OTARI Setup Calibration Kit
OTARI calibration kit for most Otari 1/4" models.
TD7500 MX50 MX5050 MTR15 etc
Nagravox Calibration kits are different to what you might expect. They are a lot more than just a calibration tape!
Developed over the last 3 years specifically for discerning audio enthusiasts and professionals, the rationale is to provide an appropriate set of tools, instructions and media to test, calibrate and setup a specific model Revox, Studer and generic tape recorder machines properly. Three resources based on the three fundamental chains of signal processing.
* INPUT OUTPUT CHAIN * PLAYBACK CHAIN *RECORD CHAIN
A cheap short generic reel of tape recorded by an enthusiast to try and make some money from his tape machine on eBay is not realistically going to help you setup and calibrate your machine properly. Calibration is the final step and is not just a process of throwing on a playback tape, tweaking some trimmers and hoping it will all come together. All 3 chains must be considered singly and then together. You also need to understand what gear and instruments are needed and how to use them. Awareness of modern tape formulations, relevant steps, differences, peculiarity's and nuances of a particular model, later factory updates not in factory manuals and hints and tips based on experience make calibration and setup a science and not a hit or miss affair.
The Nagravox calibration kit is designed to setup and calibrate your machine fully and properly. Each kit is tailored for a specific machine and your tape type preferences. Feel confident that your machine is setup and performs the way it was designed and manufactured.
PLEASE NOTE: This OTARI kit caters for most 1/4" Otari machines that have 2 speeds and 2 or more channels. You select how many speeds, equalisation and tape type. If you have a 3 speed model eg MX50 please contact us for an additional playback tape to be added to your kit (AUS$ 90 for 3.75 "/sec or $250 for 30"/sec)
Nagravox Setup and Calibration kits include:
• Playback calibration tape or tapes
• New fresh record setup tape for calibrating the record chain
• A set of detailed generic instructions, explanations, required equipment (which are not too onerous nor expensive), diagrams and check sheets to coach you on what to do. These are based on a range of generic machines that have come through our workshop over the years and incorporate Nagravox’s personal experience repairing, updating and restoring tape machine’s. The Otari kit has an additional addendum with some specific information and instructions.
You need to decide:
• Machine model and whether you may want the kit to cater for multiple models.
• Speeds and equalisation
• The tape type and formulation you will be using to set the machine up for. We recommend SM900 or LPR90 but can accommodate SM911, LPR35, SM468, ATR Master and ATR MDS36. (All currently manufactured new tape)
The playback calibration tape/s are long length on a 7" special somewhat 'ugly' blue reel (so it can’t be mixed up or easily recorded over in error) and includes a plethora of appropriate length tones (the important ones are in minutes not seconds!) at calibrated levels with full commentary and explanation. Everything on the tape relates back to the calibration manual notes and explanation.
The Record chain tape is a brand new full length 7" tape of the type you will set your machine up on.
Instruction Manuals are requested and sent to you covering detailed audio setup. Tape transport, power supply or other mechanical items are generically covered unlike our Revox / Studer ranges which are specifically detailed
SOME GUIDELINES ON TAPE TYPE
- SM900 and ATR Master are durable studio grade mastering tapes able to handle up to +6 to +9 Db saturation with minimal increase in distortion.
- SM911 is a max +3 Db tape. This 'over drive' is not the only difference but I am hesitant to pass comment on nebulous terms such as 'warmth'. You just need to try and decide for yourself. Certainly be circumspect in being guided by www forum hot air and nonsense.
- LPR90, LPR35 and MDS 36 are thinner commercial grade tape with similar (but not exactly the same) magnetic characteristics as their standard play cousins. Their main advantage is economy in that you get 44% more tape and time on a reel. However you dont get something for nothing and lifespan is reduced.
- SM900 (std play) and LPR90 (long play) have similar but not exactly the same magnetic properties despite what the manufacturer implies. Similarly for SM911 / LPR35 and ATR Master / MDS 36 . So setting up on one and using the other could mean a variation of 0.75 - 1.5 Db difference in level between std and long play and the optimum bias will also not be the same.
- How critical is it that I use the exact tape formulation all the time? You can use any tape formulation on any machine no matter what it has been set up on and it will work OK but not optimally. You wont break anything! The key here is 'optimal'.
- How many times can I re record over and play tape. I suggest the following rough use guidelines.
Commercial machines with one or more rub blocks for tape guides 200 - 400x
Commercial machines with rotating tape guides 300 - 500x
Professional machines with rotating tape guides AND electronic tape tension control 200 - 300x
Test Instrumentation and leads / adapters required for calibration
Our service manuals detail the typical instrumentation you need for calibration. Here is a summary.
- Millivolt meter - analogue not digital ( definately NOT your digital multimeter!)
- Signal Generator - required for inputting record chain pure sine waves at various frequencies and amplitudes. Digital or analogue OK.
- Adapters and cables - quite a few including dummy loads
- Oscilloscope - although not absolutely essential, an oscilloscope is really fabulous to visualise and understand what's happening. Modern ones are mostly really good, not very expensive and boast a range of useful functions such as auto setup and measurements of frequency and amplitude.
Have a look at what we have listed here:
These are nice to have but not really necessary as you can accomplish much with what's already listed.
- Frequency meter
- Wow and flutter meter