I believe they are M6 (definitely not M5). Need to be sufficient size to get enough torque for mounting.
If I were to build from scratch, I would use a T-bar mount for more surface area contact. But it seems the heatsinks get toasty warm enough.
Yeah, very nice.
That means you get to use even bigger spring washers.
I like spring washers.
Hahahahaha
Nothing like a nice clean PCB when starting out a project. That way the soldering mistake is on you if things go poof!
Quick disconnects on both front and back side:
Permaneder's boards were far from perfect. Many of the holes had to be re-drilled to fit the component leads. Furthermore, many of the holes form connections on both sides of the board so quite often I had to pre-solder 1 side and have some of the solder flow through the hole while the component leads are partially in. Because of this issue, I would be weary buying pre-stuffed Permaneder CSX1 boards without knowing they work 100%.
Another hole was drilled to fit the 0.1ohm Caddock resistors (R11 / R12)

Quick disconnects on both front and back side:


Permaneder's boards were far from perfect. Many of the holes had to be re-drilled to fit the component leads. Furthermore, many of the holes form connections on both sides of the board so quite often I had to pre-solder 1 side and have some of the solder flow through the hole while the component leads are partially in. Because of this issue, I would be weary buying pre-stuffed Permaneder CSX1 boards without knowing they work 100%.


Another hole was drilled to fit the 0.1ohm Caddock resistors (R11 / R12)

ZM better clamp the sony direct on tbar enlarging the screw hole to skip the pcb ??Fugly!
and amusing
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tnx
naah
it's good enough as prescribed
with tips SuperBQ gave us , it's just recipe for slower and even more enjoyable build
this amp is a gem - Iron and JFets
it's good enough as prescribed
with tips SuperBQ gave us , it's just recipe for slower and even more enjoyable build
this amp is a gem - Iron and JFets
Pass DIY Addict
Joined 2000
Paid Member
Nice set of images and details! Thanks for taking the time to document your build. I've got a mostly complete kit for the CSX1 amp that I have yet to build. I think I got my boards from Rush and they've been in my parts box since.
I'm starting to run out of places to stash completed amps... Maybe the downstairs bathroom needs a nice Class A amp with a small set of speakers ??
I'm starting to run out of places to stash completed amps... Maybe the downstairs bathroom needs a nice Class A amp with a small set of speakers ??
You guys need to stop dreaming and start building 😎
I've done the hard work reading 100s of pages, searching high and low about these boards. What is so bad about a 'Common Source, Transformer Coupled' circuit? Complete ground isolation via XLR input - the early vacuum tube builders knew the importance of input transformers. Even modern high end tube amps employ input transformers. Your better pro audio gear again, uses input transformers. The only reason for the lack of CSX1 builds may be it's complication? Laziness? or more likely.... lack of funds :O I do know there are some that have more than 1 pair of these boards. What would come of them when the boards are stored away, forgotten in 10 or 30 years time?
The sound? Yes! this is a VERY lovely amp and is rather a unique one. I applaud Mr Pass for bringing out the VFet for DIY and i'm certain he knew that complex builds tend not to be built. The CSX2 is a much more complicated setup ; but then it has the full step by step build instructions in this forum. My guess as time goes on, we will see fewer builds until Mr Pass releases another stash - perhaps a single ended version of the VFET?
I'm still amazed of the non-harshness of the VFet sound. Very clear yet none of the hardness in typical solid state amps (for which over the past 10 years I stayed in the DIY tube amp building camp).
Oh and I would like to ask where does the VFet sit in the area of the First Watt DIY builds (ie F series)? 20 tube watts like per chan output? Plenty enough power. Steve Guttenberg's 'Amp Camp' review says for some want more than 8 wpc and not everyone has the WAF of high efficient - large speakers in the home.
The plastic shop is slow at making the covers - said maybe next week :|
Love Zen Mod's scarcasm 🙂
I've done the hard work reading 100s of pages, searching high and low about these boards. What is so bad about a 'Common Source, Transformer Coupled' circuit? Complete ground isolation via XLR input - the early vacuum tube builders knew the importance of input transformers. Even modern high end tube amps employ input transformers. Your better pro audio gear again, uses input transformers. The only reason for the lack of CSX1 builds may be it's complication? Laziness? or more likely.... lack of funds :O I do know there are some that have more than 1 pair of these boards. What would come of them when the boards are stored away, forgotten in 10 or 30 years time?
The sound? Yes! this is a VERY lovely amp and is rather a unique one. I applaud Mr Pass for bringing out the VFet for DIY and i'm certain he knew that complex builds tend not to be built. The CSX2 is a much more complicated setup ; but then it has the full step by step build instructions in this forum. My guess as time goes on, we will see fewer builds until Mr Pass releases another stash - perhaps a single ended version of the VFET?
I'm still amazed of the non-harshness of the VFet sound. Very clear yet none of the hardness in typical solid state amps (for which over the past 10 years I stayed in the DIY tube amp building camp).
Oh and I would like to ask where does the VFet sit in the area of the First Watt DIY builds (ie F series)? 20 tube watts like per chan output? Plenty enough power. Steve Guttenberg's 'Amp Camp' review says for some want more than 8 wpc and not everyone has the WAF of high efficient - large speakers in the home.
The plastic shop is slow at making the covers - said maybe next week :|
Love Zen Mod's scarcasm 🙂
Just wondering, what kind of tech spacecraft do you have, to be in New Zealand and Canada at the same time.
@ 2picos:
Haha well prior to this COVID mess, I spent my summers in both places. Under the lockdown it was best opportunity to build something. In fact, EVERYBODY should get building! 😛
My next project - the Korg B1 once the kits start shipping.
@ Eric:
Yes Rush was great to deal with. It also helped that I didn't need matched sets (just ones in same ranking code). You should build it!
Haha well prior to this COVID mess, I spent my summers in both places. Under the lockdown it was best opportunity to build something. In fact, EVERYBODY should get building! 😛
My next project - the Korg B1 once the kits start shipping.
@ Eric:
Yes Rush was great to deal with. It also helped that I didn't need matched sets (just ones in same ranking code). You should build it!
Pass DIY Addict
Joined 2000
Paid Member
I will build my CSX1 eventually, I promise! I also have one of Zen's SissySIT amps to build, a J2 to build, a pair of 300B parafeed amps to finish, and I'm in the process now of getting my DCB1 into a proper enclosure.
Darn day job seems to keep getting in the way of my time...
Darn day job seems to keep getting in the way of my time...
The whole sony article is awesome.
My brain still doesn't digest some of it.
That's kind of normal for my brain.
Hahahaha
I hope Nelson does some follow up articles centred around these line out transformers.
My brain needs more torture.
My brain still doesn't digest some of it.
That's kind of normal for my brain.
Hahahaha
I hope Nelson does some follow up articles centred around these line out transformers.
My brain needs more torture.
Might be a repeat in another thread, I found this article quite interesting:
https://www.monoandstereo.com/2018/09/the-history-of-vfets.html
https://www.monoandstereo.com/2018/09/the-history-of-vfets.html
I was busy also with this CSX1 AMP in 2014 and built them as mono blocks with each a separate PSU. Resulting in no hum.
Pictures of your diy Pass amplifier
Pictures of your diy Pass amplifier
Keep building this nice amp!
Pictures of your diy Pass amplifier
Pictures of your diy Pass amplifier
Keep building this nice amp!
@ WalterW
Yes you were among the few that actually built the CSX1 - that thread is massively long and it took me a long time to churn through that.
My clear plastic covers arrived and spent the day fastening them.
Mind the tacky "Peel N Stick" labels. One day my son may have an interest in HiFi and will need to know what's going on in these boxes.
I will have to test how much noise by stacking:
As always, making good use of the tapered screws that came with the chassis kit. Flush is best!
Yes you were among the few that actually built the CSX1 - that thread is massively long and it took me a long time to churn through that.
My clear plastic covers arrived and spent the day fastening them.

Mind the tacky "Peel N Stick" labels. One day my son may have an interest in HiFi and will need to know what's going on in these boxes.

I will have to test how much noise by stacking:

As always, making good use of the tapered screws that came with the chassis kit. Flush is best!



Pass DIY Addict
Joined 2000
Paid Member
I like the labels! I've been thinking of a way to "document" my builds so that whoever cleans up after I'm gone has some insight about what is what. I've been thinking of taking some of these discussion threads and turning them into PDF documents and saving my notes as documents and putting it all on a SD card or USB drive that is stuck inside the chassis somewhere. I don't know what else to do to make things accessible to others...
@ WalterW
My clear plastic covers arrived and spent the day fastening them.
humm ,quite toxic.....with that temperature better a glass
I suppose I should find a way to get an accurate temperature reading on the heatsinks. My low tech method tells me I can 'just' keep my hands on the top steel rails for over 10 seconds on a hot toasty day.
@ Eric:
Labeling can cost a lot of $ - not sure about leaving an SD Card or USB drive as 1 day those may go obsolete like the 1.44MB floppy. I used the Libre Office 'Drawing' program which worked easy enough to make circles and font typing.
@ Eric:
Labeling can cost a lot of $ - not sure about leaving an SD Card or USB drive as 1 day those may go obsolete like the 1.44MB floppy. I used the Libre Office 'Drawing' program which worked easy enough to make circles and font typing.
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