Tape Guide (Q and A) (Jan. 1975)

Changing to Non-portable

Q. I own a General Electric portable stereo recorder. Recently I began to think about converting my machine into a non portable model by building a wooden case. I also thought that I would add another VU meter as well as revise the controls so that I may vary the bass, treble, and volume for each channel.

The necessary connections seem to be simple enough. But I was wondering if you foresee any difficulties.

-William K. Vinson; Kingsley Field, Oregon

A. There is scarcely an electronic project on which one does not encounter some bugs. But I don't foresee any major or unconquerable ones in your case. So long as you don't tamper with such things as record and playback equalization, bias, amount of signal fed to the record head, and amount of signal to the record level indicator, and so long as you take the usual precautions against hum pickup and against treble loss due to excessive capacitance in your leads, your project should be successful.

Tape Deck and Amplifier Hook-up

Q. I would like to play my tapes through my stereo system, which would mean connecting the outputs of my tape recorder to the inputs of my stereo amplifier. I am concerned that feeding an already amplified signal into another amplifier might do some damage. Please advise' me if this set-up would cause harm to my components.

-Robert Grip; Chestnut Hill, Mass.

A. The proper connection is to feed the outputs of your tape recorder into the high level inputs of your audio amplifiers. Such inputs would be marked Tape (not Tape Head), Auxiliary, etc. Then there is no danger of overloading the amplifier. I gather that your recorder has a self-contained amplifier and speaker. The output of your recorder should be taken, if possible, from a point prior to its power amplifier-namely from a jack marked External Amplifier. If your recorder has no such output jack, then you will have to take its output from the jack marked External Speaker.

Dolby Unit Placement

Q. I have been to three dealers of the Advent Dolby 101 Noise Reduction System, and each has given me a different answer as to whether or not I can use the 101 unit with my tape recorder.

Dealer #1 says I can, Dealer #2 says I can't unless I have some modifications made to my tape recorder, and the third dealer says I would have to buy a unit and try it. I have a Sony Auto-Reverse 660 tape recorder with a self-contained amplifier, a Shure M-65 Stereo Con version Preamplifier, and a Dual 1019 changer. I have no separate amplifier.

To record I plug the Dual into the Shure preamp, and plug the preamp into the line input of the tape recorder.

For recording, Dealer #1 says that I just have to insert the 101 between the Dual changer and the Shure preamp. In the case of playback, Dealer #1 says that I can use the 101 with my Sony if I hook it up as follows: line output of the tape recorder into the 101, and the 101 output into the line input of the Sony. Dealer #2 says I can use the 101 with my Sony in playback if I have some modifications made to the Sony. If Dealer #2 is right, is it worth the expense and the trouble to have it done?

-John Deysher; Towanda, Pennsylvania

A. The Dolby should be used be tween the Shure M-65 and the Sony 660 in recording. So Dealer #1 is wrong there. In playback, Dealer #1 is wrong again. In playback the Dolby should be used between the preamp and power amplifier sections of your Sony. There fore Dealer #2, who says you have to make a modification to your tape recorder, is correct. The modification is not a very complex one. Consult a local audio technician as to what he will charge. Also consult Dealer #2 (assuming he has the facilities for making the necessary change). And then decide for yourself whether the modification is worthwhile.

(Source: Audio magazine, Jan. 1975; Herman Burstein)

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