6LU8 Push-pull power amp and other builds

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Re: 6LU8 Push-pull power amp

Postby tony » Sun Dec 04, 2011 9:36 pm

^thanks, i am on a roll......lot's of amps to build....i have an upcoming 4D32 pp amp, 2A3 SET's, 6C33 SETs and PP, etc.....
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Re: 6LU8 Push-pull power amp and other builds

Postby tony » Fri Dec 30, 2011 9:47 am

blue, blue, my traffos are in blue:

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8k a-a primaries to 4/8/16ohm secondaries:
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with power traffo:
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4k a-a primaries to 4/8/16ohm secondaries:
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with power traffo:
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two sets of irons for two amplifiers:
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Re: 6LU8 Push-pull power amp and other builds

Postby lovejbl » Sat Dec 31, 2011 4:38 am

masarap magpatunog dyan ng blues music ha, pare ko email mo sa aking ang mga tubo maaring ma resource natin dito para maiuwi dyan. Happy New Year sa iyo and Family!
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Re: 6LU8 Push-pull power amp and other builds

Postby tony » Sat Dec 31, 2011 7:17 am

Happy New Year din to you and family......

right now i can think of 813's, when trioded, this is equivalent to an 845 or even GM70.....mu or amplification factor is even better at 8 to 4 or 5 of the 845/GM70.......this tube will be easier to drive......the added bonus is that tube is directly heated cathode type..... 8)
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Re: 6LU8 Push-pull power amp and other builds

Postby tony » Sat Dec 31, 2011 10:10 am

btw, these traffos are to be used on a 6V6 push pull amps, i got ST bottle tubes from Edrel.....the other set for a 6KD6 screen grid drive push-pull amp....
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Re: 6LU8 Push-pull power amp and other builds

Postby lovejbl » Sat Dec 31, 2011 10:59 am

tony wrote:Happy New Year din to you and family......

right now i can think of 813's, when trioded, this is equivalent to an 845 or even GM70.....mu or amplification factor is even better at 8 to 4 or 5 of the 845/GM70.......this tube will be easier to drive......the added bonus is that tube is directly heated cathode type..... 8)


cige hanap tayo!
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Re: 6LU8 Push-pull power amp and other builds

Postby romymartinez » Sun Jan 01, 2012 11:39 am

Nice creations Sir Tony!
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Re: 6LU8 Push-pull power amp and other builds

Postby tony » Wed Jan 04, 2012 10:29 am

opening 2012, i finished rehab of a Sansui BA202 power amp, since this amp used the 6RA8 triode tube which has become obsolete, the 6GK6 pentode was used instead to replace the triode and run in pentode mode.....the EL84/6BQ5 can also be used.....power is up 15 watts against the 11watt per channel original spec for the amp.....

the 6AQ8 can be replaced by 6GU7, 6CG7, 6BK7, or even a 6N1p.....

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Re: 6LU8 Push-pull power amp and other builds

Postby tony » Sun Feb 26, 2012 3:04 pm

just finished today, playing Rubber Soul album by the Beatles:

6922 buffer as first stage, 6BH11 pentode, dual triode in LTP drive....a Mullard 5-20 configuration.....except pentode mode, with screens supplied from a 2SK2563 mosfet regulator at 270 volts....plates are idling at 9watts each, cathodes are at 30mA each.....this amp is a combination fixed and self bias....

3DG4 full wave rectifier complimented by 1N4007 silicon rects.....

the 6V6 st bottles were made by Penta-Labs....Edrel have these tubes...

this power amp does not need a preamp... 8)

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Re: 6LU8 Push-pull power amp and other builds

Postby tony » Fri Mar 02, 2012 9:41 am

update:

this is my Shuguang EL34 pp amp, ultra-linear output, based on the Mullard 5-20 and HK Citation V amps....sounds fantastic, bass is tight and controlled which is a revelation.....


B+ at OPT center lead is 445 volts, tubes are biased at 33mA each.....so that they are idling at about 15 watts each.....

the front end 6J9 tube B+ is zener regulated....it is very quiet, no hiss, no hum......Hitachi 6CG7 LTp drivers....

solid state psu with big capacitor filtering, a common mode filter choke isolate the rest of the amplifier from the power supply, freds isolators ensures cross-talk between channels are minimized, with generous filtering psu ripple is held to a minimum.

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testing and setup:

fixed biasing with about 33mA on each cathodes put the tubes idling at about 14watts at idle....
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using my power monitor:
line current draw is shown:
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true power consumed at idling:
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apparent power draw:
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line frequency:
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line voltage:
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a look under the hood:
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Last edited by tony on Mon Mar 05, 2012 10:07 pm, edited 2 times in total.
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Re: 6LU8 Push-pull power amp and other builds

Postby obi » Fri Mar 02, 2012 2:33 pm

congrats on your 2 new builds sir tony!

ang lambing, pararang triode :)
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Re: 6LU8 Push-pull power amp and other builds

Postby tony » Wed Mar 07, 2012 10:01 am

this is the real triode....


2A3 SET update:

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a cascoded CCS using depletion mode mosfets in a pcboard remains to be installed:
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Re: 6LU8 Push-pull power amp and other builds

Postby camotecue » Wed Mar 07, 2012 10:42 am

tony wrote:this is the real triode....


2A3 SET update:

Image
Image
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a cascoded CCS using depletion mode mosfets in a pcboard remains to be installed:
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nice!
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Re: 6LU8 Push-pull power amp and other builds

Postby geriboy » Sat Mar 10, 2012 10:05 pm

camotecue wrote:
tony wrote:this is the real triode....


2A3 SET update:

Image
Image
Image

a cascoded CCS using depletion mode mosfets in a pcboard remains to be installed:
Image
Image


nice!


x2! :D
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Re: 6LU8 Push-pull power amp and other builds

Postby bass_nut » Sat Mar 10, 2012 11:26 pm

always inspiring to visit your pages and view your projects, kuya Tony !! 8)
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Re: 6LU8 Push-pull power amp and other builds

Postby tony » Sun Mar 11, 2012 9:08 am

bass_nut wrote:always inspiring to visit your pages and view your projects, kuya Tony !! 8)


Thanks Doc Fer,

will you be interested is say a qaud GU50 pp amp for 200 watts? or a pair of GM70 push-pull for the same power? these Russian Tubes are the bang-for the buck tubes, especially the GU-50....

i also have a quad of QE08-200 which can make 300watts, but sadly, these tubes are very rare and expensive...
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Re: 6LU8 Push-pull power amp and other builds

Postby s2kov » Sun Mar 11, 2012 11:05 am

This amp is easy to build for you! :rock: :rock:

Can't wait to see PSE amp! :lol: :lol:


tony wrote:this is the real triode....


2A3 SET update:

Image
Image
Image

a cascoded CCS using depletion mode mosfets in a pcboard remains to be installed:
Image
Image
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Re: 6LU8 Push-pull power amp and other builds

Postby tony » Sun Mar 11, 2012 12:53 pm

thanks Andy, ano nga ulit yung PSE amp? :D
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Re: 6LU8 Push-pull power amp and other builds

Postby bass_nut » Sun Mar 11, 2012 1:07 pm

tony wrote:
Thanks Doc Fer,

will you be interested is say a qaud GU50 pp amp for 200 watts? or a pair of GM70 push-pull for the same power? these Russian Tubes are the bang-for the buck tubes, especially the GU-50....

i also have a quad of QE08-200 which can make 300watts, but sadly, these tubes are very rare and expensive...


type na type natin iyan 200wpc p/p with inexpensive and readily available tubes, kuya Tony :clap: :clap:
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Re: 6LU8 Push-pull power amp and other builds

Postby Voltraizer » Sun Mar 11, 2012 2:09 pm

bass_nut wrote:
tony wrote:
Thanks Doc Fer,

will you be interested is say a qaud GU50 pp amp for 200 watts? or a pair of GM70 push-pull for the same power? these Russian Tubes are the bang-for the buck tubes, especially the GU-50....

i also have a quad of QE08-200 which can make 300watts, but sadly, these tubes are very rare and expensive...


type na type natin iyan 200wpc p/p with inexpensive and readily available tubes, kuya Tony :clap: :clap:

doc, meron akong naamoy na matinding project ah 8)
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