Hi again,
It’s been a while but ive found some time to look at the recommendations you guys have made. I have decided to go for the esp project 88.
I choose this one because I can buy the pcb, and I think at this stage designing and laying out a pcb board is beyond my capabilities. So I will use this project to learn a thing or two. This design also has some flexibility if I want to use it.
So what op amp should I use with it?
Where do I get information on the different models?
Do I get this from the press releases that accompany them or are there reviews on the net somewhere?
Cheers
It’s been a while but ive found some time to look at the recommendations you guys have made. I have decided to go for the esp project 88.
I choose this one because I can buy the pcb, and I think at this stage designing and laying out a pcb board is beyond my capabilities. So I will use this project to learn a thing or two. This design also has some flexibility if I want to use it.
So what op amp should I use with it?
Where do I get information on the different models?
Do I get this from the press releases that accompany them or are there reviews on the net somewhere?
Cheers
good move
ESP designs are no-nonsense; an important factor -if you are not a ¨minimalist¨ type of guy- is versatility. You can have tape out, various inputs, etc.
OPA2134 is a good opamp. OPA2604 is more or less equivalent.
Another nice part is OPA2132.
You´ll be limited to dual opamps in this design tough, more so if you buy the ESP pcb. So you´ll can´t experiment with some of the more sophisticated chips, ´cause those are -generally- singles. But don´t worry: you´ll be well served using dual opas.
Check out in the same site for a proper power supply -there is one very simple +/- 15volts one, labelled, if I remember well, ¨preamplifier power supply¨.
Don´t try to drive long lines of interconnects with the preamp. I think that is best suited to ¨normal¨ interconnects and loads.
And enjoy the experience!
For some info about opamps, check out http://tangentsoft.net/audio/opamps.html
allways with a grain of salt, because tastes are tastes, and the sound of op amps is a very controversial ítem.
In the same site you´ll get some good diy tips too.
Search here in DiyAudio too, cause there´s a lot of info about the matter.
Cheers
ESP designs are no-nonsense; an important factor -if you are not a ¨minimalist¨ type of guy- is versatility. You can have tape out, various inputs, etc.
OPA2134 is a good opamp. OPA2604 is more or less equivalent.
Another nice part is OPA2132.
You´ll be limited to dual opamps in this design tough, more so if you buy the ESP pcb. So you´ll can´t experiment with some of the more sophisticated chips, ´cause those are -generally- singles. But don´t worry: you´ll be well served using dual opas.
Check out in the same site for a proper power supply -there is one very simple +/- 15volts one, labelled, if I remember well, ¨preamplifier power supply¨.
Don´t try to drive long lines of interconnects with the preamp. I think that is best suited to ¨normal¨ interconnects and loads.
And enjoy the experience!
For some info about opamps, check out http://tangentsoft.net/audio/opamps.html
allways with a grain of salt, because tastes are tastes, and the sound of op amps is a very controversial ítem.
In the same site you´ll get some good diy tips too.
Search here in DiyAudio too, cause there´s a lot of info about the matter.
Cheers
I think i will go for the opa2604, that’s my initial decision anyway.
Where does everyone get there components in the UK?
Also can someone recommend a book which is good for audio applications, i want to understand this more.
My understanding of hifi equipment is that you generally do not need a preamp for the dvd, cd player or anything new. I am going to use the preamp for connecting a personal music player and an older cd player (which seems to need it) to my present amplifier and future amplifier.
I will incorporate the flexibility as it is there but I don’t really see a need for it, my future amp will also have this flexibility.
The preamp is edging closer to reality!!
Where does everyone get there components in the UK?
Also can someone recommend a book which is good for audio applications, i want to understand this more.
My understanding of hifi equipment is that you generally do not need a preamp for the dvd, cd player or anything new. I am going to use the preamp for connecting a personal music player and an older cd player (which seems to need it) to my present amplifier and future amplifier.
I will incorporate the flexibility as it is there but I don’t really see a need for it, my future amp will also have this flexibility.
The preamp is edging closer to reality!!
EDIT:
Looking at the price of getting all of this to the UK and the fact that the pcbs i am interested in are one sided, would it be a lot cheaper and just as easy for a novice like me to make my own ones, i have no experience but the designs look very symmetrical and with a image of them in front of me........
Looking at the price of getting all of this to the UK and the fact that the pcbs i am interested in are one sided, would it be a lot cheaper and just as easy for a novice like me to make my own ones, i have no experience but the designs look very symmetrical and with a image of them in front of me........
preamp
And you´ll need some sort of volume control too.
Asuming that your amplifier has a pot at the input, there´s no problem in driving it directly; that should be some sort of ¨passive¨ approach: you don´t have any active part in the signal path except the volume control.
I was using something alike, feeding the amp directly with a very good cd player -with a nice output section-, and the sound was superb. But that nice CDP died one day, and I bought a humble -but decent- DVD unit.
In the same scheme, the DVD doesn´t sounded so good. The sound was congested, metallic, and lacking in dynamica.
In a first instance, I thought that the multiplayer was the culprit, you know, because of all those comments about that ¨standalones cdp´s are always better than universal players because they´re designed to a specific function...¨, etc.
Then, one day, I made a very simple preamp -only one opa604, with a little of gain-, and inserted it between the dvd and the power amp: the sound vastly improved! I was happy, and I begun to investigate, and I learned that sometimes the output stages of some players don´t have the needed muscle to drive some loads: the cable, the input stage of the ampli, etc.
So I gave up the ¨passive¨ approach, going ¨active¨. and made another mor powerful preamp. That was my first attempt at DIY, and I enjoyed it a lot.
I don´t know where to buy Burr Brown parts in UK, but surely Farnell has them.
Books: I´ve read some, but in spanish, so I cant give you info about them.
The net is a useful tool to go ¨selftaught¨ if you search properly: check the National Semiconductors, Burr Brown and Analog Devices sites, and take a look at some application notes and documents.
Cheers.
Usually, the sources that you´ve mentioned have the sufficient voltage output to drive a power amp to decent levels, but in some cases you´ll need some additional current output to make the power amp sing as intended.
And you´ll need some sort of volume control too.
Asuming that your amplifier has a pot at the input, there´s no problem in driving it directly; that should be some sort of ¨passive¨ approach: you don´t have any active part in the signal path except the volume control.
I was using something alike, feeding the amp directly with a very good cd player -with a nice output section-, and the sound was superb. But that nice CDP died one day, and I bought a humble -but decent- DVD unit.
In the same scheme, the DVD doesn´t sounded so good. The sound was congested, metallic, and lacking in dynamica.
In a first instance, I thought that the multiplayer was the culprit, you know, because of all those comments about that ¨standalones cdp´s are always better than universal players because they´re designed to a specific function...¨, etc.
Then, one day, I made a very simple preamp -only one opa604, with a little of gain-, and inserted it between the dvd and the power amp: the sound vastly improved! I was happy, and I begun to investigate, and I learned that sometimes the output stages of some players don´t have the needed muscle to drive some loads: the cable, the input stage of the ampli, etc.
So I gave up the ¨passive¨ approach, going ¨active¨. and made another mor powerful preamp. That was my first attempt at DIY, and I enjoyed it a lot.
I don´t know where to buy Burr Brown parts in UK, but surely Farnell has them.
Books: I´ve read some, but in spanish, so I cant give you info about them.
The net is a useful tool to go ¨selftaught¨ if you search properly: check the National Semiconductors, Burr Brown and Analog Devices sites, and take a look at some application notes and documents.
Cheers.
Re: preamp
This is distressing, Federico, but reminds me of the experience of someone else a few years ago. He was a technical person, and related how he could definitely get improved sound by substituting the on-board output stage of his CD player (invariably an op-amp) with a better designed circuit. Others related similar experiences. It appeared that inferior output stages in otherwise decent CD players did exist! One shudders.
Regards.
federico moreno said:
This is distressing, Federico, but reminds me of the experience of someone else a few years ago. He was a technical person, and related how he could definitely get improved sound by substituting the on-board output stage of his CD player (invariably an op-amp) with a better designed circuit. Others related similar experiences. It appeared that inferior output stages in otherwise decent CD players did exist! One shudders.
Regards.
"Where does everyone get there components in the UK?"
I got my opa2604s from www.wnaudio.com - friendly and speedy service. If you want to try analog devices opamps AD do free samples from www.analog.com. My preference at the moment is the ad8620, but these only come as soic packages (you can get soic to dip adaptors from wnaudio...). ad8066 (another soic) is also worth a punt. I think ti do free samples of the 2132 though I wasnt too keen on that in my amp.
other components I always get from farnell - there's a minimum £20 order, but I find I soon reach that value.... free next day delivery too - bargain
have fun
I got my opa2604s from www.wnaudio.com - friendly and speedy service. If you want to try analog devices opamps AD do free samples from www.analog.com. My preference at the moment is the ad8620, but these only come as soic packages (you can get soic to dip adaptors from wnaudio...). ad8066 (another soic) is also worth a punt. I think ti do free samples of the 2132 though I wasnt too keen on that in my amp.
other components I always get from farnell - there's a minimum £20 order, but I find I soon reach that value.... free next day delivery too - bargain
have fun
preamps. dvds et al
Ufff! yes, Johan, and i don´t know really if the culprits are the subpar opamps, the implementation of the antialiasing filter, the cheap coupling caps, the muting transistors or whatever.
And is distressing, ´cause I have heard very good sound emanating of some portable discmans being used as digital sources, so I asked myself ¨...why this f**** portable sounds so good, and a more elaborated tabletop unit, with better PSU, etc, sounds inferior?¨
Maybe the compactness and the close integration of the circuit? Maybe the battery psu, and the lack of AC contamination inside the cdp?
It´s very difficult for the amateur to individualize all the variables in the output stage of a cdp, finding the weak links, and then perform a ¨not misguided¨ mod of the circuit: sometimes one ends with a sound that is worst than the original!! -that happened to me at least once, no matter what fancy caps I used, nor what usual tricks I performed-...
Sometimes I get stuck with the -subversive and heretical- idea that a little bit of equalization would solve the problem (of moribund sounding cdps), and save myself the hassle of the modification, giving me more time to enjoy the music...
Everytime that I listen to a good vinyl in my old Thorens, that crazy idea of putting a ¨hidden equalizer¨ inside the cdp climbs to my mind...
Cheers
Ufff! yes, Johan, and i don´t know really if the culprits are the subpar opamps, the implementation of the antialiasing filter, the cheap coupling caps, the muting transistors or whatever.
And is distressing, ´cause I have heard very good sound emanating of some portable discmans being used as digital sources, so I asked myself ¨...why this f**** portable sounds so good, and a more elaborated tabletop unit, with better PSU, etc, sounds inferior?¨
Maybe the compactness and the close integration of the circuit? Maybe the battery psu, and the lack of AC contamination inside the cdp?
It´s very difficult for the amateur to individualize all the variables in the output stage of a cdp, finding the weak links, and then perform a ¨not misguided¨ mod of the circuit: sometimes one ends with a sound that is worst than the original!! -that happened to me at least once, no matter what fancy caps I used, nor what usual tricks I performed-...
Sometimes I get stuck with the -subversive and heretical- idea that a little bit of equalization would solve the problem (of moribund sounding cdps), and save myself the hassle of the modification, giving me more time to enjoy the music...
Everytime that I listen to a good vinyl in my old Thorens, that crazy idea of putting a ¨hidden equalizer¨ inside the cdp climbs to my mind...
Cheers
Re: preamps. dvds et al
Never mind the amateur. Us professionals have the same difficulties, only with more stress because mostly we ought to know, or at least others expect us to. I have sometimes in frustration just scrapped something and started anew. I just don't tell.
Regards
federico moreno said:
Never mind the amateur. Us professionals have the same difficulties, only with more stress because mostly we ought to know, or at least others expect us to. I have sometimes in frustration just scrapped something and started anew. I just don't tell.
Regards
Nice Circuits Drago! It will be fun to put on the analyser programme and see what they can achieve.
Just to point out (although I think most will pick it up) that the 2nd transistor in the line amp (post#30) has its collector and emitter reversed.
Regards.
Just to point out (although I think most will pick it up) that the 2nd transistor in the line amp (post#30) has its collector and emitter reversed.
Regards.
Thanks, it's my mistake when I copied it
Johan Potgieter,
Thanks, I usually make this kind of careless mistakes. The RIAA feedback network was used by the manufacturer from the old tube days to BJTs even after the company sold to the Japanese. They keep using it for many years.
For those who are interested in the circuit please foget the one of post#30. Here the correct one.
Johan Potgieter,
Thanks, I usually make this kind of careless mistakes. The RIAA feedback network was used by the manufacturer from the old tube days to BJTs even after the company sold to the Japanese. They keep using it for many years.
For those who are interested in the circuit please foget the one of post#30. Here the correct one.
Attachments
- Status
- Not open for further replies.