You Ain't Lived...
You ain't lived 'till you wired an OPA1462AID to an 8p DIP socket to adapt it to plug into an 8p DIP socket! Changing U-1 from TL072 to OPA1462AID and changing R-1,2,3 from carbon film to metal film seems to have pushed the noise floor down a few more db. It's hard to read the output noise on the scope because I have about 10mv p/p of ps switching/amp noise and I can only see it for a second or two by unplugging the ps and reading the noise while the filter capacitors hold. My best guess is 5mv p/p noise and most of it should be below 1khz, against a peak output level of 2v p/p.
You ain't lived 'till you wired an OPA1462AID to an 8p DIP socket to adapt it to plug into an 8p DIP socket! Changing U-1 from TL072 to OPA1462AID and changing R-1,2,3 from carbon film to metal film seems to have pushed the noise floor down a few more db. It's hard to read the output noise on the scope because I have about 10mv p/p of ps switching/amp noise and I can only see it for a second or two by unplugging the ps and reading the noise while the filter capacitors hold. My best guess is 5mv p/p noise and most of it should be below 1khz, against a peak output level of 2v p/p.
Happy Holidays/Merry Christmas
Hi Guys, Happy Holidays and Merry Christmas. I accidentally broke my OPA1462A while I was trying to built a better DIP8 adapter for it, so I'm back to using the TL072 as my U-1. This video shows some of my other pre-amp mod's and my Mono cartridge jumper. I've got about 10 minutes of Robert Rheims-Christmas In Carols, played on pipe organ and chimes.
Robert Rheims, VinyLiberator Video YouTube - Vnlbr R Rheims YT imfree707.mp4
It's a 50 year old clear red vinyl mono pressing, a little scratchy, but with cart jumpered in mono, is usable. I enjoy the record and would like to share
on You Tube, please enjoy.
Hi Guys, Happy Holidays and Merry Christmas. I accidentally broke my OPA1462A while I was trying to built a better DIP8 adapter for it, so I'm back to using the TL072 as my U-1. This video shows some of my other pre-amp mod's and my Mono cartridge jumper. I've got about 10 minutes of Robert Rheims-Christmas In Carols, played on pipe organ and chimes.
Robert Rheims, VinyLiberator Video YouTube - Vnlbr R Rheims YT imfree707.mp4
It's a 50 year old clear red vinyl mono pressing, a little scratchy, but with cart jumpered in mono, is usable. I enjoy the record and would like to share
on You Tube, please enjoy.
Vielen Danke...
Thank you, Guys. Have a great week and a Merry Christmas.
Merry Xmas Edgar!
Thank you, Guys. Have a great week and a Merry Christmas.
Thanks Guy
Thanks Joachim, those are kind words and I know you have those same qualities because you can see and appreciate them in others! Lessee( US Southern for "let's see"), how do you say that.......,oh, yes!...Frohe Weinachten!
(Hahaha!, I'm an Army Brat who was born in Mannheim.)
Thanks Joachim, those are kind words and I know you have those same qualities because you can see and appreciate them in others! Lessee( US Southern for "let's see"), how do you say that.......,oh, yes!...Frohe Weinachten!
(Hahaha!, I'm an Army Brat who was born in Mannheim.)
LED Phono Strobe
Hi Guys, despite the fact that my ears told me that my 20+ year old Akai AP D2 turntable was dead-on speed, I had to see it by testing. The Akai is dead-on speed, despite being over 20 years old! Aaaah, yes, when I was young, we took a Phono Strobe Disc, like the one you can print off the web, and an NE-2 lamp-based strobe to check turntable speed. The neon bulbs are nearly obsolete, these days, and I had no intention to order any. LED's have wonderfully quick response, so I made this simple, surprisingly bright, LED Phono Strobe Light.
The circuit is wonderfully simple, but for safety's sake, don't build it unless you are sure you know the techniques for constructing safe line-powered equipment! R-1 and R-2 will run warm in the 230 volt version and need to be left uncovered. I built mine in an empty blood sugar test strips vial, so any vial, pill bottle, or other small plastic container should work fine.
RIAA for my reference
Hi Guys, despite the fact that my ears told me that my 20+ year old Akai AP D2 turntable was dead-on speed, I had to see it by testing. The Akai is dead-on speed, despite being over 20 years old! Aaaah, yes, when I was young, we took a Phono Strobe Disc, like the one you can print off the web, and an NE-2 lamp-based strobe to check turntable speed. The neon bulbs are nearly obsolete, these days, and I had no intention to order any. LED's have wonderfully quick response, so I made this simple, surprisingly bright, LED Phono Strobe Light.
The circuit is wonderfully simple, but for safety's sake, don't build it unless you are sure you know the techniques for constructing safe line-powered equipment! R-1 and R-2 will run warm in the 230 volt version and need to be left uncovered. I built mine in an empty blood sugar test strips vial, so any vial, pill bottle, or other small plastic container should work fine.
RIAA for my reference
Attachments
Last edited:
I still have a neon lamp around but your idea is good and simple. You could use a transformer though. That whould of cause be not that simple and a bit more costly.
I adjusted my turntable with a 1kHz test tone from a record and made an FFT. To my surprise different measurement records gave somewhat different results. At the end i choose a DIN record from the 70th. The tone on some other records was somewhat slow so not all lathes are running at the same speed ! A strobe is an absolute measurement though but may not track what is on th record. See the above explanation.
I adjusted my turntable with a 1kHz test tone from a record and made an FFT. To my surprise different measurement records gave somewhat different results. At the end i choose a DIN record from the 70th. The tone on some other records was somewhat slow so not all lathes are running at the same speed ! A strobe is an absolute measurement though but may not track what is on th record. See the above explanation.
From the rules: ''Certain inherently dangerous topics are not allowed. At this time they include but are not limited to: discussing power supplies directly fed by mains current without a transformer''. Its not a PSU but is direct to the wall too. Circuit diagram pulled. Don't suggest non mains isolated circuits to the public. 
Safety First!
Sorry about the violation. An LED will get accurate pulses through an AC adapter-type transformer and to use a transformer will ensure safety.
From the rules: ''Certain inherently dangerous topics are not allowed. At this time they include but are not limited to: discussing power supplies directly fed by mains current without a transformer''. Its not a PSU but is direct to the wall too. Circuit diagram pulled. Don't suggest non mains isolated circuits to the public.
Sorry about the violation. An LED will get accurate pulses through an AC adapter-type transformer and to use a transformer will ensure safety.
Attachments
Hi Edgar ,
your creativity is amasing , sometimes i am astonished , also with that
empty blood sugar test stripes vial thingie !
I like your simple creation very much .
As Joachim has said earlier in the thread , most people do adjusting the turntable ,
but the question is had the lathe the right speed unsw. ?
Greetings
Jürgen
your creativity is amasing , sometimes i am astonished , also with that
empty blood sugar test stripes vial thingie !
I like your simple creation very much .
As Joachim has said earlier in the thread , most people do adjusting the turntable ,
but the question is had the lathe the right speed unsw. ?
Greetings
Jürgen
Encouragement
Thank you for the encouragement, Jurgen. I've had a day where I needed some. The recording lathe speed might always be in question, but the strobe disc can be made pretty accurate because the angular position and number of the marks can be verified. My guess would be that a lathe's speed could be verified with a machinist's grade-accuracy, small metal strobe disc in the center of a record blank while the cutting stylus is engaged and the cutting head drag is at normal level. AC line frequency is usually accurate to a very small fraction of a percent in all countries, but even the power line frequency could "pull" a few percent in a major electric grid disturbance.
As for transformer cost, almost every DIY'er and gadget lover has extra AC adapters that don't go to anything any more and few people will ever need to buy one. The LED must flicker at the power frequency rate, fraction, or multiple, so a DC output adapter won't work!
Thank you for the encouragement, Jurgen. I've had a day where I needed some. The recording lathe speed might always be in question, but the strobe disc can be made pretty accurate because the angular position and number of the marks can be verified. My guess would be that a lathe's speed could be verified with a machinist's grade-accuracy, small metal strobe disc in the center of a record blank while the cutting stylus is engaged and the cutting head drag is at normal level. AC line frequency is usually accurate to a very small fraction of a percent in all countries, but even the power line frequency could "pull" a few percent in a major electric grid disturbance.
As for transformer cost, almost every DIY'er and gadget lover has extra AC adapters that don't go to anything any more and few people will ever need to buy one. The LED must flicker at the power frequency rate, fraction, or multiple, so a DC output adapter won't work!
Last edited:
Happy New Year
Happy New Year and many blessings Joachim, Jurgen, and Forum Guys. The Turntable/DIY Pre-Amp bug has bitten me and I'll be grooving for years to come, as those old vinyl records just sound so good!
Happy New Year and many blessings Joachim, Jurgen, and Forum Guys. The Turntable/DIY Pre-Amp bug has bitten me and I'll be grooving for years to come, as those old vinyl records just sound so good!
Good Dog!!!
Woo-hooooo!!!, even with an oversize soldering iron tip, the Brown Dog SO-to-DIP-8 Adapter made easy work of adapting National Semiconductor's high performance OPA-1642 Audio OPAmp to fit in my VinyLiberator board! With metal-film resistors in noise-critical areas, component values adjusted, and switching PS shielded, I get proper RIAA with C-2 about mid-way open and have 2.5mv p-p noise voltage, referenced to 2v p-p output level. That ratio would probably be better if my scope had been LPF at 20khz and rejected traces of PS switching noise and above-band opamp noise. Sound is nice and I'll do a You Tube soon!
Woo-hooooo!!!, even with an oversize soldering iron tip, the Brown Dog SO-to-DIP-8 Adapter made easy work of adapting National Semiconductor's high performance OPA-1642 Audio OPAmp to fit in my VinyLiberator board! With metal-film resistors in noise-critical areas, component values adjusted, and switching PS shielded, I get proper RIAA with C-2 about mid-way open and have 2.5mv p-p noise voltage, referenced to 2v p-p output level. That ratio would probably be better if my scope had been LPF at 20khz and rejected traces of PS switching noise and above-band opamp noise. Sound is nice and I'll do a You Tube soon!
Attachments
Full Fidelity Demo
Hi Guys, Here's a full fidelity demo of the VinyLiberator PreAmp. I did Hugo Montenegro's "March With Hope", leaving silence at the ends to demonstrate noise levels in absense of signal. Please enjoy. It's a VBR mp3 of about 3.9mb in vinyloversanalogaudio Yahoo Group, files section, for however long I can get away with mp3 piracy.
vinylovers http://tech.groups.yahoo.com/group/vinyloversanalogaudio/files/
Hi Guys, Here's a full fidelity demo of the VinyLiberator PreAmp. I did Hugo Montenegro's "March With Hope", leaving silence at the ends to demonstrate noise levels in absense of signal. Please enjoy. It's a VBR mp3 of about 3.9mb in vinyloversanalogaudio Yahoo Group, files section, for however long I can get away with mp3 piracy.
vinylovers http://tech.groups.yahoo.com/group/vinyloversanalogaudio/files/
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.