Rar1's first paragraph response sounds correct to me. His second paragraph seems to answer a different question than was asked however (although I don't follow the last sentence advice even at that).
About the question of whether you can use the remote-controlled Adcom to input your VCR before sending the output to your tube integrated: You would have to have a very light touch on the remote volume control, and even then it might not work out very well. You would be preamplifying the signal twice, because you'd have to use the Adcom's main outs in order to take advantage of the remote volume control. If your integrated by any chance has a 'direct' amp input, bypassing its internal preamp stage and volume control, then use that for this purpose. On the other hand, many "integrateds" don't actually contain a preamp stage, just a power amp with an input selector and a volume control, and if that's the case here, things might come out better for that experiment.
About the question of whether you can use the remote-controlled Adcom to input your VCR before sending the output to your tube integrated: You would have to have a very light touch on the remote volume control, and even then it might not work out very well. You would be preamplifying the signal twice, because you'd have to use the Adcom's main outs in order to take advantage of the remote volume control. If your integrated by any chance has a 'direct' amp input, bypassing its internal preamp stage and volume control, then use that for this purpose. On the other hand, many "integrateds" don't actually contain a preamp stage, just a power amp with an input selector and a volume control, and if that's the case here, things might come out better for that experiment.