The Amp Garage

roberto wrote:

Could a 12AX7 in parallel with resistor replace a 12AX7?

12ax7 or 12ay7?

Thanks, I corrected the mistake.

Just an idea! The internal resistance of a 12X7A triode will diminished by a 39kOhms resistor in parallel to the plate and cathode terminals to about 24kOhms. In that case the amplification factor is diminished to 1,6 mA/V * 24 kOhms = 38. The internal resistance of the 12AY7 triode is 23kOhms and t...

Anyone signal oscilloscop trace pictures of the OD-stage output for different input signal levels?

With respect, Manfred

Thanks to all for sharing and working out too.

With respect, Manfred

Many thanks too.

talbany wrote:Here a clip of my version of the Ripper!!

http://www.youtube.com/watch?v=nsGTsGJEz1A

Tony

The Link is not available for Youtube Germany.
There is a GEMA problem message.
Is a sound clip also availabel?

I found by simualtion that the power transformer secondary voltage must be about 220 Volts AC for the B+ 240 Volts DC.
Is that correct?

Thank you for the information.

The PT I have taken out of an old Radio

How much is the secondary HT Voltage value of it?

Which type of PT and OT is using in this amp?

Great sounding!
Thanks Honeydip for sharing the schematic.
Thanks 10thTx for redrawing the schematic and creating the layout.
Well done.

Is this one a Komet too?

hi bepone,

did you change any parts for the EF86 -> EF80 replacement.

cheers
Manfred

Without the resistor the EF86 works in the tirode mode.
In that case the 0.066 capacitor acts as "snubber".
I think that value is to high then.

Hi Mat,

thanks for the information!

cheers
Manfred

Is the screen gird of the 5879 really not connected?

Manfred