[DIY] 6AS7GA OTL 2x90W

[StevenYen]

1.PCB: 14PCS (150mmx100mm).
2.Input: RCA or XLR
3.Output Power: 90W
4.GE6AS7GA: 24pcs
5.ECC82: 6pcs
6.ECC83: 2pcs
7.High voltage delay protection
8.OTL dedicated speaker protection

 

[Tjj226]

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[StevenYen]

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[StevenYen]

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[savu]

circlotron ?

 

[StevenYen]

Circlotron valve amplifier is a type of power amplifier utilizing symmetrical cathode-coupled bridge layout of the output stage. Original circlotrons of 1950s used output transformers to couple relatively high output impedance of vacuum tubes to low-impedance loudspeakers. Circlotron architecture, easily scalable, was eventually adapted to operate without output transformers, and present-day commercially produced circlotron models are of output transformerless (OTL) type.

 

[astouffer]

Very nice work! The 6AS7 seems to work much better than the 6080 for OTL.

 

[bOTL]

According to a friend the only true 6AS7 is the Coke bottle shape style. If it's straight sided it is most likely a 6080 marked 6AS7. He manufactures the Messenger Pre Amp and swears the 6AS7 Coke bottle NOS sound slightly better than the straight sided 6080/6AS7. I have no horse in this race just passing on info.

 

[6A3sUMMER]

24 6AS7 tubes . . .

Filament 6.3V @ 2.5A = 15.75 Watts
24 Filaments x 15.75 Watts = 378 Watts!

How much wattage does the B+ have to provide to get 90 Watts times 2.

Do not let the Green Power Police see that amp.

 

[StevenYen]

American GE original box 6AS7GA is made in the 1960s, brand new original box, real NOS, very good sound, fine and soft sound, comprehensive, very good charm, solid low frequency, good dynamics, full mid frequency and good high frequency extension.It is a rare tube.