hi to all,
i'm new here. i have few tubes myself and i want to make a tube amp but i can't fid the right schematik so i would be thankfull if someone could help. i scavanged 2 el84 tubes from old broken radios and whit them main transformator and the output transformators. i alsso have 1 6l6gc, ECC85, 3x EM08 and more frome old tv's a friend gave me. i would be realy happy if someone would help. thanx. the problem is mostly with the output transformator. it has 3 connections primary from the tube and 2 for a 4ohm speaker marked max power for 4 watts.
i'm new here. i have few tubes myself and i want to make a tube amp but i can't fid the right schematik so i would be thankfull if someone could help. i scavanged 2 el84 tubes from old broken radios and whit them main transformator and the output transformators. i alsso have 1 6l6gc, ECC85, 3x EM08 and more frome old tv's a friend gave me. i would be realy happy if someone would help. thanx. the problem is mostly with the output transformator. it has 3 connections primary from the tube and 2 for a 4ohm speaker marked max power for 4 watts.
I've no shortage of ECC85. There also must be a chnese sub, the Dared/Fat Boy/HCT hybrid amp uses them as pre-amp tubes.
Somewhere there is a site with a series of ECC85/EL84 amps. They are PP but might give some clues if you want to go stereo SE amp.
Thread: http://www.diyaudio.com/forums/tubes-valves/66755-wims-dc-el84-amp.html
updated URL to site EL84 DC coupled tube amp
If as DF96 says, it can drop into an ECC81 circuit, search out RH84.
dave
Somewhere there is a site with a series of ECC85/EL84 amps. They are PP but might give some clues if you want to go stereo SE amp.
Thread: http://www.diyaudio.com/forums/tubes-valves/66755-wims-dc-el84-amp.html
updated URL to site EL84 DC coupled tube amp
If as DF96 says, it can drop into an ECC81 circuit, search out RH84.
dave
Attachments
hehehehe lool well thanx for everything and trying to help me...
i jus brew up a low voltage amp out of those two el84 using only one i think that on's wor of ther's bed sound quality and just 2.4 plate current as shown on foto...
i just took some aligatorclips power supply... the gird current is shown on foto, the voltage driving the tube is ~25volts it's perfectly for my headphones.
i have that feeling that somethings is bad but it's working... pretty good sound tough! if i done something wrong just say so...
OMG! i can't upload the immage!
i jus brew up a low voltage amp out of those two el84 using only one i think that on's wor of ther's bed sound quality and just 2.4 plate current as shown on foto...
i just took some aligatorclips power supply... the gird current is shown on foto, the voltage driving the tube is ~25volts it's perfectly for my headphones.
i have that feeling that somethings is bad but it's working... pretty good sound tough! if i done something wrong just say so...
OMG! i can't upload the immage!
Don't use ECC85 for audio (unless you want to experiment). The are UHF variable transconductance (= nonlinear) triodes. They are designed so that the AGC circuit adjusts their gain by varying the grid voltage. They will distort the audio signal. Better alternative is the ECC88 (lower gain) or ECC83 (higher gain). You can use also ECC81, ECC82, and you can find circuits also with ECF86, etc.
The ECC85 data sheet does not mention AGC. Example circuits for VHF front-ends using ECC85 usually omit AGC. The mutual characteristics for the ECC85 and ECC81 look very similar. The 85 really is an 81 with internal screen and different heater. Neither triode is particularly linear, but OK for small signals and possibly balanced circuits like LTP. ECC83 or 88 will be more linear in appropriate circuits.
ok i have a good schematic... but.... it's not good... as i connected the power tube as shown both way's i got red plated tubes... luky they're working...
the ecc 85 is pretty good as a preamp tube.
the first foto is the lov voltage amp... the big trafo is just for the fillaments...
later i expanded to stereo the sound was excelent...
the second should be the schematic with wich i got red plated tubes...
the ecc 85 is pretty good as a preamp tube.
the first foto is the lov voltage amp... the big trafo is just for the fillaments...
later i expanded to stereo the sound was excelent...
the second should be the schematic with wich i got red plated tubes...
Attachments
SUCCES!
so... after muh searching i finaly found 1 schematic that maybe good.
well let's hope that it is good...
just need to get all the parts.
i also scavanged some tubes aswell! many probably unusable but what can be done abut it.
so... after muh searching i finaly found 1 schematic that maybe good.
well let's hope that it is good...
just need to get all the parts.
i also scavanged some tubes aswell! many probably unusable but what can be done abut it.
Attachments
Here are another good schematic for an ECC85 and EL84 based amp EL84 Single Ended Amplifier D.I.Y .
I have buildt this amp two year ago and this little beauty are still playing, the opt are from edcor and mains from an old radio.
Anders
I have buildt this amp two year ago and this little beauty are still playing, the opt are from edcor and mains from an old radio.
Anders
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