FSSA amplifier build thread with review

Jump to Latest
#124
Thanks for the quick response to all.
Just to let you know that I am out of USSA5 (USSA3 ) pcbs. I have one set reserved for a friend and another one for me in case I want to try other variations in the future.

For the FSSA I will order a new batch of pcb of course.

I believe that most of the builders will go with FSSA2 version since matched obsolete Toshiba driver (FSSA1) are very difficult to find today. I know that for some area in the world the Sanken drivers are more difficult to find. For me it is quite easy with Digi-Key in Canada. Therefore, I can offer to buy the Sanken drivers to include with the FSSA pcb. Please indicate in the list.
The double die Exicon mosfet are sold by Profusion.
The matched input jfet are sold by Diyaudio store but hurry since they are sold very quickly.

Fab
 
Last edited:
#125
fab said:
Thanks for the quick response to all.
Just to let you know that I am out of USSA5 (USSA3 ) pcbs. I have one set reserved for a friend and another one for me in case I want to try other variations in the future.

For the FSSA I will order a new batch of pcb of course.

I believe that most of the builders will go with FSSA2 version since matched obsolete Toshiba driver (FSSA1) are very difficult to find today. I know that for some area in the world the Sanken drivers are more difficult to find. For me it is quite easy with Digi-Key in Canada. Therefore, I can offer to buy the Sanken drivers to include with the FSSA pcb. Please indicate in the list.
The double die Exicon mosfet are sold by Profusion.
The matched input jfet are sold by Diyaudio store but hurry since they are sold very quickly.

Fab
Click to expand...

How many USSA5 orders do you need for it to be viable?
 
#127
Hi Fab,

Thank YOU for all this!

Fab news, pcb to come... so happy!

Of course I am going for it and will also update the list with the Sanken you kindly propose to provide. Thanks again.

Fab, I have a shortened version of the USSA manual, but no FSSA manual, so pardon my silly questions - I would just like to avoid any mistake.

I will go FSSA-2. My understanding is that on top of the Sanken drivers you will kindly provide I need to purchase a pair of double die Exicon mosfets sold by Profusion (I guess these are the output transistors) and also matched input jfets sold by Diyaudio store.

Is this understanding correct?

If my understanding is correct, what are the matched input JFETs I need from the Diyaudio store on top of the Sanken you offer to provide?
Would that be for a complete stereo amplifier "LSK170/LSK94 Matched QUAD (GradeB)"? (sadly sold out at the moment, or is that another options in the store)?

Sorry for the numby questions!

Claude
 
Last edited:
#131
The first build impressed me so much, so i might as well try the rest.
Fab's manual is impeccable. Step by step guide so you won't miss any procedure along the way.
The 5B heatsinks and USSPA chassis is still stuck with the machinist for 2 months already.
Everyone stay safe and build lots of amps now.
 
#132
ClaudeG said:
Hi Fab,

Thank YOU for all this!

Fab news, pcb to come... so happy!

Of course I am going for it and will also update the list with the Sanken you kindly propose to provide. Thanks again.

Fab, I have a shortened version of the USSA manual, but no FSSA manual, so pardon my silly questions - I would just like to avoid any mistake.

I will go FSSA-2. My understanding is that on top of the Sanken drivers you will kindly provide I need to purchase a pair of double die Exicon mosfets sold by Profusion (I guess these are the output transistors) and also matched input jfets sold by Diyaudio store.

Is this understanding correct?

If my understanding is correct, what are the matched input JFETs I need from the Diyaudio store on top of the Sanken you offer to provide?
Would that be for a complete stereo amplifier "LSK170/LSK94 Matched QUAD (GradeB)"? (sadly sold out at the moment, or is that another options in the store)?

Sorry for the numby questions!

Claude
Click to expand...

PS: or I got it completely wrong and it is EITHER the Sanken OR the matched JFETs and not AND?

Confused now by Meanie's addition...
 
#134
Many thanks!

OK so I need the Sanken AND the JFETs, right?

If so I had it right first time and I won't touch my addition in the wishlist, that is Sanken for me 🙂

And now the big question: what JFET option should I order from the DIYstore?

Many thanks again

Claude
 
#136
You are right meanie that FSSA2 was an alternative to FSSA1. But both are equally good to my taste.

I think the Diyaudio store is already sold out now for the matched quad...🙄
You will have to rely on other sources.

Look at post 9 for the active parts you need.

Fab
 
Last edited:
#137
Ok, thanks Fab, I had a look at the schematic again.

Is my understanding correct that what you call the Sanken are in fact 2SB1259 and 2SD2081?

Fab, if strictly going FSSA-2, and if you kindly provide "the Sanken" as proposed, then in fact do I still need to source the LSK170 and LSK94 matched quads JFETS (be it from DIYaudio or else)... or I don't anymore because "the Sanken" you propose kindly are in fact replacements for the LSK170 and LSK94 matched quads and not what I identified on the schematic?

I am sorry to be a real pain tonight - must be tired as it looks straight forward for anyone but me :-(

Thanks again

Claude
 
You must log in or register to reply here.
Top Bottom