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Messages - GLouie

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Tape Tech / Re: New (to me) ST 1510A question
« on: June 10, 2011, 05:04:00 PM »
FYI, I found my April 15, 1981 literature/price list for the ST 1500A, and it was $5,750.00USD. 1/3 octave spectrum analyzer option added another $1,500.00.

I don't know what the 1510A was.

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Tape Tech / Re: Ampex ATR-700 Questions
« on: January 10, 2011, 12:10:31 PM »

I have the manual here, so I will try to supplement Steve's good advice.

I haven't seen any 1/4 inch jacks on ATR700s other than the headphone jack, so those may be a retrofit.

1-EQ- I would say for playback, use the position that corresponds to the EQ the tape was recorded in. For recording, you may choose, but NAB is standard in the USA and IEC in Europe.
2-Since each channel (1&2) has 2 inputs (A&B), you select MIC or LINE depending on what you have plugged into the inputs. Selecting MIC for "A" means you may plug microphones directly into both the channel 1 & 2 "A" inputs. MIC input mode means about 40dB more gain than LINE input mode. I would leave them on LINE to keep noise at a minimum unless you specifically want to plug a mike in. No phantom power is provided for condensor mikes that require it.
3-Mic ATT - If you do use the MIC modes, set the attenuator switches depending upon how much output signal the mike provides and how loud the sound is that you are recording, such that the loudest signal does not overload the ATR microphone preamplifier and cause clipping distortion.
4-Use REPRO mode unless you specifically are doing sel-sync work and need to monitor using the gap on the record head for playback. Fidelity is degraded when using the record head for playback, and is intended for real-time monitoring for doing overdubs.
5-I agree with Steve, leave all unused inputs knobs all the way down.
6- Factory setting for these switches are:

REC EQ 1 - Ampex 456/641 tape
           2 - Ampex 406
           3 - 3M 250

REC BIAS 1 - Ampex 641
              2 - Ampex 456/406
              3 - 3M 250

REC LEVEL 1 - Ampex level, 185 nWb/m
                2 - plus 3 dB (250 nWb/m)
                3 - plus 6dB (370 nWb/m)
(I think this just changes the meter zero)

None of these tapes are made anymore, so you really need to have the machine aligned for whatever tape you wish to use for recording. I would never accept these settings even for the indicated tape without testing. These settings are not used for playback (except the REC LEVEL which I think changes the meter zero setting).

7- the only output level knob I know of is the concentric knob on the front panel lower right. Mine are all labeled clearly as OUTPUT - ch1-ch2.  If you have additional A-B output knobs, these may be a retrofit. Or maybe early models had different labels. Otherwise, you are right, Ampex was calling the recording tracks 1-2 and the inputs A/B.

My notes indicate that this deck's polarity is pin 3 high on the XLR connectors whereas pin 2 high is now standard. However my notes also indicate that polarity is preserved on reproduce, but inverted on the LINE inputs. If correct, this infers that the LINE inputs will actually have correct polarity when fed from a contemporary pin 2 high device, but should have inverted repro polarity with pin 2 high devices. The outputs are on transformers so a mod should be easy if needed. I can't recall my method for determining this, so might be taken with a grain of salt.

Photos of the front/back panels might help determine if you have custom retrofits.


I have been unable to find a manual for my Ampex ATR-700 and need some help.

Background:  I have an Ampex ATR- 700 connected to a Tascam M-520 recording console.  The Ampex ATR -700 has only XLR inputs and outputs on the rear of the deck.  It also has 2 1/4 inchs female jacks which I don't use and I'm not sure what they are for.   The outputs on the console are low impedance balanced outputs which are either +4 or + 8 dbm (I'm not sure which because the switch for these setting is inside the board and I've not checked them).

I have recorded and played back successfully using the tape deck and the board but since I do not have the manual, I wanted to get confirmation on a few things and therefore I have the following questions regarding the Ampex ATR -700 open reel tape deck:

1. Should I have the EQ switch set on NAB or IEC?

2.  There are 2 switches on back, one for "A" and "B."  Should these be set on "mic" or "line?"  I have them set on "line."

3.  For each channel there is a microphone attenuation switch which can be set to either 0 or 20 - which is the best setting for me?  I have them set on zero.

4. On top of the cover for the head/transport are switches for "repro" or "sync."
Which is the best setting?  I have them set on "repro."

5.  There is are what I believe to be record level input knobs A & B for each of the two channels (a total of 4 knobs).  If I only have cables connoted to inputs A of each channel, should I have the knob B turned all the way to "zero" or does it matter?  I have them all set in the middle. 

6. There are switches that allow for three settings 1,2 & 3 for "Record EQ," "Record Bias," and "Record Level."  Don't know which of the three is best for my purposes.
I've been using the number 1 setting.

7.  There are two knobs which seem to control output from the deck for each channel but they are labeled CH A and CH B.  Why are they not labeled CH 1 and CH 2?



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Tape Tech / Re: lamps for Otari VU meters
« on: November 18, 2010, 10:35:42 PM »
MTR-10? I got tired of changing them after the original spares ran out. I retrofitted a bridge rectifier and 2 LEDs with resistors on each meter. Everything was from Radio Shack. The illumination is not as diffuse, although if I had tried several LED designs, I might have gotten there.

My specs are at the office, so I don't have them on hand.

4
Tape Tech / Re: Otari switches cleaning
« on: November 18, 2010, 10:30:05 PM »
MTR-10? I recall taking off the entire pushswitch frame with switches to be able to spray into the moving part of the switch, then giving a few hours sitting over a rag to drain.

I also changed the meter lamps to LEDs while I was there.

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Tape Tech / Re: Lamps for Otari MTR-10
« on: November 18, 2010, 10:22:04 PM »
got the lamps today, and they work perfectly!  While not frosted like the originals. the lumen output is the same as the originals in both  standby and use mode, the mouser.com part number is: 606-cm680

Good find - I'll have to make a note of that!

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Tape Tech / Re: Lamps for Otari MTR-10
« on: October 20, 2010, 03:54:29 PM »
I'm sure this is the wrong place for this but I didn't know where else to put it. I'm looking for the lamps for the RR FF buttons. I've not taken it apart to get a part number because the new lamp is not in my hand yet. I can't find it in the manual. Can anyone give me a part number and tell me where to buy them? Thanks.

Hi all, first post.

The MTR-10 transport button lamps are "grain of wheat" style, frosted, with bare wire leads. They would come from Otari in a white rectangular plastic carrier with the wires threaded onto the sides as contacts. There's 2 sizes of carrier, since the cue button is smaller. The original accessories kit came with a couple of spare lamps-in-carriers, and you reused the colored tops. I think it runs off the 5volt supply, so I'd guess a nominal 6volt lamp would work. Current or brightness - dunno. The bulb is about 3mm diameter.

Where I work, we have 2 machines since new (1984), and I've changed, maybe, 1 lamp. But I did order spares 20 years ago, and it appears to have the part number of WH11117U, but that might be the number of the whole switch assembly, ready to solder onto the button board. I don't see anything but the whole button board in the parts list (PB-75V). Sorry, spares belong to the State of Washington!

I would look for grain-o-wheat bulbs and replace them in the carriers.

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