Otari mx5050 8 track bypass?

[labcoat man]

Hi forum members, 
I'm brand new here, the owner of an 8 track Otari mx5050 mk4 and revox A77 in a home recording set up (I aslo have an old Akai domestic 4 track for tape delay and a 1950's ferrograph for tube glory which doubles as a nice guitar amp!).
 
I'm in the process of trying to upgrade my home/project studio and was intrigued by reading on this forum that it may be possible to bypass the playback electronics in the otari and use higher quality outboard electronics wired to the playback head for better reproduction.

I find this possibility very exciting due to my limited budget and the scarcity of top notch
vintage professional 8 tracks out there (Ampex, scully studer etc).

Just wondering if anyone who has done this may be able to set me straight on how involved this is and what has to be taken in to consideration,
one main issue would be the output level received from the playback head and what impedance, gain etc is needed to amplify the tiny signal (would a mic level pre amp be suitable for example)? and of course the ease with  which the playback head can be directly tapped ( I read here that the edge connectors would make that fairly easy on the otari).

I'm due to receive an old studer 089 mixer that has excellent transformer balanced class A pre amps but I imagine tapping the playback heads directly into the mic - line inputs sounds too easy to be true?

Any help or hot tips for a novice would be greatly appreciated.


thanks

Tim

[steveidosound]

Welcome,
The very short answer is that it is not so easy to do.
There are 2 main obstacles.
The first is that any tape playback system has an eq curve. It's not flat.
So you have to make your playback electronics follow that curve for overall flat response.
A second factor is that although mic preamps have about the right amount of gain (but no tape eq), they are probably the wrong impedance to match well with your heads.

I will now leave it to more qualified members here to suggest things.
I know some people on here were talking about upgrading the MX5050 series of electronics rather than discarding them. If your machine has 4 sets of similar stereo electronics, perhaps the mods are directly applicable. They were talking about capacitor and op amp upgrades for the most part.
I have the 1/4" 4 channel cousin to your machine BTW.

[labcoat man]

Thanks Steve ,
I'm starting to get more of a picture now
the eq curve and head impedance definietly make it more involved I imagine!

Been looking at the bottlehead and Aria options in the last hour, not sure if in my budget
but will investigate further.

Be interested to know how you find the 4 track version of the Otari.

Any more tips on improving or replacing the playback electronics by anyone out there appreciated!

Thanks

Tim

[Studer Fool]

Tim,
You've checked out the Bottlehead site, right?  See:
http://www.bottlehead.com/et/adobespc/Seduction/bottleheadtapeheadpreamp.htm
You of course would need 4 of these.  May not seem cheap, BUT there is really no less expensive route I know of.

cdw

[ironbut]

I think that in your case, you might be better off having your 8 track recapped. That's a very common practice with older pro audio gear. Since everything is X16 (record and playback), that won't be cheap, but far more affordable than starting from scratch on your record and playback amps. If you live in or near a large city, there should be one or two reel to reel techs that should be able to do this for you. One way to find them is to ask at your local Guitar Center or similar shop that sells recording equipment.
Once you find a good tech, you should think about having the entire machine checked out. Having good sounding amps in your machine is one thing, but having it pull tape and handle it correctly isn't just about being easy on your tape, it has a large effect on how your recordings will sound.

[labcoat man]

Thanks Ironbut and Studer Fool. The bottlehead option looks great, just a bit out of range for now.

There is a tech I can use who I've used for my tascam  tsr8, the Otari has been very well maintained all its life but is probably due for a check up.

 Generally it sounds pretty good (quite true to the original source on playback with a bit more oomph and presence, maybe better playback head/amp than monitoring head/amp? ) but what i noticed is that running sources through the electronics themselves and monitoring from source (without tape) tended to degrade the sound slightly when AB'd with the source bypassing the machine all together. I recently borrowed an MCI 2" 24 track with transformer balanced discrete amps and you can actually add life and depth to the sound by running through the electronics without tape!

If I need to spend significant money on upgrades or a re cap I may consider an upgrade in machine... I love the 8 track format for its simplicity and its limitations.  Anyone have a favourite higher end machine in this format? I imagine something like an ampex or studer 1" 8 track would fetch a fair bit if it could be found... then theres upkeep...

Tim