That's overkill even by the standards of overkill...
In the Hammond line, the 30VA 182K12 would be fine, but you could choose the 50VA 182L12, the 80VA 182M12 or the 120VA 182P12. Browse the catalog here. The power:cost ratio of the smaller models is low ... i.e. not very good value.. there is an incentive to get a much larger one for not very much more money. In that light I don't know which one is "best".
There are some very reasonable alternatives from Triad i.e. This one would be ideal - but they are unfortunately out of stock.
Which is why I usually recommend Digikey and the TE62072-ND as being the most cost effective, widely available option.
If I was spending near $100 for a toroid, I'd buy it from Plitron. Ask them if they have a model available with 2x12 V secondaries, electrostatic screen, and magnetic shield. They should have this pre-designed (i.e. non-custom order) already for a couple of sizes at least.
In the Hammond line, the 30VA 182K12 would be fine, but you could choose the 50VA 182L12, the 80VA 182M12 or the 120VA 182P12. Browse the catalog here. The power:cost ratio of the smaller models is low ... i.e. not very good value.. there is an incentive to get a much larger one for not very much more money. In that light I don't know which one is "best".
There are some very reasonable alternatives from Triad i.e. This one would be ideal - but they are unfortunately out of stock.
Which is why I usually recommend Digikey and the TE62072-ND as being the most cost effective, widely available option.
If I was spending near $100 for a toroid, I'd buy it from Plitron. Ask them if they have a model available with 2x12 V secondaries, electrostatic screen, and magnetic shield. They should have this pre-designed (i.e. non-custom order) already for a couple of sizes at least.
Hmm... I should really get a blog or something, but for the moment this space will do:
Updates to printed circuit boards: "the 'g' series".
By lucky circumstance and a little prodding, all four circuit boards on the pcb page are on the same letter revision: 45g, 300g, 28g and 32g. I've taken the opportunity to try and standardize the four as much as possible.
- all boards now have a specific "GND" pad for connecting to the case (normally to the same point you connect the turntable/arm ground wires to). This is instead of the old way of connecting COM to the case.
- All but 45g (the stereo VSPS) are designed for the following caps to be used in C1, C2: Wima FKP2 1000pF 5% (100V or 250V) (Wima FKP2) or Cornell-Dubilier 1000pF mica 1% or 5% (100V or 500V) (CD mica). The stereo VSPS doesn't have room, you'll have to go with metallized polyester most likely, but the flip-side is just about anything can be made to fit: 5, 7.5 or 10mm lead spacing can be accomodated, as long as the capacitor body is relatively slim.
- The 300g and 32g can use the standard Wima MKP4 series capacitors with a lead spacinig of 27.5mm for C3. There are several to choose from, in 100V and 250V ratings, 2.2uF to 4.7uF (Wima MKP4). Alternatively all the boards can fit a small non-polar electrolytic with 2.5mm lead spacing.
I'm going to make a small group order for some VSPS300 boards. Price is $45 for a set of two. (yes, far more expensive than the Phonoclone 3 - it's a matter of volumes!) I promise to provide a BOM worksheet and schematic images as I did for the Phonoclone 3. Email if interested.
Updates to printed circuit boards: "the 'g' series".
By lucky circumstance and a little prodding, all four circuit boards on the pcb page are on the same letter revision: 45g, 300g, 28g and 32g. I've taken the opportunity to try and standardize the four as much as possible.
- all boards now have a specific "GND" pad for connecting to the case (normally to the same point you connect the turntable/arm ground wires to). This is instead of the old way of connecting COM to the case.
- All but 45g (the stereo VSPS) are designed for the following caps to be used in C1, C2: Wima FKP2 1000pF 5% (100V or 250V) (Wima FKP2) or Cornell-Dubilier 1000pF mica 1% or 5% (100V or 500V) (CD mica). The stereo VSPS doesn't have room, you'll have to go with metallized polyester most likely, but the flip-side is just about anything can be made to fit: 5, 7.5 or 10mm lead spacing can be accomodated, as long as the capacitor body is relatively slim.
- The 300g and 32g can use the standard Wima MKP4 series capacitors with a lead spacinig of 27.5mm for C3. There are several to choose from, in 100V and 250V ratings, 2.2uF to 4.7uF (Wima MKP4). Alternatively all the boards can fit a small non-polar electrolytic with 2.5mm lead spacing.
I'm going to make a small group order for some VSPS300 boards. Price is $45 for a set of two. (yes, far more expensive than the Phonoclone 3 - it's a matter of volumes!) I promise to provide a BOM worksheet and schematic images as I did for the Phonoclone 3. Email if interested.
Connection schemes for RJM Audio circuit boards:
VSPS Stereo
All single channel boards, with the dedicated GND pad.
All single channel boards, with the dedicated GND pad, dual mono.
All single channel boards, without the dedicated GND pad.
All single channel boards, without the dedicated GND pad, dual mono. The stereo VSPS without the GND pad connects at the input returns like this as well.
That should just about cover everything.
Oh right, the power supply. A lot of people will be happy to see this I think:
Power switch and LED completely optional. Power transformer can be larger if desired. Diodes can be bigger and badder if desired. This power supply will work with all versions of the VSPS and Phonoclone, and pretty much anything else you care to build with op amps. Two recitfiers? Why not. I think this configuration sounds better.
/R
VSPS Stereo
An externally hosted image should be here but it was not working when we last tested it.
All single channel boards, with the dedicated GND pad.
An externally hosted image should be here but it was not working when we last tested it.
All single channel boards, with the dedicated GND pad, dual mono.
An externally hosted image should be here but it was not working when we last tested it.
All single channel boards, without the dedicated GND pad.
An externally hosted image should be here but it was not working when we last tested it.
All single channel boards, without the dedicated GND pad, dual mono. The stereo VSPS without the GND pad connects at the input returns like this as well.
An externally hosted image should be here but it was not working when we last tested it.
That should just about cover everything.
Oh right, the power supply. A lot of people will be happy to see this I think:
An externally hosted image should be here but it was not working when we last tested it.
Power switch and LED completely optional. Power transformer can be larger if desired. Diodes can be bigger and badder if desired. This power supply will work with all versions of the VSPS and Phonoclone, and pretty much anything else you care to build with op amps. Two recitfiers? Why not. I think this configuration sounds better.
/R
Andrew:
Good point about the diode current, I estimated the current incorrectly. But couldn't I just increase the resistor to 7.5-10k?
What is a "disconnecting network"? Is that the 50ohms||small cap thingy to decouple COM from earth? The power supply chassis has always been disconnected from COM, and it's worked out fine... what am I missing here?
Thanks,
/rjm
Good point about the diode current, I estimated the current incorrectly. But couldn't I just increase the resistor to 7.5-10k?
What is a "disconnecting network"? Is that the 50ohms||small cap thingy to decouple COM from earth? The power supply chassis has always been disconnected from COM, and it's worked out fine... what am I missing here?
Thanks,
/rjm
Hi,
the advantage of using the Zener is that LED brightness falls off quickly as voltage across the supply lines falls and the LED is completely off when one supply line fails.
Using a larger resistor without a Zener gives a very gradual reduction in LED brightness as the voltage falls, so gradual it might not be noticed that a rail has a short on it or has switched off.
The Zener voltage is not critical, any value can be used. The closer the Zener value to the total supply rail voltage, the quicker the LED switches off.
Hi MJL,
that location of the Disconnecting Network reminds me of a PSU I have seen elsewhere on the Forum, where an inductor was inserted into the return feed.
Do you know where that diagram came from?
the advantage of using the Zener is that LED brightness falls off quickly as voltage across the supply lines falls and the LED is completely off when one supply line fails.
Using a larger resistor without a Zener gives a very gradual reduction in LED brightness as the voltage falls, so gradual it might not be noticed that a rail has a short on it or has switched off.
The Zener voltage is not critical, any value can be used. The closer the Zener value to the total supply rail voltage, the quicker the LED switches off.
Hi MJL,
that location of the Disconnecting Network reminds me of a PSU I have seen elsewhere on the Forum, where an inductor was inserted into the return feed.
Do you know where that diagram came from?
VSPS
(rebuild. no2)
LM4562
PSU:
14+-vdc -> 9.75V with the LM3xx
RCRC-LM3xx-RC filter
10R-220uF-10R-330uf-LM3xx-10R-100uF
(Do to SPICE this combo would give -200db pssr ?)
Decouple with a 100nf X7R ceramic.
IGNORE:
The 2.2nf grey cap and the polarized caps on the outputs.
Testing
Touching ground pin, chassi, rca contact at the same time = no hum only silent noise.
Groundloop...I guess.
(rebuild. no2)
LM4562
PSU:
14+-vdc -> 9.75V with the LM3xx
RCRC-LM3xx-RC filter
10R-220uF-10R-330uf-LM3xx-10R-100uF
(Do to SPICE this combo would give -200db pssr ?)
Decouple with a 100nf X7R ceramic.
IGNORE:
The 2.2nf grey cap and the polarized caps on the outputs.
Testing
Touching ground pin, chassi, rca contact at the same time = no hum only silent noise.
Groundloop...I guess.
Attachments
Subject VSPS
Rjm:
What about cutting down the resistance in the feedback, 732K
I saw some numbers that 700K have 10uV noise (10khz in roomtemp. ) add the gain 40db and you got 1000uV noise on the output only due to the feedbackresistor.
correct me if Im wrong.
Can I hear 1000uV noise??
Cutting down the resistans by 10 you got to increase the C with 10, question is how much money you will spend on expensive polystyrene caps or by some cheap polyester
Rjm:
What about cutting down the resistance in the feedback, 732K
I saw some numbers that 700K have 10uV noise (10khz in roomtemp. ) add the gain 40db and you got 1000uV noise on the output only due to the feedbackresistor.
correct me if Im wrong.
Can I hear 1000uV noise??
Cutting down the resistans by 10 you got to increase the C with 10, question is how much money you will spend on expensive polystyrene caps or by some cheap polyester
I've joined Twitter, I figured it would be a nice way to communicate with the VSPS and Phonoclone community. I can let people know about group buys, updates and corrections, as well have discussions about what to do next.
I admit I have no idea if this will be worthwhile or not, but I thought it would be worth giving it a try.
My Twitter name is @rjmaudio.
On a related technological front, does anyone know how I can set up my web page so that when people type in and "www.phonoclone.com" URL they get forwarded to the "phonoclone.com" domain instead? Right now both work fine, but it's confusing in Google because everything comes out twice, or at least I've got half of one and half of the other listed on the search engine.
/R
I admit I have no idea if this will be worthwhile or not, but I thought it would be worth giving it a try.
My Twitter name is @rjmaudio.
On a related technological front, does anyone know how I can set up my web page so that when people type in and "www.phonoclone.com" URL they get forwarded to the "phonoclone.com" domain instead? Right now both work fine, but it's confusing in Google because everything comes out twice, or at least I've got half of one and half of the other listed on the search engine.
/R
I have ordered a big batch of VSPS stereo boards, black, double sided, 70 um traces.
No the quesion is do I offer these as boards only or as a kit. Given that the stereo VSPS is the "netry-leve" project, I get the feeling most people would prefer to buy it as a kit rather than source their own parts. I will be looking into it over the next week or so.
Q: how much would you be willing to pay for a "nice" kit?
Richard
No the quesion is do I offer these as boards only or as a kit. Given that the stereo VSPS is the "netry-leve" project, I get the feeling most people would prefer to buy it as a kit rather than source their own parts. I will be looking into it over the next week or so.
Q: how much would you be willing to pay for a "nice" kit?
Richard
The VSPS kit will be for the board and the parts that go on it, no power supply no mounting hardware. The principle will be "bang for the buck"...
Tentative parts list, for your perusal:
The board, 47b, double sided 70um trace.
NE5532 with socket (upgrade later as you like)
Wima FKP2 1nF (Mica costs a 10x more, buy yourself if you want.)
Bennic 2.2uF for C3? (not available from Mouser)
LM7812CT, LM7912CT
Nichicon FW 1000uF, 100uF
Vishay resistors for R1,2,3,4
Xicon for R5,6 (105K,732K)
Kamaya carbon comp for R7
With this build level, we are looking at an estimated kit price of ~$39, including shipping.
Tentative parts list, for your perusal:
The board, 47b, double sided 70um trace.
NE5532 with socket (upgrade later as you like)
Wima FKP2 1nF (Mica costs a 10x more, buy yourself if you want.)
Bennic 2.2uF for C3? (not available from Mouser)
LM7812CT, LM7912CT
Nichicon FW 1000uF, 100uF
Vishay resistors for R1,2,3,4
Xicon for R5,6 (105K,732K)
Kamaya carbon comp for R7
With this build level, we are looking at an estimated kit price of ~$39, including shipping.
Mouser-format BOM, you can import it directly into your Mouser account to get price and ordering info.
71-CMF5547K000FHEK|2
71-CMF55681R00FHEK|2
71-CMF552K2100FHEK|2
271-105K-RC|2
271-732K-RC|2
791-RC1/4-470JB|2
71-CMF5590K900FHEK|2
505-FKP21000/100/2.5|8
75-V730P205X9250|2
647-UFW1E102MPD|2
647-UFW1E101MED|2
595-NE5532P|1
512-LM7812CT|1
512-LM7912CT|1
575-11043308|1
553-VPT24-1040|1
625-GBPC102-E4|2
It's so easy it makes you wonder if there is any point selling a kit. You can take this BOM, edit it as you like, and just order the parts you want.
I'd really like to hear some opinions first before proceeding, that's for sure.
71-CMF5547K000FHEK|2
71-CMF55681R00FHEK|2
71-CMF552K2100FHEK|2
271-105K-RC|2
271-732K-RC|2
791-RC1/4-470JB|2
71-CMF5590K900FHEK|2
505-FKP21000/100/2.5|8
75-V730P205X9250|2
647-UFW1E102MPD|2
647-UFW1E101MED|2
595-NE5532P|1
512-LM7812CT|1
512-LM7912CT|1
575-11043308|1
553-VPT24-1040|1
625-GBPC102-E4|2
It's so easy it makes you wonder if there is any point selling a kit. You can take this BOM, edit it as you like, and just order the parts you want.
I'd really like to hear some opinions first before proceeding, that's for sure.
Hi,
maybe I am for you a good test case even if not directly interested in the VSPS kit you are proposing.
I am newbie, however I succesfully built the simple VSPS kit of skycoral and I enjoyed it very much. I bought some months ago a DL-103 cartridge and I am waiting for the Phonoclone Rhys kit and boards.
Since time is going on and the kit is still not on the way, I am looking for the possibility of sourcing myself all components, based on your detailed information.
But for me it is not easy, I am getting confused, I have difficulty to find at the same source all components, the correct resistor value and so on. Most are stupid problems I would be ashamed to ask for information on the forum (for instance, when I look for the sockets of the IC I get hundreds of proposal and I am not able to understand what is the correct one).
Your complete mouser bom list is really a gift for people like me.
Anyway, I would like a kit, even if I have to pay a little bit more.
I also think that many of us would also enjoy a kit with top quality components
Renato
Thanks very much.
For the record, the dozens of DIP sockets confuse the heck out of me too.
I've given the matter some thought and I think I can leverage the volumes such that I can protect my initial investment and still offer the kit at a price less than it would cost people to source the parts individually. In fact I've just gone ahead and ordered all the parts.
There will be precisely 100 kits. This stock should last a long time, and hopefully bring some model-T like standardization to the project. There will be an instruction sheet included.
People will still need to buy the transformer and diodes, connectors, casing and mounting hardware.
Price for the PCB+parts+shipping will be $35. I plan to have these complete and ready to ship by mid-July.
Contents: Vishay metal film resistors R1-R3, Xicon metal film resistors at 105k,732k for R4,5. Kamaya carbon comp for R6,7. Wima FKP capacitors for C1,2, polypro film for C3, Nichicon KW for the filter and bypass, National Semiconductor LM7812CT/LM7912CT, socketed TI NE5532P.
Richard
For the record, the dozens of DIP sockets confuse the heck out of me too.
I've given the matter some thought and I think I can leverage the volumes such that I can protect my initial investment and still offer the kit at a price less than it would cost people to source the parts individually. In fact I've just gone ahead and ordered all the parts.
There will be precisely 100 kits. This stock should last a long time, and hopefully bring some model-T like standardization to the project. There will be an instruction sheet included.
People will still need to buy the transformer and diodes, connectors, casing and mounting hardware.
Price for the PCB+parts+shipping will be $35. I plan to have these complete and ready to ship by mid-July.
Contents: Vishay metal film resistors R1-R3, Xicon metal film resistors at 105k,732k for R4,5. Kamaya carbon comp for R6,7. Wima FKP capacitors for C1,2, polypro film for C3, Nichicon KW for the filter and bypass, National Semiconductor LM7812CT/LM7912CT, socketed TI NE5532P.
Richard