Ampex - Gp9

[vostok88]

Does anyone out there know the main difference between Ampex 456 and GP9 for the most part?

I'm considering using the GP9 on both a 1/4-inch 2-track mastering deck, and also for a Studer 24-track 2-inch.

I've heard that the GP9 tape is a good bit 'hotter' (or allows more 'headroom') than Ampex 456.

Is this true?

Or, can anyone just explain the main sonic differences, personal preferences, or 'pro's & con's' on either one - before I buy?

- thanks guys,

[jpmorris]

Most decks are calibrated for something along the lines of 456. If you want to run them on GP9, they will need to be adjusted. GP9 requires more energy to bias properly it and not all decks can do it. It was also substantially more expensive.

Also, while there are 456-compatible formulations still in production, I'm not sure there's anything which can directly replace GP9 so you'd be limited to what you can scrounge off ebay. IMHO that's not really the way to go.

[ofajen]

IIRC, GP-9 is 3M 996 cooked in Ampex's kitchen. It's a thicker, higher output tape than 456. You can calibrate at the same reference fluxivity you would for 456 and leave the extra dynamic range as headroom, rather than trying to increase S/N. You still need to make sure the transport will be happy dealing with the thicker tape.

These days, I'm fond of BASF/EMTEC 468 and 911. I have yet to try the RMGI recreations, but when I need to buy new tape, that is where I will go.

Cheers,

Otto

[student8]

Ok,

But how can you tell (especially before-hand) that your transport can 'handle' thicker tape, like the GP9 or anything equivalent to that same tape?


- and also, if the GP9 (and other equivalent tapes) sound 'better', and much 'louder' or have much better overall 'headroom' than most of the other 'cheaper' tapes out there (such as the 456 style tapes) - other than the costs - It looks like the GP9 style tapes would be the better overall choice, - wouldn't it?

- thanks

[ofajen]

Originally Posted by student8

Ok,

But how can you tell (especially before-hand) that your transport can 'handle' thicker tape, like the GP9 or anything equivalent to that same tape?


- and also, if the GP9 (and other equivalent tapes) sound 'better', and much 'louder' or have much better overall 'headroom' than most of the other 'cheaper' tapes out there (such as the 456 style tapes) - other than the costs - It looks like the GP9 style tapes would be the better overall choice, - wouldn't it?

- thanks

OK, good point... how would you know whether a thicker tape would work?

I think it will help you if you remember that the various tape formulations and tape machines evolved together over time, and over a period of more than 30 years from around 1950 until into the 80s. Ampex 456 was several generations into that development and capable of running 6 dB hotter than the original tapes, which did not have a back coat. A lot of machines are designed to be happy with Ampex 456 and its competitors (3M/Scotch 226 and BASF 468 and 911). Later developments provided a further generation of thicker, even higher output tapes (GP-9, 3M 996, BASF SM 900. etc.).

However, a machine designed for 456 level tapes may not have the electronic capacity to bias and erase fully at that higher level (those signals have to be stronger). Further, the transport is designed to have proper transport for a certain thickness of tape. A thicker tape might impede the proper function of the capstan and pinch roller in moving the tape. With small diameter capstans (say 1/4" diameter), the change in thickness can even produce audible deviations in tape speed on certain transports.

Capstanless transports (later Stephens and Ampex ATR) will generally be OK, as will large capstan (2" diameter) machines like the 3M Mincom decks.

The bottom line is that you probably don't have much to gain (your electronics may not be happy trying to run at the higher levels) and you may have something to lose (problems with tape transport).

So, I'd point you toward the current RMGI tape lineup and SM 911 or SM 468 in particular. Check it out in North America at:

http://www.rmgi-usa.com/rmg_studio.html

I would also point you away from older tapes of that class, particularly old stock Ampex 456 and Scotch 226. Those tapes often have problems with stickiness that means the tapes won't work and can gum up and perhaps even damage your transport.

Beck has fueled a "sticky" thread (no pun intended) on sticky tapes in this forum that is worth checking out. You always see it at the top of the thread list in this forum.

Cheers,

Otto

[student8]

Yeah, I've been reading thru some of the 'Beck/sticky' threads - pretty long - but I've been reading them when I can.

However, it still doesn't answer ALL of my questions & concerns (or at least that I can find) which is why I was asking for your opinion on some of this.

(which I thank you for by the way, that was very kind & helpful.)

And again, the ONLY reason I was even considering buying some of the 'old' tapes on Ebay (mostly the ones that are still 'new in box', but still 'old' in age as well) - was to simply save on money.

I've been looking over the RMGI site (and some other dealers out there who carry RMGI tape) and the prices are much more expensive compared to the ones you find on Ebay, you know? So one of the things I was wondering, was is the 'older age', but still 'new in box' tapes on Ebay really NOT worth getting, even if it's saving you around $100 or more? Is it that bad? (honestly)

Also, if I do end up buying some new tape from RMGI - which tape do you think would be the best for my machine (Otari MTR-10, 1/4-inch, 10.5-inch reel?) - and keep in mind, my Otari machine has still NOT been 'set-up' or 'properly aligned' yet (that I know of) for any type of certain tape yet - so I'm basically trying to decide on 'one' tape to use & 'stick with' from here on out - but I want it to be of very good quality, nice headroom, good overall 'thick' sound, (well, I think you get the idea

What would be your choice (and don't worry so much about 'price difference' between the actual tape models either) - just whichever brand or model of tape you would choose if money wasn't a factor, and you KNOW would be a damn good overall choice to get & stick with for a very long time?

- thanks again btw

[FALKEN]

if u want thick sound go with 456

i recommend u get one reel of gp9 to try it out

keep in mind what otto said...gp9 came out mid 90s, not a lot was done on it...most of your favs were done on 456 or something lower bias

[student8]

I assume you mean to use the 'new' RMGI equivalent of 456 - not the original old, but still 'new' ones on Ebay?

(thanks for the recommendation by the way.)

[jpmorris]

Originally Posted by student8

I assume you mean to use the 'new' RMGI equivalent of 456 - not the original old, but still 'new' ones on Ebay?

Don't use Ampex 456. If you must use NOS or used 456 tape, try and make sure it's branded Quantegy. Most of the Ampex tape (pre-1995) is subject to the sticky-shed problem. They had the problem cracked by the time they rebranded.

[student8]

(not quite sure what 'NOS' means, but.......

I guess what I was trying to say, was do you mean if I want to use 456 (Ampex or Quantegy) - don't buy it off Ebay, but buy the 'equivalent' of it, 'new', from somewhere like RMGI.

Is that correct?

[jpmorris]

Originally Posted by student8

(not quite sure what 'NOS' means, but.......

New Old Stock. i.e. unopened Ampex or Quantegy tapes.

I guess what I was trying to say, was do you mean if I want to use 456 (Ampex or Quantegy) - don't buy it off Ebay, but buy the 'equivalent' of it, 'new', from somewhere like RMGI.
Is that correct?

Don't get Ampex, sealed or used. Just don't - it may damage your machines.

If you want new, RMGI 911 or 468 is probably best, it's either that or ATR, but ATR is twice the cost and you've already said that cost is an issue.

But if you can find an unopened box of Quantegy 456, or 911 or 468, there's no reason I can think of not to go for it. 911 and 468 will be branded either BASF or EMTEC, either one is good stuff. Tape that has actually been used is a pig in a poke, it may or may not be in good condition. Heck, it may not even be what the box or spool says it is. It's something I only usually resort to if there is no other alternative.

[Blue Jinn]

If you want something "hotter" NOS 499 might be worth looking at. It is slightly thicker than 456 with slightly hotter specs

[FALKEN]

Originally Posted by Blue Jinn

If you want something "hotter" NOS 499 might be worth looking at. It is slightly thicker than 456 with slightly hotter specs

what is the diff b/t 499 and gp9?

[student8]

Yeah, I've been wondering the same thing as well - "what exactly is the difference between 499 and GP9?"

- and also, is it safe to assume that if I want to simply 'sample' or 'try out' these various types of tape - I can just buy one of each, hear what they sound like, without having to make any 'adjustments' on my machine?

(or do I need to 'calibrate' or make any type of adjustments between each one?)

[sweetbeats]

If you are wanting to try out 499 and GP9 you are can use the same calibration settings between those two but I would suggest a rebias...unless somebody here can tell us whether or not 499 and GP9 are bias-compatible (and a bet somebody can...! )

What deck are you using?

[vostok88]

me? - I'm currently using an Otari MTR-10.

(but I have no idea as to what type of tape this machine is 'set-up' for - nor, can I find that information in the manual anywhere.)

[student8]

I'm using the otari mtr-10 as well, but I still don't even have a manual for mine yet!

Are most otari machines set-up for a certain type of tape?

[sweetbeats]

Its anybody's guess as to what your MTR-10 is setup for, Student8...they were designed to handle a wide range of tape so...I had forgetten you were using an MTR-10. My guess is that the differences between 499 and GP9 are going to be very minimal...I think they are different formulations but I have a hunch they are bias compatible. I'd still check the bias when switching until you know that answer for certain. They are both "+9" tapes though...

MTR-10 service manual here:

http://www.audioschematics.com/otari.html

I'm downloading it right now so I don't know for sure if this includes an operator's section or just the service manual...obviously no schematics. Better than nothing at any rate, and free. Send them an email and thank them. They'ce been providing the analog community a great service for free for a long time with resources, tutorials and downloads. That which is taken for granted goes away!

[FALKEN]

you should rebias for every tape, even the same kind of tape from a different batch. you can probably get away with not doing it, unless you are goi g to q different level, but it wont be exact

[Dr ZEE]

Originally Posted by FALKEN

you can probably get away with not doing it ...

The question on needs to ask himself is: "Is there really someone (or something) out there who's about to get me, that makes me worry about getting away ?"
***********

...buy one of each, hear what they sound like, without having to make any 'adjustments' on my machine?

I did so. Have found all types that I've tried are useful as they are.
But then again, I don't "interchange" with studios/producers/artists that I am not so "planning" to do busines with

[Blue Jinn]

Originally Posted by FALKEN

what is the diff b/t 499 and gp9?

Spec wise:

Oe Gs Mil

499 390 1600 2.03
GP9 370 1600 2.13
456 320 1500 1.93

According to a Quantegy paper I have, 499/GP9 share the same bias. 499 is thinner than GP9.

[ofajen]

Originally Posted by Dr ZEE

The question on needs to ask himself is: "Is there really someone (or something) out there who's about to get me, that makes me worry about getting away ?"

Precisely. If you are going to mix on the same machine you track, all you care about is that you have a total system response (from input signal to output on tape) that you can use to do your music. It doesn't have to be flat and, unless you will play back on some other machine, it doesn't have to be set up with any interoperability standard in mind. OTOH, using those standards is often easier, since the cal tapes are available and it makes for a consistent and easily repeatable process.

Cheers,

Otto

[sweetbeats]

Hey, Blue Jinn, do you know where to find specs on Scotch tape (particularly 996)? Wondering if it is thicker than 911...

[Blue Jinn]

I have a large compilation of data I have in a file. Not on this computer at the moment. I can PM you (I think) the file is about 14 MEGs though. I;ll look for the scotch pages and separate them out. Sorry, I hadn't noticed this thread had been updated or I'd responded sooner!

[Beck]

Yep, 996 is a bit thicker... 2.13 mils compared to 1.97 mils for 911. For reference, 456 is 1.93 mils.