My 2 cents...
The world's best preamp?
- the one you just built.
The world's best circuit?
- the one you just built and modified.
The world's best tube?
- the one that no one you know has one of!
My actual opinion is that it is a good idea to separate the phono stage from the line stage. Both for flexibility and design considerations.
In my own system there is no gain stage in the "preamp". Just a switching center and passive stepped attenuator.
- My feeling is that best preamp is none. -
My DAC has a low Z discrete output buffer and most of all the commercial gear has sufficiently low ouput Z to drive most any attenuator of >10Kohms just fine. I use 25kohms myself.
Properly assembled, most systems use the "preamp" for only gain attenuation, and almost never for "gain." Assuming that "line level" at "0" drives the amp to full output, and that is bloody loud, unless you've got very pianissimo source material, or incredibly low sensitivity speakers, you never really need any gain.
After that it's straight circuit design, optimization and parts selection, then implementation and layout for the best results. Don't skimp on the PS - massively overkilled, and super quiet PS usually makes enough of a difference to be heard and make the diff between version A and Z of the same circuit...
_-_-bear
The world's best preamp?
- the one you just built.
The world's best circuit?
- the one you just built and modified.
The world's best tube?
- the one that no one you know has one of!
My actual opinion is that it is a good idea to separate the phono stage from the line stage. Both for flexibility and design considerations.
In my own system there is no gain stage in the "preamp". Just a switching center and passive stepped attenuator.
- My feeling is that best preamp is none. -
My DAC has a low Z discrete output buffer and most of all the commercial gear has sufficiently low ouput Z to drive most any attenuator of >10Kohms just fine. I use 25kohms myself.
Properly assembled, most systems use the "preamp" for only gain attenuation, and almost never for "gain." Assuming that "line level" at "0" drives the amp to full output, and that is bloody loud, unless you've got very pianissimo source material, or incredibly low sensitivity speakers, you never really need any gain.
After that it's straight circuit design, optimization and parts selection, then implementation and layout for the best results. Don't skimp on the PS - massively overkilled, and super quiet PS usually makes enough of a difference to be heard and make the diff between version A and Z of the same circuit...
_-_-bear
Bear,
It all depends on what color you like. Even passive stuff has coloration to it..... Really..... this hobby is all about color!
"Hey Mark,
Whats all this Rosenbilt Grounded Grid stuff?
Do you have the schemaitc?"
You need to get the book by Bruce Rosenbilt called "Audio Reality". all of his designs are in there. I would post it except its his design, not mine. There were other gg preamps in past years as well but this one is incredible. Originally Grounded Grid amps were used in the drivers and finals of high power AM. FM., and TV transmitters.
You might also want to refer to this thread.....
http://www.diyaudio.com/forums/showthread.php?threadid=14029&highlight=
Mark
It all depends on what color you like. Even passive stuff has coloration to it..... Really..... this hobby is all about color!
"Hey Mark,
Whats all this Rosenbilt Grounded Grid stuff?
Do you have the schemaitc?"
You need to get the book by Bruce Rosenbilt called "Audio Reality". all of his designs are in there. I would post it except its his design, not mine. There were other gg preamps in past years as well but this one is incredible. Originally Grounded Grid amps were used in the drivers and finals of high power AM. FM., and TV transmitters.
You might also want to refer to this thread.....
http://www.diyaudio.com/forums/showthread.php?threadid=14029&highlight=
Mark
May I Suggest 'Nina'?
I continue to be very satisfied with my DIY 'Nina'; my unit has easily seen off
all comers.
Someone else has now built one and is also very pleased, and guess what, his
unit has also seen off all comers - and several who have heard it also want to
build one.
It's simple, in that it's a single stage; but this active loaded Kimmel mu stage does
the lot (good linearity, wide bandwidth and low output impedance).
The PSU has nothing that's not needed (it is not regulated, as a Kimmel mu stage
does not need this); but it has everything that is necesary, ie 3 good chokes and
high quality caps.
There are also some neat features that contribute to sound quality; remote
mounting of selector and volume controls to keep wiring very short; use of dual
mono volume pots; volume controls are series resistor/shunt pot type; and
rectifiers are 6CJ3 damper diodes.
Full layouts and build instructions are available from me.
For details and the cct, search for Nina, and there is a photo in the gallery.
And I'm pleased to say she really is a sweetie ...
I continue to be very satisfied with my DIY 'Nina'; my unit has easily seen off
all comers.
Someone else has now built one and is also very pleased, and guess what, his
unit has also seen off all comers - and several who have heard it also want to
build one.
It's simple, in that it's a single stage; but this active loaded Kimmel mu stage does
the lot (good linearity, wide bandwidth and low output impedance).
The PSU has nothing that's not needed (it is not regulated, as a Kimmel mu stage
does not need this); but it has everything that is necesary, ie 3 good chokes and
high quality caps.
There are also some neat features that contribute to sound quality; remote
mounting of selector and volume controls to keep wiring very short; use of dual
mono volume pots; volume controls are series resistor/shunt pot type; and
rectifiers are 6CJ3 damper diodes.
Full layouts and build instructions are available from me.
For details and the cct, search for Nina, and there is a photo in the gallery.
And I'm pleased to say she really is a sweetie ...
Yes, I took a look at the Kimmel stuff and it apprers that there are similarities but Rosenbilt incorporated one extra stage, the input stage to the Kimmel section and made the Kimmel a grounded grid. I would think that the Kimmel stuff would sound much better with a tightly regulated supply.... I've found that almost always a tightly regulated and isolated supply sounds better. The supplys would also be cleaner than they are with the CLC supply. It would be a cinch to convert the Kimmel to the GG or a GG to the Kimmel in about 15 min!
Damper diodes really are nothing more than high speed rectifiers and really old hat by todays standards. They were designed to function off of the 15,750 khz flyback transformer pulses in TV sets. The IR high speeds are really more practical to use and would also probably have less drop and they can run at even higher speeds than damper diodes can. But its certainly possible that the dampers in there give some sort of pleasing effect to the sound though, perhaps a bit "o" snake oil. I found 12AU7's to be very microphonic in the GG but switching to 6189W's got rid of that completely. The 6189W's also sound far better than the set of Telefunkens that I have here. One set that beats the 6189W's that I have are the Tung Sol 12AU7's, but again they are somewhat microphonic so I'll stick with the 6189W's.
By the way... don't forget to insall a "Grid Leak Drip Valve" on your preamp!! Any valve based unit with a grid leak resistor should have one on its side panel to avoid major flooding....
Mark
Damper diodes really are nothing more than high speed rectifiers and really old hat by todays standards. They were designed to function off of the 15,750 khz flyback transformer pulses in TV sets. The IR high speeds are really more practical to use and would also probably have less drop and they can run at even higher speeds than damper diodes can. But its certainly possible that the dampers in there give some sort of pleasing effect to the sound though, perhaps a bit "o" snake oil. I found 12AU7's to be very microphonic in the GG but switching to 6189W's got rid of that completely. The 6189W's also sound far better than the set of Telefunkens that I have here. One set that beats the 6189W's that I have are the Tung Sol 12AU7's, but again they are somewhat microphonic so I'll stick with the 6189W's.
By the way... don't forget to insall a "Grid Leak Drip Valve" on your preamp!! Any valve based unit with a grid leak resistor should have one on its side panel to avoid major flooding....
Mark
Hi,
Mark,
While I'm mostly on the same page as you are, there's really not a thing on earth that beats a damper tube when it come to outputting a clean sine wave, bar perhaps a merc. vap.
Voodoo? Allow me to doubt it.
How fast does a PS rectifier have to be?
Let's not forget that 50Hz/60Hz is how fast it needs to be, anything faster is of no use here.
Voltage drop may be an issue to some, it never was to me and frankly, I fail to see why it should be in a "medium range" HV application.
Of all the 12AU7A mutants I've ever heard the 5814A were best to my ears....
Avoid silvered plate European made 6189s like the plague unless you've a masochistic streak. They suck, they really do.
My only experience with 6189W was with the Philips/ECG which were O.K. as far as any 12AU7 goes.
Cheers,
Mark,
While I'm mostly on the same page as you are, there's really not a thing on earth that beats a damper tube when it come to outputting a clean sine wave, bar perhaps a merc. vap.
Voodoo? Allow me to doubt it.
How fast does a PS rectifier have to be?
Let's not forget that 50Hz/60Hz is how fast it needs to be, anything faster is of no use here.
Voltage drop may be an issue to some, it never was to me and frankly, I fail to see why it should be in a "medium range" HV application.
Of all the 12AU7A mutants I've ever heard the 5814A were best to my ears....
Avoid silvered plate European made 6189s like the plague unless you've a masochistic streak. They suck, they really do.
My only experience with 6189W was with the Philips/ECG which were O.K. as far as any 12AU7 goes.
Cheers,
nanana said:
If you are really interested in maintaining absolute phase (for those tracks where the mix actually paid attention to abs phase) then you need to have a switch somewhere that lets you flip the phase of the system because there is no standard at the source for abs phase. You will find abs phase flipped from album to album -- even track-to-track. (The RTP Brett mentioned has abs phase selection in the source selector switch)
Being anal about keeping your system in a non-inverted phase state when the next album you put on is in the inverted state just makes no sense to me.
dave
Konnichiwa,
Among those commercial and DIY designs I have heard (which includes an awful lot, but obviously not everything) and to my personal sonic preferences the best preamp so far is a passive, transformer attenuator based design. Running second, but quite close is the "linestage" of the Arthur Loesch Preamp, which sounds bsolutely excellent as linestage, despite measuring a little funky and using the "not for audio" 6922.
Schematics closely based on Arthurs design are notabene on my website under the various "Toccata" designs.
Give it a try, but make sure to NOT skimp on parts quality and to keep the attenuator AFTER the linestage. If needed add a input voltage divider or even a "co**** volume" attenuator before the linestage, similar to what Eduardo de Lima does with his Audiopax preamp....
Sayonara
lawbadman said:
Among those commercial and DIY designs I have heard (which includes an awful lot, but obviously not everything) and to my personal sonic preferences the best preamp so far is a passive, transformer attenuator based design. Running second, but quite close is the "linestage" of the Arthur Loesch Preamp, which sounds bsolutely excellent as linestage, despite measuring a little funky and using the "not for audio" 6922.
Schematics closely based on Arthurs design are notabene on my website under the various "Toccata" designs.
Give it a try, but make sure to NOT skimp on parts quality and to keep the attenuator AFTER the linestage. If needed add a input voltage divider or even a "co**** volume" attenuator before the linestage, similar to what Eduardo de Lima does with his Audiopax preamp....
Sayonara
Re: Re: Worlds Best Preamp
Konnichiwa,
Ahhm, noted the website now points to commercial stuff, DIY Designs here:
http://thunderstoneaudio.nav.to
Goodness gracious me, now this is political correctness gone wild. You cannot even write:
"A co**** attenuator"
You have to write:
"A c o a r s e Attenuator"
Sayonara
Konnichiwa,
Kuei Yang Wang said:
Ahhm, noted the website now points to commercial stuff, DIY Designs here:
http://thunderstoneaudio.nav.to
Kuei Yang Wang said:
Goodness gracious me, now this is political correctness gone wild. You cannot even write:
"A co**** attenuator"
You have to write:
"A c o a r s e Attenuator"
Sayonara
Hi,
Yep...Same stuff as the Philips/ECG. Biggish gray ribbed plates, right?
For the anecdote, a few years ago, after I had just about joined the forum, Brett brought up these damper diodes and I had the same reaction as you....Dampers? They must be pulling my leg....
Having since tried them out myself, I now kind of carry a torch for them....
Cheers,
Yep...Same stuff as the Philips/ECG. Biggish gray ribbed plates, right?
For the anecdote, a few years ago, after I had just about joined the forum, Brett brought up these damper diodes and I had the same reaction as you....Dampers? They must be pulling my leg....
Having since tried them out myself, I now kind of carry a torch for them....
Cheers,
Hi,
Unfortunately this situation is now very common among manufacturers as well.
I wish they would have at least the common courtesy to indicate to the user whether or not the product is inverting absolute phase.
Back in the old days we were told time and again:
"THOU SHALL NOT INVERT ABSOLUTE PHASE"
To me this is an important a piece of information unlike the raft of other specs coming with the hype, so manufacturers, please take note.
Cheers,
Unfortunately this situation is now very common among manufacturers as well.
I wish they would have at least the common courtesy to indicate to the user whether or not the product is inverting absolute phase.
Back in the old days we were told time and again:
"THOU SHALL NOT INVERT ABSOLUTE PHASE"
To me this is an important a piece of information unlike the raft of other specs coming with the hype, so manufacturers, please take note.
Cheers,
Hi,
To the best of my knowledge only the anglosaxon world is using the term "polarity" that way and then some.
To me and an awful lot of people, I'm sure, "polarity" is for things marked with a + and - sign, like batteries for instance.
Old habits die hard, SY....
Knowing which does what with regard to absolute polarity_ see, I'm learning_ within the system is a step forward IMO.
Having it advertised on the gear somehow by the manufacturer would be better still, no?
Cheers,
To the best of my knowledge only the anglosaxon world is using the term "polarity" that way and then some.
To me and an awful lot of people, I'm sure, "polarity" is for things marked with a + and - sign, like batteries for instance.
Old habits die hard, SY....
Knowing which does what with regard to absolute polarity_ see, I'm learning_ within the system is a step forward IMO.
Having it advertised on the gear somehow by the manufacturer would be better still, no?
Cheers,
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