Which test tape should I buy?

I've got a few new Walkmans I'd like to test with the NAKT-100 software. I have an extremely expensive PC with an ASRock X670-E Motherboard audio input/output and 2 Walkmans serviced by the lovely Marian.

I'd like to compare the calibration he gave these two, to the new Walkman's I just got. One of which was apparently serviced, the other which has not been at all. All my Walkmans sound extremely good but I am considering selling a few and I would like to be able to give sellers also some accurate information on the Wow & Flutter, speed and azimuth alignment of these devices have.

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tl;dr - I have the NAK T-100 software on my PC, a reputable 3.5mm to 3.5mm cable and one of the best motherboards with a very high quality soundcard input/output.

But, I don't have a test tape and I don't really know which/what I should buy.

This person from Spain is selling lots and lots of different tapes: https://www.ebay.ie/usr/chankaiche2011

This person from the UK is about 3x the price because I'd also have to pay import on etc: https://www.ebay.ie/usr/ss72post

Both claim to be recorded on a reputable tape and device. What do others think though?

I see other "official" tapes from eg. China and Japan but these range from €85 to €125 before postage. Surely I don't need to pay so much money for a test tape. Most of these expensive ones also only seem to have one tone on them (eg. 3KHz).

The NAK T-100 can do pretty much anything it seems. Here's a screenshot:


Any advice would be appreciated.

 

I bought these recently and am pretty happy with them, they do cover everything needed: https://www.ebay.fr/itm/17601392775...HB9BZJ&hash=item28fb3f654f:g:VrIAAOSwFZVlvmBH

 

+1 for @dom69 HPR tapes are excellent value, single-track recordings.

 

@euroflash : HPR being the Hanspeteroth? French eBay?

@givemeyourwalkmans there is a lot of helpful info on the T-100 software in a couple of posts here:
Nak T-100 software just got a nice upgrade | Tapeheads.net
(1) Software Simulator for Nakamichi T-100 Audio Analyzer | Tapeheads.net

 

Yes, the same set. eBay is eBay everywhere

 

Pretty sure I am using it okay. Here is a shot of the 3000hz results for my DD9 after it came back from a calibration. I'm getting the feeling the tape I got was recorded on a device that's a little slow.

All of my Walkmans regardless of type are showing about 1.5-2% slow.

 

DDs with quartz lock always measure between 2992Hz and 2997Hz (when they work properly/have been serviced) with a tape I have recorded myself on a DirectDrive quartz deck.
This compared to belt driven units which usually (but not always) measure higher than 3000Hz sometimes significantly.

I do incline to believe the tape you are using is indeed recorded a bit slow as your tape speed is way off compared to what I'm used to see on these devices.

 

Thanks for the information. If I knew exactly what speed it was recorded at, I would calibrate the NAK-T100 myself because it's possible to adjust it a little. In any case, I am pretty sure all these serviced devices (with the exception of my PX-587) are within totally normal operating speed.

I checked the feedback of the seller and most people seem satisfied with his test tapes. I guess though I got a bit of a lemon. Even the PX-587 and the HS-P202 all report "slower" than 3000hz. Yet you said that devices with belts usually report over. So I am a bit confused. I'll try and pick up another tape later and get a good read of using NAK-T100 in the meantime.

 

The NAK-T100 shows 2944Hz, so 56Hz off (that's a LOT). So even if we are to consider a belt unit that shows 3050Hz, with this tape it would still show 6Hz below at 2994Hz.
At 56Hz down, the music would sound very audibly slower, hence why I incline to believe your units have the correct tape speed, it's just your measurement tape which is off.
Ideally the tape speed should be 3000Hz +/-5Hz, with +/-10Hz being acceptable.

Edited the previous post replacing "typically" with "usually" for more clarity.
To be clear DDs should always measure in the range specified, when I service these units if the speed is below 2990Hz I consider it a problem.
Also, on DDs with quartz lock speed is never above 3000Hz, that happens only on ones without quartz which are the only ones on which tape speed is adjustable (hence why it can vary more).
DDs with quartz lock have only a wow&flutter stability adjustment, but the tape speed itself cannot be adjusted being given by the resonant frequency of the crystal itself.

On belt ones it depends a lot on the belt itself: if the belt does not have the same inner diameter, thickness and elasticity as the original, the speed will be off even if the trimpot was adjusted perfectly for previous belt.
So there's a lot of variation on belt driven units, that's why I didn't give an interval at all, just stated "typically above 3000Hz".
To be clear on belt driven units I'm reffering to how they measure BEFORE doing any adjustments with the trimpot. With adjustment it can be brought to 3000Hz +/-5Hz.

Have you tried doing the same measurements with WFGUI ? Are they identical ?

 

Hi Valentin. I didn't even know about that software. Just tried it now.

It gives pretty much the same result as you can see.

What should I do in this case? The tape + postage was $20. Should I just order a new tape? Any recommendations from where? I would really like to have my own test tape.

By the way. In terms of measuring the levels (which I guess is useless with this tape if it has been recorded badly in the first place). At what volume level should I have the walkman set on? As turning up/down the volume of course changes the result of many of the tests in NAK-T100.

Below the attached images are with my DD9. First larger image with Audacity shows Peak on W&FGUI and WRMS on NAK-T100.
Second image shows Peak on both.



Plus photos of both sides of the tape I got.



EDIT 1: You can disregard the waveform in the first image. It shows (along with the first image in the next post) some kind of artificial Nahimic noise cancellation. The final waveform image shows with all of the post-processing turned off.

 

In an effort to help others who might find this thread.

For reference:

1. I am using a gold plated 3.5mm headphone cable.
2. Plugged into my gold plated WM-DD9
3. Also plugged into a gold plated AsRock X670E Taichi motherboard (back socket).
4. I am recording using Audacity software on Windows.
5. I set the volume knob to 10 (max)
6. Dolby NC on the Walkman is off
7. Tape is Type-I so it's set to (Norm)
8. My WM-DD9 was serviced by a reputable person in Germany who only works on Sony Walkmans and has apparently fixed dozens of them.
9. Previously (first 2 waveforms) had some post-processing noise-cancelling/mic gain turned on from Naihmic by mistake. It came with my motherboard. I turned this off for the last image.
10. The test tape I got from this guy (most seem to be satisfied but some reported errors).

.wav upload 3000hz (lower your volume) this is with all the software turned off below.
https://vocaroo.com/1iZthXi8Riy9

DD9 Waveform:


EDIT: So I just realised I have some Nahimic software on my machine that comes with my PC. Which likely was polluting the results
Looks like I was right. So I disabled all of this (vocal stabilizer and static noise suppression were on + 10dB of added gain):



The Waveform now looks more what I would expect, but the results of both apps haven't improved at all:



Also I am quite sure the waveform (and sound) shouldn't get any quieter. So I think there's definitely a problem with the tape.





The frequency is still too low and both of them have W&F much higher than they should.

EDIT 2:

So I tested the STD-331E side of the tape.

W&FGUI can tell me the frequency playing which is great.

The 300hz tone, in the app it says 305-310hz
The 6300hz tone, in the app it says 6175hz
The 10000hz tone, in the app shows between 5100hz-5400hz ????
The 300hz tone, in the app it says 305-310hz (again)
The 14000hz tone, in the app shows between 6850hz-7850hz ????

So now I am really confused...

 

In regard to speed/w&f test tape, I would go with this one: https://fixyouraudio.com/product/speed-calibration-tape/
It's best to have 2 different ones anyway so you can know for sure if it's a tape problem or not.

This STD-331E seems to be a Pioneer test tape, but can't find any info about it at all.

For w&f readings high enough to get a reading. In WFGUI, you have a signal level bar, you should have at least 1 bar to get a correct reading. You have all the bars from what I see in the screenshots, so no worries there.
Once you have the level high enough for a reading, the w&f and tape speed should not vary with volume level.

 

Thanks. I meant regarding the 400hz "level test" tone on the tape. How do I ensure that I am doing that properly? I'm pretty sure it's meant to be for testing that both channels (left and right) are working properly. As they'll show different values in the top (left) and bottom (right) bars.

The issue is that I think they are supposed to display 0dB on the bars exactly. Yet that is only possible if I tweak the volume. So I am kind of confused what I am looking for.
I'll order another tape, probably this one: https://www.ebay.ie/usr/ss72post

Will just have to do it after I get back from Japan.

 

The 400Hz test tone is for Dolby levels adjustment. That adjustment can't be done by using a sound card and a PC software.
You need a TrueRMS multimeter and to know the magnetic fluxivity of that particular test tape.
Without knowing the fluxivity (160nWb/m, 200nWb/m, 250nWb/m) you can't know what the exact levels should be as those levels obviously depend on the fluxivity.
There are also both DIN and ANSI standards. This also means conversion may be needed: for example 200nWb/m ANSI = 218nWb/m DIN.

The DD9 service manual specifies at page 5 (page 8 of the actual manual) how Dolby NR level adjustment is done.
Adjustment is done with a P-4-L300 tape (which has 160nWb/m fluxivity) for an output of -30.5dB at the test point on the PCB.
These test points are located at the output of the Dolby NR ICs, so before the volume potentiometer as measuring after it will be inaccurate.
Also, when using a different test tape, you need to convert the levels.
For example a 200nWb/m ANSI tape would output 2.7dB higher than an 160nWb/m DIN tape, so that -30.5dB will become -27.8dB.
Then we need to convert this dB figure into mV, knowing that 0dB = 775mV.

The 0dB shown on the test tape doesn't mean anything if they don't tell us the fluxivity.

If you really want to check that adjustment, you need to get a test tape with known fluxivity and a TrueRMS multimeter.
Note that if you don't use Dolby at all, this adjustment is not important.

 

Wow we really don't deserve you Valentin! Thanks for such an incredibly detailed answer. <3

I don't think I'll ever have the equipment to properly test those things, so at least it means I can write it off the list as something to pay too much attention to.
Generally as long as the W&F are in line I am pretty happy.

I need more tapes that are recorded properly in Dolby-B an C anyway.

 

So I finally got my new test tape and tested it on my DD9.

W&F reports a bit lower with this tape and the frequency is 6Hz within 3000Hz. So a lot closer to what Valentin above said is considered "good".

Here's a screenshot:



The tape was bought from: https://www.ebay.ie/usr/ss72post
and is recorded on a Nakamichi ZX7.

I'm quite happy with this result. I guess I wouldn't even try to improve the speed.

For reference my other devices report a bit worse:

WM-DC2: 3007Hz | 0.083% (w&fgui) 0.14% (nak t-100)
WM-DD3: 3007Hz | 0.10% (w&fgui) 0.21% (nak t-100)
HS-P202: 3039.8Hz 0.22% (w&fgui) 0.22% (nak t-100)
HS-PX587 3045Hz | 0.78% (w&fgui) 0.76% (nak t-100)

Got to hand it to Sony's DD line. It really drastically outperforms anything with a belt!

The last 2 devices I am going to put up for sale so I don't think I'll even touch them and just sell them as-is. The P202 I can't hear anything wrong with in terms of speed/pitch or W&F etc. but the PX587 needs some work on the motor, which is sad because it's been completely recapped with tantalum caps.

 

".... a 200nWb/m tape would output 2.4dB higher than an 160nWb/m tape."
Uh, NO. That would actually be 1.94 db difference.

 

I a made a mistake there, the actual difference is 2.7dB between 160nWb/m DIN and 200nWb/m ANSI. Edited the post.
200nWb/m ANSI = 218nWb/m DIN and 20 x log10 (218/160) ≈ 2.7dB.
Forgot to mention I was reffering to an 200nWb/m ANSI (as that's my preffered tape for adjustments), otherwise indeed the difference would be 1.94dB if both tapes are DIN.

 

Are the HansPeter Roth (HPR) Dolby level tapes actually 200nWb/m ANSI? Someone posted on tapeheads that they are 200 DIN.