anything else to do to make amp more stable? thanks.

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