If I am correct the man in that PDF was measuring at 12Vrms. 17V peak. So this is around 10x larger than typical audio signals. Frequency unknown, but I would think he would have mentioned if it was frequency dependent.
IIRC 3rd harmonic increases with the square of voltage, so
0.014% / 10^2 = 0.00014% THD at 1.7V peak for the worse 3.09k resistors he tested.
IIRC 3rd harmonic increases with the square of voltage, so
0.014% / 10^2 = 0.00014% THD at 1.7V peak for the worse 3.09k resistors he tested.
Why can't listen to Sinatra on CD?
Anyway, this is pure coincidence. Sinatra on vintage audio format
This is a by-product from last weeks tests (cassette overloading).
TDK D Type 1 on AKAI CS-F14 cassette deck, Dolby off, 44.1kHz/24bit wav recordings, some 11seconds each.
Dropbox - 01 test track.wav
Dropbox - 02 test track LP Q1 3kHz-9dB.wav
Dropbox - 03 1st track -3dB rel 0VU rec level (4 pot).wav
Dropbox - 04 2nd track -1dB rel 0VU rec level (4.5 pot).wav
Dropbox - 05 3rd track 0dB rel 0VU rec level (5 pot).wav
https://www.dropbox.com/s/50hadptaano3qo4/06 4th track +1dB rel 0VU rec level (5.5 pot).wav?dl=0
https://www.dropbox.com/s/d5ceqsvh85ogmwn/07 5th track +3dB rel 0VU rec level (6 pot).wav?dl=0
https://www.dropbox.com/s/pm01jhbi0x9080j/08 6th track +5dB rel 0VU rec level (6.5 pot).wav?dl=0
https://www.dropbox.com/s/d5lmef1a3tj7j1v/09 7th track +8dB rel 0VU rec level (7.5 pot).wav?dl=0
https://www.dropbox.com/s/dfv9su4e1o41wke/10 8th track above+8dB rel 0VU rec level (8 pot).wav?dl=0
It is good that the relation btn vinyl set-up cost and listening pleasure is ill defined 😀
Happy
Scott George
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George: It's just the experience was right. We didn't actually sit down through the first 3 tracks. After all this is a 1958 vintage pressing. Remarkably quiet vinyl for the age and didn't even have to engage the mono button. It just clicked for us. Shared experience and all that.
I don't have my mono vinyl setup sorted yet so just used my Frankensignet. I'm really liking this as well as the joy of a fettled direct drive table. Will need to take it off soon for testing Scott/Hans Phantom powered head amp.
I don't have my mono vinyl setup sorted yet so just used my Frankensignet. I'm really liking this as well as the joy of a fettled direct drive table. Will need to take it off soon for testing Scott/Hans Phantom powered head amp.
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Thanks, I guessed that from looking the layout.
😉
I tried that after someone around here mentioned that a while back.
Maybe Fred ...
mlloyd1
😉
I tried that after someone around here mentioned that a while back.
Maybe Fred ...
mlloyd1
Mine's a 'Waxtime' issue off Amazon. I heard that some of these recordings are cut off CD masters (Michael Fremer has mentioned this).
But, its the original recording that sets it apart - fantastic imaging, bass with great mid-range. The backing band (Paul Weston Orchestra) is not half bad -I prefer them to the Cole Porter Songbook LP.
I wrote a little bit about it on my blog here:-
The Tale of Two Recordings
Good point!
OTOH, the plain MF's give 0.0018%, or 0.000018% @ 1.7Vp under the same setup, so why not use these for not a lot of extra $? Of course, the quality of the contacts is unknown: has anybody tried them?
I once measured significant contact rectification distortion from the famed Elma of Switzerland.
Have anyone tried this kind? EIZZ 100KAX2 24-Step Attenuator Dual-Unit 100K Stereo Volume Potentiometer 2gang | eBay
Those sound like ****. Either the resistors are fake or the switch device is the problem. You'll stop listening to your stereo.
yep. Thats what I did... Dale = plain th MF.
-RNM
Wave file down load -- HD: "The Heavy Hitters - Acoustic Project - A Little Bit Closer - 14
Boogie A
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I built a source selector/preamp for CD mastering use and used Shallco bodies for both, the feel of that mechanism and repeatable low resistance and high contact pressure can't be beat.
In the pic below I had a nice ceramic RF switch next to the two Shallcos. I had not loaded the attenuator with the RN60s when this was taken:
I have had really good luck with the Shallcos.
Cheers,
Howie
+1
Those are real crap, needs routine spray of contact cleaner just to maintain some form of connection.
3-4db max mismatch, 20% tolerance, and continuous range means low repeatability in setting the same value. Same drawbacks as most pots. But I wonder who does make the best pot?
I believe the best were Penny & Giles, but they may have stopped making them.
Another annoyance is that most of the decent audio taper pots come in values of 10k at the lowest if you are lucky. I've had a few times where I wanted 5k or even 1k and it's a custom order.
True, but he tends to use balance pots as well, I wonder whether many of the problems would be negated if more people did. My Alps Black Beauty has served me well for years
You could always join the 21st century and use one of these!
High Quality Audio Volume MUSES72320 | MUSES Official Website
Good enough for Nelson!
High Quality Audio Volume MUSES72320 | MUSES Official Website
Good enough for Nelson!
TKD Japan has a good reputation. Their larger pots CP2500 and CP2511 are excellent. Note that their log pots can only be used in true potentiometric application (true voltage divider with low drive impedance at the input and high load impedance) because of the special trimming construction.
IMO, the best gain control achievable with pots is linear taper in potentiometric circuit but not in the ususal way, rather like Bruno Putzeys did in his pre, in an Rg/Rf arrangement of an opamp inverter. Cancels pretty much every source of distortion. There are some drawbacks like infinite gain at max position (can only be avoided by a mechanical stop).
Channel imbalance is IMO a moot point, you need a balance control anyway. If you still want to mitigate tracking issues (especially with normal log pots used in the normal way), make all the audio chain M/S (that is, feed M/S to the DAC), not L/R. Maxtrix to L/R at the power amp.
EDIT: That MUSES72320 looks pretty nice
IMO, the best gain control achievable with pots is linear taper in potentiometric circuit but not in the ususal way, rather like Bruno Putzeys did in his pre, in an Rg/Rf arrangement of an opamp inverter. Cancels pretty much every source of distortion. There are some drawbacks like infinite gain at max position (can only be avoided by a mechanical stop).
Channel imbalance is IMO a moot point, you need a balance control anyway. If you still want to mitigate tracking issues (especially with normal log pots used in the normal way), make all the audio chain M/S (that is, feed M/S to the DAC), not L/R. Maxtrix to L/R at the power amp.
EDIT: That MUSES72320 looks pretty nice
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