Compact Cassette - Compact Cassette – TEAC CX-350 / CX-351
General
The TEAC CX-350 is a Stereo Cassette Deck that was produced around 198112. Here are some of its technical specifications:
- Type: 2-head, single compact cassette deck1
- Track System: 4-track, 2-channel stereo1
- Tape Speed: 4.75 cm/s1
- Heads: 1 x record/playback, 1 x erase1
- Motor: DC servo1
- Tape Type: type I, CrO2, Metal1
- Noise Reduction: B1
- Frequency Response: 30Hz to 17kHz (Metal tape)1
- Signal to Noise Ratio: 57dB1
- Wow and Flutter: 0.06%1
- Dimensions (WHD): 410 x 142 x 300mm1
- Weight: 6kg1
- Finish: silver1
- Year: 19811
Please note that this information is based on the data available on HiFi Engine1 and Reverb2. For the most accurate and detailed information, I recommend checking the product manual or contacting TEAC’s customer service.
The two TEAC decks are not in the system. The only difference between the two units is that the ‘350 is silver, while the ‘351 is black. The performance is adequate for casual playback, but really not intended for critical evaluation, and not for recording or editing. There is Dolby-B, and there is auto stop.
Note that there are two decks here
This article covers two decks, which are both pretty much identical. The detail pictures could be either machine. If there is a difference in measurement i will note that. There is really no use me placing two set of photographs to show the same procedure on each deck.
Pictures
User / Service Manual
Preliminary
When i got these machines from the ‘auction site,’ i rebuilt them with new belts and rollers. Since parts were available i bought two machines. One unit is a little rougher than the other and shows just a hint of head wear. The machines do operate correctly. I never trust a machine that hasn’t been mechanically checked and adjusted with un-obtanium test tapes.
M300 Jig in machine
I always use the M300 jig to be sure tape path alignment is set up to standard. In my system all the decks are aligned to the exact same standard. The M300 is easy to use on these particular machines.
This is the M300 Jig. It is a metal plate that is designed to test the dimension of a cassette transport.
The M300 cassette tape jig, also known as the M300 alignment gauge, is a tool used for aligning the tape path in cassette decks1. It’s designed to ensure that the heads and other parts of the deck match the standard set by the Philips patents1.
The M300 gauge consists of a back plate that imitates the inside of a cassette plus some material to account for where the tape would be2. The chisel-looking part takes the role of the tape2. The edge of this part should lay flush on guides, rollers, and heads, and at the same time, its side should be flush to the gauge plate2. This indicates correct alignment2.
The gauge is used to establish track height, parallelism (tilt), and head penetration1. The thickness of the back plate of the gauge is around 2.4mm3. The actual height gauge mounted on the flat 2.4mm stock is 3.8mm3. Therefore, the total height is around 6.2mm3.
Visible Cassette Tape Path
We have built a ‘Visible Cassette Tape Path’, which is just a normal cassette with the part of the plastic case cut out on side A. This allows you to see the tape travel in the transport. Similar to a mirror cassette, however the advantage here is that the tape is an actual production tape. It is a little more difficult to image but here is the picture of the tape in the machine. As you can see, there is no twisting or stress on the tape, and that is the reason to use this kind of tool.
Magnetic Print
This is a magnetic print of the tape tracks. Stereo 24 Hz Side A. Zoom in to get a better view. I did notice the track is really close to the edge, but i noticed that the factory azimuth and height adjustment screws, on both machines are still sealed. I will leave them as they are. This signal was a sine wave so the trace is a little hard to see, but it is there if you look closely. It looks fine.
Mechanical Tuning
It is a good idea to remove the cover and do the mechanical checks, such as belt condition, capstal thrust, and lubrication at this point. Also this is a good time to make somepictures of internal parts and settings. Any adjustable pots should be marked with a marker before any adjustments are made, and a different color marker after any adjustment. Anything that is adjusted should be marked on the inside metal cover with a date and applicable measurement values.
Wow and Flutter and Speed
This is a standard wow and flutter tape, which has a residual figure of approximately 0.02 made on the JVC [A] deck described in another page on this website. This is acceptable performance for this vintage single flywheel, belt drive machine.
Notes
The notes are copies of the pages of the sevice manual annotated with checks, along with handwritten notes of the process I used to re-certify the TEAC CX-350 and CX-351 Compact Cassette Tape Decks.
Internal View
Playback Level Standard
Measured playback to system standard Level Tapes as follws –
See notes above for specifics
200 nwb standard Dolby tape results in Vu meter +3 db
Output Level -5dbs 430 mv.
Conclusions
- These decks, introduced in 1981 are 40 years old. They are still a capable example of a generation 2 deck. With only dolbyB and manual tape selector and mechanical controls.
- These decks are not current system decks, and is included as a referance to generation 2 cassette system.
- This page is done engineering notes style.
- Standard tapes and processes used can be found under test section of this website.
- Please take a look at our other cassette recertifications, along with other systems on this website
- Please visit CarlValle.Com for additional resources and website of interest.
Revision
This is Revision:
01 – Original Article – 2024 07 21
02 – added pictures complete – 2024 07 23
And as Always:
And as always
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