Modding non technics machines

[mstcraig]

Keep us posted Doc. Thanks.

[kazoo]

Hi, just wanted to let you guys know I just picked up a Otari BIII yesterday. This thing is beautiful and I got a great price on it. This thing is almost brand new. I think the guy mentioned he only ran a couple tapes through it. I ordered a blank tape couple weeks back so tonight I will try to do a little recording. Right now I feel like a kid in a candy store and can't wait to get home. So any mods you guys come up with for this thing would be great.
Thanks,
John

[docb]

It's going to be a little while before I will get to those 5050s. We're remodeling the lab this week so I can get through the backlog more efficiently, and meantime more machines are coming in. It's getting difficult to  walk into the listening room...I plan to get a couple more 1500s shipped this week, and have a big batch of headblocks in with Greg Orton for extended response heads. Once we get through more of the backlog and I get my new tech trained I should be able to start fooling with the 5050s.

Pedal faster, Doc.

[kazoo]

FYI

The BIII only has a 2 track heads on it. So I emailed Otari asking about the 4 track playback heads and received a response.
"The heads can be bought from Adrian Pro Audio in Los Angeles. The price is $375.00. Please call 818-347-9271 and ask for Adrian."

Just wanted to pass that on.

Thanks,
John

[ironbut]

Thanks John. That seem very reasonable. I'm a Technics man myself, but rumor has it, that the heads on the RS15xx machines are the same as the ones on the 5050. I'd like to find out if that's true. At the moment, I can't for the life of me remember why I wanted to know, but it must've been super important. If any of you guys see any part numbers on your Otari heads, please post them.

[cam3xl]

Well Folks,

John French does it again.  Just got off the phone with him and for those of us on the east coast that can make the drive, conversion of the 5050IIB does not seem to be a problem.  Direct RCA line outs from the heads and switch (external to internal electronics) installed for approx. $200.  Re-lapping and aligning all four heads and cleaning 2t/4t switch $295.  At which point you will have one of the only 2 OR 4 Track, playback and recording, 3.75 OR 7.5 OR 15 ips, 7" OR 10.5" reel accepting, IEC OR NAB selectable internally, with direct out from head option TapeProject ready decks available.

Otari Owners Rejoice!  We are now players too.

If you are not so close to New Jersey, you can ship your deck, but that adds significantly to the pricing.  Also I did not make him commit to pricing, so yours may vary depending on the overall condition of your deck.

PS.  doc, I'm sure John would share the procedure with the DIY crowd once he gets it done to his satisfaction.

[ceved]

Well Folks Redux,
On my visit to ATR Services last month I reported in another thread on seeing an Otari 5050 B II in the process of being modded out to Tape Project specs.
So if you prefer York PA to NJ, freedom of choice; priceless.
Mike and Bill are the men of York!

[classicrecordings]

All that said, Jeff Jacobs has plans for some pretty heavily customized Technics machines as well, that might incorporate our electronics in a single package.

I am no technician, but from what I understand, the playback head's impedance and signal are affected as you increase the wire length from the head to the pre-amp. So, I would think that it would be best to have the wire connecting the playback head and pre-amp to be short as possible.

So, if removing the old transistor electronics and replacing them with new tube electronics is possible, then I would think think this is the way to go.

David

[Busche]

I have an Otari MX5050 B series which ATR Services in York Pa has just completed mods on.  Added extended frequency head from Flux Magnetics.  Bypassed playback electronics and substituted Aria solid state studio unit (discrete Class A operation).  Wired Mic In xlr's on back panel to accept outboard plugs.  Unit is absolutely mint (purchased new 2001), and en-route to me now.  Have tapes One-Four at home anxiously awaiting!

[Tubes n tapes]

I am no technician, but from what I understand, the playback head's impedance and signal are affected as you increase the wire length from the head to the pre-amp. So, I would think that it would be best to have the wire connecting the playback head and pre-amp to be short as possible.

In most cases the playback head is terminated with a small capacitance to avoid ripple in the top end of the frequency characteristic. Typically that capacitance is in the order of magnitude of 100pF to 300pF depending on the head used. In reality that capacitance is a combination of the cable capacitance and a physical capacitor at the input of the head amp. You can use longer cables and reduce the physical capacitor as long as the total value is about the same. Practically a cable of up to about 1 meter is feasible when you reduce the capacitor to zero.

Watch out for hum and other horrible noises due to long cables, though.

[stellavox]

I am in process of fully "going through" an A77 for a customer and will let youse know how it sounds (compared to my Stellas).  Did a high-speed, two track one up for myself probably 15 years ago but at the time I never had anything else to compare it against sonically(sp?).  It did sound VERY nice with better caps in the reproduce amps, and a front panel-mounted variable HF EQ control -  listened to many pre-records with it over headphones before I had a good speaker setup.   

I continue to recommend the A77 as a "starter deck" for those just getting into tape and on a limited budget.  They are everywhere - the Volkswagon of tape recorders.  Built like little tanks, they sound good "out of the box" and parts will always be plentiful and cheap - heck, you can buy a few decks as/for spares. 

On the Yahoogroups reel to reel chatroom, I posted an article (rejected by Audio Amateur) which reviewed all the published A77 mods along with perhaps unpublished info I got from a Revox service guy.  It's there in the "files" section somewhere.