The F5X Preamp - Page 5

EUVL · 14th December 2012, 10:28 AM

Part 2 on active devices, as promised.
Here a new pdf to combine both Part 1 & 2.

Enjoy,
Patrick

.

Samuel Jayaraj · 14th December 2012, 05:40 PM

Patrick, thanks for sharing. Just like the input devices, make some allowance of alternative output devices, including the Toshiba 2013/313 pair. Thanks.

CeeVee · 14th December 2012, 06:29 PM

Patrick,

Renesas 2SJ 76/77/78/79 and 2SK 213/214/215/216 are announced EOL

do you have any idea where there might be some genuine ones still ?

Fakes abound as usual.

Horio · 15th December 2012, 02:24 AM

If the plan is to offer both matched input and output FETs to case/project subscribers, I have a feeling that Patrick has already secured a nice stash of 2SK214/2SJ77's.

EUVL · 03:54 AM

Yes, we have enough genuine, tested devices to support at least 2 batches of this project, if not more.

They were unfortunately not too cheap. Purchase price was already ~4€ apiece.

We have very limited 2SK2013/2SJ313, and they are not pin compatible.
So it will need a new PCB and can only be supported as a limited option for those who desperately want to experiment.
Unless Mr. Zhou answers his email, whenever .....

We are also searching for other devices which are better complementaries than the above two.
But this will take time. So even if successful, it will come a year later as potential upgrades.

Default will be Renesas laterals.

Patrick

EUVL · 24th December 2012, 06:18 AM

Some more reading material for Christmas.

Merry Christmas & Happy New Year,
Patrick

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wuffwaff · 08:14 AM

Thank you Patrick,

my first christmas present this year!

One remark concerning the attenuator. -48dB seems not to be very much. I´ve got a bit over -60dB at the moment (from a X-BOSOZ with Gain 3.9x) and in some combinations (Zu Druid, NCore400) this is only just enough.

cheers,

William

EUVL · 24th December 2012, 08:03 AM

Pleasure.

Patrick

EUVL · 24th December 2012, 08:47 AM

Re attenuation :

You can always change the values by dividing the shunt resistor further by 2, or 4, or ....
You total range remains the same, limited by the 8 bit relays.
Or you can step them by a factor of 3, like 30k, 10k, 3,3k, 1k, 330R, 100R, 33R, 11R.
Then you will get -65dB.
Will need a different look-up table, but not impossible.

Patrick

wuffwaff · 24th December 2012, 09:06 AM

That's fine. Maybe I can even use my programmer again......

William

14th December 2012, 05:40 PM	#42
Samuel Jayaraj diyAudio Member Join Date: May 2001 Location: Bangalore, India	Patrick, thanks for sharing. Just like the input devices, make some allowance of alternative output devices, including the Toshiba 2013/313 pair. Thanks. __________________ Sam

15th December 2012, 03:48 AM	#45
EUVL diyAudio Member Join Date: Oct 2003	Yes, we have enough genuine, tested devices to support at least 2 batches of this project, if not more. They were unfortunately not too cheap. Purchase price was already ~4€ apiece. We have very limited 2SK2013/2SJ313, and they are not pin compatible. So it will need a new PCB and can only be supported as a limited option for those who desperately want to experiment. Unless Mr. Zhou answers his email, whenever ..... We are also searching for other devices which are better complementaries than the above two. But this will take time. So even if successful, it will come a year later as potential upgrades. Default will be Renesas laterals. Patrick __________________ xen-audio.com Last edited by EUVL; 15th December 2012 at 03:54 AM.

24th December 2012, 07:57 AM	#47
wuffwaff diyAudio Member Join Date: Aug 2001 Location: Ingolstadt Germany	Thank you Patrick, my first christmas present this year! One remark concerning the attenuator. -48dB seems not to be very much. I´ve got a bit over -60dB at the moment (from a X-BOSOZ with Gain 3.9x) and in some combinations (Zu Druid, NCore400) this is only just enough. cheers, William __________________ een ooievaar is geen konijn want zijn oren zijn te klein! Last edited by wuffwaff; 24th December 2012 at 08:14 AM.

24th December 2012, 08:03 AM	#48
EUVL diyAudio Member Join Date: Oct 2003	Pleasure. Patrick __________________ xen-audio.com

24th December 2012, 08:47 AM	#49
EUVL diyAudio Member Join Date: Oct 2003	Re attenuation : You can always change the values by dividing the shunt resistor further by 2, or 4, or .... You total range remains the same, limited by the 8 bit relays. Or you can step them by a factor of 3, like 30k, 10k, 3,3k, 1k, 330R, 100R, 33R, 11R. Then you will get -65dB. Will need a different look-up table, but not impossible. Patrick __________________ xen-audio.com


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14th December 2012, 06:29 PM	#43
CeeVee diyAudio Member Join Date: Dec 2006	Patrick, Renesas 2SJ 76/77/78/79 and 2SK 213/214/215/216 are announced EOL do you have any idea where there might be some genuine ones still ? Fakes abound as usual.

15th December 2012, 02:24 AM	#44
Horio Newbie diyAudio Member Join Date: Mar 2010 Location: San Francisco	If the plan is to offer both matched input and output FETs to case/project subscribers, I have a feeling that Patrick has already secured a nice stash of 2SK214/2SJ77's.

24th December 2012, 09:06 AM	#50
wuffwaff diyAudio Member Join Date: Aug 2001 Location: Ingolstadt Germany	That's fine. Maybe I can even use my programmer again...... William __________________ een ooievaar is geen konijn want zijn oren zijn te klein!

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