Helps to ZV9

[Flecko]

Hi all,
I like to build the ZV9 and have some questions I could not answere myself by reading the other posts and searching the side.

1.Powersupply

-The board veteran and peter daniel designed looks like the ps circiut on ZV4. But what are the resistors between the caps for? I didn' found a description for that.

-Can I use cheap rectifiers for the rectifier bridge to ground?


2.Parts

-I like to build a very good version of the ZV9, hence I orientated my partlist on Peter Daniel's build. I am sure to use the black gate (100uF/50V) caps for all places where 100-220uF are needed.
The 3W resistors should be mills mra-5.

-I am not sure which resistors I should use in the other
places. Can you give me an advice what I shall use (further mra-5?)?

-Can I use 22000uF cap instead of the 10000UF coupling cap for c1?

-Should it be a four pole like jensen or aerovox t-network?
They are very expansive and look more like a fetish to me.

-Are they worth their money?

-For the parallel cap c7 i like to use a KP cap with aluminium foil. Good choice?

3.Cooling

-I have to use two heatsinks per channel from different sice because I like to use an enclosure I have.
Wich parts get hotter, the two IRFP240 or the lu1014 and the IRFP240?

4.PCB
since there are no pcb's available anymore, I have to do it myself.
-Is there a reason why some conductors are wider
than others (ground?, magnetical fields?)?

-Can I differ from that?

Thank you very much for your help
Greetings Adrian

[Ronnal]

1 The value of the resistors is mentioned in the scematic I got with the board. They are 1 ohm 3 Watt.

Sorry dont know about the rectifiers. I used cheap ones for mine, but havent fired it up yet.

2. I cant answer your questions on resistors, but I sure would love to see someone with knowledge answer this.

I wouldnt reccomend changing the cap ratings. That may disturb your bandwith and amp performance. I think I saw one thread where Mr Nelson mentioned that those caps didn need to be that big. I believe it was in the tread "help a newbie build a Zv9".

I believe 4pole caps are for tubes.

Use good audio grade caps for both C1 and C7.

3. This is mentioned in the white paper on Zv9. The casocode transistor Q2 and the j-fet emits the most heat.

4. The with of the conductor is related to how much current traves through that conductor, as well as the quest for low loss in certain paths... I would ask Veteran nicely if you could have a copy of the file. If you will ask an electronics company to make them, please arrange a group buy. It will bring down your cost and might improve the quoality of the print.

Good luck,
Ronald

[Flecko]

Thank you for your help Ronald.

If somebody can tell me where I can get the schematic of the powersuplly used in veterans board it would be very kind. It would even better if sombody could explain the sense of the resistors used in the ps
I just know the classical type of ps, transformer-rectifierbrige-capacitor. Since everybody seems to use the version with the resistors, it must be good???

Thank you and Greetings
Adrian

[Flecko]

Hi,
I got the schematic of the ps, must have lost sight of it last time I was on unisonus...a explanation still would be nice
Greetings
Adrian

[Ronnal]

To explain how the resistors help we should keep in mind the dual function of the capacitor bank.

The primary role is to ensure that the short term power need is met without loosing supply voltage.

The secondary role is to smoothen the voltage of the power supply, filtering the noise from the grid. I think this is vhere the resistors play a role. It can be argued if the resistors will dampen the primary funtion, but I dont think that 4 paralelled 1ohms will make that much of a difference

It is a huge propability that I am missing something as the Z9 is my first amp ever

Best regards,
Ronald