Uhm, exactly.. I had just recently not very good experience with those small pana FM in my DAC.. though they are fantastic parameters wise.. but were low voltage types. changed back to some "normal" type but 63V philipses and all well again.
By the way those philips /bcc were the 037 series, they are standard but very good quality and low esr also. But it's hateful capacitor swapping and subjective audiophilia, so don't take it too seriously.
Ciao, George
By the way those philips /bcc were the 037 series, they are standard but very good quality and low esr also. But it's hateful capacitor swapping and subjective audiophilia, so don't take it too seriously.
Ciao, George
Nordic said:
If youre asking for the "old" layout.. Then I have no 45° TO92 package. But my Eagle can rotate them in every angle..
I hope I didnt misunderstand 😀
Joseph K said:
Really!
I have tons of FM type caps!
Does Nichicon UHD series better than FMs? Or where can I find Philips BCC series?
UnixMan said:
even before... it was before Brian answer!
as Brian said... at a first glance more or less it looks good.
The input cap. is out of the NFB loop(s), so it's less of a problem... except for possible coupling with other parts of the circuit, which may create spurious feedback paths (and thus possibly oscillations). To avoid any trouble (and save some PCB space too), you may mount it off-board.
The large output currents are creating strong EMF: try keeping the output (and output sense resistor) as much as possible far away from anything else, and in particular from the input and input components (notice that overall the amplifier is non-inverting: any coupling of the output with the amplifier input would likely result in positive feedback and oscillations...).
Of course there must be a balance here, since the series sense resistor is inside both feedback loops and can't be placed far from the rest... [/B]
Oh I am just noticed that sorry.
I am beginning to worry about the output pad and the 0R47 resistor!
Do you think it causes noticeable EMF in this position?
I'm sure that FM are quite good. Just put in a higher voltage type, not the lowest possible.
Would say: go ahead, build it, and then - that C4 position is a very good test point for different caps flavours.. really a worst case test, with no DC across, very sensitive and not corrected point [feedback]. Not by accident that Mauro later on used a servo there.
But until then, it's very illuminating to change caps on the fly in that point. Oscon's seemed to be good for me for a while, until I did not put that BCC high voltage one there.. Now there is a Cerafine 100V type [huge] sitting in there.
By the way, if You just go and look up Mauro's original BOM, will find a 50V Elna suggested fo that place.. 😀 I could have spared myself all this going around...
Would say: go ahead, build it, and then - that C4 position is a very good test point for different caps flavours.. really a worst case test, with no DC across, very sensitive and not corrected point [feedback]. Not by accident that Mauro later on used a servo there.
But until then, it's very illuminating to change caps on the fly in that point. Oscon's seemed to be good for me for a while, until I did not put that BCC high voltage one there.. Now there is a Cerafine 100V type [huge] sitting in there.
By the way, if You just go and look up Mauro's original BOM, will find a 50V Elna suggested fo that place.. 😀 I could have spared myself all this going around...
Wait, wait...
Were you talking about the C4 from the beginning?
If so I am totally misunderstanded!
I am using a 220u/35v Multicomp (????) non polar electrolytics.
Should I use a polar one as the original papers say?
Were you talking about the C4 from the beginning?
If so I am totally misunderstanded!
I am using a 220u/35v Multicomp (????) non polar electrolytics.
Should I use a polar one as the original papers say?
No, no, be careful I'm changing arguments constantly.. 
You understood well, first we were talking about LM318 bypasses - I'd suggest don't use less than 35V there, and try FM.
Then I said - "but You can decide it for yourself, try them out in the C4 position, it's a good point for trials"
Your choice of bipolar is not bad, but try [if only for fun] also some others..
Edit: a BG N is bipolar, also.. 😱
Ciao, George
You understood well, first we were talking about LM318 bypasses - I'd suggest don't use less than 35V there, and try FM.
Then I said - "but You can decide it for yourself, try them out in the C4 position, it's a good point for trials"
Your choice of bipolar is not bad, but try [if only for fun] also some others..
Edit: a BG N is bipolar, also.. 😱
Ciao, George
Ok...
I was confused because tired from PCB design all day.
Anyway, this is my regulated suppy + Mauro's speaker protection circuit combined;
And this is the PCB layout;
This will be for one channel. So the total amplifier will be dual mono in one case (also toroids will be dedicated).
The rectifiers (35A chasis type) and the main reservoirs will be off the board. I havent decided for the main reservoir capacitors. May you recommend a good capacitor pls? (not expensive than 20$ 😀 )
And also pls advice a good PCB maker which accepts international online orders..
I was confused because tired from PCB design all day.
Anyway, this is my regulated suppy + Mauro's speaker protection circuit combined;
An externally hosted image should be here but it was not working when we last tested it.
And this is the PCB layout;
An externally hosted image should be here but it was not working when we last tested it.
This will be for one channel. So the total amplifier will be dual mono in one case (also toroids will be dedicated).
The rectifiers (35A chasis type) and the main reservoirs will be off the board. I havent decided for the main reservoir capacitors. May you recommend a good capacitor pls? (not expensive than 20$ 😀 )
And also pls advice a good PCB maker which accepts international online orders..
Dxvideo said:
well, at least the place you've chosen for the sense resistor looks good for the overall signal paths.
Sure it does create an interfering EM field. As also the big filter caps and all the other "big power" parts does... but you have to put them somewhere.
Perhaps the best thing to do is making (at least) a double sided board, filled with ground planes wherever is possible.
Of course the ground plane(s) must be just that, i.e. a good shield and NOT be used to carry any relevant power (current). In fact in principle they should not carry ANY current at all! (well, with a bit of care about the likely current paths on the plane you may still use them for small currents).
Set up a "star" ground, with each power (and output) line running (as far as possible) along with its corresponding "GND" trace.
Wherever you have a "sensible" trace running next to a "high power" trace, add an (unused!) GND line in between. Do not put "sensible" traces "above" (on the other side of) high power ones (and GNDs). Do NOT make them parallel (on either side). If you really have to cross a power line with a sensible one, minimize the cross area -> cross perpendicularly.
Since you're gonna mount components on both sides anyway, I would arrange things so to mount all "sensible" signal parts (inputs, feedback, etc., i.e. all those components which sports any relatively high impedance connection) on one side of the board while keeping all the "big power" ones on the other.
I'd place the the LM3886 with its filter (bypass) caps, its power and output traces and connections (of course together with their corresponding GNDs lines!) on one side of the board and just about everything else on the other.
That is on the other side, laid right above the ground plane there would be all the input, feedback & compens. resistors and caps., the LM318 and its filter caps and regulators - "hidden" behind (somewhat shielded by) the LM318 power line bypass caps and "away" from inputs and feedback paths.
Using SMD components for the "sensible" parts IMHO is HIGHLY recommended. That would allow to keep them together with their connections on one side of the board above a nice ground plane on the other. If you use the relatively "big" ones, soldering SMDs is no more difficult than soldering normal "trough-hole" components.
Good luck...
Hmmm..
Then I have a problem. Because on left side as you can see, my ground plate carries a lot of current. The on board supply bypass capacitors connected to ground plate directly. But this situation can be fixed easily.
However, on the right side; Does my stopped (with 1R) clean gorund plate need to be changed with start ground? It carries nearly nothing! And it creates a natural star point at one pin of 1R stopper. Do you think I should make it normal connections and star point?
Thx..
Then I have a problem. Because on left side as you can see, my ground plate carries a lot of current. The on board supply bypass capacitors connected to ground plate directly. But this situation can be fixed easily.
However, on the right side; Does my stopped (with 1R) clean gorund plate need to be changed with start ground? It carries nearly nothing! And it creates a natural star point at one pin of 1R stopper. Do you think I should make it normal connections and star point?
Thx..
Dxvideo said:
try to think about the various current paths along the plates: electrons will always choose the "shortest" path (the one with the minimal resistance).
Consider that the copper has its own resistance, thus any current -even the smallest one- will create its own -small, but not null- voltage along the plate.
Consider that if this voltages is to appear somehow across an op-amp inputs, even a pV (picovolt!) will make a big difference!
Try to understand how this currents and voltages will interact with each other, and which point of the circuit will influence.
Depending on this considerations, it can be ok as it is... or not.
Hi,
I'm looking to build my first chip amp very soon, but I want to get started with a pre-designed kit first.
Although I have built many kinds of projects before, I haven't yet acquired the knowledge or brain power to design my own high-end amp (certainly not with the attention to detail found in most designs on this site 🙂 ).....
I've read through around a quarter of this thread so far and used the search function etc, but I can't seem to find someone who still sells kits? I'm looking for a RevC or Evolution kit, or even just a PCB (my home-made PCB's often don't turn out so well!)
Can the kits still be bought direct from Mauro, Brian, or Russ etc?
Thanks,
OzOnE.
I'm looking to build my first chip amp very soon, but I want to get started with a pre-designed kit first.
Although I have built many kinds of projects before, I haven't yet acquired the knowledge or brain power to design my own high-end amp (certainly not with the attention to detail found in most designs on this site 🙂 ).....
I've read through around a quarter of this thread so far and used the search function etc, but I can't seem to find someone who still sells kits? I'm looking for a RevC or Evolution kit, or even just a PCB (my home-made PCB's often don't turn out so well!)
Can the kits still be bought direct from Mauro, Brian, or Russ etc?
Thanks,
OzOnE.
Hey,
I'm looking to build my first amplifier also. The My_ref and the My_evolution look very interesting.
However, I am also looking at Chinese tube amplifiers, like the Yaqin 300b. I find these very interesting since they are said to sound good and they look great. However, someone on diyaudio called these Chinese amps to be merely hifi instead of high-end.
Therefore, I was wondering if someone could say something about how the My_ref and My_evolution will compare with these Chinese tube amps in terms of sound quality?
Thanks guys 🙂
I'm looking to build my first amplifier also. The My_ref and the My_evolution look very interesting.
However, I am also looking at Chinese tube amplifiers, like the Yaqin 300b. I find these very interesting since they are said to sound good and they look great. However, someone on diyaudio called these Chinese amps to be merely hifi instead of high-end.
Therefore, I was wondering if someone could say something about how the My_ref and My_evolution will compare with these Chinese tube amps in terms of sound quality?
Thanks guys 🙂
erikdebier said:
well, I've never heard one of those Yaqin 300b amp, so I can't comment on how they sound.
Yet what I can say for sure (having listened to various my_ref and my_evo makes) is that the my_ref and my_evo does sounds completely differently w/r to any "typical" tube amp, let alone a SET.
Both my_ref and my_evo definitely have a typical "solid state sound": cold and hyperanalytical. I would also say somewhat mechanical and lifeless... (*) but I'm a tube dude.
(*) not that they lack "brute force" dynamic or punch, on the contrary. But nevertheless they sound somewhat "artificial" (unnatural) and boring,
uninvolving, specially at low to moderate listening levels. A typical tube amp (specially a SET) usually sounds completely different. A not so good one may be lacking someting w/r to some "audiophile qualities", but usually you always get a smoother, more natural (someone would say "mellow" 🙄 ), more involving and overall much more enjoyable sound than just about any SS amp around.
At least IMO/IME, YMMV.
This is to say that if you like the "tube sound", I would NOT recommend you a my_ref (or my_evo), you'd likely be quite disappointed.
On the other end, if you like the hyperanalytical sound typical of so many "audiophile" SS amplifiers, than the my_ref or (better) the my_evo may be your Holy Grail. 😀
And the fixed (again) new version..
Fixed according to Unixmans advices;
- All GND connections replaced with the star ground lines.
- A non current carrier GROUND PLATE is added to the top layer.
- Some lines moved to the top layer..
Any additional suggestions?
Fixed according to Unixmans advices;
- All GND connections replaced with the star ground lines.
- A non current carrier GROUND PLATE is added to the top layer.
- Some lines moved to the top layer..
An externally hosted image should be here but it was not working when we last tested it.
Any additional suggestions?
UnixMan said:
well, I've never heard one of those Yaqin 300b amp, so I can't comment on how they sound.
Yet what I can say for sure (having listened to various my_ref and my_evo makes) is that the my_ref and my_evo does sounds completely differently w/r to any "typical" tube amp, let alone a SET.
Both my_ref and my_evo definitely have a typical "solid state sound": cold and hyperanalytical. I would also say somewhat mechanical and lifeless... (*) but I'm a tube dude.
(*) not that they lack "brute force" dynamic or punch, on the contrary. But nevertheless they sound somewhat "artificial" (unnatural) and boring,
A typical tube amp (specially a SET) usually sounds completely different. A not so good one may be lacking someting w/r to some "audiophile qualities", but usually you always get a smoother, more natural (someone would say "mellow" 🙄 ), more involving and overall much more enjoyable sound than just about any SS amp around.
At least IMO/IME, YMMV.
This is to say that if you like the "tube sound", I would NOT recommend you a my_ref (or my_evo), you'd likely be quite disappointed.
On the other end, if you like the hyperanalytical sound typical of so many "audiophile" SS amplifiers, than the my_ref or (better) the my_evo may be your Holy Grail. 😀
Thanks Unixman!
You're post definately cleared some things up for me 🙂 The problem is that I haven't heard that many audio gear, and mostly normal amplifiers. I don't have any experience with tube gear (except from my guitar amp) and also none with high-end audio gear. So it is difficult to determine what I actually prefer.
Best thing would be to listen to some amps I think 🙂
Regards,
Erik
Hi all,
I've just ordered some LM3886T's, LM318's, and binding posts etc. from Farnell - I'll soon order the rest of the bits from RS or elsewhere as they have a better selection of toroids and caps...
Does anyone have any spare RevC boards available? I can pay via PayPal or bank transfer (plus shipping to the UK). If anyone has any spares boards, it would make me a very happy chappy. 😀
I would even be interested in a pre-drilled / home-made PCB since mine can be a bit "variable", and I don't have a decent drill stand since my last one broke.
Also, are these Panasonic caps OK for the RevC, or is there a more suitable series / make of cap? (ie. what's the "standard" type which Mauro suggested / which type are most people using?)....
http://uk.farnell.com/1198552/passives/product.us0?sku=panasonic-ecos1ha103ea
Or, these ones? (as listed in Mauro's BOM)....
http://uk.farnell.com/1165579/passives/product.us0?sku=vishay-bc-components-2222-056-57103
Thanks in advance,
OzOnE.
I've just ordered some LM3886T's, LM318's, and binding posts etc. from Farnell - I'll soon order the rest of the bits from RS or elsewhere as they have a better selection of toroids and caps...
Does anyone have any spare RevC boards available? I can pay via PayPal or bank transfer (plus shipping to the UK). If anyone has any spares boards, it would make me a very happy chappy. 😀
I would even be interested in a pre-drilled / home-made PCB since mine can be a bit "variable", and I don't have a decent drill stand since my last one broke.
Also, are these Panasonic caps OK for the RevC, or is there a more suitable series / make of cap? (ie. what's the "standard" type which Mauro suggested / which type are most people using?)....
http://uk.farnell.com/1198552/passives/product.us0?sku=panasonic-ecos1ha103ea
Or, these ones? (as listed in Mauro's BOM)....
http://uk.farnell.com/1165579/passives/product.us0?sku=vishay-bc-components-2222-056-57103
Thanks in advance,
OzOnE.
I think this would be a better alternative;
http://uk.farnell.com/8820805/passives/product.us0?sku=vishay-bc-components-222210118103
Anyway,
If youre not in hurry, I can send you one of my PCBs.. However first I need to send to to a PCB manufacturer.
Or a better way; I can send you the eagle files and you can send them to a manufacturer then we can share the final PCBs..
??
http://uk.farnell.com/8820805/passives/product.us0?sku=vishay-bc-components-222210118103
Anyway,
If youre not in hurry, I can send you one of my PCBs.. However first I need to send to to a PCB manufacturer.
Or a better way; I can send you the eagle files and you can send them to a manufacturer then we can share the final PCBs..
??
Hi, dxvideo,
The main problem for me is the cost of getting PCB's manufactured. I've only ever used PCB-Pool because their support and communication is excellent. Most times it costs me around £60-£90. It's well worth it for smaller boards as you get multiples, but a tad expensive for a few prototypes.
A few people have previously suggested Olimex - has anyone had experience with them before?
If I was going to get some boards made, I would have preferred to use Russ' RevC design as it has had much endorsment by Mauro (AFAIK) and others.
Have you had many positive comments on your layout so far? What was the main aim of your design? (I haven't had chance to read the whole thread yet.)
OzOnE.
The main problem for me is the cost of getting PCB's manufactured. I've only ever used PCB-Pool because their support and communication is excellent. Most times it costs me around £60-£90. It's well worth it for smaller boards as you get multiples, but a tad expensive for a few prototypes.
A few people have previously suggested Olimex - has anyone had experience with them before?
If I was going to get some boards made, I would have preferred to use Russ' RevC design as it has had much endorsment by Mauro (AFAIK) and others.
Have you had many positive comments on your layout so far? What was the main aim of your design? (I haven't had chance to read the whole thread yet.)
OzOnE.