I completely agree that quiet power supplies are essential to a "dead silent" amp and I also think that this is essential to achieve the best sounding audio reproduction. So many designs presented here have very basic power supplies.
However I think that the performance of a primary cell can be matched or exceeded with a well designed choke regulated power supply. This technology, which some may regard as ancient & possibly redundant, works particularly well with Class A solid state amps even though it is usually associated with valve amps where ridiculously high values are needed to achieve good filtration. In a solid state amp 5mH can be quite sufficient.
In the weight department batteries & chokes may be somewhat closely matched
Ok, i have some news.
I will refer to the TSSA V1.5 schematic.
My sim schematic was a bit optimistic with R7 and R8 of value 10K. 2.2K - 3K is a more realistic value.
CCS Q8,Q9 and CCS Q5,Q7 runs at ~7mA.
R23 is 220R.
Q3 and Q4 is shorted. R28 and R29 is 1K.
R32,R33 is 220R to allow less gain reduction through U3 and U4.
R13 and R14 is 100R.
a standard current mirror with BC546B and BC556B (with 100R emitter resistors) was added to the CCS Q12, Q15 and Q13, Q14.
All in all. It is not easy to trim right now, but it works. The amp will produce crossover distortion when driven into clip. but a 1/2 second or so after we get away from clip crossover is gone.
I am satisfied with this. You will hear when the amp is driven to high!! But as soon as you turn the amp down, this will disappear.
Tomorrow i will make the mod for the other channel and listen to them.
I will refer to the TSSA V1.5 schematic.
My sim schematic was a bit optimistic with R7 and R8 of value 10K. 2.2K - 3K is a more realistic value.
CCS Q8,Q9 and CCS Q5,Q7 runs at ~7mA.
R23 is 220R.
Q3 and Q4 is shorted. R28 and R29 is 1K.
R32,R33 is 220R to allow less gain reduction through U3 and U4.
R13 and R14 is 100R.
a standard current mirror with BC546B and BC556B (with 100R emitter resistors) was added to the CCS Q12, Q15 and Q13, Q14.
All in all. It is not easy to trim right now, but it works. The amp will produce crossover distortion when driven into clip. but a 1/2 second or so after we get away from clip crossover is gone.
I am satisfied with this. You will hear when the amp is driven to high!!
But as soon as you turn the amp down, this will disappear.Tomorrow i will make the mod for the other channel and listen to them.
Hi Sonny 
So now you have four CCS-s sourcing/sinking the inputs to provide current stability against small leakage to/from the output.
The same effect but much, much simpler way is to put Vbe multiplier to mid bridge and set optimal current to ensure DC stability at least to just below clipping conditions, like you did. I think the mid bridge current would be app. the same value as extra current you're sending through inputs. Can you please check also this option? Only three parts to add to feedback bridge, simple as that.
Regards Andrej
You meant CCS Q8,Q9 and CCS Q4,Q5 runs at ~7mA?
So now you have four CCS-s sourcing/sinking the inputs to provide current stability against small leakage to/from the output.
The same effect but much, much simpler way is to put Vbe multiplier to mid bridge and set optimal current to ensure DC stability at least to just below clipping conditions, like you did. I think the mid bridge current would be app. the same value as extra current you're sending through inputs. Can you please check also this option? Only three parts to add to feedback bridge, simple as that.
Regards Andrej
As you can remember I tried NTC in SSA and with serial resistor it could be set to under/over compensation or just to be optimal.
Mid-bridge Vbe multiplier would have quite oposite tempco to the input gain BJT-s so it should compensate them optimally.
I thought as you have TSSA amp functional to be possible to test such trivial circuit. Currently I'm not in a position to test it cause I'm waiting for CSA PCB-s (cannot test without making the whole TSSA basic amp) and it is not thermal compensation which interests me, that will be solved, but rather the sufficient level of mid-bridge current to resist crossover distortions up to the clipping output level.
Thanks anyway
As you can remember I tried NTC in SSA and with serial resistor it could be set to under/over compensation or just to be optimal.
Mid-bridge Vbe multiplier would have quite oposite tempco to the input gain BJT-s so it should compensate them optimally.
I thought as you have TSSA amp functional to be possible to test such trivial circuit. Currently I'm not in a position to test it cause I'm waiting for CSA PCB-s (cannot test without making the whole TSSA basic amp) and it is not thermal compensation which interests me, that will be solved, but rather the sufficient level of mid-bridge current to resist crossover distortions up to the clipping output level.
Thanks anyway
I can see what you mean about the opposite temp-co.
I have not had a lot of time because of our baby have changed its sleeping hours. So it will not sleep in the evening and not during day. So i have to take over from my wife in the evening.
On top of that we have loads of work!
They are all at sleep right now.
I am just modifying the second channel now. So i expect that with in an hour it will play with music in stereo.
By the way.: have you tried your SSA with an diamond buffer as frontend? It would be easy to modify. Just to hear what the difference would be in a listening test.
Hello LC,
Is the CSSA the best way to go V12?
CSA is based on a previous two presented designs and will carry on best out of both. CSA front-end is suitable to drive V12 or any output stage no doubt about it. I will test it fully and as I promised, will start CSA thread after. So, a little patience here still ...
With the the current mirrors and 1K gate resistors for the renesas mosfet installed and a idle of 0.7A (Hot but not untouchable).
The sound is now seasoned with salt. It is a bit more detailed.
It does go deep, very deep. There is a lot of detail through the sound stage from bottom to the top. The sound is generally warm. It is not correct but i think most listeners would prefer it that way.
All in all it is an amp you just sits down and listen to. You don't think of trying to find mistakes in the interpretation of the music that is played.
You could find errors no doubt about that. On the weak side is the warmth it adds to the highs but you somehow forgets it as it goes very deep without the loss of precision.
It is a good amp to simple music. if you push the amp pass medium high listening level it starts to get less detailed. My speakers are 87dB so i think it is not bad at all.
What i have listened to is:
Loreena Mckennitt - Suits here voice well and the deep soundstage she has in her music. The voice is clean and upfront.
Katie Melua - Just like heaven: The guitars - it is easy to hear the plector when it runs along the wires on the guitar. The Bas is very easy to follow. The whiskers on the drums is there also. .. it is all there but also a bit on the warm side.
Then we have Tina Dickow "welcome back colour" acoustic --- It is just perfect for her music
- The music is not added a warmth colour in this case.The plectors is generally easy to hear.
Back where we started - Here voice is a bit to the rough side for a girl. you can very easy hear the large drum pedal, the piano, the violins. I am not sure if she hits the guitar or the edge of a drum or wood tube. It is easy to seperate from each other.
She also has a duet with Steffen Brandt. Hes voice is just like hearing him in you leaving room.
Agnes Obel - Louretta live in copenhagen - Philharmonics -
The piano - you can hear how deep it actually can go.
Melody Gardot - Who will comfort me - Again this the extra warmth is not a problem and here voice is very up front. But it does not put the instruments in the shadow. In the end of the song there are voices far in the background but you can actually hear what they are saying.
It is all simple music, but it does it very good. It is our taste.... My wife and i.
