how to increase volume from tape deck?

Step-up transformer.

Hi Lloyd -

I think you're on the right track. You can pickup a used Mackie mixer (like a 1202VLZ) quite inexpensively, and this would give you some EQ to play with, as well. A decent preamp would likely cost a bit more and might not have EQ, but it could be argued that it would give you better quality. Given your source material, I don't see this as a big issue - and having the EQ option might really enhance the result. I am not familiar with the transformer you mention, but it's unlikely that you will get more than +6dB of gain from a transformer without running into impedance matching problems, and +6 really isn't all that much.

Have fun!

Best regards,

Steve McCormack
www.SMcAudio.com

You got me curious about the Altec Peerless 15095, so I did a little digging. It looks like they would do the job if you are willing to deal with creating a wiring harness and perhaps mounting them in a small chassis. And they appear to be fairly inexpensive.

Given your source material, I still find the mixer option tempting because of the EQ options and easily controlled gain, but the transformers are the purist way to go.

Best regards,

Steve McCormack