To get 2210 uF cap.
Not neccessary need to install 10 uF. Start to listen with 2200 uF and sometimes later in the process add 10 uF to hear the difference.
Hi Lazycat,
I got the package few days back, can't be more happy than holding the PCBs in my hand. I see you have foil wrapped the ALF FET, how to handle this before soldering it on the board? Should I use grounding wrist strap to avoid ESD damage? or not needed.
With the quality of the assembly, I wish I choose to get the remaining semiconductors soldered by you/your team. My soldering skills are no where near
Thank you
I got the package few days back, can't be more happy than holding the PCBs in my hand. I see you have foil wrapped the ALF FET, how to handle this before soldering it on the board? Should I use grounding wrist strap to avoid ESD damage? or not needed.
With the quality of the assembly, I wish I choose to get the remaining semiconductors soldered by you/your team. My soldering skills are no where near
Thank you
very early Ge cfb V to I VSSA: http://www.diyaudio.com/forums/atta...7549d1350806656-pavel-macuras-cfp-amp-cfp.png
Looks like there is no way for controlling the output stage bias or does it run on the verge of being off ! The feedback is different too. It senses the output load current and not voltage. So you might get more of a current source than a voltage source. But then this might be good for the loudspeaker ! The 0.33 ohms seems to be in the wrong place. Doesn't seem to do much good there.
The inductor would open circuit the output stage for NFB. Is that a good thing ?
Maybe this stage wasn't actually tested as shown?
to be honest I have no idea
maybe not but this circuit is not so stupid, V to I amp with cfb should sound nice even with with thd levels. the simulation showed good behavior in class A with 1A idle.
here @365mA, still "has a potential":
Attachments
Yes it's always interesting to try out new circuits . Here I worry about how the output stage bias will be set up and stabilised . Might turn out to be a good sounding amp. If the inductor causes problems at HF one could try a resistor in parallel to avoid a complete open ckt at HF ( RF?).
To get 2210 uF cap.
Not neccessary need to install 10 uF. Start to listen with 2200 uF and sometimes later in the process add 10 uF to hear the difference.
I just listning without 10uF , used Black Gate FK 2200uF
and as PSU local suport Panasonic HFZ 470uF
Previously it was
2200uF Rubycon ZL +10uF MKT 1812 Vishay
and local PSU Panasonic FC 1000uF/50V
What I can cleary see
, soundstage image is much better without 10uFHowever to early to make final conclusions
Heatsink template
I have not yet received my VSSA, I have created a PDF for the heatsink template, please verify.
The inner rectangle is 50 x 60mm
The outer rectangle is 52 x 62mm
Happy building.
Yes thanks AKN, an isosceles triangle (equal sides) with 41,6 mm base and 26,3 mm height to be exact. Tripod made of transistors makes VSSA also mechanically stable.
I have not yet received my VSSA, I have created a PDF for the heatsink template, please verify.
The inner rectangle is 50 x 60mm
The outer rectangle is 52 x 62mm
Happy building.
+1, exactly my thoughts after looking at my PCB.
LC, thank you for your effort.
Thanks
Recieved mine today.
Looking at VSSA photographs in this thread I forgot how big they really are
LC, thank you for your effort.
Thanks
8 GB members still to be delivered when ALF mosfets will arrive. I got an official answer from SEMELAB sales.
"The current situation with this part is as follows:
This is a double die device, we have one die here (P channel) the N has been rejected at the supplier. They have sent us some samples to do trials on and we are accessing to see if these are usable.
Our die supplier rejected the die as failing. We have in this week a 300 sample batch to qualify these and await the results before we are able to move forward.
Ongoing, when we have resolved the die issue, this will not be a problem part, this is a newer part and one of ours and therefore no plans to make the ALF range obsolete.
We are working to resolve the issue which will be achieved, this has been escalated to the managers in all relevant departments and we are doing our upmost to resolve the current situation. The sample batch will be build over the weekend and testing on Tuesday late afternoon, if the results are positive we will then request the die to be shipped here. Until the samples have been tested we are unable to commit further dates.
I will again update you next week with the results over the weekend.
Kind regards.
Customer Services
Semelab Limited"
We talked about this on the phone today. I think they will get it fixed very soon as it is a die they use in all there lateral fets.
Regarding KSC3503ESTU and KSA1381ESTU. I have plenty in stock, and i will make sure if some of you by accident break them in there VSSA board that i will be able to supply them.
