Importance of warm up. I hope this helps someone

I was checking a cassette I had made last month back to the original CD source for comparison. All my equipment had been on for 4-5 hours except CD player. I cued both up and the CD player was overly clear (bright) compared to the cassette made from the same source a month earlier. I thought well since this is a cassette I should expect some roll off in the highs after a period of time but not so soon. OK everybody. Im a cassette fan. I grew up with it and I know other mediums maybe are better. OK back to the warmup. I decided to let CD player warm up for 30 mins. I compared again and cassette was a perfect copy of the CD!!!. I can only figure the CD player was not warmed up. Everything else stayed ther same and was constant. I pay more attention to warmup now. I know it was important but I did not see how much until today.
CD to cassette?
Something is realy wrong dude...
One does not need to approve of what format the CD is transferred to, the point is the CD player warmed up and sounded better.

I've had the same experience just by listening. As for cassette, perhaps Blueranger has a portable player or automobile with cassette and no CD. That's the case with one of our cars.
Thanks Albert Porter. I do have cassette in car and have portable. Marakanetz. I prefer not copying digital to digital. Analog is still better. Most big recording studios still use analog tape. If they record in digital, the digital recording can never be improved upon. With analog they can have it digitally recorded as better digital machines come into being.
Cassettes seem to me have at least one advantage over CDs for the car: they are less sensitive to the kind of rough handling that may occur when ones is doing something else -- like driving! I try to stick to copied CDs for the car, for this reason.


You can edit digital to pull out defects and add other sonics with many different things such as pro tools
Blueranger writes:

"Most big recording studios still use analog tape. If they record in digital, the digital recording can never be improved upon. With analog they can have it digitally recorded as better digital machines come into being."

I'd ask if he is sure of the validity of that statement. Analog tape, even with half-inch at 15 IPS we used to use in the lab, has problems like print through and instablility in storage. We used to rewind our tape backwards, but even so storage was a problem. Digital tape seems much more likely for use in recording studios these days, but I don't know.

I have met many people who claim that the system is without warm up necessity. I have not found this ever.
I've not had mega bucks systems, but in the 10-12 brands I have owned, they all took 20 mins to 2 hrs to warm up, *from constant on condition*. So this is not a power up, this is a signal up if you will.
Some gear like Spectral and Mitner have shown 24 hour power up in my experience. The Spectrals will actually get louder in power up.
But I'm glad to see that Warm up is being recognized.
It's a real pain, because if you take it to the enth degree you have to record a warm up copy before you record the final copy so that all circuits get that time.
I don't go that far, but it is where the theory goes isn't it?
Best Regards all.
Thanks for the input everyone. I always heard warmup was important. I thought I could hear a difference but did not have a good example to go by. There was a big difference. From thin or slightly shrill to a more rounded sound with more bottom end. Mike
I think warm up can be important (and if your CD player doesn't have tubes in it, I recommend you just leave it on all the time), but I am skeptical of the results you report. Cassettes copies are never that good, at least in my experience. When you say the cassette was a "perfect copy" of the CD, did you listen to the new cassette in the exactly the same way you listened to the one you made previously when you decided that it was imperfect? Or did you make this determination by flipping the Tape/Monitor switch on your preamp while you were making the second recording? Rapid A/B switching obscures sonic differences.
Speakers will change response as heat builds up in the voice coils --- you get thermal compression after some minutes of play as the coils inside the drivers warm up. As you play louder the compression will get worse...anywhere from 0.5 to 3DB or more in compression can be expected (enough to be plainly audible). On passive speakers it will also affect the way the passive crossover behaves as the filter will drift slightly.

This effect is volume level and speaker design might possibly be the source of your problem. Certainly, speaker thermal compression could cause the sound to go from a bright sound to a duller sound.

If you have ever played a track very loud (at the beginning) and then found yourself increasing the volume a few minutes later then you have probably experienced speaker thermal compression. (Not to be confused with an old Vinyl trick where the mastering engineer deliberately increased the level at the start of the track to help it loudness is often interpreted as better sounding)

Drublin, Thanks for your comment. After the tube cd player warmed up there was virtually no difference between the CD and tape. I have a very good tape player. Clean and demagnetize after every tape. I use Kimber KCAG cables. Use silver SST contact enhancer. I correct azimuth for each side. After I have manually set rec current and bias per manual, I then make a test recording and then readjust until I am satisfied that there is little or no perceptible difference. When I go to the other side I then test again and make adjustments. I am a nut about AB comparisons. I do that all the time. I do flip fast from source to tape but leave it for 5-10 secs and then flip back fast. There was only one cassette recording I mentioned.above. I did not record a 2nd time. After CD player warmed up I could tell no discernable difference from the month old cassette. Sometimes when I record I do hear a difference. If I cant get it right I'll junk the tape if its an old one. I always warm up tape player several hours before making a recording. The headphone jack on tape player does sound shrill until it has warmed up a while. I dont need an AB comparison for that one. I know the cassette medium has virtually become extinct. I am a dying breed. It is something I like to do.
Shadorne. Thanks for the tech info about speakers. I was using headphones. I too have noticed loudness levels on begining and end of record. I see that on the tape vu meters. I know the importance of vol levels. I will adjust CD output to same loudness of record when doing AB. When I am recording I often find the correct recording level is when you cannot hear a loudness difference between tape and source. Thanks again for response
Very impressive. I retract my skepticism.

I totally understand your continuing pleasure in making tapes. It's like a ritual.
The digital age, for all the boon that it clearly is, seems to have made music
more of a consumable rather than an artistic expression to be considered at a
Tubes really need to warm up before use. Just ask any guitar player. The effect with solid state gear is much less pronounced (and even debatable), but tubes definitely need to warm up before sounding their best, or even listenable sometimes.

Oh, and most recording studios do NOT still use analog tape. Some big budget stuff will still mix to tape, or track to tape before dumping to digital for overdubs and mixing, but tape is slowly going the way of the dinosaur.