[OT] Analog amplifier to EEE PC 901

You should tune up the Technics, with a brand new tape. You don't want to ruin an archive tape, if the capstan isn't working properly.

My recorder started eating cassette tapes, and you don't want to discover a transport problem, using a tape with valuable content.

When using Audacity on the EEE 901, you can create a swept frequency of constant amplitude, from 20Hz to 20KHz. When you play this back later from the Technics, record it in Audacity and compare the amplitude of what is played back. This will determine whether there is systematic error (equalization not right) or a dirty head.

the EEE 901 microphone input, should be able to work with a 70mV signal (some modern microphone) but it won't be good enough for a 2mV signal directly from a photo cartridge for example. The Technics will be line level (1 volt). Check your VU meter in Audacity, to see if the signal is too much. Once the controls are set, you can do your calibration run for determining relative flatness of response. Being a cassette, I would expect some rolloff over 10KHz.

You don't have to use the EEE 901 over Wifi. It would be a pain in the ass, running from one room to the other and checking on stuff. Instead, plug a 32GB SD card into the SD card slot, and dump the Audacity clip to the SD. Now, you can stay in the room with the Technics, run the EEE 901 from battery (no hum loop) and record to SD.

You'll need a dual RCA/Cinch Left and Right female to 3.5mm male adapter.

That can be plugged into the microphone hole on the EEE 901.

You can also *test* the EEE 901 is working properly, by running a 3.5mm male to male cable, from your fancy desktop line-out to the EEE 901 microphone in. And verify that Audacity on the EEE 901 is seeing analog signal presented by the desktop. You know how often these projects are let down, by the computer end not functioning correctly.

The EEE 901 can probably manage 48KHz digitization. I would not expect 96KHz or 192KHz. The low pass filter on PC audio is not correct for the 192KHz choice anyway. I've verified this by connecting two 192KHz machines together and being disappointed with the response on the recorder side. The 96KHz choice would likely work OK... if the EEE 901 had it. But I would expect 48KHz or 44.1KHz are the only options, and the 48KHz might cause the fewest issues.

I would *carefully* wind the archive tape forward and back. The Winding option does not engage the capstan. And this is just to ensure the tape is not stuck to itself. Stay in the room, keep a finger on the Stop button while you do this. Slow down when you get to the end. The leader-detection might not be working properly. You are looking for evidence the tape is "fit" for an actual EEE 901 run. My ruined tapes say "Hi".

Good luck,

Paul

From personal experience of entirely amateur dabbling, I've never found either a desktop or laptop to have A/D converters with a decent signal to noise ratio. It's all that digital stuff whizzing around in the box.

I've found even a no-name Chinese USB sound dongle costing a pound or two to have better dynamic range, as after all, the built-in sound stuff is expecting to deal with very cheap microphones in a domestic environment, which is hardly going to need much in the way of S/N ratio.

I certainly can't recommend anything, but I'd expect a named USB audio adaptor to do a much better job than the laptop, something like a low-end device from Creative Labs. Better advice would be available from professionals, or at least serious amateurs, in sound recording. There must be that kind of advice sloshing about the Net.

The EEE 901 can float on its battery, and record a tape. That should break the hum loop.

The problem with running a USB to audio, isn't the conversion as such, it's the hard ground at the remote end, versus the hard ground on the Technics. If the laptop was in the other room, then it could power the USB extended cable run and the USB to Audio on the end. The recording end would then float. Using your desktop and an extension USB cable, would be a hard ground. Using a hum-breaker-box, cuts off everything above 10KHz or so (function of transformer quality).

You could attach the USB to audio adapter to the EEE 901 and record in the same room, to the SD card slot.

Many possibilities. Just keep in mind where the ground is, or isn't :-)

I expect the audio quality of an old tape, to be pretty bad. The noise floor on my worst audio device here, would be nothing compared to what is going to come off the tape. But, we'll see what Alan discovers after the thorough Technics cleaning (head cleaner tape or whatever he has used in the past for maintenance).

I would think a quick test with the EEE 901 directly, would determine whether this project is worth doing or not. I gave up on an old collection of tape, as it looks like all of them will "wrap around the capstan" before I finish.

The condition of the tape, and what to do with/to the tape, is going to be more of an issue, than bits of the rest of it. You have time to adjust the recording end, if the source quality is present. Just plugging headphones into the Technics would tell you whether the tape is a write-off.

Paul

Sadly the mic socket on the 901 is mono!

But you have a USB port for a USB Audio Adapter.

Sound Blaster Play 3

Paul

You have a very complicated/weird way/idea or way of expressing yourself. If you want to digitise some recording, all you have to do is digitise it. What do you mean by "sending analoge by wifi???" Does your cassette deck have a WiFI on board? I doubt it. If your - EEE PC 901 netbook - what ever that is, only has MONO mic plug, you won't get stereo duh.... BTW MIC is no Line in. So get another computer/ laptop with line in and you are good. Of course a USB acd can be used but these are NOT better then the usually build in DAC ACD's. IMH.

both will be better than a cassette tape...

Why is it so hard to grasp. The recordings are on compact cassettes. The cassette player although 50 years old has had very little use, having been in storage for most of its life.

The 901 was one of the earliest netbooks (Aus). As I own both I am hoping to be able to transfer the analog recording over wifi to my fairly powerful work machine. That's it. No need to be offended.

Alan

It needs a Mac or Windows for its software. :(

No!

Avpx

Here's how I do it. I bought a cheap portable cassette player from Amazon (or even Aliexpress, it doesn't matter, they're all from the same manufacturer anyway, they just put different brand names on them).

Note: I always fast forward and rewind the tape before recording.

So far, I cannot locate any first hand proof it works. But there's an awful lot of "detected' in the list, so the driver showed up at some point.

We are working at a distinct disadvantage now with search engines. I'm pretty sure the information I need is out there, the trick is getting the search engines to work.

Paul

I tried thata few years ago but the result was awful. That is why I am restoring a high end cassette record/player. (The replacedment drive belts and capstan arrived from Spain today).

As forwarding and rewinding to ensure even tension, I always did so too. I intend to use Audacity too, once I get the raw output from the cassette player to my work machine.

Here are some test results. Using the laptop on battery and disconnected from mains, was key to getting a better noise floor. But the Play3 is not the Prince of Audio by any means. It's worth exactly what you pay for it. A RealTek would be as good.

Instead of the "hum" you might have expected as the noise floor, instead I was greeted by a "fluttering" sound. That that sank out of sight when I made the laptop recording. I have no idea where the flutting sound comes from, I *did* notice a correlation with USB mouse noise. Moving the mouse, was creating tiny spikes on the VU meter, and that was when the sending machine, was not sending a waveform.

Paul

Here are some test results. Using the laptop on battery and disconnected from mains, was key to getting a better noise floor. But the Play3 is not the Prince of Audio by any means. It's worth exactly what you pay for it. A RealTek would be as good.

Instead of the "hum" you might have expected as the noise floor, instead I was greeted by a "fluttering" sound. That that sank out of sight when I made the laptop recording. I have no idea where the flutting sound comes from, I *did* notice a correlation with USB mouse noise. Moving the mouse, was creating tiny spikes on the VU meter, and that was when the sending machine, was not sending a waveform.

Paul

Analog over WiFi???? Once your analog recording is digitized, it is digital.

And once your digital gets to wifi, it is 'analogued' again, re converted back to digital which is itself a collection of analogue components...based on the discrete (digital) movement of electrons and holes...

search for a Us sound card with stereo line level inputs, here's one, there are probably better ones around

WiFi is analog?? Source?