Originally Posted by wistily when i measure AC voltage of the air, my multimeter also says between 200 mV and 500 mV
is it normal, or is my multimeter completely crap ?
That's quite normal. Your DMM has very high input impedance, so as not to load the circuit you're measuring and affecting the result. However, when you simply wave the probes in the air, it would pick up stray electric fields. If you have it set to the AC mV range, it could very well read something quite significant.
A similar thing happens if you have an interconnect cable that is not connected to anything on one end, and plug the other end into your headphone amp. You would most likely hear hum and noise with the volume cranked up. This would worsen if the unconnected end is not soldered to a plug, but simply bare wires that you could pull apart to some distance.
Originally Posted by individual6891 I'm so glad my air doesn't have AC voltage
Like it or not, you do have AC voltage in the air due to the stray electric fields. After all, volts is simply a measure of difference in electrical potential, and if such potential is varying (whether periodic or aperiodic), it's AC.
Originally Posted by amb Like it or not, you do have AC voltage in the air due to the stray electric fields. After all, volts is simply a measure of difference in electrical potential, and if such potential is varying (whether periodic or aperiodic), it's AC.
Well you learn something new everyday
Shame I can't plug in my mobile phone into thin air.Oh wait.
Originally Posted by wistily I think that for the Jung PSU, interest will come with availability... Audiophiles always want the best, even if it's not really useful.
I think that 'interest for a Jung based supply' has to be awakened.
I for myself are intersted in a STEPS for a M3, PPA V2 and/or Pete Millet Hybrid. A STEPS looks to me a minimum for a quality supply (when money and building effort are not the first criteria). Looking at several alternatives (Welborne, Per-Anders, AOS, several wallwarts, Borbely, TREAD, WNA cascode and others) a STEPS is affordable, simple to build, tested in the field and popular for a reason (sonic results established by diy ers around the world). Furthermore that implementation gives you the possibility to use a netfilter (or not) and you can use several qualities of components at different prices. For a general diy er a confidence inspiring device. When you want something even simpler, go for a TREAD.
Why bother for a more sofisticated and more complex supply? Well, reading much information about Jung oriented supplies leaves - especially for audiofiles, who are critical and sensitive to uncertainties - something to doubt about. In my opinion it is not a point that you have to use some more components or have to put together something a little more complex.
I would like to get some more objective answers wether it is really useful to invest time and money in a more sofisticated supply than a STEPS. Do you get real and audible benefits within the context of high quality headphone amps? Untill now I have not encountered in depth reviews or explorations of the audible sonic effects of different Jung supply configurations, when using the supply for feeding a headamp. I have seen much talk about better electrical results (better noise performance, lower impedance etc) in the context of other audiocomponents.
Tangent for example raises by himself some critical questions about audible differences between a STEPS and his Jung based prototype YJPS. There were observable and measureable differences (lower mvRMS), but is such a difference discernable by our ears when one uses such a suppy with some of the latest high quality headphone amps. Or scores a Jung like supply only in other types of audio components (a super phone preamp or a sofisticated dac for example), because there the requirements are stronger?
Other suppliers of Jung like supplies claim several kind of results, technically and/or sonically. I can not look through possible commercial aspects, but have sometimes to think about the game around distorsion specs for poweramps. There are in many cases no relation and sometimes even a bad relation between commercially presented distorsion figures and actual contribution to the musical performance. As many others I preferable want to trust my own ears in the first place. Unfortunately I am not in the position to try several solutions for a supply. So - as many others - I have partially to rely on expierences and opinions of others to avoid in the first place minor solutions and start with one supply that already has proven itself as valuable.
For that reason I would like to see some experiments by more expierenced members with access to several higher quality supplies. With doing that prospective builders can make better choices. The same process is going on around ampbuilding. And for me it is very instructive to see extensive comparasions between opamps and the amps that they were tried in. Let's just broadening the perspective to another piece in the reproduction chain.
Why not execute a realistic comparasion for different supply configurations with special emphasis to supplying some of the popular high quality diy headphone amps. That brings existing information within a context where a diy er gets more insight, so he/she can reduce uncertainties and choose better.
When the results of that comparasions are, that a Jung like supply gives audible and higher quality benefits there sure will be some more interest from the community.
I think the issues with the Jung regulators is not so much the cost (they don't really cost much more...), rather that all the Jung boards (apart from P-As massive JSR04) come separately from any sort of rectification and filtering. Compare the option of that to a STEPS board which can be put together in one sitting, and four chassis holes later is done, and for only a small performance loss (and it's cheaper
), it's quite obvious why. Another thing here, is that the most popular designs here are a) opamp based, with modern opamps having excellent PSRR*, and b) are designed to run off single rails with a built in splitter.
To gain interest in discrete regulators, we need some cheap, high quality discrete amplifiers that use true ground, as opposed the virtual, and a completely self contained (except, perhaps, the transformer) power supply board. If you look at the Dyna**, the only common example around here of discrete amps, they're almost all driven off proper dual supplies.
So, Jung designs (IMO), are not worth the extra effort in non-discrete designs, and until we go all discrete throughtout seem like (a little) too much effort for most.
* the M3 and PPA v2 could conceivably benefit, though, with the discrete output stages
PS; I'm running Jung regulators for my preamp, and DAC. Not got the guts yet to hack up my Cyrus
If anyone's interested, I'm using Per-Anders Jungs for the pre, and Aos' for the DAC. My transformer, rectifier, and filter caps are on a board made by Elektor Electronics, using the 10VA Novatem (Talema) encapsulated transformer). It's possible to build a STEPS, and then bypass the regulator stage, and take the unregulated supply directly to a Jung as well, but then you still only have a single rail supply
I think my fascination with the Jung is only partially practical. To a large extent I'm simply fascinated by the design which (the more I understand it) is an amazing piece of engineering. Plus, there is something to be said for being able to use one design for all of your PSU needs without ever having to worry about noise.
That said, the points that have been made about opamp PSRR are valid and it may suggest that in the long-run there is little to no practical difference between a well built STEPS and the Jung... at least in non-discrete designs.
I do think, however, that a large subjective comparison of PSUs with several designs would really clear the air about how much low-level noise actually matters. Ah well, that's the cost of not having huge R&D budgets.
Top Mall-Fi poster. The T in META42. Formerly with Tangentsoft Parts Store
Sep 27, 2001
I think the issues with the Jung regulators is not so much the cost (they don't really cost much more...), rather that all the Jung boards (apart from P-As massive JSR04) come separately from any sort of rectification and filtering. Compare the option of that to a STEPS board...
It's the consequence of these two issues acting together that I'm talking about.
When you replace the regulation section of a STEPS with a Jung regulator, two things happen. First, you add some more parts. These truly aren't all that much more expensive; $10 at most. But second, you have to make the board bigger, which is more expensive by itself, and it also requires a bigger, more expensive case.
There's a third cost inflator, as well. I wasn't kidding when I said "five people" above. That's honestly how many people (plus or minus) have told me they were interested since I began soliciting comment in my PSU tests article. As a result, if I did make these boards, it would have to be a short run, which would probably drive up the cost to $25 per board.
Originally Posted by jamont You can make it six - I must have missed this somehow.
I bet if you started a new thread with a photo and schematic you would generate more interest than that.
I would like to second that. However on one condition. In that case I could be number seven. I am at first interested in possible gains, it has to be a winning situation. A supply is for me only an instrument, not a goal by itself.
I understand fully that there are some financial/fysical drawbacks (as pointed out by Tangent already), so I want first to know to what am I throwing my money. Another point that's already made is the real convienence of a fully intragrated supply board. For me as a builder is a STEPS also attractive because there is a reduced risk to make faults (you don't have to connect several modules or points).
When it is only to get some better thechnical messurements than I am not sure it is worth it for me. But when it gives audible advantages above something like a STEPS than I am in. For example a Jung based supply gives audible some better capabilities for recovering of soundstage, quieter running headamp (given opa's), capable of more autoritative presentation when a high quality amp/phone combination is fed with very demanding music (solo piano or quitar, solo female voices, operachoires, intonations of voilin or cello, complex orchestral works etc).
I am not advocating intensive and costly research. I am only asking for some indications from experts who already have experience in comparing some configurations for a powersupply for high quality headamps when doing the comparasion with some high quality and demanding recordings. May be that the real differences between several supply configurations are not that impressive at all. I am curious at your findings.
Originally Posted by tangent Nonsense. The LM317 is capable of 80dB ripple rejection, so there would have to be 8V (!) of ripple ahead of the regulator to get that kind of ripple at the output. Even if we presume that I designed it badly enough that it's only getting 60dB RR, you'd have to have nearly a full volt of ripple, and I assume that this was tested without a load on. No way. I don't believe it for a second.
How much can you read on your DVM? Anyway, what the instrument showed was something which we don't know what it was. It could have been noise, phenomina from low load, oscillations, who knows, the instrument is picking up hum etc etc. AC measurements of this kind requires oscilloscope also.
Originally Posted by tangent
Yes, you and the other five people who are truly willing to pay for it....
I sent out the request for comment, and the response was truly underwhelming.
Why don't make a Jung regulator and test the interest afterwords? Every parameter except for cost and size is better for a Jung retgulator.
Originally Posted by individual6891 I'm sure loads of DAC diyers would love a jung, but there's already so many implementations already. The only market would be for a jung with onboard transformer, steps style.
I'm working on a headphone amp with current feedback, Jung regulator and transformers, but this is a future project.... it's with SMD parts...
It's my QRV-06 meets JSR01 with the transformers from QRV-04.