Actually, I tried a led reference trying to get closer to 8V with the 317 and I got a bit of a surprise. The leds were flashing like a Christmas tree, which means that there are points where the motors require more than the 1.5A that the 317 offers.
That might also explain why the 2.2A 7808 sounded better and the delays in TOC reading.
So LM350 might be a better choice after all...
That might also explain why the 2.2A 7808 sounded better and the delays in TOC reading.
So LM350 might be a better choice after all...
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7808 sound amazing
Hi Dimkasta
I appreciate sharing your experiments.
It's allredy discovered from P. Daniel if I remember correctly??
Have you made a modification, made by Tibi in leter # 7300?
A gane thanks for share your expiriment aqnd conclusion.
Regards
IVO-CICI
I tried LM350 today and gave up...
7808 sounds amazing in my current setup anyway.
If I could solve the CDR and SACD skipping thingy I would have closed the project and moved on like a happy bunny
Hi Dimkasta
I appreciate sharing your experiments.
It's allredy discovered from P. Daniel if I remember correctly??
Have you made a modification, made by Tibi in leter # 7300?
A gane thanks for share your expiriment aqnd conclusion.
Regards
IVO-CICI
Hi Tibi,
I would like to know how many external super regulators you are able to use on your board (without redesigning it )
I ask this since you stated somewhere in June 2012 that you had malfunctions with using multiple superregs and advised only 8 volt.
So I am talking about the very first boards that went out.....since I may get my hands on one of those and would like to experiment.
Respect so far for your achievements
I would like to know how many external super regulators you are able to use on your board (without redesigning it
)I ask this since you stated somewhere in June 2012 that you had malfunctions with using multiple superregs and advised only 8 volt.
So I am talking about the very first boards that went out.....since I may get my hands on one of those and would like to experiment.
Respect so far for your achievements
Damn I have destroyed Q3 trying to desolder it....
Tibi can you please verify that BC848B,215 NXP Semiconductors | Mouser is a valid replacement?
Thanks
Tibi can you please verify that BC848B,215 NXP Semiconductors | Mouser is a valid replacement?
Thanks
Hi guys,
ive been playing with a 50 ohm coax attenuator with a 50 to 75 ohm matching pad for the spdif output. I didn't like the results. It took away the dynamics and details. I'll be playing with a pipad soon. Ill be using caddocks in shunt position and shinkoh or riken on the series.
what are you guys using on the spdif output?
ive been playing with a 50 ohm coax attenuator with a 50 to 75 ohm matching pad for the spdif output. I didn't like the results. It took away the dynamics and details. I'll be playing with a pipad soon. Ill be using caddocks in shunt position and shinkoh or riken on the series.
what are you guys using on the spdif output?
Get rid of as many connections as possible on your output line. I have soldered the cable directly on the output attenuator to eliminate reflection creation points.
And if you want a perfect 0,5V output, you need a 14.2dB attenuator.
I am using a Tee pad with (50 series, 32 shunt, 50 series). I have not tried the 50-75 yet.
I have selected the Tee pad because of lower resistance values in series with the signal. Jarek is very fond of his 50-75 pi-pad as well, so I would give it a serious try as well.
You can check my oscilloscope testing here
http://www.diyaudio.com/forums/digi...ansport-shigaclone-story-722.html#post3494010
And if you want a perfect 0,5V output, you need a 14.2dB attenuator.
I am using a Tee pad with (50 series, 32 shunt, 50 series). I have not tried the 50-75 yet.
I have selected the Tee pad because of lower resistance values in series with the signal. Jarek is very fond of his 50-75 pi-pad as well, so I would give it a serious try as well.
You can check my oscilloscope testing here
http://www.diyaudio.com/forums/digi...ansport-shigaclone-story-722.html#post3494010
Hi Tibi,
I would like to know how many external super regulators you are able to use on your board (without redesigning it
I ask this since you stated somewhere in June 2012 that you had malfunctions with using multiple superregs and advised only 8 volt.
So I am talking about the very first boards that went out.....since I may get my hands on one of those and would like to experiment.
Respect so far for your achievements
Hi Erik,
The very first board we have tested had oscillation problems with my LT1763 regs., manly due layout grounding scheme. Later I decided to remove these and let user to use what super reg they prefer. It was also cost effective.
Beside 8V for motor driver, there are 4 places where you can connect a 5V super reg. These are marked on board as V1; V2; V3; V4.
For your convenience, Shiga - first version - documentation is available on gdocs as well.
https://docs.google.com/document/d/1vlabZc_1If3x12ox2A5ECZxC0HLGnuOWdM-j9X4b7Q0/edit
See page 9 for power connection options.
Best regards,
Tibi
Q3 is 2SA1342 and can not be replaced with any BC type due bias resistors which are on the same silicon die with transistor.
http://vicol-audio.ro/docs/2SA1342.pdf
In case you need more info about a Shiga or Shiga parts please use my webpage.
vicol audio : shiga CD transport
Best regards,
Tibi
Since I am very pleased with the C906 tests (Duelund cast came today...to be continued) I thought it was about time to share my (personal opinion and personal setup) thoughts on regulation.
First the 8 volt regulation of the motors.
So again on my cd-testboard I mounted three regulators.
1. The standard regulation LM7808
2. The Anthony L. Weeks 8 volt Super Regulator (with pre regulation)
3. The Teddy Pardo 8 volt Super Regulator (with pre regulation)
At the moment I still have the Weeks regs implemented in my PiTbull Reference...and I wondered if there is a new kid on the block...or is it maybe better without super regs...so the motors get full power....only one way to find out.
These are the two cds we listened to
First the 8 volt regulation of the motors.
So again on my cd-testboard I mounted three regulators.
1. The standard regulation LM7808
2. The Anthony L. Weeks 8 volt Super Regulator (with pre regulation)
3. The Teddy Pardo 8 volt Super Regulator (with pre regulation)
At the moment I still have the Weeks regs implemented in my PiTbull Reference...and I wondered if there is a new kid on the block...or is it maybe better without super regs...so the motors get full power....only one way to find out.
These are the two cds we listened to
So I mounted the lot on my cd-testboard with plug ins so the switching time is kept to a minimum.
In my listening room you see the PSU this time with no transport on top...watching patiently next to my pre amp for " nicer things to come" because the winner gets implemented in that transport ....my Reference.
In my listening room you see the PSU this time with no transport on top...watching patiently next to my pre amp for " nicer things to come" because the winner gets implemented in that transport ....my Reference.
Well the results of the jury....
To my ears (and my friend) and in my setup and on my testboard etc. etc. etc.
There were clearly audible differences among the three.
First of all the difference between the standard reg and the super reg.
Also differences between the two super regs (both with the same pre regulation)
The First:
The standard 8 volt regulation sounded "rough" with less "grandeur" easily to be heard on Haydn Cello Concerto by J. Du Pre
The violins had some sort of distortion and the orchestra seemed smaller presented..and as a sideline the mechanics operated noisily when reading TOC (obviously the unleashed power without sup reg)
The Second :
The Anthony L. Weeks 8 volt Super Regulator sounded straight away a decent bit better
The sax on Harry Belafonte Sings The Blues was more palpable also guitarstrings had more dynamics and the violins on Haydn sounded a lot nicer. The voice of Belafonte had more body.
THE THIRD:
The Teddy Pardo 8 volt Super Regulator (at the moment implemented in the Mini PiTbull) yeppppp....was the clear winner.
The sax on Belafonte was lovely and rough at the same time, there was more "swing" to the song. Guitarstrings were "really life like" and violins on the HQ cd Haydn had a nice shine.
No need to say that I ordered a few more Teddy regs to do further comparisons/testing for the 5 volt lines.
(Eg. Chip and AT&T)
.....to be continued....
To my ears (and my friend) and in my setup and on my testboard etc. etc. etc.
There were clearly audible differences among the three.
First of all the difference between the standard reg and the super reg.
Also differences between the two super regs (both with the same pre regulation)
The First:
The standard 8 volt regulation sounded "rough" with less "grandeur" easily to be heard on Haydn Cello Concerto by J. Du Pre
The violins had some sort of distortion and the orchestra seemed smaller presented..and as a sideline the mechanics operated noisily when reading TOC (obviously the unleashed power without sup reg
)The Second :
The Anthony L. Weeks 8 volt Super Regulator sounded straight away a decent bit better
The sax on Harry Belafonte Sings The Blues was more palpable also guitarstrings had more dynamics and the violins on Haydn sounded a lot nicer. The voice of Belafonte had more body.
THE THIRD:
The Teddy Pardo 8 volt Super Regulator (at the moment implemented in the Mini PiTbull) yeppppp....was the clear winner.
The sax on Belafonte was lovely and rough at the same time, there was more "swing" to the song. Guitarstrings were "really life like" and violins on the HQ cd Haydn had a nice shine.
No need to say that I ordered a few more Teddy regs to do further comparisons/testing for the 5 volt lines.
(Eg. Chip and AT&T)
.....to be continued....
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Yes I have 5v chip, 5v AT&T and 8v for the motors and 12v for the clock at the moment
Ah cool. I was going to suggest the separation before any other testing.
By the way, on all of my tests, the thing sounded better with an additional 1000uF cap on the entrance of power right on the PCB. The better behavior was also verified with a scope. It s quite a nasty little thing. Both sides motors and digital stuff are quite horrible and inflict huge voltage spikes on the reg. On the motor side the swing was close to half a volt with the 7808.
Oh and do not neglect to try the big prefilter with those specific diodes I posted a few posts back. With the 7808 included.
By the way, on all of my tests, the thing sounded better with an additional 1000uF cap on the entrance of power right on the PCB. The better behavior was also verified with a scope. It s quite a nasty little thing. Both sides motors and digital stuff are quite horrible and inflict huge voltage spikes on the reg. On the motor side the swing was close to half a volt with the 7808.
Oh and do not neglect to try the big prefilter with those specific diodes I posted a few posts back. With the 7808 included.