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 NEW  Matt presents bias and operation data for the 6V6 tube in SE operation - 6V6 Single-Ended (SE) Ultra Linear (UL) Bias Optimization.

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PostPosted: 16 Jan 2010, 22:21 
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Joined: 28 Oct 2009, 02:34
Posts: 501
Location: Utrecht Nederland
Thanks Azazello,

I will try that, but maybe my power transformer cannot handle the extra load, I have 275 Volts B+ idle, now under load I have got 205 volts, if I increase the load more, my B+ will drop under 170 volts I am afraid. I have no ccs, cause the LM317 eats too much current on it's own and B+ drops to 120 volts, I tried. Next amp I will build I will use better transformers.

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Greetings from Holland, Ben

My DIY Audio Projects:
- Single-Ended 12B4A tube amp with ECC802S driver
- DIY Push-Pull KT88 tube amp (OddWatt amp from scratch)
- 832 / GU32 tube push-pull amplifier project


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PostPosted: 17 Jan 2010, 00:49 
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Joined: 28 Oct 2009, 02:34
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Location: Utrecht Nederland
Hi everybody,

well, I changed the cathode resistor to 605 ohm and I have now 32 ma cathode current at 190 Volt B+. Good enough for me.

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Greetings from Holland, Ben

My DIY Audio Projects:
- Single-Ended 12B4A tube amp with ECC802S driver
- DIY Push-Pull KT88 tube amp (OddWatt amp from scratch)
- 832 / GU32 tube push-pull amplifier project


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PostPosted: 17 Jan 2010, 07:21 
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Joined: 28 Oct 2009, 02:34
Posts: 501
Location: Utrecht Nederland
Hallo everybody,

here is the final schematic, also from the PSU. I replaced the 2nd filter cap with a 220 uF and added a 0,01 poly cap. That reduced the rest of the ripple to virtually nothing, even with sensitive headphones. I use the amp as a headphone amp, because it sounds so nice. It definitely sounds much better than my headphone amp kit, and this one is a real tube amp. This is defenitely worth building, if you have stuff laying around and are bored, build this little amp. I build mine over the weekend and perfected it over one week. You can start with a pretty perfect version and maybe make it even better. Here are the final schematics from the amp and PSU. Have fun.


Now, this setup works for me, I have now 32 mA current on the cathode and still 193 Volts of B+. If you have a better transformer, you may have to juggle the cathode resistor to not fry your tubes. Mine is now good enough, I wanna start something new. This one was a total success.

Thanks to all my friends, by name Bruce and Magnus and Nikola for their help and suggestion. Thanks guys.


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_________________
Greetings from Holland, Ben

My DIY Audio Projects:
- Single-Ended 12B4A tube amp with ECC802S driver
- DIY Push-Pull KT88 tube amp (OddWatt amp from scratch)
- 832 / GU32 tube push-pull amplifier project


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PostPosted: 17 Jan 2010, 10:14 
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Joined: 24 Feb 2009, 03:24
Posts: 562
Location: USA
Hi, BEN!
195 v are small for SRPP ECC83 for linear mode. You have for good sound 2 ways:
1. Use only 1 triode section of ECC83 or
2. Use ECC88 /PCC88/ in SRPP with resistors 220 ohm in cathodes.

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Hi End is back proportional to the number of composite parts!
Projects: OTL 6AS7 Gen, Electric, SEs 2A3 RCA, 300B JJ, 6S4S, 4P1L, EL11 Telefunken, 6AS7 RCA, 6S33S, 6S41S, 6S19P, PP 6005 Gen. Ellectric , headphone ampl. OTL Loftin White 6AS7 RCA....SE E84L& E80CC Siemens&Tel-n.
http://azazello-sound.blogspot.com/


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PostPosted: 17 Jan 2010, 11:02 
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Joined: 28 Oct 2009, 02:34
Posts: 501
Location: Utrecht Nederland
Hi everybody,

well Nikola, this amplifier is as good as it gets, the following will have a better power supply and ccs and a LM317, very important, that really helps thge sound always, did you ever try? I will send you a couple.

_________________
Greetings from Holland, Ben

My DIY Audio Projects:
- Single-Ended 12B4A tube amp with ECC802S driver
- DIY Push-Pull KT88 tube amp (OddWatt amp from scratch)
- 832 / GU32 tube push-pull amplifier project


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PostPosted: 24 Jan 2010, 19:28 
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Joined: 01 Sep 2009, 19:10
Posts: 29
Ben--

This amp looks way cool. Thanks for the PM message about it. I have many of the parts. thx again!!


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PostPosted: 24 Jan 2010, 19:39 
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Joined: 01 Sep 2009, 19:10
Posts: 29
Soundbrigade wrote:
If it was the trannies I sent you, I can send you more.

Hello - I would like to start looking for parts to build this amp. If you are the source for these trannies, please tell me about them and how I can obtain them. thank you!


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PostPosted: 25 Jan 2010, 03:09 
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Joined: 02 Mar 2009, 12:41
Posts: 1110
Location: Vänersborg, Sweden
The trannies are simple 100V line transformers. I have no other info than this given on Conrad.de website: http://www.conrad.de/goto.php?artikel=516104.
I got a package of transformers from a friend in Sweden and it is from this package I have sent
The transformer is a special one mainly used for distributing sound into wharehoses and factories on a 100V signal. As the OP-signal is pure AC, the transformers contain no airgap and can only be used in low wattage amplifiers.
Guess you can grab this one almost everywhere.

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Magnus

“If you don't know where you are going, any road will get you there.”
―Lewis Carroll


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PostPosted: 25 Jan 2010, 12:45 
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Joined: 01 Sep 2009, 19:10
Posts: 29
Thanks for the info on the OT. What load impedence is used for the 12B4 at Ben's this operating point? thx again.


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PostPosted: 26 Jan 2010, 11:38 
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Joined: 28 Oct 2009, 02:34
Posts: 501
Location: Utrecht Nederland
Hallo everybody, hallo Moonbird,

sorry for not following the thread, but I have been busy with my KT88 amp, now finished and rocking.

I know nothing about the specs of those opts, just that I got really lucky with them in combination with the 12B4A's. That little amp turned out to be a real audiophile amplifier and I didn't plan on doing that, it was supposed to be my wifes TV amp, not very loud, but easy and ever lasting, but upon listening to it I found out what I really created (with the help of Nikola and Bruce). If you wanbna build this amp, ask Magnus about the specs or where to get those. I got one more set, but those are for Nikola, sorry. Anyway this amplifier is defin itely woth building, mine is running day and night ni my living room, it is now my main amplifier. Have fun.

_________________
Greetings from Holland, Ben

My DIY Audio Projects:
- Single-Ended 12B4A tube amp with ECC802S driver
- DIY Push-Pull KT88 tube amp (OddWatt amp from scratch)
- 832 / GU32 tube push-pull amplifier project


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 Profile  
 
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