The C suffix on the devices are the high gain variety. I always use the high gain variety. So IMHO, yes, good.
I think it was Keantoken (if memory serves me correctly) that suggested going for the onsemi devices so that's what I do these days. I have no other basis to my choice. Others probably have an opinion on this. Maybe there is no significant difference.
I got 300 each, but they are from mouser - Fairchild....
I would like to buy some other items from Mouser, but they charge to much to ship to Croatia.
Can I get them for you and send them to you in a letter or
E-MAIL just joking on the email part...
Can I get them for you and send them to you in a letter or
You mean I order it to be shipped to your address?
How much Mouser shippment cost in states?
All orders I have gotten cost mostly 5 dollars, but the last one was almost 10, what the letter to Croatia cost? Compare to Mouser shipping it.
When I finish testing and there are more interested parties, I can order more PCB as I have the films now.
Manso, the follower (output buffer) is cascaded with TO220 BJTs (BD139/140, not yet mounted in the photo) and it was designed to be used as line and headphones amp.
BR Damir
Now one channel is working in NGFB and CFA mode. DC servo is working too with some time to settle, maybe some time delay will be needed to connect output(with relay).
Progress is slow, I and my wife, we do some baby sitting during a week . One of my grandsons on the attached photo.
Bimo, the potentiometer should be connected before input, could be from 10k to 50k.
I will present whole connection schematic with input selector, volume control, grounding, when I finish with testing and listening.
BR Damir
Progress is slow, I and my wife, we do some baby sitting during a week . One of my grandsons on the attached photo.
Bimo, the potentiometer should be connected before input, could be from 10k to 50k.
I will present whole connection schematic with input selector, volume control, grounding, when I finish with testing and listening.
BR Damir
Attachments
Finally I populated the PCB, and test it with signal generator and oscilloscope. It worked with no visible distortion in both mode, NGFB and CFA.
Now I connected it to DENON DVD 3910 and SENHEISER HD 580 pecision headphones. Beautiful music came out of the headphones. I was listening CD Patricia Barber and some classical music from DVD audio. I was shocked with great dynamics and crystal clear sound, really to my complete satisfaction, I use daily my first GainWire(input JFETs and different output buffer) but this one sounded better, not sure what gives that different gain block(both are current conveyor) or better output buffer. I tried Sony low impedance headphones and it worked equally well.
After some listening trough headphones I connected it to my TT amp and again it played with authority and beautifully. Bass was exceptional, voices very natural, and heights clear.
As a volume control I used Chinese step attenuator with SMT resistors and I think it is quite good, not sure if better (more expensive) attenuator could improve the sound. I was listening in both mode, NGFB and CFA and could not tell what was the preferable setting, probably due to short listening session.
To make complete pre amplifier it needs transformer 30 to 50 VA 2x15 V AC, a volume control and input selector, and a box off cause.
BR Damir
Now I connected it to DENON DVD 3910 and SENHEISER HD 580 pecision headphones. Beautiful music came out of the headphones. I was listening CD Patricia Barber and some classical music from DVD audio. I was shocked with great dynamics and crystal clear sound, really to my complete satisfaction, I use daily my first GainWire(input JFETs and different output buffer) but this one sounded better, not sure what gives that different gain block(both are current conveyor) or better output buffer. I tried Sony low impedance headphones and it worked equally well.
After some listening trough headphones I connected it to my TT amp and again it played with authority and beautifully. Bass was exceptional, voices very natural, and heights clear.
As a volume control I used Chinese step attenuator with SMT resistors and I think it is quite good, not sure if better (more expensive) attenuator could improve the sound. I was listening in both mode, NGFB and CFA and could not tell what was the preferable setting, probably due to short listening session.
To make complete pre amplifier it needs transformer 30 to 50 VA 2x15 V AC, a volume control and input selector, and a box off cause.
BR Damir
Attachments
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