Manuals
Background
A high-performing instrument is not very useful without manuals. For a vintage instrument like the MJS401/TP401/TT402 even more so. While the instrument is simple and clear enough that most functions can be used without a manual, a good manual is required for troubleshooting and calibration an aged instrument.
When I got my TT402 I started hunting the net for manuals and was disappointed to find very little information. After reaching out to a few users I finally got in touch with someone who had an almost complete copy of the printed manuals. It was Leonard Scheepsma who very kindly agreed to send me his copy so that I could scan it and share with others. Meanwhile, I had also contacted NTI AG and users in various online forums and got a few bits and pieces here and there that I could compile. This page is the result of that hunt.
You can help
I have almost ceratinly made mistakes and there are likely more versions of manuals and schematics out there. Corrections and general feedback is always welcome!
Please also contact me if you can share other scans or paper versions of missing sections or schematics. I would be very happy to publish them here as well.
Here’s how you can reach me
IMPORTANT!
While I have made my best to group these documents by instrument it is impossible to promise that every document and schematic applies to every instrument of a given model number. Designs changed and while the designs and schematics were mostly conserved over time there have also been significant changes in several modules.
DO NOT ASSUME that modules from one instrument works in a later revision. ALWAYS double-check that the schematic you have in hand agree with the instrument and PCB you are working on. Needless to say, I cannot take any responsibility for the accuracy or applicability of these documents to your individual instrument.
MJS 401D Manuals
This bundle consists of a scanned manual that was kindly provided by Leonard Scheepsma. This manual appears to have been consolidated from different sources at some point in time. E.g. some schematics are labelled with later model numbers that would not have been available when the MJS401D was marketed. I don’t know if that consolidation was done by Neutrik when distributing the manuals or if the documents were collected by some workshop that compiled their own binder with manuals to fit their instrument(s).
Also, a few sections appear to be missing, e.g. Sections 1, 2, 15, 23, 24, 29 and 30 as well as the schematic for Section 5 CCIR filter. It is not clear if all these once existed and were lost, or if some were never part of the printed manual. I’m guessing that some of the gaps may have been present in the original printed manual (e.g. Introduction) but were lost over the years. Other gaps may have been intentional, e.g. 23/24 and 29/30 where it makes more sense to skip section numbers for later use (“This section intentionally left blank.”)
I don’t know if there are any differences between the instruments but I have not seen any manuals or schematics specific for the TP401 that also did not cover the MJS401.
TP401 Manuals
The Neutrik TP401 is basically a rebranded MJS 401D so the manuals for the MJS 401D should work very well. The IEEE-408 Operating Manual is the only document from the scanned manual which is labelled “TP 401” but not MJS401D which indicates it was written for the TP401 and is not 100% applicable to the MJS401D. It is therefore provided as TP401-specific.
Download the IEEE-488 Operating Manual for Neutrik TP401
TT402 Manuals
The manuals for the TT402 have been collected from various sources. The same content has been circulated over the years and can often be found in several places. For each unique document I have picked the highest quality version and bundled them in a way to mimic the structure of the MJS401 manual.
The text sections of the service manual are missing, with the exception of the input module.
However, note that some schematics are identical in number/revision to what used in the MJS 401D, the only apparent difference is a rebranding from Technical Projects to Neutrik. For those sections, the MJS 401D manual is very likely fully applicable.
Download Neutrik TT402 manuals
TT402A Manuals
So far, the only document specific to TT402A is the IEEE-408 Operating Manual. Presumably this means that most of it, but not everything, also applies to the TT402.