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Audible Illusions Modulus

It's not popping, it's more of rushing sound. My friends says "it's nothing" since it's only audible with your ear placed against the speaker.
Am I over-reacting? I can get new tubes but I'm going to wait and see how it goes for a few days, then maybe have it looked at by my tech if I am still not happy, and let them decide if it needs tubes or not.
I try not to do tweeter whispering.

Does it sound OK or not?
I’d be interested to try @SIY grid resistor thing.
Don;t understand the circuits, but it sounds easy.
 
It's not popping, it's more of rushing sound. My friends says "it's nothing" since it's only audible with your ear placed against the speaker.
Am I over-reacting? I can get new tubes but I'm going to wait and see how it goes for a few days, then maybe have it looked at by my tech if I am still not happy, and let them decide if it needs tubes or not. Also I will mention the mod SIY has talked about.

Also the sound could be from system matching. My amps are 100 watts x 4 so lots of power to amplify the inherent noise of the pre.
Again, why do you need the preamp in the first place?
 
Again, why do you need the preamp in the first place?
I don't like the sound as much from DAC alone, even my Schiit Saga S sounds better than no pre-amp.
 
I don't like the sound as much from DAC alone, even my Schiit Saga S sounds better than no pre-amp.
A preamp isn't going to do diddly for that. It would be a ton cheaper and more effective to do some software EQ.
 
I try not to do tweeter whispering.

Does it sound OK or not?
I’d be interested to try @SIY grid resistor thing.
Don;t understand the circuits, but it sounds easy.

The sound is pretty good, I think. I do sense a bit of tube distortion, harmonics, etc. Overall it's on the warm side, but a little bright too. It's a Modulus 2C, btw.

As I enjoy listening to music from this thing, I am beginning to calm down a bit about the hissing/rushing sounds or the slight buzz on the left side. I also don't want to spend money on tubes, without knowing if it will help things.

The tubes say 6DJ8 but can’t read the brand through the case.
 
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I think I'm getting better results with the DAC turned down and pre-amp turned up. This kind of makes sense, since the DAC has a hot 5V output when maxed and I'm not sure gear was like that when this was designed. I think 2V is a more typical standard.

I don't hear distortion anymore. The hiss is just soft white noise I can only hear if my ear is next to the speaker. The buzz I thought I heard in one side is so quiet I'm not sure if I even hear it anymore...

Still, some have said changing tubes could fix the hiss.
 
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I do sense a bit of tube distortion, harmonics, etc.
That is much more likely to be an illusion rather than reality. The distortion in those circuits is almost never high enough to provide an audible coloration.

Short way of saying that the preamp is superfluous with your setup.
 
I love the glorious tube sound, so I’m dropping it off today to have the hum issue looked at. The hiss is gone from changing tubes, but the slight hum / buzz, more in the left side, persists.
 
Or the illusion that there's any tube sound.
You've made your point multiple times now. Probably time to cut the guy some slack.
He wanted to experience a tube preamp in his system. Nothing wrong with that.
 
You've made your point multiple times now. Probably time to cut the guy some slack.
He wanted to experience a tube preamp in his system. Nothing wrong with that.
I appreciate your service as hall monitor.
 
You've made your point multiple times now. Probably time to cut the guy some slack.
He wanted to experience a tube preamp in his system. Nothing wrong with that.
Thanks, not sure why he is picking on me because I liked the sound.

I dropped the unit off at the technician’s place. Changing the tubes removed the hiss but the hum, particularly in the left side, is still there. I explained this to the tech. I believe it’s old caps in the psu. I’m hoping he changes them and fixes the issue, but he said he will check out everything. He is familiar with these amps. The tube guy who sold me the Siemens and Valvo gold pin 6922’s used to sell these amps, and recommended this technician.
 
Thanks, not sure why he is picking on me because I liked the sound.
You haven’t done the basic checks needed to see if there IS an actual “sound.” Beyond the noise from oscillation, that is. What I’m trying to do is help keep you from pouring money down a useless hole.

Hum is usually a grounding issue. Bad power supply caps usually give more of a buzzy noise.
 
Hum is usually a grounding issue. Bad power supply caps usually give more of a buzzy noise.

This may be helpful. It is both. Humming and buzzing. More in the left side.

If the issue, or any hum persists after getting it back, what would be the next step to take to try to eliminate grounding issues?

Connect it to a different outlet? Right now I’m connecting everything to a Furman power conditioner plugged into a 3 to 2 prong adapter, due to old wiring.

This pre amp, like my power amps, does not have a 3 prong plug.
 
Thanks, not sure why he is picking on me because I liked the sound.

I dropped the unit off at the technician’s place. Changing the tubes removed the hiss but the hum, particularly in the left side, is still there. I explained this to the tech. I believe it’s old caps in the psu. I’m hoping he changes them and fixes the issue, but he said he will check out everything. He is familiar with these amps. The tube guy who sold me the Siemens and Valvo gold pin 6922’s used to sell these amps, and recommended this technician.
I don't know what the result will be. It does sound like your pre might have some issues. Suppose the tech fixes the PSU or other issues and you get it back. Now quiet, functioning properly etc what if it has no identifiable sound quality? I think SIY's point that it probably doesn't have a sound if functioning properly is not so extreme.

Here are measurements done by Stereophile for a Modulus 3A.

There not a lot there to make you think it has much of a sound. They do note moderate levels of DC output and that they fluctuate considerably. Maybe why you have gotten the pops on your amps at times when turning them off. They also show a rather high output impedance which might dull the sound a bit with some cables.

Tubes, Tubes, TUBES! They have great musical sound.......or so goes the myth. Just put tubes in the signal path and you might like it. You probably will like it better. I used tubes for years, and years. Tube power amps have a sound. Tube pre amps, not so much. SS pre amps not so much. So many want that tube sound and think a tube preamp gets that without the hassle of a tube power amp. Sorry, it very rarely is so.

Now if you just like the idea nothing wrong with that. But you seem to be suffering lots of trouble to gain something that is based upon a myth. SIY is actually trying to help you out.
 
I don't know what the result will be. It does sound like your pre might have some issues. Suppose the tech fixes the PSU or other issues and you get it back. Now quiet, functioning properly etc what if it has no identifiable sound quality? I think SIY's point that it probably doesn't have a sound if functioning properly is not so extreme.

Here are measurements done by Stereophile for a Modulus 3A.

There not a lot there to make you think it has much of a sound. They do note moderate levels of DC output and that they fluctuate considerably. Maybe why you have gotten the pops on your amps at times when turning them off. They also show a rather high output impedance which might dull the sound a bit with some cables.

Tubes, Tubes, TUBES! They have great musical sound.......or so goes the myth. Just put tubes in the signal path and you might like it. You probably will like it better. I used tubes for years, and years. Tube power amps have a sound. Tube pre amps, not so much. SS pre amps not so much. So many want that tube sound and think a tube preamp gets that without the hassle of a tube power amp. Sorry, it very rarely is so.

Now if you just like the idea nothing wrong with that. But you seem to be suffering lots of trouble to gain something that is based upon a myth. SIY is actually trying to help you out.
Would hitting the mute button on the pre before shutdown remove the danger?


I’m sure a good solid state pre would be wonderful too. But one difference might be how I would use them with my dac. With the Modulus 2C, I kept the two volume controls at the same level and adjusted the volume with my dac. But with other pre amps that have a remote I generally won’t do that.

I will also say my Schiit Saga S sounds much cleaner and is very quiet, but feels anemic thin and lacking in body.
 
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Would hitting the mute button on the pre before shutdown remove the danger?


I’m sure a good solid state pre would be wonderful too. But one difference might be how I would use them with my dac. With the Modulus 2C, I kept the two volume controls at the same level and adjusted the volume with my dac. But with other pre amps that have a remote I generally won’t do that.

I will also say my Schiit Saga S sounds much cleaner and is very quiet, but feels anemic thin and lacking in body.
So the Saga is going to be inaudible PERIOD! If you had a DAC with the right output level, you could insert the Saga or insert a cable. No difference you'll hear.

I know you read this forum. The idea those warm glowing tubes sound warm is one you'll not get around. If that lasts and it makes you happy then fine. If you ever tried them with someone switching them out, once your Modulus is working properly, I doubt you'd hear any difference. If you did, it would be very minor. There just isn't anything going on to make one sound very much different than the other.

No you have what 2 amps. Are you using long interconnects with those? If long enough they might cause a slight softening of the treble. Other than that, you either live happy with how things seem, or decide to find out the truth which might indicate there is nothing to it. This can work both ways. If you find there is nothing to it, and you like the idea of a well built simple tube pre then use it. You aren't losing nothing. Or you might find a freedom as you can grab any number of handy bits of gear without worrying one is better than the other. It is all up to you.

Take SIY for instance, he likes tube circuitry I think. He does projects with tubes, writes article about some of them. I don't think you could claim he is anti-tube. But he doesn't buy into the idea they are somehow different or better if they are designed right.
 
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