Wuffwaff, that is very nice perfboarding, indeed🙂 Looks good with the perforated heatsink and the blue led's onboard. Really cool work😎 Hope it sounds as good as it looks.
Steen🙂
Steen🙂
Please Wuffwaff could you draw your schematic here with changes and post some sound comments please
Your heatsink idea is awsome BTW 😉
Regards,
nar
Your heatsink idea is awsome BTW 😉
Regards,
nar
Hi,
I will draw a schematic and scan it. Comments on sound will come in a few weeks cause it´s still not build into in the preamp and I always need a bit of time listening.
William
I will draw a schematic and scan it. Comments on sound will come in a few weeks cause it´s still not build into in the preamp and I always need a bit of time listening.
William
Hi William,
Are you still working on your UGS module and are you going to compare it with the new cs-ccs-x-bosoz? I would be interested in the results.
Graeme
Are you still working on your UGS module and are you going to compare it with the new cs-ccs-x-bosoz? I would be interested in the results.
Graeme
Hi William,
Please forgive me. It is acaudio that was working on the UGS project. My mistake. But i am still very interested in your listening test results.
Graeme
Please forgive me. It is acaudio that was working on the UGS project. My mistake. But i am still very interested in your listening test results.
Graeme
Member
Joined 2002
cobra,
What do you think of the pre-amp any details you want to let us know about ? Is it connected to that parasound power amp or another kind ?
What do you think of the pre-amp any details you want to let us know about ? Is it connected to that parasound power amp or another kind ?
Parts:
R1,2: 10k
R11,12:100k
R15,16:39k
R7,8:1k2 (only needed for my balanced attenuator)
R3,4: 560R / 2watt
R5: 15k
R14: 470R (4x 470R/2 watt)
R9,10,17,19,20:220R
R18: 18k
P1: 50R / 0,5 watt
Q1,2,3,4,5: IRF610
D1-5: led blue
C1,2: 47uF BG N
C3,4: 1000uF / 63V Pan FC, parallel 10nF Wima FKP2
plus the usual zeners for input protection.
R14 is only in there because I wanted to use my existing -60V supply. It can be left out with a -10 or -15V supply
william
R1,2: 10k
R11,12:100k
R15,16:39k
R7,8:1k2 (only needed for my balanced attenuator)
R3,4: 560R / 2watt
R5: 15k
R14: 470R (4x 470R/2 watt)
R9,10,17,19,20:220R
R18: 18k
P1: 50R / 0,5 watt
Q1,2,3,4,5: IRF610
D1-5: led blue
C1,2: 47uF BG N
C3,4: 1000uF / 63V Pan FC, parallel 10nF Wima FKP2
plus the usual zeners for input protection.
R14 is only in there because I wanted to use my existing -60V supply. It can be left out with a -10 or -15V supply
william
William,
Nice work indeed, I'm glad to see someone besides me building perboard circuits! Very nice implementation of the cascode voltage reference too!
Do you have any measurement data you could post? I haven't measured mine, but my circuit simulations said that the -3dB point would be a hair under 1.0MHz. I'd like to see a pic of that 10kHz squarewave too if you can post one.
I hope that it sounds as good as it measures. Please do post your listening impressions.
Cheers, Terry
Nice work indeed, I'm glad to see someone besides me building perboard circuits! Very nice implementation of the cascode voltage reference too!
Do you have any measurement data you could post? I haven't measured mine, but my circuit simulations said that the -3dB point would be a hair under 1.0MHz. I'd like to see a pic of that 10kHz squarewave too if you can post one.
I hope that it sounds as good as it measures. Please do post your listening impressions.
Cheers, Terry
Hi,
after looking at the "nice" square waves a bit closer there seems to be some overshoot at 10 and 100kHz. Not really much but also not really nice.
Since the test setup consist of a unbalanced input and some flying wires I´m not shure if I will get the same result in the proper case.
If so this probably means I need some compensation caps
I suppose these would be placed over R15 and R16 being the main feedback resistors?
William
after looking at the "nice" square waves a bit closer there seems to be some overshoot at 10 and 100kHz. Not really much but also not really nice.
Since the test setup consist of a unbalanced input and some flying wires I´m not shure if I will get the same result in the proper case.
If so this probably means I need some compensation caps
I suppose these would be placed over R15 and R16 being the main feedback resistors?
William
Willaim,
Before you sink into despair, try bypassing the output electrolytic caps with a small value film cap. I believe that this will solve the overshoot problem. In my version, I avoided electrolytics in the signal path and used 10uF polyprop film caps.
Cheers, Terry
Before you sink into despair, try bypassing the output electrolytic caps with a small value film cap. I believe that this will solve the overshoot problem. In my version, I avoided electrolytics in the signal path and used 10uF polyprop film caps.
Cheers, Terry
Hi Terry,
I left some space on the board for bypass caps because I wanted to try some after listening to the Black Gates alone.
I will fit two of them and see if something changes. I´m not very optimistic though cause they would normaly increase the bandwidth not lower it.
William
I left some space on the board for bypass caps because I wanted to try some after listening to the Black Gates alone.
I will fit two of them and see if something changes. I´m not very optimistic though cause they would normaly increase the bandwidth not lower it.
William
Thanks,
it is always good to sleep a night over something.
Looked at the square waves again today but this time also at the input signal. This is also showing some overshoot! When I raise the output impedance of the signal generator from 50 to 600 Ohms everything gets rounded of (in AND output)
Terry,
just for fun I put a 33nF ERO MKP parallel to the output caps but I could see no influence at all (as expected)
So now I´ve got a BOSOZ wich shows very nice square waves at 100kHz (wich probably is utterly unimportant😀 ) and is flat beyond 1MHz (you know for SACD and Vinyl)
Next I will put it in it´s case and have a listen.
William
it is always good to sleep a night over something.
Looked at the square waves again today but this time also at the input signal. This is also showing some overshoot! When I raise the output impedance of the signal generator from 50 to 600 Ohms everything gets rounded of (in AND output)
Terry,
just for fun I put a 33nF ERO MKP parallel to the output caps but I could see no influence at all (as expected)
So now I´ve got a BOSOZ wich shows very nice square waves at 100kHz (wich probably is utterly unimportant😀 ) and is flat beyond 1MHz (you know for SACD and Vinyl)
Next I will put it in it´s case and have a listen.
William
William,
Glad to hear you found things working properly in the end. Although amplitude linearity beyond 100kHz probably doesn't make any difference, if you look at the phase response you'll see that phase lag starts at much earlier frequencies. I designed the circuit to keep the phase change within the audible range nice an low (if I recall it is less than 5° at 20kHz, and doesn't reach 10° until ~80kHz).
I look forward to hearing your opinion on the change in sound with the addition of the cascode.
Cheers, Terry
Glad to hear you found things working properly in the end. Although amplitude linearity beyond 100kHz probably doesn't make any difference, if you look at the phase response you'll see that phase lag starts at much earlier frequencies. I designed the circuit to keep the phase change within the audible range nice an low (if I recall it is less than 5° at 20kHz, and doesn't reach 10° until ~80kHz).
I look forward to hearing your opinion on the change in sound with the addition of the cascode.
Cheers, Terry
The sound
Hi,
after listening for a few days to my "new" CS-CCS´ed x-bosoz I must say that the difference is bigger than expected🙂
It´s a bit like the difference between my Aleph5 and Aleph-X:
tighter bass, less bloom, more room information and a better separation of instruments during complex passages. It also seems to have less compression and sounds somehow faster.
One nice thing about this is that altough it sounds less "romantic" it is still possible to listen for hours without listening fatique. The other is that allthough the new version sounds better I never had a problem with the old one and would reccomend it anytime.
Please note that besides cascode and constant current source there are some more changes:
1. Output caps are now BG N 47uF 50V instead of 2x WIMA MKS4 10uF (no space for those and I´m not afraid of elcos anymore after using them in the output stage of my x-bosoz cd output stage with very good results)
2. Output resistors are 1k2 instead of 2k2
The rest including the supply and all of the wiring are exactly the same as it is a drop in replacement for my previous board. I will change my standard x-bosoz (output caps and resistors) and test it again (should take only 15minutes to change from one to the other)
William
Hi,
after listening for a few days to my "new" CS-CCS´ed x-bosoz I must say that the difference is bigger than expected🙂
It´s a bit like the difference between my Aleph5 and Aleph-X:
tighter bass, less bloom, more room information and a better separation of instruments during complex passages. It also seems to have less compression and sounds somehow faster.
One nice thing about this is that altough it sounds less "romantic" it is still possible to listen for hours without listening fatique. The other is that allthough the new version sounds better I never had a problem with the old one and would reccomend it anytime.
Please note that besides cascode and constant current source there are some more changes:
1. Output caps are now BG N 47uF 50V instead of 2x WIMA MKS4 10uF (no space for those and I´m not afraid of elcos anymore after using them in the output stage of my x-bosoz cd output stage with very good results)
2. Output resistors are 1k2 instead of 2k2
The rest including the supply and all of the wiring are exactly the same as it is a drop in replacement for my previous board. I will change my standard x-bosoz (output caps and resistors) and test it again (should take only 15minutes to change from one to the other)
William
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