What Tape Should I Use?

What Tape Should I Use?

This section is designed for those who may need a little help deciding on Open Reel analog recording tape choices. This is a general chart and is very subjective with some people using certain tapes in totally different applications over others, but this chart is derived from the many communications we've had with our customers as well as from the factory:

Since Quantegy and AMPEX are gone, what are the equivalents?

Here's a simple chart:
AMPEX 407/457- Try RMGI LPR-35
AMPEX 456- Try ATR Studio Master or RMGI SM911
AMPEX 499/GP9- Try ATR Studio Master or RMGI-EMTEC SM900 (Pro decks only for SM900)
AMPEX 480 (For Nagra)- Try RMGI-EMTEC SM911

What Are Pancakes of Tape?


Pancakes are a great, inexpensive way to buy tape and not have to invest in the cost of metal reels if you already have compatible flanges. Maybe you have a number of good metal reels with old, bad, spliced up tape on them and you want to simply replace the tape. If you buy pancakes of tape, you'll get  the tape wound on a standard NAB hub (the plastic thing the tape is wound on), bagged and in a cardboard ECO box which is just large enough to hold the pancake of tape. (See photos in our tape section.) Important:::  You must be very careful handling a pancake of tape, as it can turn into a spaghetti if improperly handled, or you can damage the edges of the tape. We are not responsible for tape damage caused by improper handling. To use a pancake, they normally must have metal flanges mounted on them. To make a reel, you need one flange set and one hardware set. Also, almost all NAB style 3M, AMPEX, or Quantegy flanges will fit the RMGI or ATR hubs. ATR and RMGI hubs of 1/4" or 1/2" tape are nearly identical and are compatible.

Standard Tape Lengths and Times:

There are two standard lengths of tape available per reel size. You can get 7" reels in 1.5 mil 1200 foot (1250 foot for ATR Studio Master) or 1 mil 1800 foot lengths. Also, in the 10.5" format, 2500 feet or 3600 feet.   1800' versus 1200' is the difference between 48 minutes and 32 minutes at 7.5 IPS, and 3600' versus 2500' is the difference between 96 minutes and 66.7 minutes at 7.5 IPS one way. Double that if you have a stereo 1/4 track deck and you record both "sides" of the tape. Please see our Tape Time Chart.

General Tape Suggestions:

The following chart is a general idea of the applications and tapes our customers have been telling us they use successfully for those applications. When in doubt, it's always better to use a tape of better quality to achieve the best sound for your application. Our most popular tape for studio use is ATR Studio Master followed by SM900, and the most popular tape for home users is ATR Studio Master, then RMGI SM911 or LPR35 for longer record time.

Applications Tape Suggestion
1/4" Formats Available
Live Recording, CD Recording, Mastering Digital Protools Recordings, Use on Better Consumer Decks
All Studio Quality Decks +9dBm recommended operating level
ATR or RMGI SM900
SM900: 1200' on 7" Reels,   2500' on 10.5" Reels or Pancakes
ATR: 1250' on 7" Reels, 2500' on 10.5" Reels or Pancakes.

CD Recording, LP Recording, Live Recording on Tascam and Otari, or use on Consumer Decks. Version LPR-35  is 1 mil version of SM911, +6dBm recommended operating level.
ATR Studio Master, RMGI SM911 or LPR35
SM911: 1200' on 7" Reels,  2500' on 10.5" Reels,  2500' Pancakes
LPR35: 1800' on 7" Reels,  3600' on 10.5" Reels,  3600' Pancakes
ATR: 1250' on 7" Reels, 2500' on 10.5" Reels or Pancakes
Home Recording of CDs, FM Broadcasts, LPS +6dBm Recommended Operating Level.
RMGI SM911 or ATR Studio Master
SM911: 1200' on 7" Reels,  2500' on 10.5" Reels,
 2500' Pancakes

Nagra IV Applications Low Print
RMGI SM468
600' on 5" Reels, 1200' on 7" Reels, 2500' on 10.5" NAB Reels and Pancakes


Generally speaking, when recording on a good quality deck from a dynamic source, use SM911 or SM900 unless you need longer recording time. In that case use LPR35. There is no long play version of SM900 because of the heavy amount of oxide on the tape. If you're recording live material, we strongly suggest SM900 for the increased dynamic range, headroom, and lowest noise characteristics. SM900 tends to be the most transparent tape with an amazing sound field. Consumer Note: RMGI-EMTEC LPR35 is a drop in replacement recommended by Maxell to replace their now discontinued XLI 90B and XLI 180B. You shouldn't need any deck adjustments either for excellent response, and these tapes are lower noise tape to begin with.  Although AMPEX 456 is the widest used of all tape of all time, it was simply because it was most easily available here in the USA, was pretty much first with a +6 operating level, and was heavily promoted in the heyday of analog recording in studios. LPR35 is a long play version of  SM911 with the same oxide as SM911 but on a thinner base. Both are +6 recommended operating level tapes compared to +9 for SM900 and +10.25 for ATR Studio Master. .

RMGI 468 is designed for more non critical applications, but still has a large following for its sound. RMGI 468 is widely used on NAGRA recorders worldwide and this tape meet their special transport needs.

What the heck is an operating level?

All quality analog recording tapes are designed not only to record best in particular speed ranges, but also at certain "operating levels." If you can visualize recording something at 0 VU on your meters with a deck set up for AMPEX 632, then imagine
you could be recording 9 dB "louder" on the tape without tape saturation. To record on your deck 9 dB "louder" without pinning the meters, imagine turning down the output amplifier level by this 9 dB. Your meters would now be reading 9 dB less. To make this up and record at 0 dB again, you'd increase the record level control. Basically, that's how its done in the rough of it.

What does this get you?  By recording more audio level on the tape, the residual hiss in the background is reduced significantly because this hiss level is more or less constant between tape types. You can check this out yourself by recording something
at 0 VU and then the same thing at -9 VU. Turn up you're sound system to hear the -9 VU recording at the same volume
at the recording at 0 VU. You'll hear a big difference in the background noise. This is the main advantage of a +6 tape like 456 or a +9 tape like GP9.

Why can't I just record louder on the tape I have, rather than go with SM911 or SM900? Tape that's designed to work at a +9 or a +6 have thicker coatings of oxide on them. The thicker the coating, the higher the sound level will be before the tape "saturates" or distorts.  In fact you will notice that SM900 is stiffer than SM911 even though they're both "1.5 mil" tapes.

Can I use SM900 for the increase in transparency yet not adjust my deck to a +9 operating level? Sure. But you won't get the large decrease in background noise that you could have if you did.

Can I compromise to say a +7 rather than +9? My deck's electronics might not like +9.  There's no reason why you can't.
But keep in mind your  tapes will all be recorded at an odd level.  You can experiment with this to find the highest sound level your deck will handle without nasty distortion. Record something with a lot of loud percussive sounds like a snare drum or a piano from a CD. If your deck's electronics are "clipping" or distorting, you'll hear a very audible grinding type distortion.
Tape saturation is very soft. Sounds like someone added a lot of compression to the audio and removed some of the high frequencies.

What the heck is tape bias all about?

I hear about bias settings all the time... what is it? All analog tape decks use a high frequency "tone" mixed in with the audio when recording. The audio and the bias tone, around 100KHz, are fed to the record head to implant the audio patterns onto the recording tape. Bias is NOT involved in the playback process. The bias helps energize the tape oxide to allow the audio to be more easily implanted on the oxide. Since the bias frequency is so high, it is not stored on the tape after being recorded. All that is left is the actual audio.

I have switches on my tape deck for low, normal and high bias. Is this good enough? Maybe. Maybe not. Assuming you have a decent quality tape deck, and speaking in general terms, and assuming your tape heads are clean and demagnetized, when recording high quality music, the high frequency audio played back off of tape should sound almost if not totally identical to the source audio. If the audio off of tape is muffled with less high end than the source material, there might be TOO much bias being applied to the tape when recording. Conversely, if the audio off of tape is "brighter" than the source material, there might be too little bias being applied to the tape when recording. The bias signal applied to the tape when recording is meant to vastly reduce distortion. Ideally, if you apply the right amount of bias, your frequency response through the recording and playback cycle will be flat and you will have the least amount of distortion possible.

So what switch position should I use? In the quick, do it by ear. Experiment. You won't wreck the tape. Use the switch position that sounds closest to the original source material.

I want to do this right. My "normal" setting is too bright sounding and my "high" bias setting is muffled. Now what? Your tape deck may not be applying enough bias signal on the "normal" setting, and too much on the "high" bias setting. The first step, and the easiest, is to try different tapes to find the one that works best with your deck as it's set up. US Recording has a tape sampler with different commonly used RMGI-Emtec tapes. You may find a tape that works best for your deck as it's already set up. Different tapes have different bias requirements. You might get lucky and find one that falls right into one of your preset switch positions.