zen without feedback

[apassgear]

I would say that a CRC is not good enough. I could belive a CLC with at least 15mH.

 

[steenoe]

Good point Dave.

As a matter of fact, you are right, ofcourse As I said, I consider a pair of single driver speakers for this amp!

Steen

I’m sure you could find those caps at Digy Key, I guess 15mf at 35V are good enough. But you don’t have a US passport!!!

I wasnt looking for the caps Only the footprint for them in Eagle My passport is valid all over this globe I guess!! I deal with people from Japan, Taiwan, Canada, China, Italy....... Even the States This is a very nice hobby indeed, you get connected to people all over the planet I love that

 

[steenoe]

Circuit for the "Zen Single Ended Current Source Amplifier"

Apassgear, I like that schematic! Nice work
9240 CCS and regulated supply!!! Just my kind of thing Easy enough to modify my old ZenV1 (Somewhat modded allready)
I would like the Zener protection though! You never know when some dumb*ss comes along and fiddle with your setup

Steen

 

[Magura]

I would like the Zener protection though! You never know when some dumb*ss comes along and fiddle with your setup

Steen

Mostly damage is done by the resident dumb*ss

.....but that aside I agree that the zener protection is a good idea with no drawbacks.


Magura

 

[steenoe]

Mostly damage is done by the resident dumb*ss

Yep, the Girlie thingie.... Women and technic, I mean Come on You are doomed

Steen

Now if they could just learn the start sequense........

 

[Magura]

Now if they could just learn the start sequense........

Monkey see, monkey doo.....it's been known to work quite well on other spieces

Magura

 

[Ejam]

Apassgear Schematic

Looking at your schematic, I think there should be a 50k resistor to ground in front of the C6. In the original Zen schematic (TAA 2/94) this resistor was designated R9 (47k5). Also, if you look at the F2 manual's specs you'll see that the amp has a 50k input impedance.

Regards

Ejam

 

[steenoe]

Looking at your schematic, I think there should be a 50k resistor to ground in front of the C6. In the original Zen schematic (TAA 2/94) this resistor was designated R9 (47k5). Also, if you look at the F2 manual's specs you'll see that the amp has a 50k input impedance.

I did give a lot of consideration to R9!
But as NP say's, the input impedance for this is, quoting Mr Pass himself!!

As to input impedance, it will be the Gate resistor to ground

Read post #82 or there about!!
I figured R9 in the original circuit woudn't help?

Steen

 

[Blues]

The setting of the 200k pot will probably be just above 50k (thus setting the input 50k impedance) for a voltage on the Q1 Drain at around 12V. >50k will just about set the voltage gain at 16db or so.

 

[steenoe]

(thus setting the input 50k impedance)

Thanks a lot, Blues Now I see, .. the Gate resistor to Ground!! The pot

Steen

 

[steenoe]

This is totally OT, but I have just got to share today's event with you Guess what, my girl invited some of her friends over (Girls )
I did prepare a 3 dish dinner for them, so I am today's hero!! Take a look at these babes They loved my food, so I am happy

Steen

 

[steenoe]

One more pic! They loved the sound of my setup too
I kind of favor these two girls! Go figure why!!

 

[steenoe]

Just thought this thread could use a little color

Steen

 

[Dozuki]

I think you need to add one more 7.5 v zener to the string, you only have 30 volts with 4 of these, less 4 volts that the pass mosfet is going to drop. As the schematic stands you will have about 26 Volts, not the expected 33 as shown in the schematic. Other than that looks good

-D

 

[apassgear]

Just thought this thread could use a little color

Nice girls and party, I'm sure they loved you system. What could make a father more proud

 

[apassgear]

I did give a lot of consideration to R9!
But as NP say's, the input impedance for this is, quoting Mr Pass himself!! Read post #82 or there about!!
I figured R9 in the original circuit woudn't help?

Steen

To my thinking R9 of the original article only works as a termination for the source and could be needed if you use a low impedance one, and maybe an even lower value. It wont have any influence on the amp itself

 

[apassgear]

A protection zener could be used, the original Zen did have one, but subsecuent iterations did not. So to keep the Zen spirit did not add one.

I will add the zener protection, as an option, on a subsecuent revision of the circuit.

 

[Blues]

Here's more or less apassgear's F2 circuit with some ckt sims....+/-9Vmax, 2.8A bias, 5Wrms into 8ohms...just replace transistors with your favorite fets.

 

[Blues]

here it is..sorry.

 

[Blues]

Vout response at 8ohms...