That seems like a subjective opinion based on your personal preferences. One of the objectives of the H2 is for the user to determine for themselves if they enjoy the addition of H2 harmonics. Not everyone will. But to unequivocally state that its an undesirable approach is misguided IMHO.
Hmm, does not reflect my experience, although obviously all this is very subjective.
I built the B1 KORG and played with the H2 levels (in 0.1V steps) and also with its negative and positive phase. I (and that's just me in my very own set up) could defo hear the differences and prefered (should I say fell surprisingly in love as I know these are just harmonics playing psychoacoustic tricks on me?) negative H2 with about half the usualy recommendated distorsion level. Still very H2 dominant.
Yes, H2 level varies with input level and is small at low levels, yes it is not linear with level nor does it even vary proportionaly to H3, yes it is not what an engineer (I am one) wants to see in terms of distorsion levels ... but after carefull comparisons I have to admit it does sound better to me like that, on all kind of music, and even long term... and it does sound consistent across levels and instruments and not like an odd loudness aha effect. There is simply more behind music perception than what is usualy measured: that area needs probably digging and H2 has defo a role to be precisely defined.
Oh, and it 'sounds' more transparent like that, no doubt to me at least. One should Give it a try and find out by himself: it is not just nice but also educative IMHO...
Having said all that, "Taste and colours" and your experience may differ of course... that's also part of the fun
Claude
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Gotta stop talkin' to myself...
To further clarify the situation, I connected the H2 directly to the XA's with copper interconnects rather than my H-T Photon ICs.
BOTH channels still whine!
Rookie move on my part that I did not try the "bare" H2 before embarking on upgrades! Oh, well!
The voltage from the "input" regulator which was written on the board is 15.65V.
Tell me how to get the Vs you need and will gladly report them.
Note that I only have a multimeter to work with.
There would be several reasons that PMA didn’t have a positive experience with his H2 device.
I think we can hear positive effect of H2 more with full range, or simpler speaker crossover design than complex 3 way. With 3 way system, H2 effect would be rather unpredictable due to cancellation that occurs at different frequency/phase points, and it's not too hard to imagine that it can be messy. H2 signature of power amp also matters, and it was already explained by the master.
Also, I noticed that 2 amps with very similar distortion signature do not sound similar at all. I'm pretty sure that H2 has a correlation with the sound, but I’m not sure if it does always imply causation. I mean, even if PMA’s H2 device has the exactly same distortion figure as your B1 KORG, his device may sound completely (and objectively) different from yours. Are you sure that you like the sound of B1 KORG because of H2? What you like can be microphonic or something else.
Are the jfets designated by the circular components on the colored graphic of the circuit board...
i.e., 2 adjacent to the 2 R4s?
i.e., 2 adjacent to the 1 R6?
Do I connect probes between the +'s and ground?
Thank you for your patience and tutelage.
Hi Plasnu,
Perhaps my post wasn't clear? Trying again...
I don't want to start a debate and I am defo not commenting if the OP is pleased or not with his device or his sound... how could I?
I am solely commenting on:
"There is no sonic advantage of H2 addition. Up to some level it remains inaudible, then it starts to mess the transparency". That doesn't match my tests playing solely with H2 levels.
I can say that for me playing with the (H2) trim pots does indeed make quite a sonic difference. Better or worst is subjective, but a difference 'yes'. I doubt that the trim pot position has an effect on microphonics variations that you suggest I could like
Are there microphonics? Perhaps... Do I like the sound? Yes! But that wasn't the point. The point is playing with H2 solely does impact the sound and for me at a certain H2 level and with negative phase it does sound better than no H2 or other lower or higher H2 levels, so my case differs from what the OP stated. That's all what I wanted to say.
That is in my system quite audible with very simple LS and no filter at all (my HP!!!) and also with my LS which are... 4 ways Infinitys that have, err, quite a complex filter (sadly).
I am with you that H2 signature of power amp... and IMHO also source does matter a lot. For me there is quite a sweet spot and I don't want to overdo it re 'total H2 level of the entire reproduction system'. In short, if your source, or as suggested your power amp, does produce already the right level of H2 you like adding the B1 Korg won't be a good idea. As of me, I liked best half the suggested level, which sounds like a lot less but is in fact still quite a lot of H2... but that's just me.
All IMHO, don't want a debate, just saying that playing with H2 was a revelation for me and for sure more research work should take place. And yes, distorsion signature and levels for sure don't say much about the sound: eventhough they would look similar sound can differ quite a bit as numerous mags with lab tests have revealed over the decades.
I hope I made my previous post clearer on H2 impact, while still outlining experiences may differ for each individuals and / or perception levels and I respect that very much of course
Claude
Perhaps my post wasn't clear? Trying again...
I don't want to start a debate and I am defo not commenting if the OP is pleased or not with his device or his sound... how could I?
I am solely commenting on:
"There is no sonic advantage of H2 addition. Up to some level it remains inaudible, then it starts to mess the transparency". That doesn't match my tests playing solely with H2 levels.
I can say that for me playing with the (H2) trim pots does indeed make quite a sonic difference. Better or worst is subjective, but a difference 'yes'. I doubt that the trim pot position has an effect on microphonics variations that you suggest I could like
Are there microphonics? Perhaps... Do I like the sound? Yes! But that wasn't the point. The point is playing with H2 solely does impact the sound and for me at a certain H2 level and with negative phase it does sound better than no H2 or other lower or higher H2 levels, so my case differs from what the OP stated. That's all what I wanted to say.
That is in my system quite audible with very simple LS and no filter at all (my HP!!!) and also with my LS which are... 4 ways Infinitys that have, err, quite a complex filter (sadly).
I am with you that H2 signature of power amp... and IMHO also source does matter a lot. For me there is quite a sweet spot and I don't want to overdo it re 'total H2 level of the entire reproduction system'. In short, if your source, or as suggested your power amp, does produce already the right level of H2 you like adding the B1 Korg won't be a good idea. As of me, I liked best half the suggested level, which sounds like a lot less but is in fact still quite a lot of H2... but that's just me.
All IMHO, don't want a debate, just saying that playing with H2 was a revelation for me and for sure more research work should take place. And yes, distorsion signature and levels for sure don't say much about the sound: eventhough they would look similar sound can differ quite a bit as numerous mags with lab tests have revealed over the decades.
I hope I made my previous post clearer on H2 impact, while still outlining experiences may differ for each individuals and / or perception levels and I respect that very much of course
Claude
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I apologize I made you feel that your previous post was unclear. I fully agree with you. Everyone should have a different opinion about H2 experiment.
Since this is an experiment, I personally want to hear more negative comments about H2 in this open discussion. Saying something negative about H2 is not easy in this atmosphere
, and I just wanted to support PMA's opinion mainly because of this reason. I did not intend to start debate with you.I'm a believer of single ended amps. I have been experimenting H2 because I really want to know why single ended amps sound good to my ears. I would say my experiment is still unsuccessful. I still have a mixed feeling (finger-crossed) about pre-generated H2 distortion based on my experiment so far.
All clear Plasnu
Negatives... or kind of, yep, here we go:
1) I have set up a certain H2 level on my B1 Korg, but I do realise that this "optimal level" may vary if using HP or LS. Further, if changing a component all this will needed to be done again probably. As said I "feel" (but can't prove, more research work is required here) that for me there is a given optimal H2 level for the entire (HIFI) system, from source to amp... or perhaps even to LS if they do produce H2 (??). So each component change means tweaking again, and my ideal setting might not be yours if systems differ, eventhough we would like the same H2 profile / level. Just a felling. Positive is I see all this as a nice plus and now I do know how the sound varies with he trim pot so adjustment should be easier / quicker.
2) Well, I have to confess all this negative phase and H2 level outlines how much we do hear / process with our brain vs just our ears (hello psychoacoustic), and somewhere a negative could be that I don't like to be tricked so easily LOL! But then Papa did it so nicely and I discovered something about me and... I like it better that way, with negative phase. Ahhhh!
Have fun experimenting and thanks again for sharing your findings
Claude
Negatives... or kind of, yep, here we go:
1) I have set up a certain H2 level on my B1 Korg, but I do realise that this "optimal level" may vary if using HP or LS. Further, if changing a component all this will needed to be done again probably. As said I "feel" (but can't prove, more research work is required here) that for me there is a given optimal H2 level for the entire (HIFI) system, from source to amp... or perhaps even to LS if they do produce H2 (??). So each component change means tweaking again, and my ideal setting might not be yours if systems differ, eventhough we would like the same H2 profile / level. Just a felling. Positive is I see all this as a nice plus and now I do know how the sound varies with he trim pot so adjustment should be easier / quicker.
2) Well, I have to confess all this negative phase and H2 level outlines how much we do hear / process with our brain vs just our ears (hello psychoacoustic), and somewhere a negative could be that I don't like to be tricked so easily LOL! But then Papa did it so nicely and I discovered something about me and... I like it better that way, with negative phase. Ahhhh!
Have fun experimenting and thanks again for sharing your findings
Claude
Using "2ND HARMONIC GENERATOR" as reference and taking readings LEFT to RIGHT, I measure 5.485 V; 5.54 V; 19.7 V respectively.
Did I get the "right" answers?
From the left, measured 5.44V 5.48V 15.65V (same as noted on pcb)
At your prompt I did remove the LED meter and whine went away which is great.
Having said that, my intent was to have the meter be a built-in indicator of both power ON and a reading of the (adjustable) output voltage so would have a way to reset to original value without messing with meter. Is there a way to wire into the circuit to fulfill my goal without creating the whine?
I think I wired it properly with RED/WHITE to center pin of regulator and BLACK to ground. Hopefully this is correct?!
Mini DC 0-30V BLUE LED 3-Digital Display Voltmeter
Guaranteed QUALITY! We DO NOT sell inferior goods! This high-accuracy meter displays number from 0.01 t0 30.0V.
Some cheaper meter only reads from 0.1 to 30.
If you have any questions, please feel free to ask and contact us to resolve the issue before opening a case.
Thanks a lot!
The display color is bright blue, It is much beautiful in reality than in picture!
Specifications:
- 100% brand new and high quality.
- Measuring range: DC 0V--30V
- Input range: DC 2.7V-30V
- Max Input: DC 30V. The device can be damaged if input is over 30V
- Display Color: BLUE
- Display: Three 0.36 "digital tube
- Measurement accuracy: 0.1%
- Refresh rate: about 300mS / times
- Input impedance: About 100K
- Dimensions:33mm*15mm*10mm
- pitch of holes:28mm
- aperture size :2.8mm
- Operation Temp: -10℃-+65℃
If you have any questions, please feel free to ask and contact us to resolve the issue before opening a case.
Thanks a lot!
Wiring:
- Red wire: Power supply +
- Black wireower supply -, Measured -
- White wire: Measured +
In light of resolving whine issue by removing the LED meter from the H2 circuit, tried a couple of things...
(1) Powering the meter with the wall wart rather than the Vout of the regulator = NO NOISE
(2) Powering the meter with a 9V battery = NO NOISE
Will include an ON/OFF switch while I am at it.
On to listening