According to Lamm pin 3 is not left unused, but shorted to ground - it is why I do not appreciate the idea of using a XLR cable, shorting the inverting output of the DartZeel preamplifier. These should never be called Pseudo or quasi XLR, they are single ended XLR!
In order to test for residual noise just insert an RCA plug with a short between signal and ground or a XLR with pin 2 shorted to 1.
According to Lamm pin 3 is not left unused, but shorted to ground - it is why I do not appreciate the idea of using a XLR cable, shorting the inverting output of the DartZeel preamplifier. These should never be called Pseudo or quasi XLR, they are single ended XLR!
In order to test for residual noise just insert an RCA plug with a short between signal and ground or a XLR with pin 2 shorted to 1.
Mike has a battery preamp. It is irrelevent to test with shorted plugs unless they are the length of the cables plus a few feet. Plus there are some parasitic loops possible from the charging cord, if it is even connected (and not on).
The path to the ML can be much lower impedance for numerous airborne things, if they can get in. Batteries are not particularly low impedance.
A more telling test would be to unplug the power connection to the DartZeel and try the SE interconnects again, note if there were more or less Anoise. That would be informative about possible parasitic functions.
Mike has a battery preamp. It is irrelevent to test with shorted plugs unless they are the length of the cables plus a few feet. Plus there are some parasitic loops possible from the charging cord, if it is even connected (and not on).
The path to the ML can be much lower impedance for numerous airborne things, if they can get in. Batteries are not particularly low impedance.
A more telling test would be to unplug the power connection to the DartZeel and try the SE interconnects again, note if there were more or less Anoise. That would be informative about possible parasitic functions.
It is not relevant if do not know how or are not interested in interpreting the data coming from the test. The noise in this condition is the intrinsic noise of the ML3 heard through the MM7 speakers, nothing added. Mike will immediately have a reference to what is possible to get in his system - theoretically he should be able to achieve something similar after fine tuning the system.
BTW, Mike has version II of the DartZeel preamplfier - we do not know exactly how the balanced stage is implemented. In version I it was carried with a Neutrik transformer, I think its not used anymore. But I am not sure.
It is not relevant if do not know how or are not interested in interpreting the data coming from the test. The noise in this condition is the intrinsic noise of the ML3 heard through the MM7 speakers, nothing added. Mike will immediately have a reference to what is possible to get in his system - theoretically he should be able to achieve something similar after fine tuning the system.
BTW, Mike has version II of the DartZeel preamplfier - we do not know exactly how the balanced stage is implemented. In version I it was carried with a Neutrik transformer, I think its not used anymore. But I am not sure.
I do know that there is no longer any transformer in either the XLR input or output in dart pre version II. and that version II input is much higher performing, as I used it with the Trinity dac and was very impressed.
OTOH while yesterday I did enjoy the absence of noise from the XLR output, later it was clear that for whatever reason the RCA output into the RCA input on the ML3 performed quite a bit better. there are a few variables involved so we are not just hearing these interface issues. the XLR interconnects were generic, the pair less than $50 value, and they were brand new and raw. the RCA's I've had for 5-6 years, are fully broken in as well as recently spent 5 days on my cable cooker, and have a retail value of over $3000. and the noise difference is not hardly noticeable.
the XLR performance seemed blunted and compressed, and had a bit of glare. it sounded one dimensional and lacked bass.
was that mostly the circuit difference? or mostly the cable? or a combination? don't know. I do have a slightly higher level XLR I will try later this week and i'll make sure it's had some cable cooker time.
I do think that in single ended configuration the dart pre seems to be a great pairing with the ML3, magical even. each plays to the other's strengths.
I do know that there is no longer any transformer in either the XLR input or output in dart pre version II. and that version II input is much higher performing, as I used it with the Trinity dac and was very impressed.
OTOH while yesterday I did enjoy the absence of noise from the XLR output, later it was clear that for whatever reason the RCA output into the RCA input on the ML3 performed quite a bit better. there are a few variables involved so we are not just hearing these interface issues. the XLR interconnects were generic, the pair less than $50 value, and they were brand new and raw. the RCA's I've had for 5-6 years, are fully broken in as well as recently spent 5 days on my cable cooker, and have a retail value of over $3000. and the noise difference is not hardly noticeable.
the XLR performance seemed blunted and compressed, and had a bit of glare. it sounded one dimensional and lacked bass.
was that mostly the circuit difference? or mostly the cable? or a combination? don't know. I do have a slightly higher level XLR I will try later this week and i'll make sure it's had some cable cooker time.
I do think that in single ended configuration the dart pre seems to be a great pairing with the ML3, magical even. each plays to the other's strengths.
Well, the ML3 is single ended after all and you are comparing expensive (presumably good) RCAs vs. dirt cheap XLR. Not a surprising result I would say.
thanks to you and Ben for taking the time last night to give me feedback on my new toy. glad you liked it....figured you would. and you are rarely if ever a wow guy.
I do know that there is no longer any transformer in either the XLR input or output in dart pre version II. and that version II input is much higher performing, as I used it with the Trinity dac and was very impressed.
OTOH while yesterday I did enjoy the absence of noise from the XLR output, later it was clear that for whatever reason the RCA output into the RCA input on the ML3 performed quite a bit better. there are a few variables involved so we are not just hearing these interface issues. the XLR interconnects were generic, the pair less than $50 value, and they were brand new and raw. the RCA's I've had for 5-6 years, are fully broken in as well as recently spent 5 days on my cable cooker, and have a retail value of over $3000. and the noise difference is not hardly noticeable.
the XLR performance seemed blunted and compressed, and had a bit of glare. it sounded one dimensional and lacked bass.
was that mostly the circuit difference? or mostly the cable? or a combination? don't know. I do have a slightly higher level XLR I will try later this week and i'll make sure it's had some cable cooker time.
I do think that in single ended configuration the dart pre seems to be a great pairing with the ML3, magical even. each plays to the other's strengths.
Sooner or later you will get a great noiseless system. My intention was suggesting a few simple tests that could show some systematic in technical noise minimization, minimizing speculation and time waste. I think we should avoid an excessive subjective analysis in the initial configurations. IMHO you ruin the XLR performance of your preamplifier when you short the inverted phase in XLR mode, as both phases share the same power supply. Knowing about that Cardas adapters do not short the pin 3 to ground, but connect it through a resistor to emulate the load of a balanced amplifier.
Sooner or later you will get a great noiseless system. My intention was suggesting a few simple tests that could show some systematic in technical noise minimization, minimizing speculation and time waste. I think we should avoid an excessive subjective analysis in the initial configurations. IMHO you ruin the XLR performance of your preamplifier when you short the inverted phase in XLR mode, as both phases share the same power supply. Knowing about that Cardas adapters do not short the pin 3 to ground, but connect it through a resistor to emulate the load of a balanced amplifier.
When I bought my ML3’s I spoke to Vlad about use of interconnect from preamp to amp he stated use RCA. I told him I needed a 10 meter run and was worried about noise in the signal from the long IC as well as loss of signal His comment to me was that the RCA was preferred and he guaranteed no noise or loss of signal from the long run. If I incurred any he offered a full money back guarantee. There was none
When I bought my ML3’s I spoke to Vlad about use of interconnect from preamp to amp he stated use RCA. I told him I needed a 10 meter run and was worried about noise in the signal from the long IC as well as loss of signal His comment to me was that the RCA was preferred and he guaranteed no noise or loss of signal from the long run. If I incurred any he offered a full money back guarantee. There was none
It is not relevant if do not know how or are not interested in interpreting the data coming from the test. The noise in this condition is the intrinsic noise of the ML3 heard through the MM7 speakers, nothing added. Mike will immediately have a reference to what is possible to get in his system - theoretically he should be able to achieve something similar after fine tuning the system.
BTW, Mike has version II of the DartZeel preamplfier - we do not know exactly how the balanced stage is implemented. In version I it was carried with a Neutrik transformer, I think its not used anymore. But I am not sure.
If the ML3 had a bunch of self noise then his XLR would be just as loud, and the noise wouldnt change with IC's lengths. Unless his amps were damaged in shipping, he will have the same silence potential as everyone else using them. So it bares no use as a test, since people with much more sensitive speakers hear nothing.
Unplugging the power to the preamp is still something worth a try, but obviously it'll have to be plugged back in to charge batteries even if it eliminated the noise (and I am not betting it will, but it is important to know).
If the ML3 had a bunch of self noise then his XLR would be just as loud, and the noise wouldnt change with IC's lengths. Unless his amps were damaged in shipping, he will have the same silence potential as everyone else using them. So it bares no use as a test, since people with much more sensitive speakers hear nothing.
Unplugging the power to the preamp is still something worth a try, but obviously it'll have to be plugged back in to charge batteries even if it eliminated the noise (and I am not betting it will, but it is important to know).
If you had looked at the specs and real measurements of the ML3 you would understand why this test. People who reported listen in very different conditions, with different speakers. We can never exclude the hypothesis Mike amps can have a noisy tube, it would immediately spot it. Besides it would provide an audible reference for comparisons. I am not going to loose my time arguing with you, it is useless. Bye.
If you had looked at the specs and real measurements of the ML3 you would understand why this test. People who reported listen in very different conditions, with different speakers. We can never exclude the hypothesis Mike amps can have a noisy tube, it would immediately spot it. Besides it would provide an audible reference for comparisons. I am not going to loose my time arguing with you, it is useless. Bye.
He had a noisy tube we swapped out but that's a different thing, this is a ground issue Francisco. Not unique to them but both ML2 & specially ML3 are sensitive to ground resistance imbalance between equipment, specially the ML3 and I've dealt with it in almost every setup I've been involved in including my own. Russ & Marty visited a friend yesterday with ML3's, he had the same noise problem which I took care of for him and it's completely silent now. The amp is always dead silent by itself but ground noise creeps in sometimes with the connection of the pre but usually after connecting other equipment to pre's inputs.
I do think that in single ended configuration the dart pre seems to be a great pairing with the ML3, magical even. each plays to the other's strengths.
It was exactly what my "non expert" test would have diagnosed in three minutes ...
BTW, I am used to ground resistance imbalance - I have owned the conrad-johnson ART preamplfier, a dual mono preamplifier with two separate power supplies . And I managed to get a noise free system connected to the premier 350 - a stereo amplifier with 34 dB gain!