I guess that's possible, although I got them from the same eBay supplier agdr's got his lme49990-on-adapter from. But for now I'll stick to the muses opamp!
Lowest voltage noise. Current noise is a high 2 pA/rtHz, and will dominates when MM cartridges are used. See datasheet page 12 and my attached plot.
For an MM cartridge (impedance 600~2k), the AD797 is about equal to the NE5534A or indeed any audio opamp, since they all pretty much reduce to the resistor (Johnson) noise from around 1 kohms to around 100 kohms. Because that is what they are designed to do: give the best noise performance in typical audio applications. The AD797 as a preamp following a 100k volume pot. would, in comparison, be very poor.
@CHiroshi Not fake. If it was oscillating (and 75C temps suggest it was) it will likely not be operating at near its datasheet specifications for noise, PSRR, etc.
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I read this thread, I remembered someone who made actual measurements of VSPS a reverse RIAA. He measured frequency response; equality comparison of the two channels and three operational noise different.
I sought answers was in 2315; 2321; 2330; and 2351. It was WIREHEAD.BE.
Regards, Joseph.
I sought answers was in 2315; 2321; 2330; and 2351. It was WIREHEAD.BE.
Regards, Joseph.
Cable capacitance question. I am using two different ICs from the Phonoclone 3 to a Wright WLA-12 pre-amp. I have one set of ICs that measure about 90pf (VH audio silver helical DIYs) and another set of shielded twisted pair DIYs that measures about 550pf. Is there a reason to pick one over the other? The cartridge to PC3 is a silver Litz loom and I'm not changing that unless significant reasons present. Comments welcome.
No technical reason, no. I think you can go by preference there.
ps: IC = integrated circuit.
/R
Hello.
I'm in the task of building the VSPS 300 kit.
I bought two nice aluminum boxes 1306 Silver Aluminum Mini Power Amp Enclosure Power Supply Box Case DIY | eBay and New Amgis Toroidal Audio Power Transformer 50VA 2X12V 12V 0V 12V 12 0 12 | eBay, one for the phono stage and one for the PSU.
It has occurred to me that if the PSU har 1 toroidal transformer with two secondary 12v and 4 bridges of diodes, the VSPS could be set to "dual mono".
I'm right or I'm wrong.
All this to not include two toroids.
Regards.
I'm in the task of building the VSPS 300 kit.
I bought two nice aluminum boxes 1306 Silver Aluminum Mini Power Amp Enclosure Power Supply Box Case DIY | eBay and New Amgis Toroidal Audio Power Transformer 50VA 2X12V 12V 0V 12V 12 0 12 | eBay, one for the phono stage and one for the PSU.
It has occurred to me that if the PSU har 1 toroidal transformer with two secondary 12v and 4 bridges of diodes, the VSPS could be set to "dual mono".
I'm right or I'm wrong.
All this to not include two toroids.
Regards.
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Mono equals one channel all self powered.
Dual mono equals two channels EACH self powered.
sharing the PSU makes a NORMAL stereo amplifier
sharing the transformer feeding two paralleled PSU is still stereo.
Thanks AndrewT. As I have just 1 toroidal configuration I will start in stereo.
Then I'll do another toroidal and dual mono configuration.
In the case of the PSU can be placed another toroidal equal to what I have.
Besides the advantage will be dual mono it is that also left with toroid 50 watts per channel. Greetings and thanks.
Then I'll do another toroidal and dual mono configuration.
In the case of the PSU can be placed another toroidal equal to what I have.
Besides the advantage will be dual mono it is that also left with toroid 50 watts per channel. Greetings and thanks.
The only significant advantage I find with monoblock compared to any of the multi-channel amplifiers is tolerance to hum and buzz is improved.
Every multi-channel amplifier inside an enclosing, protecting, conductive chassis loses that advantage.
I have never found a way to wire a dual channel amplifier that gives the equivalent tolerance to hum and buzz as available in a pair of monoblocks.
Every multi-channel amplifier inside an enclosing, protecting, conductive chassis loses that advantage.
I have never found a way to wire a dual channel amplifier that gives the equivalent tolerance to hum and buzz as available in a pair of monoblocks.
Hello AndrewT. My English is not very good, so I have not understood what you wanted me to say.
I understood that the advantages of a dual mono lost by placing the circuits in the same chassis ?.
I really thought about doing dual mono to minimize the influence of one channel over the other and improve the soundstage. I was wrong then.
But no matter I have already purchased the components and the price of a phono stage with power supply wall wart (Pro ject), I will cntruir one of best looking and best performing hope. Greetings Jose.
I understood that the advantages of a dual mono lost by placing the circuits in the same chassis ?.
I really thought about doing dual mono to minimize the influence of one channel over the other and improve the soundstage. I was wrong then.
But no matter I have already purchased the components and the price of a phono stage with power supply wall wart (Pro ject), I will cntruir one of best looking and best performing hope. Greetings Jose.
Hello Jose,
Channel separation is intrinsically pretty low in vinyl, so any effect dual mono would have on separation will be well below the limit of audibility (even though some might disagree)
So don't worry about that.
On the other hand, Andrew T's comment about hum and buzz (practically AC noise and ground loops) still stands and is the major advantage of choosing a dual mono setup.
Hope this helps clear thing up.
Regards,
Nick
Channel separation is intrinsically pretty low in vinyl, so any effect dual mono would have on separation will be well below the limit of audibility (even though some might disagree)
So don't worry about that.
On the other hand, Andrew T's comment about hum and buzz (practically AC noise and ground loops) still stands and is the major advantage of choosing a dual mono setup.
Hope this helps clear thing up.
Regards,
Nick
Thanks Hajj. At the same moment that you are sending the message, I was reading an article about advantages or dual mono configuration.
They are right. The only audible advantage is what you mentioned.
What I thought about stereo separation and soundstage is inaudible according relate. In addition to the generality of people it has at least the line preamp is stereo, throwing away the improvements that part of the system is dual mono.
But I take this thread to get me out of doubt. Why you say that this or that phono stage is more or less soudstage; further; the sound is "forward" etc.
That part of the circuit makes this happen ?.
I have modest audio system (Marantz CD5400; Rotel RA 970BX; B & W DM602 speakers, wires Van den HULL CS 122 bi-wired; Audio Technica cartridge AT440MLa; direct AP2400 Aiwa turntable, phono preamp DIY).
I could appreciate what I mention using different preamps; different readers cd, always of course in the same room and the same disposition from speakers.
For better soundstage with some than with others note ?.
Sorry, it is not the luar to raise these issues, but the opportunity was given.
Cheers
They are right. The only audible advantage is what you mentioned.
What I thought about stereo separation and soundstage is inaudible according relate. In addition to the generality of people it has at least the line preamp is stereo, throwing away the improvements that part of the system is dual mono.
But I take this thread to get me out of doubt. Why you say that this or that phono stage is more or less soudstage; further; the sound is "forward" etc.
That part of the circuit makes this happen ?.
I have modest audio system (Marantz CD5400; Rotel RA 970BX; B & W DM602 speakers, wires Van den HULL CS 122 bi-wired; Audio Technica cartridge AT440MLa; direct AP2400 Aiwa turntable, phono preamp DIY).
I could appreciate what I mention using different preamps; different readers cd, always of course in the same room and the same disposition from speakers.
For better soundstage with some than with others note ?.
Sorry, it is not the luar to raise these issues, but the opportunity was given.
Cheers
Dual mono within the same chassis does not help with tolerance to hum and buzz .
Only monoblock or true balanced impedance connections can do this by avoiding the loops created between source and receiver.
I did not mention separation of PSU from Preamp.
The problem loop is between the Preamp and the power amp.
A pair of monoblocks breaks this loop.
All stereo amps including dual mono that are inside a common chassis do not break this loop. A dual mono does not break this interconnect loop.
Only a pair of balanced impedance inputs has the potential to break the interconnect loop when a common Receiver Chassis is used.
The problem loop is between the Preamp and the power amp.
A pair of monoblocks breaks this loop.
All stereo amps including dual mono that are inside a common chassis do not break this loop. A dual mono does not break this interconnect loop.
Only a pair of balanced impedance inputs has the potential to break the interconnect loop when a common Receiver Chassis is used.