The power supply design is pretty simple and nothing special and most of all the opamp decoupling is poor and in general the RC filter on opamp supply lines is better than nothing but it doesn't isolate much the diamond buffer currents that reach the opamp.
The zener mod gives a first nice improvement but performance would improve replacing the 47R resistors and decoupling capacitors with even a simple transistor/zener based shunt regulator like the one I've implemented in my My_Ref variant:
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Not speaking for people in general, only for myself but any classAB amp is going to create noise on its power supply. Noisy power supplies are the no.1 enemy of great sound in my experience - and my experience isn't unique. There is a reason classA is revered and in my estimation the reason is that it comes with quieter supplies.
Definitely inferior PRaT.
You can compare against your own amp - adding more caps or increasing the bias in the OPS may well indicate that what you have now isn't transparent.
The power supply design is pretty simple and nothing special and most of all the opamp decoupling is poor and in general the RC filter on opamp supply lines is better than nothing but it doesn't isolate much the diamond buffer currents that reach the opamp.
The zener mod gives a first nice improvement but performance would improve replacing the 47R resistors and decoupling capacitors with even a simple transistor/zener based shunt regulator like the one I've implemented in my My_Ref variant:
As I wrote about the XP-7, 22uH low resistance inductors in series with the opamp supplies made a huge difference in LTSpice.
I've bought the parts to make that mod on the XP-7, but I want to get familiar with it first so that I can say what if any diffence the mod makes.
I've measured the 50pairs of BC550C/BC560C's.
Got some semi-close matches. Ordered än additional 25pairs hoping to get closer matches.
Measured the BD139/140's taken from my old BCL clone.
The BD140 were very close, the BD139 not at all.
Measured the first 20 BD140's.
Bad cell phone pics, sorry about that.
Got some semi-close matches. Ordered än additional 25pairs hoping to get closer matches.
Measured the BD139/140's taken from my old BCL clone.
The BD140 were very close, the BD139 not at all.
Measured the first 20 BD140's.
Bad cell phone pics, sorry about that.
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very interesting project.
how to match transistors using multimeter?
thanks.
You should use something like this:
2016 NEW LCD 12864 Mega328 Transistor Tester Diode Triode Capacitance LCR ESR Meter free shipping-in Integrated Circuits from Electronic Components & Supplies on Aliexpress.com | Alibaba Group
usually transistor tester like that only measure HFE and Vf (Vce).
what value should be match on this amp: Vce, Vbe or HFE?
sorry my bad english
The power supply design is pretty simple and nothing special and most of all the opamp decoupling is poor and in general the RC filter on opamp supply lines is better than nothing but it doesn't isolate much the diamond buffer currents that reach the opamp.
The zener mod gives a first nice improvement but performance would improve replacing the 47R resistors and decoupling capacitors with even a simple transistor/zener based shunt regulator like the one I've implemented in my My_Ref variant:
I read a post from you some years ago at this forum, and you stated the Panasonic Fx is quite good, but Elna Silmic II is better.
I have now replaced my Silmic II and KZ Muse cap´s in the power supply in my DAC and headphone amp with Panasonic FR as many people told me the Silmic II and KZ Muse is only for use in signal path - including Nichocon themself. And I´m really pleased twith the replacement.
Did I misunderstood you or are you still convinced they are better than Panasonic Fx anywhere they are used?
I liked the Panasonic FR in the PSU section! But it's also a matter of synergy. I didn't like them in combination with my favorite opamps. I needed something that tuned down a bit of the harshness that the FR introduced. The LXZ do indeed sound a bit more neutral like ClaveFremen earlier in one of his first posts stated. So I sticked with the LXZs. But I could have gone with the Panasonic FRs or FMs anytime if these were the caps I had lying around. It's just tuning the margins. What I think of the FR caps is that they sound more open and transparant than the LXZs. also a bit more detailed. But the sound flattened a bit and got a bit harsh on the high end. A problem I was trying to counter at the time.
Maybe icm with other caps they don't sound that harsh. It's all about the combination of components that makes a sound signature. That's what I found out.
If my LXZ caps would go bad I would place the FRs in without any problems and tune in some other place to get the sound again that I like. After building and finishing my DAC this week I will focus again on the Lehmann to tune it according to the DAC sound. Maybe I'll try the Panasonic FR caps again instead of the LXZs.
For now I've decided to do a small upgrade. Got my hands on some Wima Black Box 22nf caps. They are supposed to be better than every red wima cap. Since I got the red Wima FKP2 (or FKP4, don't remember) caps installed this could be opening up the sound a tad more since I know the AV100 caps did a bit better than the Wima FKP caps at the opamp. So I'll keep you guys posted. They have the same footprint (5mm).
Maybe icm with other caps they don't sound that harsh. It's all about the combination of components that makes a sound signature. That's what I found out.
If my LXZ caps would go bad I would place the FRs in without any problems and tune in some other place to get the sound again that I like. After building and finishing my DAC this week I will focus again on the Lehmann to tune it according to the DAC sound. Maybe I'll try the Panasonic FR caps again instead of the LXZs.
For now I've decided to do a small upgrade. Got my hands on some Wima Black Box 22nf caps. They are supposed to be better than every red wima cap. Since I got the red Wima FKP2 (or FKP4, don't remember) caps installed this could be opening up the sound a tad more since I know the AV100 caps did a bit better than the Wima FKP caps at the opamp. So I'll keep you guys posted. They have the same footprint (5mm).
What do you guys think of claritcaps esa caps?
They are about twice the price of the standard mundorf mkp caps (which I find the most hideous parts from my device). Since ClaveFremen noticed me about that removing the input caps with a good DAC makes a big difference I guess there is still a lot to be gained here.
The claritycaps look very nice as a bonus and from what I've read they seem to be quite alright. The mundorf caps won't go to waste. They will find a place back on the other board which will be tuned as a pre amp for my active speakers since they require a different sound than my headphones to my liking.
I will upgrade the small win a fkp2 caps with wima black box caps and the mundorf mkp input caps with some sleek claritycaps (which I find a rediculous name BTW for a cap brand, but that would alter performance just as much as the mundorfs being ugly haha)
They are about twice the price of the standard mundorf mkp caps (which I find the most hideous parts from my device). Since ClaveFremen noticed me about that removing the input caps with a good DAC makes a big difference I guess there is still a lot to be gained here.
The claritycaps look very nice as a bonus and from what I've read they seem to be quite alright. The mundorf caps won't go to waste. They will find a place back on the other board which will be tuned as a pre amp for my active speakers since they require a different sound than my headphones to my liking.
I will upgrade the small win a fkp2 caps with wima black box caps and the mundorf mkp input caps with some sleek claritycaps (which I find a rediculous name BTW for a cap brand, but that would alter performance just as much as the mundorfs being ugly haha)
It depends on the application... for opamp decoupling (not I/V or diamond buffer/current pump) and signal path, absolutely.
But not the brown/white ones you can find from reputable sellers, Elna screwed up something with them to be ROHS compliant.
Black/Gold ones or older Silmics are better.
Other good caps are Nichicon KZ, FW, FG.
IMHO, this is non-sense.
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...
Though when the decoupling is on current hungry opamps, like in I/V, diamond buffers or current gain stages, a low impedance cap works (and sound) better, my favourite is NCC LZX, very neutral and balanced.
Panasonic Fx are excellent caps but have several flaws in audioband, IMHO.
One of them is that hint of harshness Cidious is talking about and the biggest one, IMHO, is that they're not balanced.
Wasted money, not much better than MCAP and not so balanced.
Vishay V735P is a much better choice or even better Mundorf Supreme (plain ones, not the oily or silverish ones)
These are all I can find and they look weird to me!
At this price range the Mundorf supreme caps are just not an option they are also twice the size of the normal MCaps and wouldn't fit nicely.
But thnx for your response!
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Measured, all 150 BC550C/BC560C I have now.
I had to measure alot of them again, as ambient temp was different from when I measured them the first time and they didn't measure the same.
Closest I got was:
BC550C:
571 - 645mV, 645mV
BC560C:
571 - 659mV, 660mV.
I hope that is close enough as that is what I'll use.
I had to measure alot of them again, as ambient temp was different from when I measured them the first time and they didn't measure the same.
Closest I got was:
BC550C:
571 - 645mV, 645mV
BC560C:
571 - 659mV, 660mV.
I hope that is close enough as that is what I'll use.
I was just on a BCL reading binge and came across your thread, as well as your rude TaoBao seller:
https://item.taobao.com/item.html?id=346229307
Going to emulate what you've done, trying to eek the rev 7 board from him. Working on getting a parts list together, unless you have one?
https://item.taobao.com/item.html?id=346229307
Going to emulate what you've done, trying to eek the rev 7 board from him. Working on getting a parts list together, unless you have one?
Maybe you're having more luck with this prick. I wanted to buy an A1 headamp kit from him too, but same arrogant attitude. He can put his hole shop where the sun doesn't shine.. never buying from him again! (the board quality is exceptionally good though haha)
I have a partial parts list with most basic parts on it. Bought from a really reliable and friendly shop that only sells high quality genuine parts for an honest price. They pair the transistors for you that you only have to buy what you need. I've got fantastic results with them. I've got another shop for the blue dale resistors and then you will only need to finish it with some specialised parts from seperate shops. If you are interested send me an pm and I will send you all the info.
Atm I'm doing 3 projects
1: modifying my almost brand new DT770 250 ohm that I barely use. They are barely burned in. I don't like the harsh painful highs with female vocals and the tin can mids. I've decide to upgrade and debug them. Since I also have the DT1770s which are fairly easy to drive and are closely based on the DT770, but with 45mm tesla drivers, slightly different pads, different dampening inside and a detachable higher grade cable, I've ordered:
50mm Tesla drivers in 600 ohm flavor
Some cotton balls
Dampening paper
Some other tuning/debugging materials
Canare 4E6S microphone cable
MPS Mini xlr connectors
Amphenol 6.35 plug
High quality copper wire for internal wiring
Pleather DT1770 earpads
I will start debugging this week when everything is put together. I will keep a log on Head-fi because there doesn't see, to be a dedicated space for it on this forum. I hope they will perform near or actually better than DT1770 because the DT770 is still flawed but I'm not modifying such a set of cans.. they will stay original as you can understand.
2nd project will kick off tomorrow when the last parts come in. My ES9018 DAC! REALLY looking forward to do this one because it will be the brains of my audio operation with the lehmann being it's heart and my headphones and speakers being the muscle hehe. I will modify and tune that one too to my liking. I will keep a log here in the digital section from tomorrow.
3rd project is upgrading an Aune X1SE dac/preamp/headamp. It will be a gift for my uncle. I will be cleaning up the power supply a bit and recap some things. My uncle will be pleased with such an versatile and decent sounding compact device.
Next to that I am still planning to roll some parts on the lehMann since the 470uf 50V caps make the sound a bit to buttery and slow now after extensive burn in. The red wine fkp2 caps will be replaced with wima black box caps and I will try some claritycap ESA caps to see which combination sounds best. I will put the other ones in my second lehman which I'm building from spare parts.
Never done..
I have a partial parts list with most basic parts on it. Bought from a really reliable and friendly shop that only sells high quality genuine parts for an honest price. They pair the transistors for you that you only have to buy what you need. I've got fantastic results with them. I've got another shop for the blue dale resistors and then you will only need to finish it with some specialised parts from seperate shops. If you are interested send me an pm and I will send you all the info.
Atm I'm doing 3 projects
1: modifying my almost brand new DT770 250 ohm that I barely use. They are barely burned in. I don't like the harsh painful highs with female vocals and the tin can mids. I've decide to upgrade and debug them. Since I also have the DT1770s which are fairly easy to drive and are closely based on the DT770, but with 45mm tesla drivers, slightly different pads, different dampening inside and a detachable higher grade cable, I've ordered:
50mm Tesla drivers in 600 ohm flavor
Some cotton balls
Dampening paper
Some other tuning/debugging materials
Canare 4E6S microphone cable
MPS Mini xlr connectors
Amphenol 6.35 plug
High quality copper wire for internal wiring
Pleather DT1770 earpads
I will start debugging this week when everything is put together. I will keep a log on Head-fi because there doesn't see, to be a dedicated space for it on this forum. I hope they will perform near or actually better than DT1770 because the DT770 is still flawed but I'm not modifying such a set of cans.. they will stay original as you can understand.
2nd project will kick off tomorrow when the last parts come in. My ES9018 DAC! REALLY looking forward to do this one because it will be the brains of my audio operation with the lehmann being it's heart and my headphones and speakers being the muscle hehe. I will modify and tune that one too to my liking. I will keep a log here in the digital section from tomorrow.
3rd project is upgrading an Aune X1SE dac/preamp/headamp. It will be a gift for my uncle. I will be cleaning up the power supply a bit and recap some things. My uncle will be pleased with such an versatile and decent sounding compact device.
Next to that I am still planning to roll some parts on the lehMann since the 470uf 50V caps make the sound a bit to buttery and slow now after extensive burn in. The red wine fkp2 caps will be replaced with wima black box caps and I will try some claritycap ESA caps to see which combination sounds best. I will put the other ones in my second lehman which I'm building from spare parts.
Never done..
I'm actually quite fond of the DT990 pros, but settled with the Sennheiser Amperiors haha. PM sent!
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