# Zen Variations Part 2 Posted

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#### Nelson Pass

Paid Member
The Zen Variations Part 2: The Penultimate Zen's Current
Source has been posted on www.passdiy.com

#### jam

Thank you Mr.Pass.

Jam

#### carpenter

Thanks

Wow. This is a great read! I can't express my appreciation enough, Mr. Pass.

Thanks.

John Inlow

#### anelar

A very interesting read, I can't wait for more !

Thanks a lot mr Pass!

Ps. My Girlfriend wasn't that happy about it though she couldn't distract me for a couple of hours.

#### Asen

Very interesting indeed! But isn't the input impedance of the Zen-Aleph too low? And one more question - R5 is 4k7 or 47k?

Regards

#### lohk

Resistor values ?

Three digits and a multiplier is somewhat confusing: Multiply by Zero ?
Or does it mean 0 = x1, 1 = x10, 2 = x100 etc. ?

Can you enlighten us Master Nelson ?

Klaus

#### lohk

Ok, thanks Harry, I've just read it.
That makes sense, I just was a bit unsure and wanted some proof.
I think that value code do infact print wery well on small resistors, but I prefer the old convention with k and R for schematic diagrams. This seems easier to read (in terms of comprehension) for me.

Klaus

#### Geoff

Asen

Yes but, as NP indicates, wait for Part 4.

R5 is 47k5

Geoff

#### grataku

Ah, Nelson is trying to be cute, again. I have never been a big fan of the way in which the + lines are not connected but T are in the aleph schematics, either. Thank god he went back to the connecting dots. I guess he has the right to entertain himself. Personally, I think that the 3 digit plus multiplier is silly and dangerous. Why introduce an unnecessary degree of confusion?
I can see a bunch of people going out to buy 1k and 4752 ohms instead of 100 and 47.5K resistors and blowing stuff up. I suppose one could argue that's natural selection at work.
Whateva'.

#### mozfet

Zen Again!

Wow! pretty amazing, as a past Aleph 3 owner, I was just about to build an Aleph 30 (just bought 100 IRFP240) but the Aleph Zen should be even better, judging by comments various people have made, including NP, more 'life' more 'real' I gues I should build both, as the Aleph circuit really apeals to me, its funny but from comparing the circuits I would judge the Aleph 30 to be the more capable from a sonic point of view, Ho-Hum!

Big thankyou to Nelson Pass the Saint of Solid State! the Master of MosFets!

I cant wait for the final articles and the 'Pukka' Circuit board, No really I cant wait, I'm going to build one in a couple of weeks time!

Mozfet.

#### dieringe

I upgraded my Zen yesterday.
Yes, I bought 1000 Ohm resistors, and used
4.75k (2 means 2 digits back and a k?) for R5 first...

It should probably be indicated that the current you actually get with the "feedback" is 3A.
I made R1 bigger to have 2A again, as I think my
heatsinks are too small for 3.

I use IRFP064N for Q1, IRFP140 for Q2,
and ZTX653 for Q3. These are easier to get
here. Anything wrong with this?

The result is as it is told: better bass, much cleaner, more power. More like a "real" amp.
Thank you. I can't wait for part 4.

martin

#### Asen

Geoff

I'll wait for part 4, but this circuit has an input impedance of about 680-690 Ohms /20Hz-20kHz/, which means that it neads a follower in front of it. I'm not sure the BoZ would be a good solution.

Dieringe

Are you sure about the 4.75k resistor?

Regards

#### dieringe

Asen: of course it has to be 47k5. 475 and 2 zeros, just like the colour code.
with 4.75k you have Q1 conducting without input and get 5V or so at the drain of Q1 instead of 20V.

#### dieringe

Asen: I am driving it with a BoZ without problems (so far)

#### Asen

Dieringe

I asked you about the R5 because 4.75k is what you wrote in your previous post.

#### grataku

One more time (it's not going to hurt).
multipliers:
0=10^0=1
1=10^1=10
2=10^2=100
3=10^3=1000
etc.

the multiplier...multiplies: 5600 ohms or 5k6 would be 560X10^1=5601

examples:
3k9=3901
390k=3903
39R0=3.901 or 39.00 ain't that fu**ed up?
0R220=0.2200 (or 0.02201) vide supra for comment
As you can see it's not a nomenclature of general applicability, not everybody can or cares to measure one thousand of an ohm.

So if Nelson was consistent he would have used 2502 for the 25k trimpot, or talk about an impedance of 4702 for the future Zen Part 4.

#### Nelson Pass

Paid Member
Sorry about the confusion. I use RN55D's almost
exclusively, and that's how they are marked;
three digits and a multiplier, and using this
reduces my in-house confusion.

You have to admit, it does say so on each schematic.

#### janey

hello.
How this amplifier ( with aleph current source ) drive 4 ohm load.
If we run amp in balanced mode can the C1 and C4 be removed
from circuit.
Thanks

Janey

#### kimarin

Balanced Aleph Zen

Thats an interesting qustion. If you make 4 Zens and make a stereo balanced amp, could you then drive a 4 ohms speaker?

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