Information Terminals M-300, cassette tape transport alignment gauge

The regular service of analogue machines which will involve the mechanical alignment then electrical alignment / calibration is really important if you’re attempting to get optimum transfers and reduce any risk of damaging the potentially fragile tape.

While some of our machines are serviced by others we like to regularly check them and have gradually brought our regular servicing in house. Of course this needs specialised tools, test tapes and gauges, often totally unavailable new now.

On a lucky eBay day I happened to win one of these beauties, an Information Terminals M-300 gauge. This enables you to accurately set the tape guide height and also the head stroke. It is a universal gauge and can be used across many decks.

information_terminals_m300-boxed copy

Nakamichi tape deck owners have had a hard time doing this part of their servicing as the original Nakamichi gauges are very very rare now as is this.

A member of the naktalk mailing list though recently borrowed our gauge and has had it measured and will soon have a small batch CNC machined and made available. These remanufactured gauges will have a few small modifications to improve the design.

Thanks to Willy at many more tape deck transports will be able to be aligned correctly.



Willy Hermann,
How am I going to buy one from this reproduce M-300 Alignment Guage from Naktalk?

Best regards


Would you care to measure and share the measurement details of the gauge at 0,Min and Max。

Christian Arnold


for my Braun C4 i need an M300,

can you help me ?

Who can i buy it ?

sorry for my english


Fantastic… never seen one of those and not particularly useful now but could be for testing the physical properties of audio cassettes:

…To verify the validity of the technological choice based on the liner lubrication, a mechanical torque measurement of audio cassettes was effected by means of an apparatus “Information Terminals M400 Cassette tester”. Such measurements are generally made by manufacturers of audio cassettes for the production quality control; the instrument substantially measures the current absorbed by the motor which keeps the tape rotating and permits the reading of the mechanical torque (in g*cm). The readings, according to the quality control practice, are made at the beginning and at the end of the tape rewinding…

Jim Eriksson

I have a M-300 for sale. Make an offer.

Hi Jim

Thanks for your message but one is enough for us at the moment!
These are very useful tools though and should fetch a good price on eBay, especially if advertised globally.


Still have the M300 cassette gauge? The price, please?

Kari Orourke

I have a m300 information terminals for sale original straight edge if someone is interested email me at

If still have the m300, im interesed.
Contact me, please via email. Thanks.

Jim Eriksson
Still have the m300 ?!

Hi Jim

Thanks for your comment – I’m afraid this M300 isn’t for sale but copies have been made of this actual gauge and Willie Hermann Services in the US were selling these and may be doing so still.

First, I’m posting here because this is the ONLY reference to the Information Terminals M400 currently showing up in searches. It is referenced in a European Patent application, but not with any degree of specificity of application.

I snagged that M400 “widgetoid “on an offer. (I probably still paid too much-it was a curiosity purchase.)
What I found was what I suspected I’d find. 8 1980s AA Duracells having done what Alkaline batteries do, but to the Duracell’s credit, they didn’t create as much destruction and havoc as the Energizers do, FWIW. The battery compartment still has contemporary replacements. The tape drive works fine. The circuitry appears to function but the meter does not. Something very unwell went on inside that Modutec housing. I suspect that the section on the right contained some sort of cable, either a 1/8” TRS power cable/adapter or (less likely, but who knows?) some kind of removable head interface. It appears to me that the head is there basically as a place keeper for whatever drag co-efficient it applies. Most of the detritus (Seeds? What was that stuff?) cleaned off just fine. If anyone knows anything more about these little curiosities, I’d appreciate hearing from you. I’m trying to restore it to functionality, even though its value has to lie more in its being a historical artifact rather than a diagnostic tool. I can’t find any grams/cm replacement Modutec meters out in the wild, but perhaps something can sub out and I can replace the meter face, which is removable. TIA…

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