Hi Gabor
Probably you overlooked that in the first batch I got only 200 pcs. of ALF mosfets from Semelab. To be correct to the ones who ordered and payed complete sets from the early start, I have to follow GB list and these 200 pcs. will go to them first. When the rest 100 pcs. ordered ALF-s will be received, as promised, you'll get them as well to make comparison.
Regards, Lazy Cat
Hello
That would be perfect!!!
Thank you
Greetings Gabor
35 g for stereo
Please weight and show us both finished PCB modules.
Hardly wait to see your final implementation.
I will for sure be interesting seeing all different VSSA implementations - Your reward after all work.
I sneak in with a halfway report. Almost 100% VSSA weight gain, now at healthy 74g.
Elcaps are on back order, I'll get them on Monday.Attachments
@Salas: This is a follow-up to my earlier bw measurements and estimate. The earlier pics were not usable, these are from a re-do. (The Wavetek makes it hard to repeat a test exactly at over 1 Mhz) I tried using a bench supply (on the right in the last pic) to get a better ground reference for the tests, but that only helped slightly if at all, so this is going to be the best I can do with this source.
HF rolloff:
To show input and output signals same size while using two different scales, I used the screen calibration adjustment to scale (normalize) the channels. In other words, I used the screen-cal adjustment to tweak the display, but NOT the measurements.
To measure sine wave P-P voltage and frequency at the same time on this scope, the cursors have to be 1/2 wave apart, delta-T represents 1/2 of the period, and f=1/(2*delta-T). Only 1 channel can be measured at a time, so when the signal starts to phase shift, only the delta V2 is relevant.
The signal source is an old Wavetek analog signal generator, Most of the waveform distortion visible in the tests above 1 MHz is from the generator, not from the VSSA circuit (verified). Amplitude and rise/fall times are correct.
Pics:
#1 - 100 kHz since wave, input and output in phase, no attenuation.
#2 - 1.1 MHz, -2db
#3 - 1.3 MHz, -3db
#4 - Setup, as tested
HF rolloff:
To show input and output signals same size while using two different scales, I used the screen calibration adjustment to scale (normalize) the channels. In other words, I used the screen-cal adjustment to tweak the display, but NOT the measurements.
To measure sine wave P-P voltage and frequency at the same time on this scope, the cursors have to be 1/2 wave apart, delta-T represents 1/2 of the period, and f=1/(2*delta-T). Only 1 channel can be measured at a time, so when the signal starts to phase shift, only the delta V2 is relevant.
The signal source is an old Wavetek analog signal generator, Most of the waveform distortion visible in the tests above 1 MHz is from the generator, not from the VSSA circuit (verified). Amplitude and rise/fall times are correct.
Pics:
#1 - 100 kHz since wave, input and output in phase, no attenuation.
#2 - 1.1 MHz, -2db
#3 - 1.3 MHz, -3db
#4 - Setup, as tested
Attachments
... because in the middle of this thread I was kindly asked by many VSSA followers to prepare a group buy, not my intention at the first place when started this thread. Now even more obvious when faced with a looots of work needed to make its realization and that everything is running well. Costs will be covered for me but more of importance is that audio community will hear the results of a small little amplifier for not so big costs and to have a pleasure with their DIY activity.
... 
Also too many posts about GB info is not nearly much fun
I must agree with @apexaudio. A parallel thread would have been more neat.
It is still time to ask the moderation to jump all related posts to a new separate GB thread.
Also too many posts about GB info is not nearly much fun
So I see you're quiet VSSA thread follower, otherwise wouldn't be bothered.
Look guys I agreed to go into GB in one condition only, all to stay in one thread, if that would be broken count me out.
Regards Lazy Cat
I see it as a group buy on a project LC brought to a high degree of development and nothing more. If he wanted to offer it in unlimited quantities for significant profit on an ongoing basis then I'd say to the commercial sector or should go. As it sits I think it should stay put. My two cents.
