TP-028, Nat Adderley's Work Song is now available

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Hi All,
Just wanted to introduce myself and my latest project - producing a Tape Machine.
It is based on my trusty Stellavox SM8 which I've used to record over 300 concerts [http://www.metaxas.com/recordings.html ]
and has the blessing of Georges Quellet - founder of Stellavox.
As I'm still researching some of the parts, any info on Tape Head suppliers et al would be appreciated.
warm rgds,
Kostas Metaxas
www.metaxas.com
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General Discussion / Re: HOW TO USE THE CALIBRATION TAPE
« Last post by High and Outside on March 07, 2018, 01:19:11 PM »
And here's part two:

These are the instructions for using the test tape published by The Tape Project. The process is similar to what you would do with an alignment tape from a standards lab, but with one or two differences.
We have included two signals on the test tape which allow you to confirm the correct polarity of your system.

All musical sounds (except some synthesized sounds) are asymmetrical to some degree. Assuming that the recording has been made in a way that preserves all sounds in the same polarity, and assuming that the release format presents them in the correct polarity, you will be able to be sure that they are being reproduced in your listening room at the same polarity with which the sounds were originally produced. (Both of the above assumptions are correctly realized sometimes, and sometimes not.)

The first polarity signal is a tone of approximately 1Khz which has had the bottom of the waveform clipped, while the top of the waveform is intact. Displayed on an oscilloscope the difference is obvious. Check the signal at different points as the signal flows through your chain and you will easily see each reversal of polarity. (If you listen to this tone you may think it sounds distorted. It IS distorted: half of the waveform has been severely clipped.)

If you want to be sure of getting correct polarity all the way through to your speaker output, you are better off getting a popper and using the second signal on the tape. But in the absence of a popper, here is the best you can do with this tone and a 'scope: If you get to the point where your amp connects to the speaker and the tone is IN polarity, then the speaker output should be IN polarity if it is wired correctly. If you see the tone at this point OUT of polarity, reverse the connections to both speakers.

For some years polarity test sets have been made which consist of two parts: a "pop" generator, and a receiver. These are commonly called "Polarity poppers" (or by people who don't value precision in their technical communications, "Phase poppers"). Our second polarity signal on the tape is merely the recorded output of one of these pop generators. Assuming you have one of these polarity test sets (highly recommended, very very useful and only about a hundred bucks) you can just play this portion of the tape and measure the output of the speakers. The number of polarity reversals through the chain is immaterial. When it comes out of the speakers, either it's IN polarity or you reverse the connections at both speaker terminals.

It's really just as straightforward as it seems, except for one thing: measuring the polarity of loudspeakers is fraught with hidden traps. It is beyond the scope of this paper to do an exhaustive review of the technique of using this instrument, but we'll give you two valuable pointers. First hint: hold the receiver in front of one driver, say the midrange driver. Your reading may be unequivocal, or it may bounce back and forth between positive and negative. If it doesn't give you a steady reading, try different positions until you find one that does. Then check the woofer and the tweeter. Again you may have to look for a position that gives you a steady reading. You might expect that all the drivers will give you the same reading, either positive or negative. Your expectations might be confirmed, or you may be in for a rude shock. Some speaker/crossover designs reverse polarity at each crossover point. If you find this to be the case with your speakers, you're on your own as far as deciding which polarity to settle on for the system.

Following these procedures will assure that you are getting the correct polarity when listening to tapes from The Tape Project. But what about your other sources? The first thing to do would be to check the polarity from your other line inputs using both halves of your test set: plug the pop generator into each line input in turn and check it downstream with the receiver. If they are all the same as the reading you got from the tape, that's a good first step. It doesn't guarantee that the components you plug into those inputs follow the polarity conventions, but you can hope.

Wind the tape back to the beginning and hit play. ALWAYS store your test tape (in fact any important tape) flatwound at play speed. This assures that the tension is even within the pack, and that edges are smooth, which will prevent edge damage.
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General Discussion / Re: HOW TO USE THE CALIBRATION TAPE
« Last post by High and Outside on March 07, 2018, 01:15:27 PM »
The first newsletter linked above is no longer available online (so if you have one, put it up on eBay for big bucks! Vintage! Extremely Rare!!)

So I am posting the text of it here, slightly edited:

These are the instructions for using the test tape published by The Tape Project. The process is similar to what you would do with an alignment tape from a standards lab, but with one or two differences.

Before you begin, the tape machine must be in good mechanical condition. You can never achieve proper playback unless the tape path is working as it was designed, without excessive wear of any parts, including the heads. Additionally everything must be scrupulously clean.

The tape contains tones for setting levels, the EQ curve and azimuth. The levels and EQ are electrical adjustments. Azimuth is a physical adjustment of the relationship between the playback head and the tape. The test tape also has two sections for checking polarity.

You will need meters for doing the basic setup of level and EQ. An oscilloscope is highly recommended for adjusting azimuth, and necessary for using the polarity tone. A popper is necessary to take advantage of the polarity pops. This will be explained in Part 2, the polarity section of these instructions. If your tape machine has VU meters these may be accurate enough for the level and EQ adjustments. If not, you will have to use an external meter.

In most parts of the procedure, it is important that the steps be done in a certain order, as each adjustment builds on one which came before it. So please pay close attention to the sequence of the steps and perform them in the order described. A few of the adjustments interact with others, so occasionally you will be directed to back up and repeat a few steps.

Consult the manual for your machine, and make sure you know where the adjustment points are for level, high frequency EQ, low frequency EQ, and azimuth.

Now, with the preliminaries out of the way, let's begin.

Your test tape is supplied tails out, so please place it on the takeup side of the machine, which is generally on the right. Thread it as required for your machine and rewind it to the beginning. Play the first tone, which is 1Khz. Adjust the output level control to "0" VU or any other convenient reading on your meter.

The second tone is 10Khz. Play it and adjust the high frequency equalizer to the same level you previously set at 1Khz. (This is an example of the order of adjustments being significant. You are setting the HF EQ in relation to the level you set at 1Khz, so obviously the 1Khz must be set first. The same is true when you set the Low Frequency EQ.)

Now it's time to check azimuth. Ideally you will have the two channels feeding an oscilloscope in X-Y mode. Play the 15Khz tone and adjust the azimuth for the highest and steadiest reading on the two VU meters. Be careful—you should not have to move the adjustment very far. If it seems that you have to move it quite a ways, or if the optimum is hard to find, stop and figure out why. Enlist the aid of a technician if necessary. You don't want to get so far out of adjustment that you wind up on one of the false peaks. Then looking at the Lissajous pattern on the oscilloscope, fine adjust the azimuth until the pattern resembles a straight line.

Azimuth can affect the previous adjustments, so wind back to the beginning and repeat the 1KHZ and 10Khz tones, tweaking if necessary. While playing the 10Khz tone, check the Lissajous pattern on your scope. If all is well, it will look as good as the trace at 15Khz did. If it's way off, it is an indication that you got the azimuth onto a false peak (since the two tones are not harmonically related their false peaks won't be at the same place.)

We have provided three frequencies for adjusting the Low Frequency EQ. This is because there are always inconsistencies in the LF range, commonly known as head bumps. Having these three frequencies will allow you to find the best compromise for your machine. As a starting point play the second LF tone, 60 Hz, and set the LF adjustment for the same level you previously set at 1Khz. Then play all three LF tones, noting their readings. If it suggests you may be able to get it flatter overall, try trimming it again, and check the readings of all three tones. Continue until you are satisfied that you have the flattest LF response that you can achieve with this machine.

This completes the alignment for frequency response and azimuth. If you are not going to be checking polarity at this time, wind the tape back to the beginning and hit play. ALWAYS store your test tape (in fact any important tape) flatwound at play speed. This assures that the tension is even within the pack, and that edges are smooth, which will prevent edge damage.



Part 2 will appear in the next issue, and cover the use of the polarity pops included on the Tape Project Alignment Tape.
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Tape Project Machines / Re: Tape path kits - end of production
« Last post by Daves Basement on February 27, 2018, 12:41:46 PM »
Just spoke with Josh at Bottlehead and no more upgrade kits are available.  I am in the process of updating / upgrading my Otari MX5050 and wondering if anyone who ordered a kit will either be cancelling theirs or else sell me their kit.  Thanks.

David D.
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Tape Project Machines / Re: Tape path kits - end of production
« Last post by Daves Basement on February 27, 2018, 11:55:03 AM »
Was wondering if it is too late to order the upgrade Kit for an Otari machine.  I just saw your post.

Thanks,

Dave
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Doc & Merle Watson / Re: Listening Impressions-Doc & Merle Watson
« Last post by russe41 on February 13, 2018, 02:24:46 PM »
Is there anyway to list song titles?
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Tape Project Machines / tape stage preamp question
« Last post by Jayeltex on February 12, 2018, 09:35:40 AM »
I am presently using an Eros tape head preamp and it's been +/- OK....if I make a jump to the Tube Repro,  how much of a sonic difference
will there be.  There a very large cost difference,  will the cost difference equate to the sonic difference ?

Love some input...Thanks
jay
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Tape Project Albums - general / Re: TP-029 Istomin/Mozart back in stock
« Last post by High and Outside on February 11, 2018, 05:16:26 PM »
Aaaand they're back!
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General Discussion / Cello Palette
« Last post by wiwo on February 07, 2018, 12:47:14 AM »
Dear all,

I'm using the Audio Suite and Audio Palette few years.

Just few days ago, I found the "Hom" noise from left channel, I found a problem on some components be oxidized... @[email protected]

However, I want to fix it but I can't find any schematic or calibration method available.

I'm highly appreciate if anyone can share me how to calibrate such device?

Wish to see someone can support me here... thanks a lot!

Best regards,
Willi
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Tape Project Albums - general / TP-030 now in stock
« Last post by High and Outside on February 05, 2018, 07:27:57 PM »
Doc & Merle Watson--Never The Same Way Once

You'll find it on the website in the Roots category.
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