FSSA amplifier build thread with review

Hi Brianco
WoW this is quite a change from FSSA (100W class AB) to F5-USSA (<=25W class A). The latter is only an F5 with different parts and value but using USSA philosophy and of course using the 2SK1530/2SJ201. It was discussed in a now closed forum...It is somehow similar to EUVL design I believe. For the pcb I have simply used an F5 clone pcb from EBay and put my parts in.

Fab

P.S. I have found where I put the schematics on this forum:
Virtual Audition of Very Simple Quasi MOSFET Amp

Thanks Fab,

Apologies for delay but been unwell again - seems I may need a pacemaker ac.to Docs.

I have now it seems added dyslexia to my worries (my now deleted order contradictions!)

I have removed my name from the list and will grateful if you will order for me according to your advice.

Low Impedance speakers c. 88/89Db sensitivity. I would like a USSA for these, I have x2 sets boards from last round, but no Sanken devices of any kind (or Tosh drivers). SO I will be grateful if youcan get me two sets as appropriate for your advised USSA use.

I have all of your recommended front end devices - BCs/2SK/2SJ/ etc - and for outputs have about 60pairs of matched 2SK1530/2SJ201 - ditto - 2SC5200/2SA1943. I also have matched ALF20/20 pairs, I have NO Tosh 313 pairs.

I do not have to use these outputs as I can order whatever you recommend.

I also have a pair of Maggies which require a decent power amp. For these I suspect a FSSA is the best bet. I also want to build an FSSA for a great friend, so would like your advice on this: preferably different models so that I get the choice for myself when tested!!!

Hope that this makes sense.
 
AnthonyA . 2 sets FSSA2 and 1 set ussa 3b+ Ntc, poly cap, sanken+ caddock
nfsgame - 1 set FSSA
Vunce - 1 set FSSA
Stretchneck - 3 sets fssa and 1 set ussa
ClaudeG - 1 set FSSA with Sanken
meanie - 1 set FSSA1 (toshiba driver)
zman01 - 1 set FSSA
touchdown - 1 set FSSA with Sunken
Analogico - 2 sets USSA3/5
Kalamin - 1 set FSSA with Sanken

Note: assume I do not have USSA pcb at this moment.
@Brianco: please clarify if you require FSSA pcb.

And for the FSSA only related list:
AnthonyA . 2 sets FSSA2 and 1 set ussa 3b+ Ntc, poly cap, sanken+ caddock
nfsgame - 1 set FSSA
Vunce - 1 set FSSA
Stretchneck - 3 sets fssa and 1 set ussa
ClaudeG - 1 set FSSA with Sanken
meanie - 1 set FSSA1 (toshiba driver)
zman01 - 1 set FSSA
touchdown - 1 set FSSA with Sunken
Kalamin - 1 set FSSA with Sanken

That makes 24 pcbs. I can buy 30 pcbs to allow a few late inquiries. That should give probably less than 10$ CAD per pcb excluding shipping. Final Price to be confirmed.

Shipping will be a fixed price this time because only small variation between countries by Airmail no tracking.
All prices in CAD$:
Pcb (2) : <=20$
Packaging : 1$
Shipping : 14$
Sanken (4): 12$
Other parts (only special cases) by PM
 
Thanks Fab,

Apologies for delay but been unwell again - seems I may need a pacemaker ac.to Docs.

I have now it seems added dyslexia to my worries (my now deleted order contradictions!)

I have removed my name from the list and will grateful if you will order for me according to your advice.

Low Impedance speakers c. 88/89Db sensitivity. I would like a USSA for these, I have x2 sets boards from last round, but no Sanken devices of any kind (or Tosh drivers). SO I will be grateful if youcan get me two sets as appropriate for your advised USSA use.

I have all of your recommended front end devices - BCs/2SK/2SJ/ etc - and for outputs have about 60pairs of matched 2SK1530/2SJ201 - ditto - 2SC5200/2SA1943. I also have matched ALF20/20 pairs, I have NO Tosh 313 pairs.

I do not have to use these outputs as I can order whatever you recommend.

I also have a pair of Maggies which require a decent power amp. For these I suspect a FSSA is the best bet. I also want to build an FSSA for a great friend, so would like your advice on this: preferably different models so that I get the choice for myself when tested!!!

Hope that this makes sense.

Hi Brianco
No problem take care of your health first.
No problems I will send you Sanken drivers since you have already bought the USSA5 pcb sets.

As for recommendations I would rather leave that to other members since I have no experience with the Maggies. For more difficult speakers FSSA is more recommended compared to USSA5. You can build FSSA1 and 2 but the latter requires Toshiba mosfet drivers. Only accepted output for FSSA is double die lateral mosfet -as your ALF20N20/20P20.

Let me know if you want FSSA pcb.

Fab
 
Last edited:
Group buy list update

AnthonyA . 2 sets FSSA2 and Ntc, poly cap, sanken+ caddock
nfsgame - 1 set FSSA
Vunce - 1 set FSSA
Stretchneck - 3 sets fssa
ClaudeG - 1 set FSSA with Sanken
meanie - 1 set FSSA1 (toshiba driver)
zman01 - 1 set FSSA
touchdown - 1 set FSSA with Sunken
Kalamin - 1 set FSSA with Sanken
Spind - 1 set FSSA

That makes 26 pcbs. I can buy 30 or 40 pcbs to allow a few late inquiries. That should give probably less than 10$ CAD per pcb excluding shipping. Final Price to be confirmed.

Shipping will be a fixed price this time because only small variation between countries by Airmail no tracking.
All prices in CAD$:
Pcb (2) : <=20$
Packaging : 1$
Shipping : 14$
Sanken (4): 12$
Other parts (only special cases) by PM

For USSA3/5 pcb inquiries please use the USSA5 pcb group buy thread otherwise it can be complicated for me to keep track of requests...

Fab
 
Last edited:
Hi Brianco
No problem take care of your health first.
No problems I will send you Sanken drivers since you have already bought the USSA5 pcb sets
As for recommendations I would rather leave that to other members since I have no experience with the Maggies. For more difficult speakers FSSA is more recommended compared to USSA5. You can build FSSA1 and 2 but the latter requires Toshiba mosfet drivers. Only accepted output for FSSA is double die lateral mosfet -as your ALF20N20/20P20.

Let me know if you want FSSA pcb.

Fab
================

@Fab,
Many thanks indeed.

....I am adding my name to the FSSA list for x2 stereo sets of FSSA boards + all necessary Sunken devices for the x2 USSA and x2 FSSA options. That will keep me going for a while!

Really appreciate all you are doing for these amps. and builders

To All:
I would very much like to obtain a pair each of well matched Toshiba 2SJ313Y &
2SK2013Y. PLEASE PM if you can supply genuine devices. Many thanks.
 
Last edited:
AnthonyA . 2 sets FSSA2 and Ntc, poly cap, sanken+ caddock
nfsgame - 1 set FSSA
Vunce - 1 set FSSA
Stretchneck - 3 sets fssa
ClaudeG - 1 set FSSA with Sanken
meanie - 1 set FSSA1 (toshiba driver)
zman01 - 1 set FSSA
touchdown - 1 set FSSA with Sunken
Kalamin - 1 set FSSA with Sanken
Spind - 1 set FSSA
Brianco - x2 stereo FSSA sets + All Sanken
 
Group buy status

AnthonyA . 2 sets FSSA2 and Ntc, poly cap, sanken+ caddock
nfsgame - 1 set FSSA: paid ok
Vunce - 1 set FSSA
Stretchneck - 3 sets fssa + 4 sets of Sanken
ClaudeG - 1 set FSSA with Sanken: paid ok
meanie - 1 set FSSA1 (toshiba driver) : paid ok
zman01 - 1 set FSSA
touchdown - 1 set FSSA with Sunken
Kalamin - 1 set FSSA with Sanken: paid ok
Spind - 1 set FSSA: paid ok
Brianco - x2 stereo FSSA sets + All Sanken
topicreader - 1 set FSSA + Sanken

16 sets thus 32 pcbs.


Shipping will be a fixed price this time because only small variation between countries by Airmail no tracking.
All prices in CAD$:
Pcb (2) : 16$
Packaging : 1$
Shipping : 14$
Sanken (4): 12$
Other parts (only special cases) by PM

Fab
 
Last edited:
AnthonyA . 2 sets FSSA2 and Ntc, poly cap, sanken+ caddock
nfsgame - 1 set FSSA: paid ok
Vunce - 1 set FSSA: paid ok
Stretchneck - 3 sets fssa + 4 sets of Sanken
ClaudeG - 1 set FSSA with Sanken: paid ok
meanie - 1 set FSSA1 (toshiba driver) : paid ok
zman01 - 1 set FSSA
touchdown - 1 set FSSA with Sanken
Kalamin - 1 set FSSA with Sanken: paid ok
Spind - 1 set FSSA: paid ok
Brianco - x2 stereo FSSA sets + All Sanken
topicreader - 1 set FSSA + Sanken ?
Tomtest - 1 set FESA + Sanken ?

17 sets thus 34 pcbs?


Shipping will be a fixed price this time because only small variation between countries by Airmail no tracking.
All prices in CAD$:
Pcb (2) : 16$
Packaging : 1$
Shipping : 14$
Sanken (4): 12$
Other parts (only special cases) by PM

Fab



I need more received payments to do the pcb ordering.🙄
Fab
 
Last edited:
Group buy update

AnthonyA . 2 sets FSSA2 and Ntc, poly cap, sanken+ caddock
nfsgame - 1 set FSSA: paid ok
Vunce - 1 set FSSA: paid ok
Stretchneck - 3 sets fssa + 4 sets of Sanken : paid ok
ClaudeG - 1 set FSSA with Sanken: paid ok
meanie - 1 set FSSA1 (toshiba driver) : paid ok
zman01 - 1 set FSSA
touchdown - 1 set FSSA with Sanken : paid ok
Kalamin - 1 set FSSA with Sanken: paid ok
Spind - 1 set FSSA: paid ok
Brianco - x2 stereo FSSA sets + All Sanken
topicreader - 1 set FSSA + Sanken ?
Tomtest - 1 set FESA : paid ok

17 sets thus 34 pcbs?


Shipping will be a fixed price this time because only small variation between countries by Airmail no tracking.
All prices in CAD$:
Pcb (2) : 16$
Packaging : 1$
Shipping : 14$
Sanken (4): 12$
Other parts (only special cases) by PM

Fab
I need more received payments to do the pcb ordering.🙄
Fab[/QUOTE]
 
Group buy update

AnthonyA . 2 sets FSSA2 and Ntc, poly cap, sanken+ caddock
nfsgame - 1 set FSSA: paid ok
Vunce - 1 set FSSA: paid ok
Stretchneck - 3 sets fssa + 4 sets of Sanken : paid ok
ClaudeG - 1 set FSSA with Sanken: paid ok
meanie - 1 set FSSA1 (toshiba driver) : paid ok
zman01 - 1 set FSSA : paid ok
touchdown - 1 set FSSA with Sanken : paid ok
Kalamin - 1 set FSSA with Sanken: paid ok
Spind - 1 set FSSA: paid ok
Brianco - x2 stereo FSSA sets + All Sanken
topicreader - 1 set FSSA + Sanken ?
Tomtest - 1 set FESA : paid ok

Almost there for the payment of pcbs so I can order them.

I am well advanced in the build manual revision so I should be able to send it maybe tomorrow to those who have paid so far.

Fab