If you follow the link on the RJM site to the Project page, it is explained that the Emerald is basically a combination of the Phonoclone and an improved MM circuit, and for MC use it will be sonically very similar to the Phonoclone.
I built the Phonoclone and associated power supply years ago and it sounded superb, it was replaced by a Manley Chinook which was better but not by a huge margin. I would have no hesitation building the Emerald, Richard's designs are excellent!
I built the Phonoclone and associated power supply years ago and it sounded superb, it was replaced by a Manley Chinook which was better but not by a huge margin. I would have no hesitation building the Emerald, Richard's designs are excellent!
@Superchunk
The Phonoclone is replaced by the Emerald project. The information for the project including the BOM is still online though it is no longer updated. You can download the board files to get your own boards made, but I recommend the Emerald as being more versatile while maintaining the same sound.
The Phonoclone is replaced by the Emerald project. The information for the project including the BOM is still online though it is no longer updated. You can download the board files to get your own boards made, but I recommend the Emerald as being more versatile while maintaining the same sound.
See the notification I got from Mouser below. The 12V 3 terminal voltage regulator, LM7912CT is "End of Life".
This one hits hard. It feels like the end of an era.
For the time being there's generic alternatives from ST and others that I will be using for the VSPS kits, but I imagine eventually those too will disappear.
This one hits hard. It feels like the end of an era.
For the time being there's generic alternatives from ST and others that I will be using for the VSPS kits, but I imagine eventually those too will disappear.
Mouser Electronics received a lifecycle change notification from the manufacturer regarding a product you had interest in or purchased within the last two years. Please click on the part number to view product details and similar products for replacements. |
| Manufacturer | Part # | Mouser Part # | PO# | Part Status |
|---|---|---|---|---|
| STMicroelectronics | L7812CP | 511-L7812CP | 28484907 | Not Recommended for New Designs |
| ON Semiconductor | LM7912CT | 512-LM7912CT | 11160974 | End of Life |
Thank you for choosing Mouser Electronics for your electronic component needs. Regards, Mouser Electronics |
I am sorry if I'm raking up an old topic again but I should very much like to master the maths involved in the VSPS so that I can try other EQs. I can twiddle on a Spice simulation but feel that it should be possible to predict. Many backs of envelopes have been wasted trying to find the 'hidden' Time Constants in this staggeringly elegant & simple design. A pointer to, say, an article in WW or similar would be a start...
See post #4,369 in this thread. I posted a spreadsheet that has the RIAA eq network calculations.
The formulas were published by Stanley P. Lipshitz, On RIAA Equalization Networks. Journal of the Audio Engineering Society, June 1979.
The VSPS uses a Lipshitz "c" eq network while the vast majority of commercial gear uses a Lipshitz "a" network.
It may be difficult to get an eq network with exact RIAA specs using off the shelf components. The stock network is quite accurate as is. It may be better to match component values between channels rather than try for an eq network with exact RIAA specs.
I also recommend taking a look at the OPA1642 datasheet. This has good writeup of a single op amp active feedback phono stage. That example uses a Lipshitz "a" network and is about as accurate to RIAA spec as you can get.
The formulas were published by Stanley P. Lipshitz, On RIAA Equalization Networks. Journal of the Audio Engineering Society, June 1979.
The VSPS uses a Lipshitz "c" eq network while the vast majority of commercial gear uses a Lipshitz "a" network.
It may be difficult to get an eq network with exact RIAA specs using off the shelf components. The stock network is quite accurate as is. It may be better to match component values between channels rather than try for an eq network with exact RIAA specs.
I also recommend taking a look at the OPA1642 datasheet. This has good writeup of a single op amp active feedback phono stage. That example uses a Lipshitz "a" network and is about as accurate to RIAA spec as you can get.
Wizard - very many thanks. I realised on reading through Lipshitz that I simply do not have the higher mathematics necessary to follow "...and thus it can be shown..." at this level! I have in my time devised Excel sheets for tone arm geometry &c but yours is in a different league. Is there anywhere on your Network Calculation sheet where the time constants are entered as primary data?: since the VSPS is so simple (to make) I have been hoping to use it for other EQ standards for my earlier LPs & 78s.
It's possible but not easy to customize the time constants in a single op amp active feedback design due to how the components interact with one another.
Another approach would be to use a passive design like the Hagerman Bugle which separates the time constants between three gain stages. You could pick up a Bugle pcb and look at the schematic for the Bugle Pro for an example on how to customize for different eq using rotary switches.
Another approach would be to use a passive design like the Hagerman Bugle which separates the time constants between three gain stages. You could pick up a Bugle pcb and look at the schematic for the Bugle Pro for an example on how to customize for different eq using rotary switches.
Thanks again. I quite understand that a split design simplifies matters but I'd managed to enter up the formulae given in
https://www.andyc.diy-audio-engineering.org/phono-preamp/index.html
into a workable spreadsheet & had hoped that the same was possible for other network configurations. With my andyc speadsheet it is quite rewarding to see NARTB, BSI 78 & other three-constant EQs solved & ready to compare on Spice!
https://www.andyc.diy-audio-engineering.org/phono-preamp/index.html
into a workable spreadsheet & had hoped that the same was possible for other network configurations. With my andyc speadsheet it is quite rewarding to see NARTB, BSI 78 & other three-constant EQs solved & ready to compare on Spice!
It's been a while, but from memory I got as far as the following on RIAA simulation.
what I couldn't do, due to my lacking or working ability with Laplace transforms, or access to software like Mathmatica that solves those kinds of equations for me, was generate a frequency response directly from a given RC network. Hence I had to kludge my way through the problem by generating solutions in LTSpice and then outputting the response data to compare against the reference curve in excel and calculate the deviation. Essentially I iterated the solution manually.
/R
- using the excel worksheet, I could generate the frequency response for a given set of time constants
- using LTSpice, I could generate the frequency response for a given RC network, or the entire VSPS circuit
what I couldn't do, due to my lacking or working ability with Laplace transforms, or access to software like Mathmatica that solves those kinds of equations for me, was generate a frequency response directly from a given RC network. Hence I had to kludge my way through the problem by generating solutions in LTSpice and then outputting the response data to compare against the reference curve in excel and calculate the deviation. Essentially I iterated the solution manually.
/R
With friends we want to do a boutique “capacitor tasting” meeting. We want to be as close as possible to the source, the PhonoClone is a perfect candidate. I’ve a nice GlassWare selector switch to do quick pairwise comparisons.
The quoted value for the phonoclone is 2.2uF, I’ve installed the TRT dynamics at the moment, but the pairs we have are all higher values: 2.7uF to 3.3uF. I’m not an expert but higher values should reduce the -3db frequency point of the implied high-pass filter.
My line stage has a nominal input impedance of about 30K. It should be ok with higher values. Am I correct?
/P
* * *
PS: by the way available toys are
The quoted value for the phonoclone is 2.2uF, I’ve installed the TRT dynamics at the moment, but the pairs we have are all higher values: 2.7uF to 3.3uF. I’m not an expert but higher values should reduce the -3db frequency point of the implied high-pass filter.
My line stage has a nominal input impedance of about 30K. It should be ok with higher values. Am I correct?
/P
* * *
PS: by the way available toys are
- 3.3uF, Jupiter Beeswax PiO
- 2.7uF, 800Vdc Jantzen Superior Z-Cap Capacitor
- 3.3uF, 630Vdc Obbligato Gold Premium Capacitor
- 3uF, military grade vintage russian teflon caps (really huge)
Foreword: please, don’t blame me for the following question because I am pretty sure it has been asked already… but this thread is huge! I tried to search for it but I get too many false positives.
Can somebody point me to comments on the comparison between Emerald vs Phonoclone for MC only? I’m a DL103 fanatic so if there have been comparisons using this cart it would be great.
If the Emerald would sound just as good as the Phonolcone on MC, I'd probably replace it due to the possibility to play with mc carts, I’m not sure.
/P
Can somebody point me to comments on the comparison between Emerald vs Phonoclone for MC only? I’m a DL103 fanatic so if there have been comparisons using this cart it would be great.
If the Emerald would sound just as good as the Phonolcone on MC, I'd probably replace it due to the possibility to play with mc carts, I’m not sure.
/P
there are few choices for carbon composition resistors on Mouser. Is there an alternative resistance value or resistor type you can recommend for R5?
Built a BOM on Mouser, seems fairly cost effective.
Also the OP amps are not available, and the ones that are are much cheaper, like less than $1, whereas the specified ones are over $5. Is this cost difference because of availability, or are current production opamps just as good?
Roger
Built a BOM on Mouser, seems fairly cost effective.
Also the OP amps are not available, and the ones that are are much cheaper, like less than $1, whereas the specified ones are over $5. Is this cost difference because of availability, or are current production opamps just as good?
Roger
Why on earth are you using carbon composition resistors??? Sorry, I have to ask.
They were all we had when I started. Ask any old engineer today (most have passed), if they had a better option they would have used them. They absolutely do not want higher distortion and / or noise. They did not intend their equipment to sound like that. I know because I have rebuilt many old classics for engineers and they strongly prefer lower distortion. That is what their goal was to start with.
Now for guitar amps - yes. Absolutely because we don't want to change the sound. They are for creating music, but your home reproduction equipment should not alter the sound.
They were all we had when I started. Ask any old engineer today (most have passed), if they had a better option they would have used them. They absolutely do not want higher distortion and / or noise. They did not intend their equipment to sound like that. I know because I have rebuilt many old classics for engineers and they strongly prefer lower distortion. That is what their goal was to start with.
Now for guitar amps - yes. Absolutely because we don't want to change the sound. They are for creating music, but your home reproduction equipment should not alter the sound.
Hi Roger,
I would only ever use a carbon composition as a stopper resistor on tube grids or mosfet gates (normal resistors are fine there). They have value in RF circuits because they are non-inductive. They can be noisy when you pass DC current through them, and they drift over time.
They tend to change value with applied voltage and temperature as well. Not great characteristics for signal stages! (= distortion).
I would only ever use a carbon composition as a stopper resistor on tube grids or mosfet gates (normal resistors are fine there). They have value in RF circuits because they are non-inductive. They can be noisy when you pass DC current through them, and they drift over time.
They tend to change value with applied voltage and temperature as well. Not great characteristics for signal stages! (= distortion).