Squarewave
Here with the Tek scope. Its clear than the pc scope but still you can see the rounding left up and down edges at 10k, not much but still there.
Board history
Board JLCPCB, grabers provided by ZM
Original Toshiba, 2SK170 matched pair from John La Grou
ZTX 450, 550 where selected and matched using Ian Fritz method (less 0.2mv)
2SC3503 and 1381 were matched (less 0.3 mv)
All resistors from Mouser RN60D type
Caps are from Digikey WIMA, Nichicom fine gold ufg type
Pots from Bourns
As always recommendations, opinions and critics are welcome.
Here with the Tek scope. Its clear than the pc scope but still you can see the rounding left up and down edges at 10k, not much but still there.
Board history
Board JLCPCB, grabers provided by ZM
Original Toshiba, 2SK170 matched pair from John La Grou
ZTX 450, 550 where selected and matched using Ian Fritz method (less 0.2mv)
2SC3503 and 1381 were matched (less 0.3 mv)
All resistors from Mouser RN60D type
Caps are from Digikey WIMA, Nichicom fine gold ufg type
Pots from Bourns
As always recommendations, opinions and critics are welcome.
Attachments
Squarewave
I have several question for does Threshold gurus. In the NE FE board cap 11 is listed as 0.15 (no units) in the shrinked ZM board this cap is listed as cap 2 and has a value of 15n? Im using 15n.
Could it be that the circuit behave like this as per design?
Does the boards need to be loaded for this type of test?
Testing to 50Khz sine wave looks perfect. Squarewave get more rounded in the upper left rise and in the low rigth side of the square?
I have several question for does Threshold gurus. In the NE FE board cap 11 is listed as 0.15 (no units) in the shrinked ZM board this cap is listed as cap 2 and has a value of 15n? Im using 15n.
Could it be that the circuit behave like this as per design?
Does the boards need to be loaded for this type of test?
Testing to 50Khz sine wave looks perfect. Squarewave get more rounded in the upper left rise and in the low rigth side of the square?
I tried to use same cap footprints as Pa, and if I wrote 15n for C11, that's typo
it is 150nF, bypass for elco at neg input, ref to schm in post #1
not relevant for square wave
C4 is there to suppress possible surprises, but Pa sez it's good without
don't fret anymore with scope, all is good to my eyes
just confirm same behavior with next channel pcb and that's it
loading of FE with OS shouldn't change much, or anything
it is 150nF, bypass for elco at neg input, ref to schm in post #1
not relevant for square wave
C4 is there to suppress possible surprises, but Pa sez it's good without
don't fret anymore with scope, all is good to my eyes
just confirm same behavior with next channel pcb and that's it
loading of FE with OS shouldn't change much, or anything
Last edited:
NE FE schematic for OS stage
Advice needed: the pic label s150 schematic is my estimate schematic for connecting the FE to the OS. Is this correct. The schematic was posted by NP in the first post.
The pic label s150 schematic os, containing circulate components I do have them. I have two options mounting then in the FE boar or replacing them in the os of the s150 board. Any recommendation?
Advice needed: the pic label s150 schematic is my estimate schematic for connecting the FE to the OS. Is this correct. The schematic was posted by NP in the first post.
The pic label s150 schematic os, containing circulate components I do have them. I have two options mounting then in the FE boar or replacing them in the os of the s150 board. Any recommendation?
Attachments
Greenhorn incoming…
First off, thanks to all you bright people on DIYAudio for keeping my hands and mind busy building stuff to enjoy, esp NP and ZM for their invaluable contributions 😊
I fancy a go at building this amp (ZM’s FE board), I’ve build a couple of amps previously, but they were pretty much follow m’leader stuff. So bear with me as I ask some stupid, boneheaded questions…
I’ve put together a BoM for ZM FE boards and the 6 way OS and I don’t understand a couple of things from the schematic. I would appreciate if someone more knowledgeable than me could post a BoM or message me one please.
The switch T. I saw the answer that it is a Thermostat, but could someone point me on Mouser what one of these looks like please?
Also, I was confused about the TH1 being either a NTC or PTC, which one is it supposed to be? I assume like the one in the F5T which needs to rest on the heatsink. Again, I would be very grateful if someone could point me at a Mouser part please.
For output devices, having read through the thread, I was considering either Sanken 2SA1695 / 2SC4468 or 2SA2223A / 2SC6145A?
Thinking about a 6U, 400mm Modushop case would be big enough with +/-30V rails.
Ta.
First off, thanks to all you bright people on DIYAudio for keeping my hands and mind busy building stuff to enjoy, esp NP and ZM for their invaluable contributions 😊
I fancy a go at building this amp (ZM’s FE board), I’ve build a couple of amps previously, but they were pretty much follow m’leader stuff. So bear with me as I ask some stupid, boneheaded questions…
I’ve put together a BoM for ZM FE boards and the 6 way OS and I don’t understand a couple of things from the schematic. I would appreciate if someone more knowledgeable than me could post a BoM or message me one please.
The switch T. I saw the answer that it is a Thermostat, but could someone point me on Mouser what one of these looks like please?
Also, I was confused about the TH1 being either a NTC or PTC, which one is it supposed to be? I assume like the one in the F5T which needs to rest on the heatsink. Again, I would be very grateful if someone could point me at a Mouser part please.
For output devices, having read through the thread, I was considering either Sanken 2SA1695 / 2SC4468 or 2SA2223A / 2SC6145A?
Thinking about a 6U, 400mm Modushop case would be big enough with +/-30V rails.
Ta.
Th is NTC, of value shown in schematic
either small blob-looking case, or screw-like case, or small blob epoxied in metal holder with fork for screw
switch is either small plasticky rectangle or small can with ears for 2 screws
see that I'm lazy to search
though -
example 1 ( find similar with , say , 65C and be sure it is Normaly ON) : 1NT01L-7944 Sensata Technologies | Mouser Europe
example 2 (take care of resistance, find proper one) : https://eu.mouser.com/ProductDetail...CALUG02A103F161A/?qs=vmHwEFxEFR9omPXj4FV5XQ==
either small blob-looking case, or screw-like case, or small blob epoxied in metal holder with fork for screw
switch is either small plasticky rectangle or small can with ears for 2 screws
see that I'm lazy to search
though -
example 1 ( find similar with , say , 65C and be sure it is Normaly ON) : 1NT01L-7944 Sensata Technologies | Mouser Europe
example 2 (take care of resistance, find proper one) : https://eu.mouser.com/ProductDetail...CALUG02A103F161A/?qs=vmHwEFxEFR9omPXj4FV5XQ==
good
you do know that both of them need to be paced on heatsink ...... somewhere at mid position