Member
Joined 2009
Paid Member
Hi,
Talking about sth doesn't necessarily mean advertisising .... or do You think You're advertising Naim?
It had been a commercial product ... and in this case I'm just presenting an example of a concept, that may come close to Your idea, or that may generate new ideas.
And yes, I like it very much .... great sounding, very neutral, quite flexible.
Joachim Gerhard liked it and used it at the Highend show in Munic 2015 to present a fully balanced signal path from pickup to speakers for his first time.
The Balancer and Output drivers are all-JFET feedbackless circuits.
I also did the complete casing design (Volume knob and display)
jauu
Calvin
Talking about sth doesn't necessarily mean advertisising .... or do You think You're advertising Naim?
It had been a commercial product ... and in this case I'm just presenting an example of a concept, that may come close to Your idea, or that may generate new ideas.
And yes, I like it very much .... great sounding, very neutral, quite flexible.
Joachim Gerhard liked it and used it at the Highend show in Munic 2015 to present a fully balanced signal path from pickup to speakers for his first time.
The Balancer and Output drivers are all-JFET feedbackless circuits.
I also did the complete casing design (Volume knob and display)
jauu
Calvin
Last edited:
Gain in the buffer if needed ? If a more fancy switching idea used if could be part of the same circuit. It could have a headphones setting if the buffer has plenty of current.
50 posts later and there's still no drawing of a concept but already thoughts about certain parts and circuits
Drawing of a concept? ... Common, this is a discussion and is about a hobby!
I feel at work now
What is the deadline?This thread shows a total disrespect for Niam in that we all seem to feel we can do better, that's good. Before long it could be a universal preamp. The references to NAD were excellent. Nowhere at DIY Audio do we get such open minds usually. On one thread I was silly enough to join one would think the guys had designed the op amps themselves. OK they all knew more than me about this and that op amp, none offered a circuit that we might build and adapt.
The better thing about Naim was Mother and Daughter PCB's. Although that is not the best idea if being picky it was useful. I find being able to reuse circuit chunks as Naim did a prime idea ( as op amps do ). I don't mind DIL sockets for op amps as they allow research and don't ruin the sound.
The better thing about Naim was Mother and Daughter PCB's. Although that is not the best idea if being picky it was useful. I find being able to reuse circuit chunks as Naim did a prime idea ( as op amps do ). I don't mind DIL sockets for op amps as they allow research and don't ruin the sound.
One thing to note. This thread stated in the TGM10 thread based on the old Naim NAP140. Many said the Naim idea was preamp and power amp should have in combination the bandwidth limiting to make the combination work correctly. Julian Vereker gave out warnings without any real facts as to it being a bad idea to supply just the power amp to customers as Quad did ( I think Quad were 70% power amps sales in some periods ). Thus it seemed prudent to try to complete the TGM10 project in the Naim style.
One thing to note is TGM10 has been months and years of doing mostly nothing. All the dicussion is about the way it works ( NAP 140 ). Gradually as time went by I learnt to respect that. However this thread is different and pleases me no end. All I would say is keep it simple. What the TGM10 thread proved is it allows all and everyone to join in and keeps it low cost. Naim was always proudly simple and made you pay more for that.
JG was/is famous at High End. Now one of us.
One thing to note is TGM10 has been months and years of doing mostly nothing. All the dicussion is about the way it works ( NAP 140 ). Gradually as time went by I learnt to respect that. However this thread is different and pleases me no end. All I would say is keep it simple. What the TGM10 thread proved is it allows all and everyone to join in and keeps it low cost. Naim was always proudly simple and made you pay more for that.
JG was/is famous at High End. Now one of us.
Member
Joined 2009
Paid Member
What about these LDRs ?
I've read a lot of comments about the use of Light Dependent Resistors (LDRs) that can be used as non-contract input selectors and non-contact attenuators.
It seems a key weakness is poor matching which requires some sorting of parts, but not much more hassle than finding a good dual-gang potentiometer with good matching either perhaps. It's a solvable issue.
The other potential weakness is distortion. There has been a lot of internet traffic on this topic too and I plan to study it further. The use of LDRs is a bit 'non traditional' but those people who have used it seem to like it an awful lot so it bears some scrutiny. However, I'm a bit leery given that it's one of those things that some folk will call out as 'less than hi-end' and others will promote as 'once you heard one you will want to keep it'.
I've read a lot of comments about the use of Light Dependent Resistors (LDRs) that can be used as non-contract input selectors and non-contact attenuators.
It seems a key weakness is poor matching which requires some sorting of parts, but not much more hassle than finding a good dual-gang potentiometer with good matching either perhaps. It's a solvable issue.
The other potential weakness is distortion. There has been a lot of internet traffic on this topic too and I plan to study it further. The use of LDRs is a bit 'non traditional' but those people who have used it seem to like it an awful lot so it bears some scrutiny. However, I'm a bit leery given that it's one of those things that some folk will call out as 'less than hi-end' and others will promote as 'once you heard one you will want to keep it'.
this was very unique, stands out in the crowd.
Last edited:
There are various workarounds to the matching issue now. I built an LDR potentiometer a few years ago and it was the single biggest improvement to my system, especially considering the cost. Try one, I am sure you will be impressed.
http://www.diyaudio.com/forums/anal...d-ldr-volume-source-selection-controller.html
Last edited:
Member
Joined 2009
Paid Member
Bigun, please use discrete. It is more challenging
Explore new idea.
awwwww, but I never got the chance to use Opamps before
For the phono, I am using discrete, based on the NAD3020. I really like this design.
For the regulators, I am seriously thinking to use discrete shunt regulator. I think of it like an 'electronic capacitor'. I would use the side panel of the chassis as a kind of heatsink for the transistors.
Nigel Pearson, I fully support you in this. By providing in the scheme the possibility of turning on / off the part of the NAC circuit, in which five transistors, with a gain of 10.
What exactly this effect of combining the two components of NAIM is related to - one can only assume: a single-cycle (unbalanced scheme) or temporary correction of the pulse fronts ("attacks"), which changes the overall "contrast" of the sound. Particularly affecting the high-frequency components of sound. At the same time, many people often notice the effect of additional focusing of sound sources in a common stereopanoram.
To this, I really do not see any special prerequisites, since there are almost no corrective capacitors in the circuit. But it seems that the entire NAIM system operates on the transmission accuracy in the "amplitude-time grid", and not in the "amplitude-frequency" one. After all, it is on the "attack" and "dynamics" of sounds that the first attention is paid!
All written above - a purely personal opinion, which may "not coincide with the opinion of the editors
".
Member
Joined 2009
Paid Member
Nigel Pearson, I fully support you in this...All written above - a purely personal opinion, which may "not coincide with the opinion of the editors
I have consulted with the Editor
I think it would be a lost opportunity not to include the Naim gain stage as one of the options in this modular design.
Are we talking about the "321" board (attached) ?
It's probably 'safe' to trim the gain, say to 5, without impacting the signature sound that is being sought. But the improved power supply I have in mind may make a difference compared with the original NAC 32 etc.
Attachments
Greetings! Yes, it is this part of the scheme. You can try to reduce its gain, for this it is necessary to change the depth of feedback. But, as it affects the sound - you need an auditory test. I think that you could evaluate the expediency and influence - by making at least a preliminary layout of the scheme. And make sure: there is an improvement for you or not.
Member
Joined 2009
Paid Member
Modular
It’s going to be modular in the sense that I have no plans to make an all-on-one pcb for this project. I use Eagle layout and would prefer to stick with what I’m familiar with. The freeware version I have limits the size of the pcb I can layout. Also, I find I can cope better with designing and debugging a smaller pcb. My last (first) attempt at a preamp didn’t work out. I crammed a lot of stuff on one board without prototyping it first and didn’t get the results I wanted.
My current thinking: allow for 3 different pcb designs x 2 channels = 6 boards. They will be mounted vertically, held in place by an angle bracket bolted to the side of the chassis. Any ‘hot’ transistors will be placed near that edge of the pcb so they can be mounted against this angle bracket for heat-sinking to the chassis.
I’d like to include a triode in there somewhere, just for the ‘fun of it’ to inject some optional ‘masking distortion’ for those bad recordings. I don’t know how the heck I justify that but I’ll think about it
I want a smoothly varying volume control so a stepped attenuator or relay system is out. It has to be a traditional ganged potentiometer, or LDR based. The input selector can be relay based.
It’s going to be modular in the sense that I have no plans to make an all-on-one pcb for this project. I use Eagle layout and would prefer to stick with what I’m familiar with. The freeware version I have limits the size of the pcb I can layout. Also, I find I can cope better with designing and debugging a smaller pcb. My last (first) attempt at a preamp didn’t work out. I crammed a lot of stuff on one board without prototyping it first and didn’t get the results I wanted.
My current thinking: allow for 3 different pcb designs x 2 channels = 6 boards. They will be mounted vertically, held in place by an angle bracket bolted to the side of the chassis. Any ‘hot’ transistors will be placed near that edge of the pcb so they can be mounted against this angle bracket for heat-sinking to the chassis.
I’d like to include a triode in there somewhere, just for the ‘fun of it’ to inject some optional ‘masking distortion’ for those bad recordings. I don’t know how the heck I justify that but I’ll think about it
I want a smoothly varying volume control so a stepped attenuator or relay system is out. It has to be a traditional ganged potentiometer, or LDR based. The input selector can be relay based.
The reason I said about MC33078/79 is I like deadbug circuits ( No PCB ). Even with my Parkinson's like problems I can still do it. DIL14 is the easier layout. How I choose the 33079 was it ticked all the boxes. The circuit looked very simple inside the chip ( trace the real signal path ). It's fast at 16 MHz. And about the same noise as a NE5532 ( I banked up 3 sections and got a beautiful sound in parallel ). Unlike a 5532 it is a bit more stable. If you add a resistor of CCs to the output it will be rather like the Naim sound. Class A SE has a bit more second harmonic. Buffers are a personal thing. I think I like them class AB PP into a higher loading and put up with a bit of hiss. The LM324N is dreadful into less than 10K ( ? ). It is true class A PP if lightly loaded. This seems true of others that hide the class B side better. If you lookat the 33079 distortion graghs they are very OK. I have used gain 120 and had a lovely sound ( Ortofon MC SPU ) . Overal gain circa 20 000 @ 20 Hz or 2000 at 1 kHz.
The true story is I was so fed up with my bits of junk I was using I bashed together a preamp out of TL074's that I had in the shed. I listened to it and thought it sounded dreadful. Then a friend came to stay and brought along her Garrard 401, Schroeder arm and Lyra PU with Black Cube phono. She insisted we listen to the TL074 preamp ( it seemed to have improved for being run ). I have to say it was one of the best sounds I ever heard. Before her going home I built her one using 33079's including a phono amp which she very kindly said beat the Cube. As she returned to the Black Forest I got phone calls from vaious Audiophiles in Belgium and Germany. Funny thing is the 33079 never really was beaten if op amps. All the others seem to have that electric blue sound. LT1115 was one.
The true story is I was so fed up with my bits of junk I was using I bashed together a preamp out of TL074's that I had in the shed. I listened to it and thought it sounded dreadful. Then a friend came to stay and brought along her Garrard 401, Schroeder arm and Lyra PU with Black Cube phono. She insisted we listen to the TL074 preamp ( it seemed to have improved for being run ). I have to say it was one of the best sounds I ever heard. Before her going home I built her one using 33079's including a phono amp which she very kindly said beat the Cube. As she returned to the Black Forest I got phone calls from vaious Audiophiles in Belgium and Germany. Funny thing is the 33079 never really was beaten if op amps. All the others seem to have that electric blue sound. LT1115 was one.
An advantage of a single PCB, all-in-one design is: you can hide the rat's nest of wires that interconnect the back panel, the power supply sub section, the amplifier sub sections, and the front panel.
A "modular" design needs flywires. Lots of flywires. Especially if there are numerous circuit options selected by front panel switches or remote control operated relays.
So I recommend thinking early and thinking hard, about where the boards are going to mount within the chassis, what position on the boards the flywires are going to connect, and how the flywires are going to be routed inside the chassis to avoid crosstalk.
For example: consider the regulated DC power supply wiring including the "star on star" grounding (if used) and the ground lugs of the input jacks and output jacks. How are you going to route those (twisted pair?) cables? When you're all done, does the result achieve Ground Is Ground Is Ground Everywhere?
A "modular" design needs flywires. Lots of flywires. Especially if there are numerous circuit options selected by front panel switches or remote control operated relays.
So I recommend thinking early and thinking hard, about where the boards are going to mount within the chassis, what position on the boards the flywires are going to connect, and how the flywires are going to be routed inside the chassis to avoid crosstalk.
For example: consider the regulated DC power supply wiring including the "star on star" grounding (if used) and the ground lugs of the input jacks and output jacks. How are you going to route those (twisted pair?) cables? When you're all done, does the result achieve Ground Is Ground Is Ground Everywhere?
Member
Joined 2009
Paid Member
About MM and MC option ?
I gave up my Vinyl from when I was a kid many years ago; got seduced by the silver disc (most of which have since been thrown out due to horrendous recording quality). Then a couple of years ago I got some interest in it again - to bring back the fun factor, like using real charcoal for BBQs. My TT is nothing fancy, an old PL-2 that I found on eBay with an Ortofon of some kind. I don't know squat about hi-end vinyl, I don't even know how to ensure my TT is properly set up so I'm thankful that it works as-is. I only have 3 records, all a gift from a friend and they are heavier and thicker than I remember. Once I have a system assembled I plan to enjoy choosing and acquiring some more vinyl.
The same friend gave me a Grado cartridge, not a fancy one though and it is sitting in a box somewhere. For all I know, an MM phono amp is all I'll ever need. I don't even know why MC is supposedly better. I read somewhere that there's no real difference between MM and MC in terms of the cartridge accuracy but in times past there were sound differences because of how they were terminated/loaded at the amplifier side. Get the loading / termination correct and MM is as hi-end as MC. Some people found the best loading for MM was an inductor, even another cartridge! Anyhow, I could, I suppose, add a pre-preamp circuit for MC which would feed into the NAD3020 based MM RIAA circuit. Some call it a headamp. But it's more work and more parts and I am not convinced that I consider including the capability for MC input ?
Buffer: Nigel - how would you compare the Naim buffer (Sziklai class A loaded on a CCS) with the MC33079 ?
Gain: Nigel - do you favour the MC33079 over the Naim, or the Haffler (posted early by Nico - looks very nice) ?
Mark - good questions - I will get back to you on this with some ideas.
I gave up my Vinyl from when I was a kid many years ago; got seduced by the silver disc (most of which have since been thrown out due to horrendous recording quality). Then a couple of years ago I got some interest in it again - to bring back the fun factor, like using real charcoal for BBQs. My TT is nothing fancy, an old PL-2 that I found on eBay with an Ortofon of some kind. I don't know squat about hi-end vinyl, I don't even know how to ensure my TT is properly set up so I'm thankful that it works as-is. I only have 3 records, all a gift from a friend and they are heavier and thicker than I remember. Once I have a system assembled I plan to enjoy choosing and acquiring some more vinyl.
The same friend gave me a Grado cartridge, not a fancy one though and it is sitting in a box somewhere. For all I know, an MM phono amp is all I'll ever need. I don't even know why MC is supposedly better. I read somewhere that there's no real difference between MM and MC in terms of the cartridge accuracy but in times past there were sound differences because of how they were terminated/loaded at the amplifier side. Get the loading / termination correct and MM is as hi-end as MC. Some people found the best loading for MM was an inductor, even another cartridge! Anyhow, I could, I suppose, add a pre-preamp circuit for MC which would feed into the NAD3020 based MM RIAA circuit. Some call it a headamp. But it's more work and more parts and I am not convinced that I consider including the capability for MC input ?
Buffer: Nigel - how would you compare the Naim buffer (Sziklai class A loaded on a CCS) with the MC33079 ?
Gain: Nigel - do you favour the MC33079 over the Naim, or the Haffler (posted early by Nico - looks very nice) ?
Mark - good questions - I will get back to you on this with some ideas.
Last edited:
Member
Joined 2009
Paid Member
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.