Chaîne stéréo à double platine cassette

What is the "digital interface" for if it doesn't allow transfer to USB??

THis cassette deck does not have a digital audio interface to allow transfer to USB

Pressing the line button while recording does nothing; line does not light up, source does not switch from deck A to line in. Brand new unit.

Pressing the LINE Button should light up LINE and should switch to LINE IN Recording.

Auto-reversal at end of tape when recording?

One direction play

can you use this unit to convert cassette audio tapes to a usb? If not, doyou have such a product?

This is just a cassette deck

it won't latch and I need to record tapes immediately. please contact me back with instructions as this is a brand new deck. I went to the q&a but didn't get a real answer that worked. please respond. thank you!

Please contact us via email so we can address you concern about the  cassette deck

I'm wondering a couple things about this unit. Can I direct line in through RCA and record to a tape then duplicate that cassette without any extra equipment? And is it possible to line out to headphones without an amplifier? Not concerned about speakers, just headphones.

Yes you can direct line in through RCA and record to a tape then duplicate that cassette after recording on it.
The unit does not have a Headphone out

WHat is the best speaker for this unit and how can I set up head phones from that there is no head phone jack

You need an amplifier for it and a speaker

https://pyleusa.com/products/p3201bt

https://pyleusa.com/products/phqbs62

how do I record? I tried selecting the line in button but it won't light up and when I press record it won't stay down. it also won't stay down when I hit play and I can barely hear the audio

If the audio source is external going in to the RCA Line port of the PT639D press Line button to engage Line IN
If it is Tape to Tape Dubbing, no need to engage Line button

Make sure the record level knobs are properly set

Is the Noise Reducing system compatible with Dolby?

YES

How to get warranty

As long as you still have the eReceipt that was sent to you when you purchase the the unit online. 
Just make sure to have a screenshot of it and send it to us to verify your warranty coverage

How can I record from the cassette to my iTunes

You will need to use an audio interface

Can I record my voice onto a dubbing tape?

If the Deck is connected to a Mic Mixer. That is possible

What does the "auto backspace" feature of the PT639D do? Does it refer to the ability of the deck to automatically rewind a tape or switch from Side A to Side B?

Auto Rewinding

The Play button won’t stay on. If I hold it down, the tape plays. But if I let go the music stops. I find this to be very in-handy. It happens on both the A and B decks. I must be doing something wrong.

Press button till you hear a click