1. Install double 5mm pitch Vishay 0.1uF film caps (one above PCB, one underneath PCB, so 0.2uF) instead of the designated 100uF across the 5 Leds rows.
2. Use 10R 5W Rset resistors instead of the 68//68R near the edges. That will make the CCSs run some serious current and its audible. You need to install the Mosfets underneath PCB with bent legs upwards like in power amps and bolt them down to some plate so they sink. With 68//68R 1/4W or 100//100//100R 1/4W can work without sinks but that is not all it can give subjectively. 15-0-15VAC 50VA Tx at least. Have a good building time.
Thanks Salas for this information.
Morfeus, instead of an e-mail i post it again here.
I simply used the ELV phonostage for modification. It costs only 19.90 € and has all you need on board. The version you heard is done with a double LME49720 Opamp. You could use the LME49990 for even lower noise but it is not available in double so you have to use a jumper board if you take the ELV case. Elcaps are Pannasonic FC or FM. The 2200uF to ground is a Nichicon LG polymer you get at Farnell. It is critical for success. Resistors are Dale 0.1% antimagnetic from Schuro. You can use Holco from Farnell. Caps in the RIAA have to be 1% tolerance and best Styroflex or Silver MICA.
I use LCR Styroflex from RS or Farnell and Silver MICA from Reichelt. You find the MICAs under Styroflex on the Reichelt webpage ( silly, isn´t it). MKP1832 ( or even KP ) from Vishey-Röderstein are also very good or buy Styroflex from Oppermann. They cost virtually nothing.
The circuit as shown is good for 60dB of gain so no transformer for MC is necesary. For MM use 270 Ohm instead of 27 Ohm. Yes, it sounded great on your system. I liked your
system best on the event. Great job on the aestetics too. Never heard Green Cones so well. Untill that day i was thinking this is a stupid way to do it but i changed my mind.
Considering how little such a spaeker costs they absolutely not destroy the ears.
P.S. the bypass caps are BC components MKT but you can use Epcos, Wima, Rifa too.
You can modify your VSPS to use my choise of components too. I think the sound got more fleshed out when we tried my version.
Again, i have trouble to upload. I try again later.
Morfeus, instead of an e-mail i post it again here.
I simply used the ELV phonostage for modification. It costs only 19.90 € and has all you need on board. The version you heard is done with a double LME49720 Opamp. You could use the LME49990 for even lower noise but it is not available in double so you have to use a jumper board if you take the ELV case. Elcaps are Pannasonic FC or FM. The 2200uF to ground is a Nichicon LG polymer you get at Farnell. It is critical for success. Resistors are Dale 0.1% antimagnetic from Schuro. You can use Holco from Farnell. Caps in the RIAA have to be 1% tolerance and best Styroflex or Silver MICA.
I use LCR Styroflex from RS or Farnell and Silver MICA from Reichelt. You find the MICAs under Styroflex on the Reichelt webpage ( silly, isn´t it). MKP1832 ( or even KP ) from Vishey-Röderstein are also very good or buy Styroflex from Oppermann. They cost virtually nothing.
The circuit as shown is good for 60dB of gain so no transformer for MC is necesary. For MM use 270 Ohm instead of 27 Ohm. Yes, it sounded great on your system. I liked your
system best on the event. Great job on the aestetics too. Never heard Green Cones so well. Untill that day i was thinking this is a stupid way to do it but i changed my mind.
Considering how little such a spaeker costs they absolutely not destroy the ears.
P.S. the bypass caps are BC components MKT but you can use Epcos, Wima, Rifa too.
You can modify your VSPS to use my choise of components too. I think the sound got more fleshed out when we tried my version.
Again, i have trouble to upload. I try again later.
In
my system the preamp was a JGSELF. The MC input is a Hybrid INA and the RIAA is made with the values as the Self Precission Preamp. I use OPA1641 FET instead of NE5532 ( plus a lot of other changes ) so i can in total avoid 9 elcaps and two foils in the signal path. The JGSELF has being documented here before.
My "BIG" spaekers are the MPL described on my MPL thread and on Holgers webpage. The woofer i had is exactly the one i am using.
my system the preamp was a JGSELF. The MC input is a Hybrid INA and the RIAA is made with the values as the Self Precission Preamp. I use OPA1641 FET instead of NE5532 ( plus a lot of other changes ) so i can in total avoid 9 elcaps and two foils in the signal path. The JGSELF has being documented here before.
My "BIG" spaekers are the MPL described on my MPL thread and on Holgers webpage. The woofer i had is exactly the one i am using.
Hi Joachim,
really nice all that. Would have loved to listening to your MPL Speakers.
As you will have recognized, there was another setup with wide-band
and ribbon tweeter (is that the right word?) which i quite liked.
Would you please be so kind and fit in the schematics of JGSelf setup
FF2010 preamp of yours? Finding schematics confuses me a bit ;-)
greetings Ulf
really nice all that. Would have loved to listening to your MPL Speakers.
As you will have recognized, there was another setup with wide-band
and ribbon tweeter (is that the right word?) which i quite liked.
Would you please be so kind and fit in the schematics of JGSelf setup
FF2010 preamp of yours? Finding schematics confuses me a bit ;-)
greetings Ulf
Here is the MC input and two alternative MC inputs i tryed. The simple balanced was implemented and i could switch between it and the hybid Ina. The MM circuit has a mistake. It needs 5 10nF instead of 4. Servos in the headamp and linestgae are not necesarry. You can connect that node to ground. The MM stage has a passive pole that makes the RIAA perfect until supersonic and it is all in one go after Self but with Fet Opamps for lower DC offset. The subsonic filter has the IEC pole switchable and is optimised for my Lyras in a medium mass arm. Actually the stage sounds best with the IEC switched off. You can leave out the whole subsonic filter but then you need one coupling cap. To avoid the cap use a servo. I like the sound better with subsonic filter. It is cleaner and faster in the bass.
Hi Joachim,
thanks a lot.
i´ve got some questions concerning usaiog-1 tsc.
1. I can´t find nichicon LG available in Germany (farnell, RS, Bürklin). Is
there an alternative?
2. How to manage inputimpedance when using MC cartridges? Just paralleling
R over 56K?
3. lme49720 will run up to 36Volts. Would you expect a sonic advantage when
using higher voltage?
Greetings Ulf
thanks a lot.
i´ve got some questions concerning usaiog-1 tsc.
1. I can´t find nichicon LG available in Germany (farnell, RS, Bürklin). Is
there an alternative?
2. How to manage inputimpedance when using MC cartridges? Just paralleling
R over 56K?
3. lme49720 will run up to 36Volts. Would you expect a sonic advantage when
using higher voltage?
Greetings Ulf
Hello Ulf !
The Nichicon LG is availlable at Farnell. In the search engine type in 2200uF and voltages under 6V and then you find it. It is hard to find an alternative because there is not much space on the ELV PCB and we need the low ESR. There are some low impedance SMD caps that could fit. Nichcon, Elna, Rubicon and others make them. Maybe you can find a subtitude in the Frolyth range in the Bürklin catalog. You could use a low voltage Pannasonic FM too.
Yes, simply parallel resistors to the 56k. I did not do that in my sample because it sounded fine right away. I build a circuit like that for a friend with 300 Ohm loading that sounded fine in his system. Yes, when you supply the circuit with more voltage you get more overload margin. When you go over +-13V the noise gets a bit up. Stephan Horwege and i prefer +-13V but other like Syn08 like to supply the Opamps with the highest posibe voltage to get more dynamic range. I simply used the inbuild voltage regulators in the ELV, so that is the reason for the low voltage. My friend that as a version of that circuit in his preamp has a +-13V Placid Twisted Pear supply.
You know, this little stage was never ment to be High End but funny enough it actually sounds mighty fine. Modern Opamps are good enough to work with high gain without audible distortion and elegant simplicity is often a good recipy for fine sound.
The Nichicon LG is availlable at Farnell. In the search engine type in 2200uF and voltages under 6V and then you find it. It is hard to find an alternative because there is not much space on the ELV PCB and we need the low ESR. There are some low impedance SMD caps that could fit. Nichcon, Elna, Rubicon and others make them. Maybe you can find a subtitude in the Frolyth range in the Bürklin catalog. You could use a low voltage Pannasonic FM too.
Yes, simply parallel resistors to the 56k. I did not do that in my sample because it sounded fine right away. I build a circuit like that for a friend with 300 Ohm loading that sounded fine in his system. Yes, when you supply the circuit with more voltage you get more overload margin. When you go over +-13V the noise gets a bit up. Stephan Horwege and i prefer +-13V but other like Syn08 like to supply the Opamps with the highest posibe voltage to get more dynamic range. I simply used the inbuild voltage regulators in the ELV, so that is the reason for the low voltage. My friend that as a version of that circuit in his preamp has a +-13V Placid Twisted Pear supply.
You know, this little stage was never ment to be High End but funny enough it actually sounds mighty fine. Modern Opamps are good enough to work with high gain without audible distortion and elegant simplicity is often a good recipy for fine sound.
I have an idea for a Transformer Balanced MC Input Stage with Zerro Field technology.
In this circuit the transformer secondary is part of a shunt feedback system that cancels distortion and low frequency rolloff in the input transformer. C1 and R15-R16 make a high pass. R15 - R16 should have the oproximate DC resistance of the primary. In my example
the secondary has 2 x 100 Ohm and 1000uF x R15 ( R16 ) give a response down -3dB at 2 Hz.
In this circuit the transformer secondary is part of a shunt feedback system that cancels distortion and low frequency rolloff in the input transformer. C1 and R15-R16 make a high pass. R15 - R16 should have the oproximate DC resistance of the primary. In my example
the secondary has 2 x 100 Ohm and 1000uF x R15 ( R16 ) give a response down -3dB at 2 Hz.
After fumbling around with MC phonostages for over one year i think i found a way to avoid DC through the Cartridge in a DC coupled parallel symmetric common base stage.
Actually i had shown a common emitter circuit that has that feature based on the Essex Low Fuzzy Distortion Phonostage. I will post the principle here again. What i did is simply reverse the principle and voila, i can now adjust the input offset to zerro. I build i simple MC stage based on the Hiraga Current Mirror to prove the concept. DC conditions are stable and i try to listen to it on the weekend. My circuit has theoretically 6dB less noise and ten times less second harmonic. PSU rejection is also better and i have several ideas to improve it. I am still working on the values so no details are given at the moment.
Actually i had shown a common emitter circuit that has that feature based on the Essex Low Fuzzy Distortion Phonostage. I will post the principle here again. What i did is simply reverse the principle and voila, i can now adjust the input offset to zerro. I build i simple MC stage based on the Hiraga Current Mirror to prove the concept. DC conditions are stable and i try to listen to it on the weekend. My circuit has theoretically 6dB less noise and ten times less second harmonic. PSU rejection is also better and i have several ideas to improve it. I am still working on the values so no details are given at the moment.
I build the circuit from yesterday and it works beutifully well. Bias is rock stable and i can bring it down lower then i can measure. What i need is a better DC meter. I found one that is not too expensive. Noise is low with the transistors i use ( 0.55nV/qHz) and can can be brought down to 0.3nV/qHz with the usual suspect. Initially i put the transistors in one channel into wrong polarity. Measured with a transistor tester they survived but they developed some flicker noise and had to be subsituted. Be carefull if you do something like that. They are not usable for ultra low noise work afterwards.
I listened to it and i was again surprised how well such a simple circuit can sound.
I measured frequency response and it is -3dB @ 2MHz driven by a 6 Ohm impedance.
I listened to it and i was again surprised how well such a simple circuit can sound.
I measured frequency response and it is -3dB @ 2MHz driven by a 6 Ohm impedance.
Dear Joachim,
please let me point out that All In One Go Transimpedance RIAA is possible since 20 years...
Looking forward to meet you again,
A.
Hi as-audio. I have shown AIOG circuits here before. For example varieties of the Essex phonostage from the mid 80th. I called one "Second Return From The Abbys". But it is true, after talking to you i got the idea to try that with the MPP Nova and my transimpedance circuits. I had given up on transimpedance stages because i got harsh critique because of potential DC into the Cartridge. I have solved that now satifactory. The circuit playes well and Bias is stable. Somehow this idea for BIAS cancelation also was inspired by a discussion we had about Buffers. One of them used a trimmer for output offset cancelation. So i counted one and one ( as-audio + Hawksford ) and found the solution. Thanks for inspiring discussions ! I also got a lot of input from Invisible Force so my think tank got a lot bigger.