The final location 300, route d'Ampère - D73 69250 Poleymieux-au-Mont-d'Or - Google Maps (on the way home)
Prety nice sound out of it so far, no hum, but this is not suprise as it is balanced, I think it need a bit more time to setle in I have used polistirene caps for the RIAA and they take a while, I will tri and change those with same different ones eventualy.
Power supply which cover the 80 %of board space is working realy well and noise level is very low (nedle up) quite plesant noise vise when runningon the blank tracks and no sign of overloading on scratched records.
I had to place a second 20Rin parralel (10R) now to get the gain up with my Elitte and not using any loading at present, Just have to wait for Her shopping Neighbours out to give it a serious going over, still preaty easy build with no fussing about, the only component I had to select where the RIAA caps to get the 2 channels matching.
First listening Impressions
This is purely based on my set up, ancillary equipment my personal taste and same prety worn test gear.
I like it....
More to folow.
Power supply which cover the 80 %of board space is working realy well and noise level is very low (nedle up) quite plesant noise vise when runningon the blank tracks and no sign of overloading on scratched records.
I had to place a second 20Rin parralel (10R) now to get the gain up with my Elitte and not using any loading at present, Just have to wait for Her shopping Neighbours out to give it a serious going over, still preaty easy build with no fussing about, the only component I had to select where the RIAA caps to get the 2 channels matching.
First listening Impressions
This is purely based on my set up, ancillary equipment my personal taste and same prety worn test gear.
I like it....
More to folow.
A few thoughts . . . .
I think you did a fantastic job with the layout and construction of this project. However, I would offer a few observations re the design of the front end. I realize that simplicity was a major goal, but sometimes it takes a little extra circuitry to get the best performance.
Because your input stage uses just one op-amp stage to handle the differential input, you lose a lot of the advantages of using a true differential instrumentation-type configuration using 3 stages. You lost good CMNR (common mode noise rejection) with the low gain. You lose good S/N performance by using 23,500 Ohm resistors in series with each leg (10-13 dB beyond what is necessary).
Also, the input impedance to each leg is not equal and therefore has imbalance that will further degrade noise rejection. Thevenizing the input resistance yields 23,500 Ohms for the inverting leg & 188,500 Ohms for the non-inverting leg. Remember the inverting input pin is at virtual ground!
Using the 3 stage instrumentation amp configuration, you can keep the series resistance as low as possible, keep the resistor values closely matched within 0.1% or better & use high gain with the diff amp to maximize common mode rejection ratio (CMRR). Then, you'll realize the fantastic, low noise performance that a true differential front-end is capable of.
I hope that this helps you and others that desire the advantages of true differential inputs.
I think you did a fantastic job with the layout and construction of this project. However, I would offer a few observations re the design of the front end. I realize that simplicity was a major goal, but sometimes it takes a little extra circuitry to get the best performance.
Because your input stage uses just one op-amp stage to handle the differential input, you lose a lot of the advantages of using a true differential instrumentation-type configuration using 3 stages. You lost good CMNR (common mode noise rejection) with the low gain. You lose good S/N performance by using 23,500 Ohm resistors in series with each leg (10-13 dB beyond what is necessary).
Also, the input impedance to each leg is not equal and therefore has imbalance that will further degrade noise rejection. Thevenizing the input resistance yields 23,500 Ohms for the inverting leg & 188,500 Ohms for the non-inverting leg. Remember the inverting input pin is at virtual ground!
Using the 3 stage instrumentation amp configuration, you can keep the series resistance as low as possible, keep the resistor values closely matched within 0.1% or better & use high gain with the diff amp to maximize common mode rejection ratio (CMRR). Then, you'll realize the fantastic, low noise performance that a true differential front-end is capable of.
I hope that this helps you and others that desire the advantages of true differential inputs.
@bardkallestad, Thanks for your thoughts on this project, as you noticed the main goal of this project was simplicity and sound. Both have been accomplished (I think 
), the sound quality has been confirmed by multiple experienced listeners and listening groups. Even the MC version sounds very good although the noise level is a bit higher then needed.
As I have done no electronic design in the 30 years before this one design, then I did do a power amplifier and some line-stuff, my 'return' to electronics showed me the incredible quality of modern op-amps, this made me think 'what can be accomplished with these?', and this RIAA was the result.
Maybe I will have an other look at the 'modern'-op-amp RIAA and design and other one in the future, but at the moment I an real busy with a 'current-conveyor' power amplifier.
), the sound quality has been confirmed by multiple experienced listeners and listening groups. Even the MC version sounds very good although the noise level is a bit higher then needed.As I have done no electronic design in the 30 years before this one design, then I did do a power amplifier and some line-stuff, my 'return' to electronics showed me the incredible quality of modern op-amps, this made me think 'what can be accomplished with these?', and this RIAA was the result.
Maybe I will have an other look at the 'modern'-op-amp RIAA and design and other one in the future, but at the moment I an real busy with a 'current-conveyor' power amplifier.
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I did it so in my project in order to outperform the simple INA163 phono...
https://docs.google.com/file/d/0BzbIeQI27Ljoa2VrbTVrRHJzZVE/edit
Cost and simplicity wasn't object here
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I did it so in my project in order to outperform the simple INA163 phono...
https://docs.google.com/file/d/0BzbIeQI27Ljoa2VrbTVrRHJzZVE/edit
Cost and simplicity wasn't object here
That looks great
but such complexity was not in the scope of this project here. This here was to proof (and it did) that a relatively simple opamp RIAA can do the work, and can sound extremely good.Power Scrubbing Ad-Infinitum . . .
Yee-Gad! I thought I was anal about clean DC power . . . .
Nice job on the construction and layout. I commend your zeal.
If I may be so bold as to nit-pick:
1. After 24v regulators, U61 and U62 caps across LEDs, on super clean DC????? (huh?) If worried about diode noise, put them earlier in power ckt.
2. U13 and U17 caps in the final DC filter could be 470nF to lower the F3 down to a few Hertz, placing it 5 octaves below the 100 or 120 Hertz ripple freq.
3. I seriously question the need for two sections of the input filter on the raw input, in light of all the filtering done after this.
Do you own stock in the capacitor industry?
Yee-Gad! I thought I was anal about clean DC power . . . .
Nice job on the construction and layout. I commend your zeal.
If I may be so bold as to nit-pick:
1. After 24v regulators, U61 and U62 caps across LEDs, on super clean DC????? (huh?) If worried about diode noise, put them earlier in power ckt.
2. U13 and U17 caps in the final DC filter could be 470nF to lower the F3 down to a few Hertz, placing it 5 octaves below the 100 or 120 Hertz ripple freq.
3. I seriously question the need for two sections of the input filter on the raw input, in light of all the filtering done after this.
Do you own stock in the capacitor industry?
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Thanks for the comments.
First; this was my first project design and build in 30 years
Point 1: Yes, you are right, but would it really make a difference
Point 2: Yes, probably.
Point 3: This is high-end
no money spared.Lately I have been designing PSU's with a active line regulation of -85dB at 10Mhz, maybe I will publish my latest work. But be aware, that is not cheap
To long since promised review...
But first...
I had FDW balanced on a 5-pin plug now TT is on normal RCA
IMO 5 pin is beterer (fell free to get big red biro to correct spelling mistakes I will feel free to suggest alternative use for it while U waiting for my next post. CAPISH ?!)Not going to start FiFi revolution now I will have to fit both
But first...
I had FDW balanced on a 5-pin plug now TT is on normal RCA
IMO 5 pin is beterer (fell free to get big red biro to correct spelling mistakes I will feel free to suggest alternative use for it while U waiting for my next post. CAPISH ?!)Not going to start FiFi revolution now I will have to fit both
Attachments
Done!
Double plugs on input eventually I will change TT back to 5 pins for now compromise aloud for direct swap between 2 Preamp stages.
Compromise not whit wire quality it is 99.999 % pure silver double Teflon coated from Advent (yes cheaper than from FiFi specialised dudes)
Current set up again compromise as one have to put up whit couch be in the way and the F5 hidden behind it.
Beat FiFi being part of garden rookery or life as single.
Compromise not whit the recorded material lets talk about it for a minute or 2
Double plugs on input eventually I will change TT back to 5 pins for now compromise aloud for direct swap between 2 Preamp stages.
Compromise not whit wire quality it is 99.999 % pure silver double Teflon coated from Advent (yes cheaper than from FiFi specialised dudes)
Current set up again compromise as one have to put up whit couch be in the way and the F5 hidden behind it.
Beat FiFi being part of garden rookery or life as single.
Compromise not whit the recorded material lets talk about it for a minute or 2
Attachments
On The record
I have been using this one for years as the very first one I take to shop and put on spinner.
Many a time sale assistant remain speechless after a 30 seconds listening section and me walking out of shop (please do not waste my and your time)
I rarely listen to it, not my glass of Prosecco (past12 o clock bar is open)
Grace Jones Slave to the Rhythm
I have 2 copies of it the first one is the original first print catalogue number GRACE1 from Island records
The second copy is allegedly a DMM (direct Metal Mastering) for Manhattan Island Records catalogue Number is 062 24 2447 1
Please post your catalogue numbers when U talk about records as your copy may not be the same as the one I have
In this case my favourite issue is the first one Catalogue Grace1 as it feel much crispier cleaner and whit much betterer hi range
The second is considerably louder
3.9 V peak out of first one 5.4 peak out of second from the first track on side one.
Check this site out to be truly surprised.
http://www.discogs.com/Grace-Jones-Slave-To-The-Rhythm/master/56303
As I said music wise not my real thing but (at the time I was working both in a FM radio station and a Disco run by the Italian Mafia) one of the very best recording that came out on 1985 is pretty simple whit loads of spoken words panning effects laughter and dynamics absolutely perfect as a test records provided U stick to the oldest issues.
I suspect the most recent ones will suffer from compressed dynamic ranges tank you not digital basterds for this gift.
Going for spot of lunch now while U digest this
I have been using this one for years as the very first one I take to shop and put on spinner.
Many a time sale assistant remain speechless after a 30 seconds listening section and me walking out of shop (please do not waste my and your time)
I rarely listen to it, not my glass of Prosecco (past12 o clock bar is open)
Grace Jones Slave to the Rhythm
I have 2 copies of it the first one is the original first print catalogue number GRACE1 from Island records
The second copy is allegedly a DMM (direct Metal Mastering) for Manhattan Island Records catalogue Number is 062 24 2447 1
Please post your catalogue numbers when U talk about records as your copy may not be the same as the one I have
In this case my favourite issue is the first one Catalogue Grace1 as it feel much crispier cleaner and whit much betterer hi range
The second is considerably louder
3.9 V peak out of first one 5.4 peak out of second from the first track on side one.
Check this site out to be truly surprised.
http://www.discogs.com/Grace-Jones-Slave-To-The-Rhythm/master/56303
As I said music wise not my real thing but (at the time I was working both in a FM radio station and a Disco run by the Italian Mafia) one of the very best recording that came out on 1985 is pretty simple whit loads of spoken words panning effects laughter and dynamics absolutely perfect as a test records provided U stick to the oldest issues.
I suspect the most recent ones will suffer from compressed dynamic ranges tank you not digital basterds for this gift.
Going for spot of lunch now while U digest this
Attachments
More compromises
I don't have any white trufles left so got to make do whit the trufle paste but the prosecco is prety good
WTF review ????
Not to worry caming up ...
After 3 years Frans Balanced is out of the suitcase I had to use bit of wire from TT to PSU box to ground TT tonearm and.... total silence thing is broken what do U espect after 3 years
I don't have any white trufles left so got to make do whit the trufle paste but the prosecco is prety good
WTF review ????
Not to worry caming up ...
After 3 years Frans Balanced is out of the suitcase I had to use bit of wire from TT to PSU box to ground TT tonearm and.... total silence thing is broken what do U espect after 3 years
Attachments
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But no is not
Is just much quieter than other one
And other one is pretty unfair competition being R2 Paradise.
Frans Balanced is playing away still on that Grace Jones album... just turn volume down a little bit to get a feel and set volume to that 3.9 V and then... she is back and 4 V out of 87dB speaker apparently is enough to disturb neighbours and I am to chicken to be single so time to tidy up and while there is same time left I am going to drag the lot to the loft sod stupid RCA Phono Plugs and go back to the 5 pins one!
Just have to make adaptor for when things are travelling around...
Frans balanced so far did a pretty good job, is going to stay for a while, I already know that there is a single note from a particular track that I need to listen 2
Tomorrow?
Is just much quieter than other one
And other one is pretty unfair competition being R2 Paradise.
Frans Balanced is playing away still on that Grace Jones album... just turn volume down a little bit to get a feel and set volume to that 3.9 V and then... she is back and 4 V out of 87dB speaker apparently is enough to disturb neighbours and I am to chicken to be single so time to tidy up and while there is same time left I am going to drag the lot to the loft sod stupid RCA Phono Plugs and go back to the 5 pins one!
Just have to make adaptor for when things are travelling around...
Frans balanced so far did a pretty good job, is going to stay for a while, I already know that there is a single note from a particular track that I need to listen 2
Tomorrow?
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