As nice and entertaining Dave can be, here is an old but finely structured soldering education series from Pace. Highly recommended. What it lacks in modern neat tricks for manual SMD assembly and rework, there are many other specialized individual videos to find in.
https://www.youtube.com/playlist?list=PL926EC0F1F93C1837
@LC,
I made a mistake I am afraid as I posted this question in the wrong thread!!
Quote:
Originally Posted by brianco
@LC:
Can you please advise which heat-sinks you have chosen for this amp?
Many thanks,
Brian
SK157 I'm waiting for.
__________________
SSA BIGBT HP + SSA CCS
TSSA BIGBT HP
It should have been in THIS thread! [ SK157 would be overkill here?]
I made a mistake I am afraid as I posted this question in the wrong thread!!
Quote:
Originally Posted by brianco
@LC:
Can you please advise which heat-sinks you have chosen for this amp?
Many thanks,
Brian
SK157 I'm waiting for.
__________________
It should have been in THIS thread! [ SK157 would be overkill here?]
@Salas and Vgeorge:
Many thanks. I have now watched these videos and learnt much which will be of value and which will result in better work.
Brian
Many thanks. I have now watched these videos and learnt much which will be of value and which will result in better work.
Brian
PSSA: Pretty Simple Symmetric Amplifier or DC coupled VSSA
Thought I'd post this slightly modified version of the VSSA for some feedback. If you think this should go in a separate thread, let me know.
Instead of the AC coupled VSSA, the addition of a couple of small transistors on the front end allows the current feedback to come to a single node. Offset adjustment is done via one of the current sources. Here's the schematic and a 2KHz spectrum. It seems to have very similar performance to the VSSA on square wave reproduction too.
CCS are set to about .5mA and the output bias is set to around 200mA.
Thought I'd post this slightly modified version of the VSSA for some feedback. If you think this should go in a separate thread, let me know.
Instead of the AC coupled VSSA, the addition of a couple of small transistors on the front end allows the current feedback to come to a single node. Offset adjustment is done via one of the current sources. Here's the schematic and a 2KHz spectrum. It seems to have very similar performance to the VSSA on square wave reproduction too.
CCS are set to about .5mA and the output bias is set to around 200mA.
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Hi Pete 
All SSA projects intentionally avoided diamond buffer in the input stage. The reason is mainly subjective. As you can see the results are similar so why bother with two extra transistors, as these are two extra variables for instability in the equation. I extensively tested diamod buffer, also listened the same amp with and without it, before started SSA thread and to MHO it sounds worse then SSA only.
But if you like to advance with the project you can start new thread and bring the design to PCB.
Regards Andrej
All SSA projects intentionally avoided diamond buffer in the input stage. The reason is mainly subjective. As you can see the results are similar so why bother with two extra transistors, as these are two extra variables for instability in the equation. I extensively tested diamod buffer, also listened the same amp with and without it, before started SSA thread and to MHO it sounds worse then SSA only.
But if you like to advance with the project you can start new thread and bring the design to PCB.
Regards Andrej
Hi fellow diy-ers. Hi Andrej. How are you?
Just a few hours ago my ugly board was finished. It's singing some vocals now.
Looking at the schema of vssa I honestly doubt(ed) that it would come even close to its mom soundwise, especially with those electrolytics in the feedback node. But damn, it did! Not just sonics, but the offset, it's fixed and rock steady at 110mV, no different from turn on to right now, no trimming. Man I like this, Fantastic! Finally the last boss in the game has been defeated.
Also the different current injection node is something that tempted me so much that I had to give it a shot just to see that it actually works. It went very well. Got paid in full. Learned something new.
The amp is nothing less than a beautiful gift, simple, transparent, like an earth globe made of glass. Thanks again LC. We are indeed lucky to have you around.
shaan
How are you?Just a few hours ago my ugly board was finished. It's singing some vocals now.
Looking at the schema of vssa I honestly doubt(ed) that it would come even close to its mom soundwise, especially with those electrolytics in the feedback node. But damn, it did! Not just sonics, but the offset, it's fixed and rock steady at 110mV, no different from turn on to right now, no trimming. Man I like this, Fantastic! Finally the last boss in the game has been defeated.
Also the different current injection node is something that tempted me so much that I had to give it a shot just to see that it actually works. It went very well. Got paid in full. Learned something new.
The amp is nothing less than a beautiful gift, simple, transparent, like an earth globe made of glass. Thanks again LC. We are indeed lucky to have you around.
shaan
Hi fellow diy-ers. Hi Andrej.
Just a few hours ago my ugly board was finished. It's singing some vocals now.
Looking at the schema of vssa I honestly doubt(ed) that it would come even close to its mom soundwise, especially with those electrolytics in the feedback node. But damn, it did! Not just sonics, but the offset, it's fixed and rock steady at 110mV, no different from turn on to right now, no trimming. Man I like this, Fantastic! Finally the last boss in the game has been defeated.
Also the different current injection node is something that tempted me so much that I had to give it a shot just to see that it actually works. It went very well. Got paid in full. Learned something new.
The amp is nothing less than a beautiful gift, simple, transparent, like an earth globe made of glass. Thanks again LC. We are indeed lucky to have you around.
shaan
Hi Shaan
Been playing with network streamer player (media renderer) last days, since this should be my source for the future use. It is capable of 24/192 bit perfect streaming from any network shared library and so far it works nicely.
I congratulate you to try VSSA, but let me tell you that you should try the one from my signature link. Although stability compensation scheme is now quite a bit different and it works perfectly, will present measurements plots and pics later this week.
Regards Andrej
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