twitchie said:Hi Manuel,
I don't have 1M and 10ohm resistors
I etched it, but looking at it, I'm not that happy with it - I think the traces are too close together, although I did go as far as drilling and putting on the top layer graphics.
I started changing the layout again today.
Just wondering if anyone else has tried this one yet and if anyone has any impressions yet?
Stephen
My boards are so far populated. I hope I can make somme tests tomorrow after work and post some impressions.
Many thanks to you, Mr. pass.
Manuel
vdi_nenna said:
Vince,
a few years ago i bought a +10k package of metalfilms by the cheap, including values such as 1M.
Not that i was totally out of resistors, think the deal on Russian made resistors i couldn't resist was a couple of months before the big score.
Sooner or later, they always come to good use.
Lineup Audio, 2SK170GR jfet-boz version 1.0
People hevent got anything else to do, than download Nelson Pass PDF.
... Well, for myself speaking: I do not do much anything else
----------------------------------------------------------------------------------
Comment to my attached SCHEMATIC
Lineup 2SK170GR Jfet BOZ - beta version 1.0a
Eventhough there are a coupe of things I would do different
and change, compared to Nelson's Qucikly posted simple circuit,
I have used same values as Nelson, in this version.
As far as I could .....
From several reasons, including:
1. Make it easy for those already having Nelson's original in mind.
2. By having similar conditions,
we can make as fair a comparison, as possible.
3. I trust Nelson Pass much. He has got experience and knows.
... you wouldnt like to change a winning setup
- not in football teams - not in amplifiers
just about the only being different in my version:
... is adding a current handling 2N5401 PNP, to 'help the jfet'
(I tried a BC640 type here fisrt, but trying like 6-7 different
the 2N5401 as 'the best'
Because this tranasistor works better at 9mA,
which is bit too high for best operation in BC560C / BC640-16.
... as 2SK170GR
is the variant I can buy up here, I use this ( IDSS max = 4.80mA, in my test circuit )
... Input Cap is optional - most cases you will NOT need it.
But just in case, you may keep it. It doesnt do no harm.
Supply Voltage is 30VDC, well regulated**.
The DC operation voltage at Ouput node is: ~10.5 VDC.
** I recommend the use of one
cheap & good TL431 adjustable zenerdiode ( 2.5V - 36V max)
plus a simple follower NPN Transisitor.
One that can deliver 10mA = total supply current
Regards
Lineup Audio Labs, the design division
/lineup
Nelson Pass said:Maybe you would like to try this first.
Attachment: jfet boz small.pdf
This has been
downloaded 338 time(s).
People hevent got anything else to do, than download Nelson Pass PDF.... Well, for myself speaking: I do not do much anything else
----------------------------------------------------------------------------------
Comment to my attached SCHEMATIC
Lineup 2SK170GR Jfet BOZ - beta version 1.0a
Eventhough there are a coupe of things I would do different
and change, compared to Nelson's Qucikly posted simple circuit,
I have used same values as Nelson, in this version.
As far as I could .....
From several reasons, including:
1. Make it easy for those already having Nelson's original in mind.
2. By having similar conditions,
we can make as fair a comparison, as possible.
3. I trust Nelson Pass much. He has got experience and knows.
... you wouldnt like to change a winning setup
- not in football teams - not in amplifiers
just about the only being different in my version:
... is adding a current handling 2N5401 PNP, to 'help the jfet'
(I tried a BC640 type here fisrt, but trying like 6-7 different
the 2N5401 as 'the best'
Because this tranasistor works better at 9mA,
which is bit too high for best operation in BC560C / BC640-16.
... as 2SK170GR
is the variant I can buy up here, I use this ( IDSS max = 4.80mA, in my test circuit )
... Input Cap is optional - most cases you will NOT need it.
But just in case, you may keep it. It doesnt do no harm.
Supply Voltage is 30VDC, well regulated**.
The DC operation voltage at Ouput node is: ~10.5 VDC.
** I recommend the use of one
cheap & good TL431 adjustable zenerdiode ( 2.5V - 36V max)
plus a simple follower NPN Transisitor.
One that can deliver 10mA = total supply current
Regards
Lineup Audio Labs, the design division
/lineup
Attachments
Lineup Audio Lab improved 2SK170 Jfet BOZ version 2.0a
I guess this was not a comment to my posted circuit.
Because I have still, for simplicity, bias at ground without cascode.
I have told this before:
I am not a man 'who cascode anything I see'
I guess Nelson Pass missed my post.
I have no comment to this.
He is often in A Great Hurry (not to miss train to heaven?),
I would imagine
------------------------------------------------
Lineup Audio Lab improved 2SK170 Jfet BOZ version 2.0a
-------------------------------
- Attached is the SquareWave at 10 KHz, with 4Vpeak / 10 kOhm output
- For my basic circuit, see previous post schematic.
Following criteria setup was used, for trimming for optimal performance:
1. Input bandwidth restricted to 3-300000 Hertz, -3dB (no junk outside this will even enter into 2SK170GR
2. LOAD was changed, temporarily to 4k7 = heavier, worst case, load
3. Test frequency input was set to 10000 sinus ( 10KHz)
( on the borderline of what most mature people can hear )
Was found that with these criteria, 2SK170 / 2N5401 combination
works best at slighly higher Voltage, 12-13 Volt, and a bit lower bias, ~7.5mA
(compared to 10.5 Volt / 9mA in my Version 1.0a)
Regards
lineup
----------------------------------------------------------------------------
Below is result for trimmed Version 2.0a
Shows the following Simulated Squarewave, at 4 Volt Peak output:
The frequency is 10 kHz Square
hmmm,Nelson Pass said:
I guess this was not a comment to my posted circuit.
Because I have still, for simplicity, bias at ground without cascode.
I have told this before:
I am not a man 'who cascode anything I see'
I guess Nelson Pass missed my post.
I have no comment to this.
He is often in A Great Hurry (not to miss train to heaven?),
I would imagine
------------------------------------------------
Lineup Audio Lab improved 2SK170 Jfet BOZ version 2.0a-------------------------------
- Attached is the SquareWave at 10 KHz, with 4Vpeak / 10 kOhm output
- For my basic circuit, see previous post schematic.
Following criteria setup was used, for trimming for optimal performance:
1. Input bandwidth restricted to 3-300000 Hertz, -3dB (no junk outside this will even enter into 2SK170GR
2. LOAD was changed, temporarily to 4k7 = heavier, worst case, load
3. Test frequency input was set to 10000 sinus ( 10KHz)
( on the borderline of what most mature people can hear )
Was found that with these criteria, 2SK170 / 2N5401 combination
works best at slighly higher Voltage, 12-13 Volt, and a bit lower bias, ~7.5mA
(compared to 10.5 Volt / 9mA in my Version 1.0a)
Regards
lineup
----------------------------------------------------------------------------
Below is result for trimmed Version 2.0a
Shows the following Simulated Squarewave, at 4 Volt Peak output:
The frequency is 10 kHz Square
Attachments
