F5X -- the EUVL Approach - Page 22

NYCOne · 20th May 2011, 02:42 PM

Quote:

Originally Posted by CeeVee

These are very difficult to source, the 2sj74s i mean, i got some from AMB labs but they all have IDSS in the high 10mA range.
The matched sets from Spencer are in the same range.

2SK170BL in the 6mA and 7 mA range are easier to find.

I am very sympathetic to anyone doing a balanced build.

I have a large number of match JFETS in EVERY Idss range, even sets already matched for the degeneration difference. I did this for my builds.

Let my know by PM if you need a set of matched Octets, or if you would like two matched Quads.

I used an Octet, and have sent other Octets to other builders, but they are a much more difficult match, as you might imagine.

EUVL · 20th May 2011, 03:20 PM

May I suggest you open a thread at the swap meet forum for your very generous offers.

Most sincere thanks,
Patrick

Horio · 20th May 2011, 03:22 PM

I have a (150) 2SK170-BL's, and I've matched 50 of them. So far I have been getting a nice range of values with most of them in the 6-9mA range. Hopefully the remaining 100 jfets are nicely distributed as well. Once I get the remaing jfets matched, I can probably help out a few people as well.

EUVL · 03:31 PM

You can see a typical distribution of Idss for a large enough batch (in this case 500) of 2SK170s and 2SJ74s.
The measurements were done in January 2009.
(Blue is 2SJ74.)

The next best thing to 2SK389 / 2SJ109 ?

Patrick

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NYCOne · 06:15 PM

Quote:

Originally Posted by EUVL

May I suggest you open a thread at the swap meet forum for your very generous offers.

Most sincere thanks,
Patrick

Not interested in a business, just trying to help your builders.

None the less, I'll post something.

EUVL · 04:49 AM

We got the prototype case parts back after some revisions and re-finishing.

We shall post them part by part today.
Assembled later in the week.

Starting with the front panel.

Patrick

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EUVL · 04:49 AM

Followed by the cradle, transformer feet, regulator heat sink & PCB, and associated parts.

The plates joining the heat sink will get a much better looking (in design) revision later.
The heat sinks will get re-anodised (to all black).

And the O-Rings will get white silicone.

.

EUVL · 04:50 AM

The structural parts :

machined extrusion angles, cross bars, handles, ...

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EUVL · 04:53 AM

Main heat sink (Conrad MF35-151) feet and bottom covers.

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EUVL · 24th May 2011, 04:52 AM

Machined Delrin Cap PCB Mount to hold 2 PCBs (top & bottom).

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20th May 2011, 03:20 PM	#212
EUVL diyAudio Member Join Date: Oct 2003	May I suggest you open a thread at the swap meet forum for your very generous offers. Most sincere thanks, Patrick

20th May 2011, 03:22 PM	#213
Horio Newbie diyAudio Member Join Date: Mar 2010 Location: San Francisco	I have a (150) 2SK170-BL's, and I've matched 50 of them. So far I have been getting a nice range of values with most of them in the 6-9mA range. Hopefully the remaining 100 jfets are nicely distributed as well. Once I get the remaing jfets matched, I can probably help out a few people as well.