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Audio grade caps have a quite low ESR so they're perfectly fine for decoupling and on output of regulators and always an improvement over the standard caps they usually replace...
Actually Clave the opposite is true. The output impedance of all IC regulators like the LM317 or 7815 rises with increasing frequency due to the gain of the active element having to drop with frequency for stability. The regulator output can thus be modelled as a small inductance which forms an LC circuit with the regulator's output capacitor. This LC circuit will ring if not properly damped, which is what the ESR of the output capacitor does. If you use a low ESR audiophile cap in this position it is much more likely to cause ringing than a cheapo cap with higher ESR.
Audio grade caps have a quite low ESR so they're perfectly fine for decoupling and on output of regulators and always an improvement over the standard caps they usually replace...
Actually Clave the opposite is true. The output impedance of all IC regulators like the LM317 or 7815 rises with increasing frequency due to the gain of the active element having to drop with frequency for stability. The regulator output can thus be modelled as a small inductance which forms an LC circuit with the regulator's output capacitor. This LC circuit will ring if not properly damped, which is what the ESR of the output capacitor does. If you use a low ESR audiophile cap in this position it is much more likely to cause ringing than a cheapo cap with higher ESR.
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Quite a low ESR but not as low as the Panasonic FM/FC/FR mikaelmark was referrring to, which for sure can give the sort of problems you're correctly pointing to.
No way a Silmic/Cerafine/KZ/FG/FW have a such low ESR to give problems on the output of regulator...
So what size and series of Panasonic or United Chemi-Con would you recommend using after 7815/7915 regulators?
Also, would you recommend using .1uF film caps after those electrolytics?
Thanks...
Here's a useful article with graphs showing what happens with output capacitors of various kinds on the output of an LM317 : Simple Voltage Regulators Part 2: Output Impedance
Small update.
I've solder in the BC550C & BC560C.
Though it may look very close, there are no shorts around the BJT's.
Closest match I could get out of the 75 pairs.
I used slightly larger heatsinks than the ones marked on the silkscreen.
I'll use the same, modified, heatsinks for the BD139's/BD140's.
I'm waiting for more of the above transistors to arrive so that I can get a close matches as possible. Also waiting for the missing resistors.
I may cut traces from the LM317/337 in the future and add jumpers so that I can swap between on-board PS and external PS/Vregs (LT1083's, Shunt reg or something else).
I've solder in the BC550C & BC560C.
An externally hosted image should be here but it was not working when we last tested it.
Though it may look very close, there are no shorts around the BJT's.
An externally hosted image should be here but it was not working when we last tested it.
Closest match I could get out of the 75 pairs.
An externally hosted image should be here but it was not working when we last tested it.
I used slightly larger heatsinks than the ones marked on the silkscreen.
I'll use the same, modified, heatsinks for the BD139's/BD140's.
I'm waiting for more of the above transistors to arrive so that I can get a close matches as possible. Also waiting for the missing resistors.
I may cut traces from the LM317/337 in the future and add jumpers so that I can swap between on-board PS and external PS/Vregs (LT1083's, Shunt reg or something else).
The XP-7 clone with matched resistors, all quality parts etc is starting to sound VERY good with my Fidelio X2's.
(This without having tried the inductor on the supply rails mod yet)
It's also "only" fed by a LM317/337 Reg, though with good parts.
There are quite a few better options for Vreg than the standard config LM317/337.
I'm impatiently awaiting the parts needed to finish the BCL clone as I am very curious to compare the two.
And I'm also eager to see how it compares to my, now dead, old BCL clone with inferior components and layout.
I've got a few opamps to test when it's done, OPA1652, OPA2134, OPA2604, OPA2111KP, OPA2132, OPA2107, my jfet discrete opamp, LME49720NA etc etc.
(This without having tried the inductor on the supply rails mod yet)
It's also "only" fed by a LM317/337 Reg, though with good parts.
There are quite a few better options for Vreg than the standard config LM317/337.
I'm impatiently awaiting the parts needed to finish the BCL clone as I am very curious to compare the two.
And I'm also eager to see how it compares to my, now dead, old BCL clone with inferior components and layout.
I've got a few opamps to test when it's done, OPA1652, OPA2134, OPA2604, OPA2111KP, OPA2132, OPA2107, my jfet discrete opamp, LME49720NA etc etc.
Since you're getting into winding your own coils, you could make inductors for supply line filters, prior to the LM317/337. I have a schematic on my blog, a project I'm working on at the moment. I doubt the inductors would fit in your case though as they're about 20mm cubes.
I've replaced some more caps and it turned out for the better!
I've replaced the The Wima FKP2 22nf caps with Wima Black Box caps of the same value on the opamp and input position. This made a slight improvement. The sound is just a tad cleaner and brighter but not losing body or anything. (Working in margins here. Don't expect these changes to totally change your device, its fine tuning)
After that I've tried some different electrolytes for the opamp positions. I had the big Nippon 470uf 50V caps there. They were very forgiving and buttery but I started missing the details in the high range.
I decided to give the Nippon AWJ 220uf 25V caps a try (same size as Elna Silmic II and Muse KZ audio caps. These are the highest grade audio caps from Nippon). I found this already an improvement over the ASF caps. But I was still longing for a bit more openness. Well there I put in the 220uf Silmics II.. Immediately the sound got more detailed. Though they still have to run in and I know they will get even a bit better. I lost some bass with the silmics but I got a lot of natural flavored detail back for it.
For opamp position in this circuit:
Nippon ASF - Very VERY buttery and jazzy sound. Forgiving to every genre. I could almost (less detailed) replicate the same sound when I accidentally mistook a 470uf 35V Panasonic FM for a Silmic when swapping caps in the sockets.
Nippon AWJ - More detailed. Still buttery and great lower end extension. Still I was longing for a bit more openness (Didn't give em time to properly burn in, may have opened up a bit more)
Elna Silmic II - Even more detailed. Less bass but great open soundstage without being muddy. Very nice with acoustic snare strikes. A bit more harsh on female vocals but more natural.
I also have some Nichicon Muse KZ in the 220uf 25V lying around.. I am really happy with the Silmic II sound so I didn't try them. But for the sake of completing a full roundup of the major (reasonably priced) high-end audio grade caps, maybe I should try them too.. just because I can.
Have ordered some ClarityCap ESA 2.2uf caps that will be in today. Very curious how they compare to the somewhat cheaper Mundorf MCap MKPs. If they sound the same or better I will keep the Clarity Caps anyway for design reasons. Together with the black Wima caps it will be total bad *** haha.
I am REALLY pleased with what I achieved with this build. There is not much to wish for. I am still swappign opamps sometime. Between discrete OPA111VMs and OPA2604AP (good version) The OPA111VM forwards the voices a bit, especially female voices but the voices are a bit less natural than with the OPA2604AP. The OPA2604AP is a really natural sounding opamp but lacking somewhat in clarity. It's more balanced, but I find it a bit messy. So I decided to order myself a pair of OPA604APs to use on a dual board. Maybe this will clean it up a bit.
Other opamps I have and have swapped in roundup comparison:
OPA627BPs - This one is faster and very detailed but sounding more artificially and less depth in the soundstage. It does do good over the whole range but I prefer the somewhat more natural liquid sound from the above mentioned BBs.
OPA111AM - most relaxt sounding opamp with great soundstage and warmth. But lacking in speed and clarity. It's a bit more laid back but very relaxt sounding. It does have the same signature as the VMs but just more relaxt, laid back and a bit more lazy.
OPA2134AP - not bad overall, but dull and lacking in bottom end. Not comparable with any of the other opamps
Some AD dual opamp - good sound. Bit less neutral sounding. Colors the sound a bit. is very detailed though and tight. Good allrounder if you like the somewhat different sound color than the BB or TIs.
Further I am still building ES9018 DAC and Modding DT770
I've replaced the The Wima FKP2 22nf caps with Wima Black Box caps of the same value on the opamp and input position. This made a slight improvement. The sound is just a tad cleaner and brighter but not losing body or anything. (Working in margins here. Don't expect these changes to totally change your device, its fine tuning)
After that I've tried some different electrolytes for the opamp positions. I had the big Nippon 470uf 50V caps there. They were very forgiving and buttery but I started missing the details in the high range.
I decided to give the Nippon AWJ 220uf 25V caps a try (same size as Elna Silmic II and Muse KZ audio caps. These are the highest grade audio caps from Nippon). I found this already an improvement over the ASF caps. But I was still longing for a bit more openness. Well there I put in the 220uf Silmics II.. Immediately the sound got more detailed. Though they still have to run in and I know they will get even a bit better. I lost some bass with the silmics but I got a lot of natural flavored detail back for it.
For opamp position in this circuit:
Nippon ASF - Very VERY buttery and jazzy sound. Forgiving to every genre. I could almost (less detailed) replicate the same sound when I accidentally mistook a 470uf 35V Panasonic FM for a Silmic when swapping caps in the sockets.
Nippon AWJ - More detailed. Still buttery and great lower end extension. Still I was longing for a bit more openness (Didn't give em time to properly burn in, may have opened up a bit more)
Elna Silmic II - Even more detailed. Less bass but great open soundstage without being muddy. Very nice with acoustic snare strikes. A bit more harsh on female vocals but more natural.
I also have some Nichicon Muse KZ in the 220uf 25V lying around.. I am really happy with the Silmic II sound so I didn't try them. But for the sake of completing a full roundup of the major (reasonably priced) high-end audio grade caps, maybe I should try them too.. just because I can.
Have ordered some ClarityCap ESA 2.2uf caps that will be in today. Very curious how they compare to the somewhat cheaper Mundorf MCap MKPs. If they sound the same or better I will keep the Clarity Caps anyway for design reasons. Together with the black Wima caps it will be total bad *** haha.
I am REALLY pleased with what I achieved with this build. There is not much to wish for. I am still swappign opamps sometime. Between discrete OPA111VMs and OPA2604AP (good version) The OPA111VM forwards the voices a bit, especially female voices but the voices are a bit less natural than with the OPA2604AP. The OPA2604AP is a really natural sounding opamp but lacking somewhat in clarity. It's more balanced, but I find it a bit messy. So I decided to order myself a pair of OPA604APs to use on a dual board. Maybe this will clean it up a bit.
Other opamps I have and have swapped in roundup comparison:
OPA627BPs - This one is faster and very detailed but sounding more artificially and less depth in the soundstage. It does do good over the whole range but I prefer the somewhat more natural liquid sound from the above mentioned BBs.
OPA111AM - most relaxt sounding opamp with great soundstage and warmth. But lacking in speed and clarity. It's a bit more laid back but very relaxt sounding. It does have the same signature as the VMs but just more relaxt, laid back and a bit more lazy.
OPA2134AP - not bad overall, but dull and lacking in bottom end. Not comparable with any of the other opamps
Some AD dual opamp - good sound. Bit less neutral sounding. Colors the sound a bit. is very detailed though and tight. Good allrounder if you like the somewhat different sound color than the BB or TIs.
Further I am still building ES9018 DAC and Modding DT770
I'll have a look mate.
Thanks!
I've got a bunch of radial "H-Core" ferrites to collect at the post office.
Should be perfect for winding 22uH or similar inductors to use in series with supplies for less current hungry devices
Still waiting for the turn-counter-thingy to arrive...alot of stuff has been taking a while to arrive lately.
diyAudio
Last mods..
Replaced the Mundorf MKP caps with the ClarityCap ESA caps. Can not hear the difference clearly because the Silmic caps are still burning in so I notice the sound changes from time to time.. But I LOVE the sound now. The Silmic caps were a huge improvement. But the whole machine looks meant to be now.
Also switched from the 2xOPA111VMs to my new 2xOPA604APs they are a little less forward than the OPA111VMs, but in return I get a lot more natural sound and the same nice traits that the OPA111VM has, like wide and deep soundstage, good detail etc. The 2xOPA604AP are definitely dwarfing the more common OPA2604AP. They are much tighter and more on the spot. The OPA2604AP ****** up to often with that and felt messy and somewhat unorganized. Well problem solved.
I will only do one more improvement on this device for now and it will be purely aesthetically.. I will sleeve the braided transformer wires! Because it just doesn't match..
Last mods..
Replaced the Mundorf MKP caps with the ClarityCap ESA caps. Can not hear the difference clearly because the Silmic caps are still burning in so I notice the sound changes from time to time.. But I LOVE the sound now. The Silmic caps were a huge improvement. But the whole machine looks meant to be now.
Also switched from the 2xOPA111VMs to my new 2xOPA604APs they are a little less forward than the OPA111VMs, but in return I get a lot more natural sound and the same nice traits that the OPA111VM has, like wide and deep soundstage, good detail etc. The 2xOPA604AP are definitely dwarfing the more common OPA2604AP. They are much tighter and more on the spot. The OPA2604AP ****** up to often with that and felt messy and somewhat unorganized. Well problem solved.
I will only do one more improvement on this device for now and it will be purely aesthetically.. I will sleeve the braided transformer wires! Because it just doesn't match..
Attachments
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Small update again.
Almost done now. Tried working with wood for the first time.
I like how it looks but I'm terrible at it.
I'm sorry about the bad pics, taken with my phone in bad light.
Wiring is a bit sloppy, I'll tidy that up and I still need to wire in the HP jack and insert an opamp.
Don't know what kind of wood it is, got it for free from a local hardware store's scrap-bin.
Almost done now. Tried working with wood for the first time.
I like how it looks but I'm terrible at it.
I'm sorry about the bad pics, taken with my phone in bad light.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Wiring is a bit sloppy, I'll tidy that up and I still need to wire in the HP jack and insert an opamp.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Don't know what kind of wood it is, got it for free from a local hardware store's scrap-bin.
I did the final wiring, popped in an OPA1652 and flicked the switch.
No problems at start-up.
With no source connected and no load, DC offset stabilized at around 15mVdc/channel.
A bit on the high side imho.
Resistors, transistors etc are all matched.
Could be the OPA1652 I guess, I'll try later with an OPA2134.
No problems at start-up.
With no source connected and no load, DC offset stabilized at around 15mVdc/channel.
A bit on the high side imho.
Resistors, transistors etc are all matched.
Could be the OPA1652 I guess, I'll try later with an OPA2134.
With a pair of Sony IEM's and my phone as source, I got around 10mVdc/channel.
It played music, no noise at all that I could hear.
A bit of a "pop" when flipping the switch (on), silent when turning off.
Something that struck me though was that the heatsinks got hotter and hotter until I didn't feel comfortable with it after about 20min or so.
At first I thought it could be oscillating opamp (OPA1652AIDR), but that would not explain the vreg heatsinks being just as hot.
I've used heatsinks that are bigger than the ones on the silkscreen.
Measured input voltage (AC), about 17Vac from my 0-15vac 0-15vac 1A toroid transformer from Velleman.
A few pics to show the heatsinks etc.
Any ideas as to why the vreg and transistor heatsinks gets so hot?
I can't have made a mistake when "center-tapping" the dual secondary toroidal transformer as that would have given wastly different measurements.
It played music, no noise at all that I could hear.
A bit of a "pop" when flipping the switch (on), silent when turning off.
Something that struck me though was that the heatsinks got hotter and hotter until I didn't feel comfortable with it after about 20min or so.
At first I thought it could be oscillating opamp (OPA1652AIDR), but that would not explain the vreg heatsinks being just as hot.
I've used heatsinks that are bigger than the ones on the silkscreen.
Measured input voltage (AC), about 17Vac from my 0-15vac 0-15vac 1A toroid transformer from Velleman.
A few pics to show the heatsinks etc.
Any ideas as to why the vreg and transistor heatsinks gets so hot?
I can't have made a mistake when "center-tapping" the dual secondary toroidal transformer as that would have given wastly different measurements.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Make sure the heatsinks of the voltage regs are isolated from the ground! I had a problem with a voltage regulator in my DAC project. Turned out to be a short of the heatsink with the ground.. that way it will just pull current through.. they do get quite warm under load in my setup too but when I stop playing music they cool down a bit again. I can touch the heatsinks. I see your heatsinks touching or almost touching the capacitors! That's a big No No!
The heatsinks are, very, close to the caps but not touching them.
I can hold a finger on the heatsinks, as per the old rule so to speak, without it being painful/burning.
With the "silkscreen" heatsinks, the PCB takes some of the heat away, that could explain why these heatsinks feel warmer.
I have no shortage of heatsinks so I could go bigger...
At times like these I kick myself for not having gotten a temp gun yet.
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