I know about food poisoning I had the same a few years ago on December 24th following a Christmas meal at a restaurant. My wife, my sister in law and myself were all sick all evening and night..🙁
I hope you will get better soon
Are your batteries rechargeable or big capacity because of the 50-60ma per channel for bias current 🙄
Fab
I hope you will get better soon
Are your batteries rechargeable or big capacity because of the 50-60ma per channel for bias current 🙄
Fab
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Hi fab
Yes it will be my 2nd usspa.
I made so I could play with to a friend with high end equipment. He was so impressed with the last one and asked for a unit to be parked at his home. He is using single ended tube.. So it's something different. It's like.. Expensive better? Sometimes nahh
This will be integrated with rjm emerald phono. That's a good project.. If anyone care to diy a phono. We also tested with some of the best.. No problem with quality.
With a switch for cd and phono, so it will be easy to compare later.
Perhaps this time.. I will try studer 900 power supply. Then make a comparison with other supply since the supply will be on separate box. Easy to compare. But need rebias everything with every change
I made some material change.. That guy have a very revealing and clean sounding system. So soften it some with carbon resistors. And a slightly more dirtier supply. He got all the slam already one could wish for so...
Happy new year all
Yes it will be my 2nd usspa.
I made so I could play with to a friend with high end equipment. He was so impressed with the last one and asked for a unit to be parked at his home. He is using single ended tube.. So it's something different. It's like.. Expensive better? Sometimes nahh
This will be integrated with rjm emerald phono. That's a good project.. If anyone care to diy a phono. We also tested with some of the best.. No problem with quality.
With a switch for cd and phono, so it will be easy to compare later.
Perhaps this time.. I will try studer 900 power supply. Then make a comparison with other supply since the supply will be on separate box. Easy to compare. But need rebias everything with every change
I made some material change.. That guy have a very revealing and clean sounding system. So soften it some with carbon resistors. And a slightly more dirtier supply. He got all the slam already one could wish for so...
Happy new year all
Hi Anthony
I am glad to know that your friend also likes the USSPA. Was it version 1 or 2 he listened to?
Fab
I am glad to know that your friend also likes the USSPA. Was it version 1 or 2 he listened to?
Fab
Hi fab
V1, he heard
But im making v2. And aiming to be more rounded weighty textured , it should suite his system more. As he have diamond tweeter and carbon cones. Need more mid. Just waiting for the supply kit
V1, he heard
But im making v2. And aiming to be more rounded weighty textured , it should suite his system more. As he have diamond tweeter and carbon cones. Need more mid. Just waiting for the supply kit
Done for the day.
I'm not using kemet cap this time.. Want to sound less clean and see how it goes
Waiting for supply
Hi AnthonyA
The specified power supply caps combination has been selected (from Nippon Chemicon white paper) for optimal impedance response against frequency band. Your new cap should also work even though not optimized🙄
Without knowing exactly what you mean by “less clean” have you tried to modify H2 level using one optional resistor as per section 7 of the manual?
I thought that the goal was to be clean😉
Fab
The specified power supply caps combination has been selected (from Nippon Chemicon white paper) for optimal impedance response against frequency band. Your new cap should also work even though not optimized🙄
Without knowing exactly what you mean by “less clean” have you tried to modify H2 level using one optional resistor as per section 7 of the manual?
I thought that the goal was to be clean😉
Fab
Hi Fab
. I will learn how to adjust H2 using scope with my friend later. The jfet is getting scarce so it's not very tightly match, could only manage 0.6ma diff . Will be better I learn to use the oscilloscope.
Darn.. I should have ordered the caps with u.. Lol let's light it up first
. I will learn how to adjust H2 using scope with my friend later. The jfet is getting scarce so it's not very tightly match, could only manage 0.6ma diff . Will be better I learn to use the oscilloscope.
Darn.. I should have ordered the caps with u.. Lol let's light it up first
Hi AnthonyA
The scope function will not show H2 unless the scope has FFT function.
Your jfet are very well matched if they only have 0.6ma difference on IDSS 😉
You should have reduced H2 with that good match 🙄
For the different cap type it is not that much a big deal, it is just that I want things to be optimized as much as possible...😎
Good luck
Fab
The scope function will not show H2 unless the scope has FFT function.
Your jfet are very well matched if they only have 0.6ma difference on IDSS 😉
You should have reduced H2 with that good match 🙄
For the different cap type it is not that much a big deal, it is just that I want things to be optimized as much as possible...😎
Good luck
Fab
Hi AnthonyA
So this this the USSPA2 with different PSU caps?
For the R and C of the FSSA amp, I just sent you the proof of shipment with the date. Let’s wait a little more time before concluding...
Fab
So this this the USSPA2 with different PSU caps?
For the R and C of the FSSA amp, I just sent you the proof of shipment with the date. Let’s wait a little more time before concluding...
Fab
Yup that's the one. Super big heatsink. I bought the studer 900 power supply and 1963/3015 for compare ... It's been 2 months.
Ya no worries. Seem Mr postman is busy about nothing as usual.
Ya no worries. Seem Mr postman is busy about nothing as usual.
Yes as per section 7 of the manual, only one side at a time should be adjusted but you can install 10k ohms pot for each side and set to 10k ohms for both to start with. Afterwards start reducing the value on one side only. The noticeable effect will only show once you reach less than 1K ohms or less. You may have to readjust dc offset during that process.
Fab
Fab
I'm going to learn how to use the fft for this and report the differences.
Can you please post some output pictures of the fft for reference? I don't understand the curves
Can you please post some output pictures of the fft for reference? I don't understand the curves
Hi Fab sorry for Dumb questions as u know I know nothing much.
I haven't mounted the pcb on fssa.. So when is a good time to tweak it? Also it's a bad position once all box installed its very difficult to reach for the trimpot
It's only adjustable for positive h2 on both usspa and fssa ? Or both positive and negative?
I haven't mounted the pcb on fssa.. So when is a good time to tweak it? Also it's a bad position once all box installed its very difficult to reach for the trimpot
It's only adjustable for positive h2 on both usspa and fssa ? Or both positive and negative?
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Pot on a pcb always makes it difficult to adjust once board is installed in the amp...
You can tweak it with heatsink installed horizontally.
Depending which side you use (positive or negative) it can go either way but probably not symmetrically because without adjustment you have already H2 present on a polarity thus less margin to increase H2 on the other polarity.
Fab
You can tweak it with heatsink installed horizontally.
Depending which side you use (positive or negative) it can go either way but probably not symmetrically because without adjustment you have already H2 present on a polarity thus less margin to increase H2 on the other polarity.
Fab
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