woodturner-fran said:
Sorry I missed this !
I used mainly standard regs with a trimmer pot (separate +/-v reg for each ) when trying out voltages, I had to finely adjust each supply to reduce hum.
Around +/- 10v was the best in my case, they was adjusted a few mV's over for one and below for the other
I still get very low DC offset on one Counterpoint (few mV's) and in the 20mV's for the other
t. said:
Oh gawd, now I've heard everything......
In Fran's Buffalo, what could the IEC filter possibly be doing to the incoming AC power, that wouldn't otherwise be overwhelmed by:
Transformer
Rectifier diodes
Snubber caps
CLRC filter
LM317/337 linear regulators
For Buffalo: additional fixed linear regulators and buffering
For IVY: an additional teddyreg
Please, give me something - ANYTHING - more convincing than the vague audiophoolia of loose dynamics and muddy bass......
Beefy said:
Try it yourself and compare😉
To me it sounded FLAT lacking involvement with the IEC filter, I tried it , didn't like it so ripped it out and binned it, easy as that!
BTW Fran wanted an opinion from somebody else who HAS tried and compared an IEC filter, sorry for the vague audiophoolia but it seemed more polite than saying it sounded crap so I ripped it out😀
Hi Beefy,
yeah, I know the whole thing seems ridiculous, but you ask what could it possibly be doing. Well I don't know. The same question could also be posed as to why it was there in the first place, ie what was it doing in the case in the first place?
The fact is that the IEC filter was already in the case I used, it was a digidesign box that housed some video switcher or something. A comercial product that had a power supply board. Theres obviously a reason for the makers using these things in the first place, otherwise they wouldn't. Presumably they helped cut down on measured noise in a studio environment, but I don't know.
I just used it cos it was there and was handy. One less piece of casework to do!!
So heres what I'm going to do. I'm gonna get the DAC back off my friend, hook it up here and have a listen. Then I'm going to rip out that IEC filter and fit an ordinary IEC inlet. Listen again and see can I hear any improvement. It will take a few days to do all this, but I will report back here one way or the other. I only asked about the filter cos it was the only thing really different in the two builds.
I have a vague memory of people generally having a bad opinion of these filters in general, but I can't pin it down.
Anyway, I'll experiment and report back I think.
Fran
yeah, I know the whole thing seems ridiculous, but you ask what could it possibly be doing. Well I don't know. The same question could also be posed as to why it was there in the first place, ie what was it doing in the case in the first place?
The fact is that the IEC filter was already in the case I used, it was a digidesign box that housed some video switcher or something. A comercial product that had a power supply board. Theres obviously a reason for the makers using these things in the first place, otherwise they wouldn't. Presumably they helped cut down on measured noise in a studio environment, but I don't know.
I just used it cos it was there and was handy. One less piece of casework to do!!
So heres what I'm going to do. I'm gonna get the DAC back off my friend, hook it up here and have a listen. Then I'm going to rip out that IEC filter and fit an ordinary IEC inlet. Listen again and see can I hear any improvement. It will take a few days to do all this, but I will report back here one way or the other. I only asked about the filter cos it was the only thing really different in the two builds.
I have a vague memory of people generally having a bad opinion of these filters in general, but I can't pin it down.
Anyway, I'll experiment and report back I think.
Fran
"In general" might be a stretch. I use them and like them quite a bit and have seen them on truly high-end DIY equipment like a few Beta22 builds (including my own) and some fancy thousand dollar+ tube amps.
Personally, I can't tell much of a difference, but feel better knowing that any power ripple / surge will be suppressed.
Thats the best way to know for sure Fran, its easy to compare with and without, maybe the one I tried wasn't very good😕
The main reason I tried one was because it was recommended, the guy said it filters out noise on the mains which I thought would be great so I tried it, unfortunately the music never sounded right, god knows why but it sounded very flat to me.
A dac like the Buffalo can give a very impressive 3d sound and be quite convincing, those filters ruined that to my ears
The main reason I tried one was because it was recommended, the guy said it filters out noise on the mains which I thought would be great so I tried it, unfortunately the music never sounded right, god knows why but it sounded very flat to me.
A dac like the Buffalo can give a very impressive 3d sound and be quite convincing, those filters ruined that to my ears
t. - flat is a bit how I would describe the sound. More detail alright than the analog out of his transport, but a bit thin and just not much magic. Not bad at all by any means but not as good as I know the buffalo/IVY to be.
counterpoint: I am running mine at 10.75V I think. I have the same offsets as you but never had any noise/hum at all. Seems very stable in operation and very good sound I have to say. Compliments to the TP fellas on it. FWIW, the guy I built the second buffalo for is waiting for them to be released!!!
Fran
counterpoint: I am running mine at 10.75V I think. I have the same offsets as you but never had any noise/hum at all. Seems very stable in operation and very good sound I have to say. Compliments to the TP fellas on it. FWIW, the guy I built the second buffalo for is waiting for them to be released!!!
Fran
woodturner-fran said:
Well that is easy. They typically act as a low-pass filter to prevent high frequency noise on the AC line. Think noise in the range 10k-10MHz.
Here's an example: http://www.schaffner.com/components/en/_pdf/Datasheet FN280 e 13.pdf
Of course, it would audiophile heresy to suggest that their full dynamics and tight bass comes purely from noise, now, wouldn't it?
woodturner-fran said:
Certainly worth trying it without the filter then and seeing what you think, its one reason I'm very careful what I try now tbh.
Maybe the filters go better with a brighter dac 😉
I wonder if your transistors was better matched than mine in the Counterpoint? the hum was only very low though so wasn't much of a problem for me, trimming the voltages slightly eliminated it anyway.
I second the compliments to the TP guys, their doing a great job, products like these make it such a great hobby to be into
Beefy: OK, that makes sense as my box would have been used in a studio where I reckon there might have been a lot of switching power supplies and what not.
Don't know anymore than that about what they do though, and sonic effects. Not an EE, just really an assembler! Look - I can't be fairer than to do the experiment and report back. I'll even get the friend over so that its not just my ears that will compare.
t. - my transistors were not matched at all. just a lucky dip, ordered the number I needed and stuck them in one after another as they came out of the bag. I used a LCBPS to supply both boards. Didn't fiddle with balancing the +/- voltage, just set each to the same value. It wouldn't be something else causing the hum would it? Grounds and all that?
Counterpoint definitely worth it. I must go and try the IVY now as a line stage in another DAC.... put it to work again.
Fran
Don't know anymore than that about what they do though, and sonic effects. Not an EE, just really an assembler! Look - I can't be fairer than to do the experiment and report back. I'll even get the friend over so that its not just my ears that will compare.
t. - my transistors were not matched at all. just a lucky dip, ordered the number I needed and stuck them in one after another as they came out of the bag. I used a LCBPS to supply both boards. Didn't fiddle with balancing the +/- voltage, just set each to the same value. It wouldn't be something else causing the hum would it? Grounds and all that?
Counterpoint definitely worth it. I must go and try the IVY now as a line stage in another DAC.... put it to work again.
Fran
Beefy said:
You may find that these things do more harm than good, they also add higher mains impedance
If I heard no difference I'd never have bothered commenting but seeing as though Fran also notices the one using a filter to sound flat I think its worth the time trying to compare it with the thing removed
Hi Russ and Brian.
I was wondering something about the IVY:
Have you tried it with no cap in the feedback loop nor on the input, but a solid one on the output?
Or course you let HF go through the chip. But this is a very fast chip! So it should be able to deal with it. Plus you said it doesn't like feedback caps that much.
Of course, You'll have more HF on output because even a good filter won't filter as much as amplifing it less first.
(well, that's not true but you got the idea). But... It may not be enough to be critical.
I think I'll try this on my boards, but if you already had a point of view on the subject...?
Thanks,
Nicolas
I was wondering something about the IVY:
Have you tried it with no cap in the feedback loop nor on the input, but a solid one on the output?
Or course you let HF go through the chip. But this is a very fast chip! So it should be able to deal with it. Plus you said it doesn't like feedback caps that much.
Of course, You'll have more HF on output because even a good filter won't filter as much as amplifing it less first.
(well, that's not true but you got the idea). But... It may not be enough to be critical.
I think I'll try this on my boards, but if you already had a point of view on the subject...?
Thanks,
Nicolas
Now I'm confused.
The R17-20 with the kit were 0 ohm jumpers, but the manual specifies 21 ohms.
Of course the jumpers mean 10nF in the feedback loop - sure to kill any HF response.
Are these to be removed and replaced with 22ohm resistors? Over here we don't get any precision parts, @best 1% resistors of dubious quality. I think I need help now!
Separately I read the manual, and figured I also have to remove C13-16 totally.
The R17-20 with the kit were 0 ohm jumpers, but the manual specifies 21 ohms.
Of course the jumpers mean 10nF in the feedback loop - sure to kill any HF response.
Are these to be removed and replaced with 22ohm resistors? Over here we don't get any precision parts, @best 1% resistors of dubious quality. I think I need help now!
Separately I read the manual, and figured I also have to remove C13-16 totally.
glt said:
Apologize if I offended anyone. Some of us are trained engineers and can't think outside of the scientific method. Appreciate very much the contributions of everyone in this thread/forum.
glt said:
Thanks for that. I still wonder about a full 10nF in the feedback loop, but I guess I better shut up and finish this thing already. I got the transformers today - ~20VA, 18V and 30V center-tapped EI transformers, so I'll have to cut the taps open to get independent windings. Posting listening impressions tomorrow.
glt: no offence taken by me anyway! To be honest a healthy dose of skepticism is rightly needed in the audiophile world. No harm at all.
Fran
Fran
I just realised that the feedback resistor is 187 ohms, which means 10nF is probably good for 85KHz or so... I'm going senile, I think.
Russ,
Just a question.
I have put ferrite beads between the grounds of my batteries. The sonic impact is huge!
Now i want put a ferrite bead between analog ground and digital ground of the Sabre chip. Is that possible on the Buffalo print design?
If yes, can you send a picture wich trace to be cut?
Just a question.
I have put ferrite beads between the grounds of my batteries. The sonic impact is huge!
Now i want put a ferrite bead between analog ground and digital ground of the Sabre chip. Is that possible on the Buffalo print design?
If yes, can you send a picture wich trace to be cut?
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