Telex Replica Cassette Copier strange track doubling issue

[Yacob Glowniss]

Hey yall! Thanks for any help you may be able to offer with this problem--

So, I have a used Telex Replica Cassette Copier that I purchased recently to make small runs for my tape label. I've thoroughly cleaned the heads before this run of duplicating tapes. But listening back, I've run into this issue where it sounds like the track has recorded twice at 2 different speeds and volumes?

My initial mix is there in the forefront but underneath it the tape is playing the same thing quieter and faster, so the whole thing ends up garbled. Any idea what might be causing this problem and if it's something i could repair at home?

Thanks!

 

[gecko zzed]

Can you be sure that you but in blank cassettes to start with? If they already had stuff on them, it's possible the erase head is not doing its job properly

 

[Yacob Glowniss]

Yes, these are purchased blank tapes from the manufacturer. And the underlying track is the same as the music I'm dubbing onto it, at a different speed.