In this NS10 schematic, there is hidden another elegance, NP's style. Look at the arrangement of Q2, Q3, R8. If you look at it, there's nothing special, just ordinary connection. But it really clever. This arrangement makes the Q2 works towards a CCS with value of 0V6/R8. Q2 doesn't experience current fluctuation, it works in steady current, even the output current is fluctuating with signal (because the load is Resistor, R9).
Look at the attached schematic.
The designer wanted to have steady current for Q53's load. He put Q8, D15, D16, R104, R110, Q42 (that's 6 components) for achieving that effect. NS10 only puts Q2,Q3,R8 (3 components) to have the same effect.
The final load is the same, plain R, R9 for NS10 and R112 for the attachment.
Beautifull, right.......
Look at the attached schematic.
The designer wanted to have steady current for Q53's load. He put Q8, D15, D16, R104, R110, Q42 (that's 6 components) for achieving that effect. NS10 only puts Q2,Q3,R8 (3 components) to have the same effect.
The final load is the same, plain R, R9 for NS10 and R112 for the attachment.
Beautifull, right.......
Attachments
Have a look at this review:
http://forum.audiogon.com/cgi-bin/frr.pl?rprea&1129311740&read&d14&zzlFerrari&&
Amazingly low distortion and speed for such a simple design but should we expect anything less from NP?
Can you measure the specs of your re-engineered unit to see if they are similar?
Tom
EE
http://forum.audiogon.com/cgi-bin/frr.pl?rprea&1129311740&read&d14&zzlFerrari&&
Amazingly low distortion and speed for such a simple design but should we expect anything less from NP?
Can you measure the specs of your re-engineered unit to see if they are similar?
Tom
EE
That review is from yours truly. Have always thought that this NS 10 from Threshold, was often under appreciated and over looked as a genuine break through in solid state preamps.
By the look of this thread it appears that there is a renewed interest in the NS 10.
With the work that Jon Soderberg has done on the NS 10, it will serve my needs for the foreseeable future. The overall sonic signature of the NS 10 is incredible. And to think that this was NP first preamp is nothing short of a tour de force.
If you can find one of these, the search is worth the effort. In 47 years have had a lot of amps and preamps including other Threshold pre amps. But I gotta tell'ya the NS 10 is something special, although it came out in 1976 or 1977 or so.
By the look of this thread it appears that there is a renewed interest in the NS 10.
With the work that Jon Soderberg has done on the NS 10, it will serve my needs for the foreseeable future. The overall sonic signature of the NS 10 is incredible. And to think that this was NP first preamp is nothing short of a tour de force.
If you can find one of these, the search is worth the effort. In 47 years have had a lot of amps and preamps including other Threshold pre amps. But I gotta tell'ya the NS 10 is something special, although it came out in 1976 or 1977 or so.
Attachments
Hi, Tmblack,
I don't know how to measure those specs like in the review. Can you show me how to measure those numbers?
From the review, yeoldstereo = ferrari?
This NS10 is special. If you look for a transistor based preamp that sounds like tube, this is the one, because it is a singleton system, not a differential system. That's why the sound is more "complete" like the review said.
If you have heard this preamp, and go back to ANY (yes, I mean ANY) preamp that based on differential system, you will feel that something is "missing" in the differential based system (compared to this singleton based system). But remember, the choice for Q1 is important, it dictates what pattern of the harmonics, by the input/output transfer function of this Q1. I like Jfet better in the place of Q1.
Another important aspect : FAST. It has feedback to emitors, current feedback, it's much faster than feedback to opposite base (inverting input in differential system). This feedback ensures linearity (if you compare it to non-feedback system)
It consist only a single stage, make it faster and have minimal phase shift. No wonder the review said the response is up to Mhz number. If the frequency response is up to Mhz numbers, the phase shift within the first 20khz bandwith should be very small.
Try this test. Play this preamp to the fastest musical programme you have. Maybe a heavy classical full orchestra, maybe a heavy jazz with that big bass guitar with the fastest finger playing it, maybe the fastest piano+cymbal combo you have, or anything you can find. This preamp will pass all that musical test with excellent grade. You can hear each musical instrument clearly without mud, no matter how fast the whole music is.
I don't know how to measure those specs like in the review. Can you show me how to measure those numbers?
From the review, yeoldstereo = ferrari?
This NS10 is special. If you look for a transistor based preamp that sounds like tube, this is the one, because it is a singleton system, not a differential system. That's why the sound is more "complete" like the review said.
If you have heard this preamp, and go back to ANY (yes, I mean ANY) preamp that based on differential system, you will feel that something is "missing" in the differential based system (compared to this singleton based system). But remember, the choice for Q1 is important, it dictates what pattern of the harmonics, by the input/output transfer function of this Q1. I like Jfet better in the place of Q1.
Another important aspect : FAST. It has feedback to emitors, current feedback, it's much faster than feedback to opposite base (inverting input in differential system). This feedback ensures linearity (if you compare it to non-feedback system)
It consist only a single stage, make it faster and have minimal phase shift. No wonder the review said the response is up to Mhz number. If the frequency response is up to Mhz numbers, the phase shift within the first 20khz bandwith should be very small.
Try this test. Play this preamp to the fastest musical programme you have. Maybe a heavy classical full orchestra, maybe a heavy jazz with that big bass guitar with the fastest finger playing it, maybe the fastest piano+cymbal combo you have, or anything you can find. This preamp will pass all that musical test with excellent grade. You can hear each musical instrument clearly without mud, no matter how fast the whole music is.
You need a radio frequency generator and at least 50Mhz oscilloscope
I would think to measure propagation delay and freq. response of real unit but my simulation says it only goes to a Mhz or 2.
But I can't buy the 2SK30. How about 2N5458 or 2N3819?
I can't get the output transformer for Choky's preamp, so maybe an actual tube like 6922 would make a real sweet replacement for Q1?
Regards,
Tom
EE
To truly appreciate the NS 10 listen to the early Telarc digital to LP recordings, although most of these are in CD format now, the LPs were truly over the edge recordings. Most of these were done in late 70s and at that time provided a glimpse into the then coming digital medium.
Theshold supplied many preamps and power amps to Telarc for these recordings, as they were the only products at that time that were capable to handle these extreme recordings.
The Telarc LPs were cut at 1/2 speed in pure digital and transferred to analog LP. Absolutely no compression,limiting or editing was used in this process. The muscians had to be right on from the start and play without fault. Several of the early Telarc LPs won grammys for their technical achievement. I was with CBS at the time and this type of recording caught us of guard and soon after we started developing the digital to LP process.
When the early Threshold gear made its debut, many of the High End salons of the time used these Telarc recordings to demo the Threshold product.
One such was the Frederick Fennel Telarc 5038. This is a glorious piece of work not only to listen to, but as an use to evaluate a system. It is difficult to play properly and will tax all components to their maximum response. Picture of this LP appears with this post. This album has powerful low and high frequency transients and I urge due caution in playing this for the first time. Over the years I have seen this album destroy a lot of gear due to lack of caution. If you find this LP, be most careful and use very moderate volume settings, till you are comfortable that your gear is capable of the demands placed upon it by this recording. At times this recording is frightening, the hair will stand up on your neck and you will swear the anvil strikes and snare drum passages are about to literally come through the speakers!
However a properly operating Threshold NS 10 will handle this piece like a knife through hot butter, with that being said this recording has a way of exposing other weakness's in the audio system.
Yep yeoldestereo is Ferrari on Audiogon. Been in this hobby since 1957 when it was kits,tubes and mono. I haven't done any building or modding for quite some time. In fact last kit I did was a Hafler DH200 for a friend of mine and that was 1984 I think.
Without question the membership here is far more gifted than I when it comes to actual execution of these designs. With that being said my hat is off to the respondents of this thread. In a short time now I have learned a lot on the technical side.
My best to all of you.
Theshold supplied many preamps and power amps to Telarc for these recordings, as they were the only products at that time that were capable to handle these extreme recordings.
The Telarc LPs were cut at 1/2 speed in pure digital and transferred to analog LP. Absolutely no compression,limiting or editing was used in this process. The muscians had to be right on from the start and play without fault. Several of the early Telarc LPs won grammys for their technical achievement. I was with CBS at the time and this type of recording caught us of guard and soon after we started developing the digital to LP process.
When the early Threshold gear made its debut, many of the High End salons of the time used these Telarc recordings to demo the Threshold product.
One such was the Frederick Fennel Telarc 5038. This is a glorious piece of work not only to listen to, but as an use to evaluate a system. It is difficult to play properly and will tax all components to their maximum response. Picture of this LP appears with this post. This album has powerful low and high frequency transients and I urge due caution in playing this for the first time. Over the years I have seen this album destroy a lot of gear due to lack of caution. If you find this LP, be most careful and use very moderate volume settings, till you are comfortable that your gear is capable of the demands placed upon it by this recording. At times this recording is frightening, the hair will stand up on your neck and you will swear the anvil strikes and snare drum passages are about to literally come through the speakers!
However a properly operating Threshold NS 10 will handle this piece like a knife through hot butter, with that being said this recording has a way of exposing other weakness's in the audio system.
Yep yeoldestereo is Ferrari on Audiogon. Been in this hobby since 1957 when it was kits,tubes and mono. I haven't done any building or modding for quite some time. In fact last kit I did was a Hafler DH200 for a friend of mine and that was 1984 I think.
Without question the membership here is far more gifted than I when it comes to actual execution of these designs. With that being said my hat is off to the respondents of this thread. In a short time now I have learned a lot on the technical side.
My best to all of you.
Attachments
this Leach design preamp from many years ago had a non-differential line stage:
http://users.ece.gatech.edu/~mleach/papers/wbpreamp/feb77article.pdf
i wonder how it sounds in comparison; i used a duplicate differential stage as my line dirver when i built this years ago.
mlloyd1
http://users.ece.gatech.edu/~mleach/papers/wbpreamp/feb77article.pdf
i wonder how it sounds in comparison; i used a duplicate differential stage as my line dirver when i built this years ago.
mlloyd1
lumanauw said:
tmblack said:
?
nope with just 2x25V
in fact-I think that will be just hopeless mix from two good approachs;
key factor in WOT preamp is :
1. OPT approach- meaning that signal energy preservation is No.1 (or primary thing-if you wish )
2. decent active element (even EC8020 if you can find ,or triode wired 7788) with absolute minimum of surounding elements , and
3.gorgeous supply,both for anode and for heating
seems to me that NS10 is simillar type of jewell, and it's sacrilege to spoil it with sort of bstrdizing,if you know what I mean
and now-only if Emperor of latheral thinking think to say something about Lumanauw's component values..............
contrary to my usuall approach to every seen schmtc- I don't feel any urge to change anything in Emperor's values or ideas ,even on microplan..........except his sneakers,maybe. ......
Many thanks to Nelson Pass for posting the published specs on the NS 10.
My first NS 10 was a production model along with the 400A amp.If memory serves me correct the production NS 10 had a somewhat different circuit board, or at least it was different in color. This NS 10 prototype has the blue and gold circuit board and the previous one had,if I remember right had a yellow and gold circuit board. Not sure what the difference may have been.
Anyway had these until about 1981 when the house was broken into, so replaced these with another 400A, but by then the NS 10 and SL 10 was out of production. So went with the FET 2 for the preamp. The 400 A was very probably one of the last produced,but dealers was able to get one new.
This occupied my system for about 16 years or so, until another break in. Then tried several other amp, preamp combinations.Until I found a CM Labs 914 power amp and coupled that to a Forte Model 2 preamp, was the system until the world wide web tied us together.
Most of you will not remember CM Labs. It was a very small high end manufacturer in Danbury,CT. So no need to elaborate on CM Labs, but nonetheless made some terriffic power amps. Their pre amps on the other hand left a lot to be desired.
So recently I have been able to get back to what has made me really happy and that is the NS 10 and 400A. So the 400A I have now is another late production unit and to my surprise was able to find a NS 10 prototype. So I am set for a very long time. Being 62 now this should be last stop.
I will have to say that while the FET 2 preamp was very good, to my ears it fell short of the NS 10.
Many thanks to Nelson Pass for the extraordinay build quality on these Threshold products. These are true lifetime products, that only require minimal service some 20 years down the road. Damn few products built during that same period of time, have the outright longevity of the early Threshold gear. And it appears from these posts that these designs remain cutting edge to this day.
Like I said back to the future and once again I have that super silly grin on my face listening to this system.
My first NS 10 was a production model along with the 400A amp.If memory serves me correct the production NS 10 had a somewhat different circuit board, or at least it was different in color. This NS 10 prototype has the blue and gold circuit board and the previous one had,if I remember right had a yellow and gold circuit board. Not sure what the difference may have been.
Anyway had these until about 1981 when the house was broken into, so replaced these with another 400A, but by then the NS 10 and SL 10 was out of production. So went with the FET 2 for the preamp. The 400 A was very probably one of the last produced,but dealers was able to get one new.
This occupied my system for about 16 years or so, until another break in. Then tried several other amp, preamp combinations.Until I found a CM Labs 914 power amp and coupled that to a Forte Model 2 preamp, was the system until the world wide web tied us together.
Most of you will not remember CM Labs. It was a very small high end manufacturer in Danbury,CT. So no need to elaborate on CM Labs, but nonetheless made some terriffic power amps. Their pre amps on the other hand left a lot to be desired.
So recently I have been able to get back to what has made me really happy and that is the NS 10 and 400A. So the 400A I have now is another late production unit and to my surprise was able to find a NS 10 prototype. So I am set for a very long time. Being 62 now this should be last stop.
I will have to say that while the FET 2 preamp was very good, to my ears it fell short of the NS 10.
Many thanks to Nelson Pass for the extraordinay build quality on these Threshold products. These are true lifetime products, that only require minimal service some 20 years down the road. Damn few products built during that same period of time, have the outright longevity of the early Threshold gear. And it appears from these posts that these designs remain cutting edge to this day.
Like I said back to the future and once again I have that super silly grin on my face listening to this system.
Attachments
I don't know if NP was ripped off or not but these Naim preamp circuits look a lot like the NS10.
I was thinking of replacing R9 with a CCS and look at what someone already did:
http://www.acoustica.org.uk/t/naim/preamps.html
Comments?
Tom
EE
I was thinking of replacing R9 with a CCS and look at what someone already did:
http://www.acoustica.org.uk/t/naim/preamps.html
Comments?
Tom
EE
Apparently on this side of the pond, the Mundorf Caps are the latest buzz in caps.
With the apparent cancelled production of Black Gate Caps, are the Mundorf the next generation of caps to replace the Black Gates?
Anyone have any info or ideas on this?
Or better yet anyone here used the Mundorf Caps?
With the apparent cancelled production of Black Gate Caps, are the Mundorf the next generation of caps to replace the Black Gates?
Anyone have any info or ideas on this?
Or better yet anyone here used the Mundorf Caps?
The NS 10 sounds fabulous with a CD Player. This was somewhat of a surprise to me. I knew from the start that the NS 10 was going to be great with analog sources, that was a given.
But to find out that it excels as well with digital sources was a suprise. But I guess I shouldn't have been, knowing the pedigree.
I am not a big fan of digital so I don't spend a lot in this area.The current CD Player is a Onix XCD88, which is same as the Music Hall 25 CD Player and use a Sony MD 501 Player/Recorder.
The NS 10 can handle the digital components with extraordinary ease that most preamps past or present have difficulty in presenting a liquid signature from the digital medium.For some reason it takes the edge off the digital signature. I can't remember how many times I thought I had an LP on only to realize it was a CD.
Using a Threshold 400A with the Threshold NS 10, overall I could not be more pleased with this combination.
Without question in my mind, the Threshold NS 10 is one of those ageless gems from the mind of NP. That pretty much says it all.
But to find out that it excels as well with digital sources was a suprise. But I guess I shouldn't have been, knowing the pedigree.
I am not a big fan of digital so I don't spend a lot in this area.The current CD Player is a Onix XCD88, which is same as the Music Hall 25 CD Player and use a Sony MD 501 Player/Recorder.
The NS 10 can handle the digital components with extraordinary ease that most preamps past or present have difficulty in presenting a liquid signature from the digital medium.For some reason it takes the edge off the digital signature. I can't remember how many times I thought I had an LP on only to realize it was a CD.
Using a Threshold 400A with the Threshold NS 10, overall I could not be more pleased with this combination.
Without question in my mind, the Threshold NS 10 is one of those ageless gems from the mind of NP. That pretty much says it all.