DIY F2 clone

[jacco vermeulen]

Originally Posted by Tea-Bag

L=8/6.28*10000hz I get .000127 which I think is

0.127mH

[Tea-Bag]

Originally Posted by jacco vermeulen

0.127mH

Thanks Jacco,
I am afraid to do first order, somethin with no cap - I would like to put cap in there. Well other xover is second order.

[OllBoll]

One thing I've thought about is the power supply of the F2J, I already have a fairly good CRCRC supply so I wonder how much of the top part I can skip and how much I need to keep.

If I understand correctly I can skip atleast R23-R26 but can I skip more of the circuit? And is LED1, C6 and R22 needed for the circuit?

[OllBoll]

Another thing I've wondered is about the load impedance.

I'm planning on biamping 2x 8 ohm mids. I will remove the parallel resistor since I want a current source with as high output impedance as possible to reduce driver distortion.

The question though is if I would get better performance from connecting the mids in series or if I should parallel them. If I've understood correctly the best would be to connect in series but I'm no expert so I might as well ask here =)

[generg]

Originally Posted by OllBoll

One thing I've thought about is the power supply of the F2J, I already have a fairly good CRCRC supply so I wonder how much of the top part I can skip and how much I need to keep.

If I understand correctly I can skip atleast R23-R26 but can I skip more of the circuit? And is LED1, C6 and R22 needed for the circuit?

I think LED1 and R22 are not needed, C5 (i did not see C6) reminds me of the 10uF at the output of the BA PSUs, I suppose not bad against oscillation.

No, I do not think you can skip more, the remaining parts are all important for the CCS with the upper IRF.

But the anti plopp might be either the combination of C4 and R21.

Or are R23-26 also important for this function?

[OllBoll]

Originally Posted by generg

I think LED1 and R22 are not needed, C5 (i did not see C6) reminds me of the 10uF at the output of the BA PSUs, I suppose not bad against oscillation.

No, I do not think you can skip more, the remaining parts are all important for the CCS with the upper IRF.

But the anti plopp might be either the combination of C4 and R21.

Or are R23-26 also important for this function?

It seems I read the schematic wrong at first, I thought I saw that C6 was included with R22 and the Led, which I also foun strange

But aren't R23-26 just like the series resistors in a normal CRC psu, like the one recommended for the F5? So I who already have a CRCRC can skip them since they won't add any real value.

[generg]

yes I think also the R23-26 are not capable to do a real delay for the plop

I just saw I took the old circuit and you the new one ......

therefore we mess up C4 and C6

[Spooky Electric]

Originally Posted by OllBoll

...they won't add any real value.

Hmm, just a little inductive coefficient. Easy (and cheap!) enough to checkout how this precious performs with or without it...

[OllBoll]

Another thing I've thought about:

Is it okay if C4 and C6 are say 20 cm away from the rest of the circuit?

I would prefer the amp to be as flat as possible for ease of mounting, so I thought I'd move the big capacitors to a kinda buffer-board ~ 20 cm away.

And secondly, is there a reason C4 and C6 are exact those values? Would it be a problem to exchange them both with a single one with a much higher value?

And thirdly, is the 24V V+ supply in the schematic expected to be raw output from an 18V transformer or is it expected to be filtered with say a CRC?

[generg]

Originally Posted by OllBoll

Another thing I've thought about:

Is it okay if C4 and C6 are say 20 cm away from the rest of the circuit?

I would prefer the amp to be as flat as possible for ease of mounting, so I thought I'd move the big capacitors to a kinda buffer-board ~ 20 cm away.

And secondly, is there a reason C4 and C6 are exact those values? Would it be a problem to exchange them both with a single one with a much higher value?

And thirdly, is the 24V V+ supply in the schematic expected to be raw output from an 18V transformer or is it expected to be filtered with say a CRC?

I do not know if you can put the caps so far away, but why not simply trying it? Connected with a thicker cable ....

As you can see in the two schemes I posted the C6 was added later, maybe to make less hum or the plopp still lower, I would say you can combine....May be for lower ESR!
Yes of course after the rectifier you need CRC!