Where are the ZV9 builders???

[Fuling]

Thank you!
Those white caps are Rifa PH169 10000uF 70V, I got them from a friend who removed them from some telecom equipment.
The amp does quite a good job driving my speakers (CSS FR125S + Gamma BBK200 in sealed boxes with passive first order crossovers).

Still, I´m curious how it would sound with higher bias and a "passive" CCS (or choke loaded).

 

[Magura]

Still, I´m curious how it would sound with higher bias and a "passive" CCS (or choke loaded).

It will sound GOOD


Magura

 

[Fuling]

I believe you!

If i can locate (or wind) a pair of suitable chokes I´ll give it a try someday, otherwise I might get me a pair of big heatsinks and try a passive CCS version.

I do have some chokes at hand already but I´m not sure they´re suitable, I have four 112mH @ 2A and eight 25mH @ 3A.
I could use either 2x112mH per channel and watch out for saturation as the bias approaches 2A or 4x25mH and hope to get away with the lowish inductance.
The 112mH ones are EI cores about the size of 80VA transformers, the 25mH´s are smaller dual C-core types. Both types have airgaps.

A pair of 250mH 4A chokes on dual C-cores would be nice...

 

[Tyimo]

Chokes

Hi Fuling!

A pair of 250mH 4A chokes on dual C-cores would be nice...

Something like this....?

Tyimo

 

[Fuling]

Hi Tyimo!

Beautiful, where did you get those chokes???

 

[Tyimo]

Thanks!
They was in my junk box. I mean the SM120 hypersil iron set. The chokes are 185mH with very big (1mm) airgap and 1.32mm wire. Basicaly the whole amp made from "recycled" parts.
(The amp is not a ZV9....)

Greets:
Tyimo

 

[meanman1964]

Tyimo,

Very nice amp.I can't keep up with you
What kind of amp is that?

 

[Fuling]

Tyimo: I wish I had a junkbox like yours...
I can get EI cores and wire without problems, but C-cores would be cooler.

 

[Tyimo]

Hi Meanman1964!

Thanks!
This is the 30W version of my design, you know.....
I wanted to write you about it, but I need a couple of days to burning in.
In this weekend I will send you some info.

Greets:
Tyimo

 

[Tyimo]

Fuling:

I wish I had a junkbox like yours...

Oh, don't do it! My junkbox is almost empty now.
I have left over only 2 pair simple C-core set (400W) without bobin, a 4KV toroid, some caps around 100.000uF and couple of heatshinks. I don't know what to do with them...... Maybe a balanced version?

I think it would be good to open a Choke loading thread, where we could collecting the experiences.
What do you think?

Tyimo

 

[Fuling]

Tyimo: I have similar stuff in my junkbox(es), except that my biggest cores are 420VA EI-types and my biggest toroid transformer is "only" 750VA.

I think there are a few threads about L-loaded SS amps already, we could bring one of them back to life instead of starting a new one.

 

[flg]

...
I think there are a few threads about L-loaded SS amps already, we could bring one of them back to life instead of starting a new one.

 

[Fuling]

http://www.diyaudio.com/forums/showthread.php?threadid=108602&highlight=

 

[flg]

 

[Vix]

Hi,

I have a question for Steen:

Are you using your Zv9 with feedback (as in the original schematics), or without one? (with Aleph CS disconnected)

Lately I've been playing with my Zv9, and tried diferent value of feedback resistors...

At the moment, I got pleasing sound with those values:

R17: 31.7 K (27K +4.7 K)
R16: 2.7 K

Plus I connected 15 ohm resistor across the speaker terminals...

So I guess that I got something between a voltage and current amp, with miniscule amount of feedback...

 

[steenoe]

Hi Vix. I think you are on the right track. I am using mine without the Aleph CCS and with no feedback at all. I think this results in too much "Discobass" as we used to call it. Discobass is above 100hz! I cant blame NP for wanting to stuff the Abby's mouth with a half pound of dacron. I have also installed the recommended // filter. (10r/10uF/10r as far as I recall) I think the amp needs a little feedback, to tame the upper bass output. I could use a little more deep bass, but thats not possible from a 6" driver, so its all about smoothing the excisting soundstage.

 

[Vix]

Thanks a lot.

If you keep the original R17 at 47K, you can try 3.9 or 4.7 K for R16. Or, even better, place 2.2 K reistor + 4.7 Kohm trimpot in series for input R (R16. As you change it, the amount of feedback will change, thus affecting the gain, and , more important, tonal balance. Boiled water, I know, but the effect is interesting.

 

[Uselink]

Hi everybody!

I am not a professional in building such things. More amateur.
I try to build Zen 9 . This week i will make the PCB for the amp part. This is Peter Daniel type PCBs. But i have no any thoughts about good power supply for the Zen 9.
I saw many circuits of power supply but can not choose right.
Please give me advice what circuit i can use for it.

With the best wishes,
Aleksey.

 

[yggdrasil]

Finally finished my Zen 9. Have had it lying in the workshop almost finished for a couple of years.

Anyway I got the transformer and heat sinks a few weeks back, and here it is.

 

[VladimirK]

Here is my current version of upgraded Zen9. My new PMC EB1i power demanding loudspeakers are very happy with these monoblocks, excellent sound without any reservations even at the low end. Classic music, metal, jazz, organ, everything is amazing. The square wave picture is for 3,2Ohms resistive load, 15V peak-to-peak, 10kHz, C8=15pF. With C8=5pF the picture is still OK.