It's coming together -- showing the Maida regulator and the old RIAA section:
If you want to really, really nicely clean up a PAS chassis, try carburetor cleaner.
An externally hosted image should be here but it was not working when we last tested it.
If you want to really, really nicely clean up a PAS chassis, try carburetor cleaner.
Sure. Gain is 26dB (x20). Input is balanced or unbalanced, and depending on choice of transformer, 10k or 15k (can be made higher with a Zobel on the transformer secondary). Output is balanced, rated at 20V out (it was created for driving a balanced-in, unity-gain power amp). With a balanced load, output impedance is about 400 ohms. For a single ended load, the inverting output alone is taken.
OK -- took it for a test drive on the bench -- SY reported -68dB 2nd Harmonic, -92dB 3rd Harmonic. The one shown here measures -69 dB, -103 dB 3rd ! All of the R11, R12 resistors I purchased from Mouser came very tightly grouped around 15K.
I used Electro-Harmonix 6SN7 and 6922 -- the transformer I have is not center tapped so I wired the heater in series and raised one leg by the B+.
I used Electro-Harmonix 6SN7 and 6922 -- the transformer I have is not center tapped so I wired the heater in series and raised one leg by the B+.
An externally hosted image should be here but it was not working when we last tested it.
I know that SY likes the non-Darlington version of the Maida for its simplicity. For the cost of another TIP transistor, LM329 and a couple of resistors you can get the souped up version. I showed a single-sided design here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=142420&highlight=
It's much easier to get the parts if you use 2 3-watt resistors to set the voltage.
I am going to have these boards burned as well.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=142420&highlight=
It's much easier to get the parts if you use 2 3-watt resistors to set the voltage.
I am going to have these boards burned as well.
Instead of "Irish step dancers" these depletion MOSFETs remind me of the ladies on the IRT-Lexington Ave. subway going back uptown after a hard day in the canyons of Wall Street:
An externally hosted image should be here but it was not working when we last tested it.
