Bias amp 2 audacity
Sorry to make my first thread a question,also apologies if this has been discussed,I had a search and couldn’t,like I’ll explain in a moment, With some decks, even high-end ones, it is simply not possible.Im new here, been reading a few weeks, getting ideas for my setup to play guitar and since I’ll do it on headphones,it seemed the place to ask, Just need to keep one thing in mind that the most important thing is, when setting bias, to match input and output signals as close as possible. Try a recording of your fav music, it should sound like you have never experienced before, you would hear music from a very quiet back ground, and it would not cause you listening fatigue, you can listen to music for hours and hours. For that, I would suggest you get a test tone of 400 hertz, and feed it to your deck till it reads 0 VU. Once you arrive at that, you need to set up the recording levels or input levels on your deck. As recording continues, you can switch between source and tape, and try to find a point where the source and tape sound very close to each other, identical would be perfect. You can use a FM tuner for this purpose, keep the output level knob at maximum. To the OP, you need to record, on your cassette deck, white noise at -20db.
I understand this is an old thread, but I thought I share my experience with forum members.
Three head machines can be a different story but it is still a labor intensive job. There were a few machines where it might be worth doing such as some Nakamichi's. Typically, the labor is completely out of line with the worth or ultimate performance of the machine. When I ran my repair shop I would not attempt these on a typical two head machine. On a two head machine all of these are a royal pain. Then you need to adjust the play equalization using the alignment tape. You really need alignment and calibration tapes to get the record/play head azimuth right before attempting any other adjustments. The problem with aligning a tape machine is there are so many competing adjustments. Don't mess with the bias without a service manual or you will get in trouble.
Maybe there is some confusion between bias and equalization. And following that of course - what frequency should I get? Why are bias preset values stated as 70 or 120 us instead of frequencies in Hz?Īny thoughts on the above much appreciated I guess what I want to know is - can I just hook up a cro or frequency counter to the record / play head and then adjust / check bias frequency (with machine in record mode / no signal)? Is there a better point to test from? In most cases I can establish where the actual adjustment pots are.
However I recently did this on an early 80s Harman/Kardon which resulted on a significant improvement in recording quality. In most cases the heads seem to be in good condition and free of visible wear.Īlmost all of the machines I work on are two head, so tuning by ear is more time consuming. This is after I have carefully cleaned and demagnetized the heads, and taken care of general service items (including de-oxit in record / play switch where applicable). In most cases, I don't think any adjustment is necessary, but sometimes I get decks where the recordings sound either dull or distorted (to greater and lesser extents) - or just generally a bit 'crap' compared to a good machine using the same tape. I service them all the time, so this is something I really should know - but being self taught (albeit with years of experience) it would be great to get a rundown from an expert. Wondering if anyone can give me some straightforward advice on checking or resetting the bias on cassette decks.