Cheer up mate🙂 You will have so much more satisfaction from a real NP system, that you will forget about all your previous.................. Do I need to say more, just let me know😉
All the chipamp guys will get surprised😀 😀
Steen 😎
Coming in a bit late I guess...
This might be the best layout by far I’ve seen for this preamp. Excellent work Russ, please receive my congratulations, I like those FET’s aligned to the side of the board which makes them easy on heatsinking, 😎 at least from my humble DIY point of view.
One thing I noticed on the schematic is the lack of protection on Q4/5 gates. I know many of us don’t like zeners there but being a passive devise as long as the voltage is not exceeding the zener rating it does not intrude on the signal.
If this is going to be a group buy I would suggest having the opinion from other members interested on the boards. I would vote to add them and if someone doesn’t like these just don’t solder them.
I’m in for a couple of boards
This might be the best layout by far I’ve seen for this preamp. Excellent work Russ, please receive my congratulations, I like those FET’s aligned to the side of the board which makes them easy on heatsinking, 😎 at least from my humble DIY point of view.
One thing I noticed on the schematic is the lack of protection on Q4/5 gates. I know many of us don’t like zeners there but being a passive devise as long as the voltage is not exceeding the zener rating it does not intrude on the signal.
If this is going to be a group buy I would suggest having the opinion from other members interested on the boards. I would vote to add them and if someone doesn’t like these just don’t solder them.
I’m in for a couple of boards
Russ, what is the lead spacing of the C4/C5 caps on the amplifier board? If I'm reading it right it's 15mm and finding a 10uF film cap in that package is hard to say the least. Did you have a specific part in mind when you chose that footprint?
/U.
/U.
No worries 😀
i,m looking forward to get my hands on these boards. 😉
sub or no sub..--- i want one 😎
/Z
i,m looking forward to get my hands on these boards. 😉
sub or no sub..--- i want one 😎
/Z
Nisbeth said:
Hi Nisbeth,
I have some MKPs that fit, but I am willing to add some more pads for bigger radial type caps.
I actually plan on using 33uf axial foil caps.
EDIT forgot to mention that the LS is for 10 or 15mm caps, which you can get.
Cheers!
Russ
Re: Coming in a bit late I guess...
First of thank you so much. I have been having a lot of fun with this project. Great designs naturally inspire interesting layouts. 🙂
This is my first ever Pass design, and yes even my first ever FET design, so I am not sure how to implement what you are asking for as far as the Q4/5 gate protection zeners. Let me take a stab at it.
A quick description would be very helpful.
Cheers!
Russ
apassgear said:
First of thank you so much. I have been having a lot of fun with this project. Great designs naturally inspire interesting layouts. 🙂
This is my first ever Pass design, and yes even my first ever FET design, so I am not sure how to implement what you are asking for as far as the Q4/5 gate protection zeners. Let me take a stab at it.
A quick description would be very helpful.
Cheers!
Russ
The zeners would be connected from +in to gnd and -in to gnd.
Take a look at the BosoZ paper here: http://www.passdiy.com/pdf/balzenpre.pdf
Oh, by the way that reading is pure gold😉
Steen😎
steenoe said:
Thanks Steenoe, thats exactly what I thought, but I wanted to be sure. Thanks!
Cheers!
Russ
Russ, just as Steen has pointed, add a B2B 9V zeners parallel to R16/17, this will protect the gates from static electricity when you connect signal cables from the source.
Member
Joined 2002
Re: New improved safer version. 🙂
Looks super nice 😀.. Is this a stereo channel or mono ?
Russ White said:Here you go. I actually like this much better! 🙂
Cheers!
Russ
Looks super nice 😀.. Is this a stereo channel or mono ?
Member
Joined 2002
jleaman said:
Balanced, but I believe you should be able to tie In- and GND together and use it single ended. I will defer to the experts though for the final answer.
Cheers!
Russ
Member
Joined 2002
Definitely Twisted.
Sign me up for two boards and a psu board. I'll do beta again if you want to take them through the cycle.
Sign me up for two boards and a psu board. I'll do beta again if you want to take them through the cycle.
Exactly correct. In fact, you can run single ended in to single ended out if you attach both the -in and -out to ground. If anyone is interested, I put together an arrangement that allows me to switch between SE and Bal inputs and outputs from the front panel in my old CC-CCS-X-BZLS thread. This circuit is very, very flexible, part of the reason I like it so much.
Cheers, Terry
Member
Joined 2002
metalman said:
Ya i like it.. ill have to build one so i can hear the change in sound from my tube pre-amp to this pass labs pre-amp.