Having a number of playback/digitizing issues with Nakamichi DR-1 deck and Topping E2x2 interface, not sure which. Need help.

[GodzFire]

Having a number of playback/digitizing issues with Nakamichi DR-1 deck and Topping E2x2 interface, not sure which. Need help.

Finally got all the stuff together to digitize some cassette tapes. Nakamichi DR-1 tape deck (https://www.hifi-classic.net/review/nakamichi-dr-1-43.html), Topping E2x2 Audio Interface for ADC connected to Mac with USB-C (https://www.audiosciencereview.com/...ds/topping-e2x2-audio-interface-review.49127/) and Tisino Dual RCA to XLR Cables for connection between (https://www.amazon.com/dp/B083R4FMK3).

However I'm running into some problems and I'm not sure where they are stemming from (see pics):
1- There's high frequency "noise" as shown in the spectral frequency display in the 14khz and up range that shouldn't be there, even when the tape is silent
2- Either the left channel is louder than the right, or the right is quieter than the left. It's not any of the recordings settings, they are both matching. These tapes have been recorded on two other tape decks prior and on both of those their channels were even, so I don't think it's the tapes.

Last picture is the deck inside (It looks like there's hairs/dust but that's just the camera/light and hyper close up). It was cleaned with 99% IPA. The audio quality itself is extremely good.

I also have a few technical questions too on properly digitizing using an audio interface:
1- For best quality/hiss, should the output be low on the tape deck and higher on the audio interface or vice versa?
2- I can seemingly monitor one channel, 1 (left) or 2 (right), but not both together like stereo. If I do both they are just mono in my headphones.

Posting this in here and general audio section because I'm not sure which this falls into properly, I hope that's okay.

 

[GodzFire]

This is recording a blank silent side of a tape.

 

[DY2]

Beautiful DR-1, but quite old, which is why it needs attention when servicing.
From your picture you can see that both axles of the pressure rollers are worn, thinned in diameter and have impurities on them. This translates into the tape not running correctly and with a risk of deformation. Also in the picture you can see the playback heads are quite worn, you can no longer see the blue paint on the heads, a sign that this Deck has been used a lot.
I have a different model, but inside you will also find semi-adjustable ones to set the Bias parameters and the signals on the channels as well as other settings for recording.
I recommend that you, if you haven't already, change the belts, idler, pressure rollers as they are the original ones as seen in the pictures, clean the heads and play dedicated cassettes, I use TDK SA-90, they are very good and play flawlessly on Nakamichi.
If you have already solved the problem in the meantime, skip my message, anyway I'll leave you some pictures so you can see what the playback head and the pressure rollers look like, the old one and the new one, as well as the inside where you need to adjust.

 

[JeffS7444]

Was the original source FM radio? USA broadcasts incorporate a 19 kHz pilot tone, and cassette decks frequently offered a mpx low pass filter switch to eliminate it when recording.

 

[JXBJXB]

@DY2 the OP has photos of a DR-1 which has the dual capstan, three head Sankyo transport. The three discrete Nakamichi-made heads are quite a bit different than the ones in your post which appear to be from a single capstan two head. The heads in the DR-1 have no “blue paint” on them in the first place and are also incredibly long lived — mainly due to the pressure pad lifter which you can also see in the OP photos.

Also - especially if this deck has never been adjusted internally the various calibrations should not be touched until the mechanical alignment can be confirmed. The Sanyo three heads require specialized gear to properly align and calibrate and unless one possesses the proper gauges it is best left to a Nak tech.

 

[DY2]

I'm sure you're right, I also mentioned that I have another device with two heads.
On the DR-1, the heads were made in-house at Nakamichi, on the CR-1 they were produced externally, and the paint on the head determines their origin, in addition to the degree of wear.
I know they are made to last a long time, mine is 40 years old and still performs well.
If no one has touched the inside after all these years, everything should be in order, but the author writes that not everything is ok.
I only wrote my opinions, this after I serviced my Nakamichi.
And I hope you can see the mess in the playback head area, as well as those rollers and axles that need to be cleaned.
Otherwise, the mechanics seem to be from the same period as mine.