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[gaborbela]

Hello Jap

I only can open the first attachment.
That is a very well described site , even PC board layout! I think I can use it!!
Thank you very much

Greetings gabor

 

[soundbrigade]

Hello

Can someone help me with a good 6L6GC tube amp schematic, please.
Something not over complicated.

How about this one?
Ming Da MC34B

 

[gaborbela]

Suondbrigade that very nice!
Thank you
I only miss the OP primary (8K or 6K?)
Also any idea the 6L6GC heater VA rating.
Greetings gabor

 

[VictoriaGuy]

Also any idea the 6L6GC heater VA rating.
Greetings gabor

Google '6L6GC tube specs' and you will find something like this which will give you 'typical' operating conditions.
Heater is 0.9A @ 6.3 volts

 

[VictoriaGuy]

How about this one?
Ming Da MC34B

Thanks, Magnus. Filed away here.....

 

[soundbrigade]

Gaborbela: Around 6K Raa.
Plz note that this one runs in classA and therefore produce lower power than a more traditional class AB.
There's however a slight modified version Ming Da MC34B schematic mod 1.

 

[gaborbela]

Thank you very much.
All resistors are 1/2W?
You know if I purchase the parts Tubes, Irons,etc is good to know I have a schematic I can finish it.
I think a pair 6L6GC even in Class A mode would gave me more than enough power.
I'm after the sound quality not just power. 5-10W more than enough.
Greetings gabor

 

[soundbrigade]

I'd go for 1W in most cases unless stated otherwice.

 

[Miniwatt]

And now back on topic..

 

[PMA]

I owed a photo of a tube preamp

SRPP+ with several mods, to work as a line stage. Great PCB, John!

 

[mhouston]

PMA: You appeared to have used a sealed out-door power tranni. Any reason for this?

 

[PMA]

No special reason. This is just a sample evaluation and I had that transformer in stock.

 

[mhouston]

Some of the more experienced builder use EI power trannis and not toroid. They claim more iron makes them better.

 

[Bas Horneman]

They claim more iron makes them better.

It's not the iron that makes them better.

Toroids couple noise from the mains to the secondary because of capacative coupling moreso than EI apperently.

 

[mhouston]

Supposedly less iron makes them cheaper to make. With our local power owned by a private compnay they are allowed to push the mains trannies to 110% capacity to your house. Therefore noise on the mains is higher.

 

[PMA]

No comment on iron

The remark on lower coupling capacitance of the EI transformer is correct.
Toroidal transformers have usually 5 - 10x higher coupling capacitance, but, on the other hand, emitted electromagnetic field is lower, so less troubles with magnetic field interference coupling.

 

[jorgovanko]

One more 12B4A preamp

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

One of the best line stages!

Cheers

 

[nigelwright7557]

SRPP valve front end with class D output.

An externally hosted image should be here but it was not working when we last tested it.

 

[Bas Horneman]

One of the best line stages!

Wow! Lots of work went into that. Looks real neat with all the pcb's.

 

[boywonder]

One more 12B4A preamp

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

One of the best line stages!

Cheers

Wow, impressive! That's really nice right down to the motor driven attenuator. Sweet!