List of common preamp sources?

[Shannon Parks]

I'd like a "tight" list of ten sources for my new 12B4 Arduino linestage project. What am I missing in this list? How would you change the way it is worded? What should I omit?
Folks can mod the open source code as they see fit, but I'd still like a very useful list from the get go. Thanks!

Shannon

Code: Select all

 char inputLabel[10][12] = {
                 "CD Player   ",
                 "Turntable   ",
                 "MP3 Player  ",
                 "DVD Player  ",
                 "Bluetooth   ",
                 "Tape Deck   ",
                 "Radio       ",
                 "Television  ",
                 "Computer    ",
                 "Smartphone  "
                 };

[msmpe]

Although tape is not so popular anymore, I'd still suggest both RtR and Cassette - I run both. Also the all inclusive AUX should be included. Are you doing a line out? How about a tape or processor loop? What about auxiliary channels out: center, subwoofer, ambiance (side)? Can provisions be made to bi-amp?

Sounds like fun...

[kheper]

'Radio" could be described more clearly as "Tuner". "IPAD, IPOD, etc." are missing. "(Line out jacks)" could be appended to "Computer" and "Television".

[20to20]

And just to complicate things, you could have "old spec" 1v p-p CD/DVD IN and "new spec" 2v p-p CD/DVD IN.

[Shannon Parks]

Although tape is not so popular anymore, I'd still suggest both RtR and Cassette - I run both. Also the all inclusive AUX should be included. Are you doing a line out? How about a tape or processor loop? What about auxiliary channels out: center, subwoofer, ambiance (side)? Can provisions be made to bi-amp?

Sounds like fun...

I can do Reel-to-Reel and Cassette. I had Auxiliary in my prototype, but had mistakenly left it off this list. One does need a catch all. No line out or loop features, and is just stereo. The simple EQ circuit (a bass boost) lends itself to bi-amping with some mods, I think.

'Radio" could be described more clearly as "Tuner". "IPAD, IPOD, etc." are missing. "(Line out jacks)" could be appended to "Computer" and "Television".

Radio --> Tuner, you bet. iPad, iPod can be generalized in the "MP3 Player" and "Computer" category - It would be great to have two or three or four labels to catch all these modern devices. Don't want to tick off the Android guys, either.

And just to complicate things, you could have "old spec" 1v p-p CD/DVD IN and "new spec" 2v p-p CD/DVD IN.

There are two specs? I thought it was always 2V? One nifty feature will be two gain settings, +0dB and +9dB, so high level output devices can be set to the lower output and that info will be saved.

Shannon

Code: Select all

 char inputLabel[10][12] = {
                 "CD Player   ",
                 "Media Player",
                 "DVD Player  ",
                 "Computer    ",
                 "HDTV        ",
                 "Turntable   ",
                 "Reel-to-Reel",
                 "Cassette    ",
                 "Tuner       ",
                 "Auxiliary   "
                 };

[20to20]

There are two specs? I thought it was always 2V? One nifty feature will be two gain settings, +0dB and +9dB, so high level output devices can be set to the lower output and that info will be saved.

Shannon

Code: Select all

 char inputLabel[10][12] = {
                 "CD Player   ",
                 "Media Player",
                 "DVD Player  ",
                 "Computer    ",
                 "HDTV        ",
                 "Turntable   ",
                 "Reel-to-Reel",
                 "Cassette    ",
                 "Tuner       ",
                 "Auxiliary   "
                 };

Could be the "standard" line out for CD and first DVD/CD players was RMS @1V. I found out about the new 2V standard a few years ago when I bought a new player and found I could only turn the volume control up to 2 before the windows started rattling. Had to get some Harrison line attenuators. The signal spec could be RMS and not p-p. ?? I think P-P is for video.

[kheper]

Could be the "standard" line out for CD and first DVD/CD players was RMS @1V. I found out about the new 2V standard a few years ago when I bought a new player and found I could only turn the volume control up to 2 before the windows started rattling. Had to get some Harrison line attenuators. The signal spec could be RMS and not p-p. ?? I think P-P is for video.

If I remember correctly, there are low-level devices (mics, guitar pickups, phono cartridges, etc.) and line-level devices (compressors, tuners, CD players, etc.). The standard for line-level was 1 Volt. Probably - over the decades, CD players experienced "volt creep" from 1 to 2. As long as you have a pre-amp with a volume control, the aux, tuner, cd, etc. inputs (expect for phono) will work with any line-level device.

[kt88pppamp]

I thought line level, nominally, as a standard, was 0.447V peak. Pk-Pk it would be about 1 volt. RMS, 0.316 volts.

Magnetic (MM phono), my cart calls for 0.004 volts peak nominally. Some MC's I've seen as low as 150uV.

[20to20]

I thought line level, nominally, as a standard, was 0.447V peak. Pk-Pk it would be about 1 volt. RMS, 0.316 volts.

Magnetic (MM phono), my cart calls for 0.004 volts peak nominally. Some MC's I've seen as low as 150uV.

Each device has its own spec. My "new" Panasonic DVD/CD player lists analog audio out @2v RMS and I have a Sony SACD/CD player that also uses 2V RMS audio out. Unfortunately I've long ago tossed my manuals for my old CD only players but I'd STGod they speced output @ 1V. My confusion on that was from the DVD "video" out spec on my DVD player that sends 1V p-p signal. But I'm still certain the old CD specs were 1v (RMS). I had a mixer that would give you a 0db out at 1V or 2V, selectable by a switch. I suppose that was to be compatible with other equipment that was coming along and changing to the higher signal levels. I never used the 2v out on that.

[kt88pppamp]

To compensate for the variations, I made a differential amplifier preamp with a normal volume and a "master gain" that adjusts the feedback between 100% and the maximum gain of the stage. It works great and is perfect for compensating for those truly non-universal line-level standards.

Has anyone done anything similar?