Ok, test complete. Yes, this is essentially the same test as when I swapped one cable out for the Monster cable.
The result was the same. There is no distortion. The bass is clean and there is no hint of any "whiny" interference noise as I change the volume.
It's like whenever two LC-1 cables are used in tangent, this is the formula for opening the gates of hell... |
U guys think I should just try some different cable?
I seem to be out of options with my current BlueJeans LC1s. |
Hmm, no phono in... just a pair of RCA's. It's a Yamaha M-40 power amp.
The plug isn't polarized.
In the manual, it says to connect the ground to the pre-amp ground if there is a buzz. Unfortunately my pre-amp has no ground.
You were right about switching the ICs. Last night I started to think... 'wait, this doesn't make sense that it would only be coming though one channel.' I swapped the ICs with another pair, and the issue was solved.
I have no idea how this could happen - maybe something is wrong with the shielding on one of my ICs? They are brand new, so I didn't suspect that at all.
Incidentally, I had to turn my amp on and off many times while switching power configurations around. Also, some music was distorted in that right channel (crackly, fuzzy) at times... could any of this have damaged my amp / speakers? |
Hmm... interesting. Well, the cord is already going back... but that's good to know for the future.
Any chance the static distortion did speaker / amp damage? Everything sounds fine, but I would like to know if such distortion is the same as amplifier clipping...? |
Ok... I have to revive this thread. I just received my new replacement cable as well as a new passive pre-amp. I hooked everything up and **suprise!** the whining interference noise is back in full force!
So, I started to switch around the orientation of my interconnects. I have one from my DAC to my pre and the other from my pre to my amp. Pretty standard.
Now, I have found a configuration that works pretty well, but not perfect... there is still a very faint 'whining' noise when my volume on my pre-amp is set between 8 and 11 o'clock. Beyond that, it's dead silent.
Now, tell me how this makes any sense... at all:
Let's say interconnect 1 has terminals A and B. Interconnect 2 has terminals C and D.
Here here my results, running sequentially from DAC to pre-in to pre-out to amp:
A-B-C-D : loud whine
A-B-D-C : loud whine
B-A-C-D : loud whine
B-A-D-C : loud whine
C-D-A-B : loud whine
C-D-B-A : loud whine
D-C-A-B : loud whine
D-C-B-A : dead silent except for faint whine at low volume
I don't get it... at all. What gives? If it's a shielding problem, then shouldn't configuration A-B-C-D also work just as well?
What should I do? |
Ok... definitely frustrated now.
Even with configuration "D-C-B-A" when at volumes other than 'full' on my pre-amp, I get this really fuzzy, static interference when lower frequencies are strong (deep base).
This is the second passive pre-amp that has done this and it is a different make than the first... sooooo, I think it's safe to rule that out at the culprit...
It's these cables I bet... They are BlueJeans cables, though... I thought these were supposed to be pretty good??? |
It was caused by the LC-1 using shield as the return? What does this mean? Why was it bad only when connected to my pre-amp? What types of cable should I be looking at as a replacement?
Thanks everyone for the help - much appreciated. |
Another update -
I just swapped out one of the BlueJeans ICs with an old Monster IC I had and the problem is completely gone... no whining or distortion at all.
Unfortunately, I don't want to use my old Monster cables... so I guess I will have to send all my BlueJeans cables back and get something else. Bummer. |
You think so? IDK, it seems weird that just swapping out one of the interconnects fixed everything...
Plus it isn't the typical 60Hz humm.. it's like 2-3 kHz... more of a whine. Also, there is that strange distortion in my lower bass region.
All I can think is there is some sort of interference between 2 BlueJeans cables that are near eachother and have a different magnitude of the same signal going through them (the one after the pre-amp will be attenuated unless it's at full volume).
Sucks... |
So what alternatives to BlueJeans do you guys think I should try? I need to stay around that same cost, unfortunately ($40 per cable max). |
Ya... I'll try the grounding thing and let you know how it goes.
Would this be the same as grounding my amp to my power conditioner? I tried that... and it altered the nature of the distortion, but did not remove it. |
Grounding issues are always 60Hz hums though, right?
This one is like 2-4KHz... and varies as I alter the volume levels of my pre-amp. |
Ya, in that early post I had thought that going straight into the wall had worked. It ended up that it repressed the noise quite a bit, but the distortion of lower frequencies was still there and the high-pitched whining had turned into a static 'fuzzy' background.
I'm going to go try some old cheap interconnects I have laying around real quick. I'll report back. |
WAIT! NO! I was mistaken. Upon closer listening, I do still have some distortion in my right channel... right channel only. And this is only with lower frequencies.
The 'whine' sound is certainly gone though. |
Ok, so... now I'm going to bypass my pre-amp all together and run straight into my amp from my DAC via a 2ft LC-1 cable. |
I just wanted to add... this distortion, again, completely goes away with my pre-amp turned all the way up. |
Sooo... actually there is no need for me to run straight into the amp from my DAC... I know it will be perfect. It has been that way for a few days and it was fine. Also, the fact that it goes away with my pre-amp turned up all the way indicates that something is awry in that area of the chain. |
Sorry for all the posts -
Ok, what I'm going to do is try a different amplifier and see if the same thing happens. |
The thing is... it sounds perfect when I run my DAC directly into my AMP.
OK, so.. here's what I just did:
I didn't use my other amp (integrated) simply because I didn't have the right terminals on my speaker wire. I did, however, use it solely as a pre-amp feeding my amp (whereas the pre-amp I have been using was a little passive w/ volume control).
Using my older integrated as a pre-amp, the noise was MUCH MUCH worse. Again, it was primarily in the right channel.
I switched the RCA's connected at the back of my power-amp, and sure enough, the distortion completely switched channels as well. So, we know it isn't a malfunction on the part of the amp I suppose.
It must be line interference somehow... I really don't get it still.
I'm now going to try connecting my amp chassis to the ground on my temporary pre-amp. |
Ok, Chassis on amp connected to chassis on DAC or pre-amp = zero difference at all (full distortion still present). |
oh no I havent tried that... I will right now. |
Jea48 - Your on the right track.
I just hooked up a long run of crappy RCA cable from the analogue outs of my PC. It was the same set-up just with a different source than the DAC... and there is no noise or distortion at all.
So... the problem isn't the cables, but rather something with the output of the DAC interacting with the pre-amp.
It's weird that the DAC sounds excellent when going straight into the AMP.
So, Tvad - I'm going to take your advice and try to ground the DAC to the pre-amp. What is the best way to do this? There is no 'ground' provision on my pre-amp or my DAC, unfortunately. |
You got it Kijanki.
That sounds perfect now. Man, that was crazy.
Ok, so... for some reason I can run LC-1 from my DAC directly into my amp without a problem... but I cannot run LC-1 from my DAC into my pre-amp.
I would have never guessed this... how weird. I had to try a thousand different things to figure this one out.
So, why would this be the case? I'm pretty clueless on this one. |
I do have everything plugged into the same outlet. It's all on a power conditioner, actually. I think the confusion there arose when I was switching my power plugs around everywhere to see if that would make a difference.
I tried grounding the DAC to the pre-amp chassis earlier but it didn't seem to make the slightest bit of difference. The screws on my DAC are really small, but I made pretty good contact with them.
So, even though LC-1 cables use shield as a return, I still shouldn't have this problem? What exactly does it mean to use shield as return? |
awwww maaaaan. Well, thanks for the help man. |
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Alright... I took the DAC and hooked it up in a separate system on a separate circuit (only using the same LC-1 cable) annnd the noise was still there. Why it would disappear when going direct to my amp (as well as my old integrated) is a mystery to me. |
Sooo..... is my DAC faulty? |
Anyone? What is a cable that has a return through the shield? |
So is this sort of interference problem known to occur sometimes with this type of cable?
Does this problem I'm having mean my DAC has a problem? |
Well I took the DAC out of my system last night and hooked it up to a second system using LC-1 for the output. The same interference noise occured
I had three pairs of LC-1 cable and tried all three as outputs from my DAC to my pre, and they all had the same problem.
If I switch cable, everything is great. If I use the LC-1 to run straight from my DAC to my amp, everything is great. It's only when running LC-1 from my dac to a pre-amp that things get ugly.
Here is my system:
Digital feed from PC via Blue Jeans Digital Coax ->
Audio Mirror D2 NOS DAC ->
Blue Jeans LC-1 ->
Richard Lee Audio Passive Pre-amp ->
Blue Jeans LC-1 ->
Yamaha M-40 ->
Blue Jeans (Belden 5000) speaker cable ->
Green Mountain Audio Continuum 1s ->
Ears.
For power:
-Computer is on separate power conditioner (this isn't the problem as I experienced the noise with the computer turned off)
-DAC and amp plugged into Furman Elite 15i. DAC is fed by Iron Lung Jellyfish power cable, amp by it's stock power cord.
That's it.
You mentioned the 'loose connection' thing... and I was thinking of something along similar lines. While nothing feels loose, the connectors on the back of my DAC are considerably long. What if the farthest I can push in the LC-1 onto these connectors just isn't enough to make contact with something that is necessary. I don't really understand the details of how this works yet, so this is a shot in the dark... |
I just wanted to add... the cable would only slide down about half way of the connector post on my DAC. At that point the connector would stop because it was hitting the plastic at the back of the space between the outter ring and the inner rod of the RCA connector.
Even if this was it, it still doesn't make sense to me why it would be fine when I run directly to my amp... something to do with not having 2 different signal wires running different amplitudes maybe? |
It really doesn't sound like the DAC is defective, does it? It seems more like something silly like an incompatible RCA connector... |
I contacted BlueJeans and they told me that this has happened with a few other people as well. As silly as it sounds, he/she told me that I just needed to 'push harder'. There are these 'tension fingers' that form a tight lock on the RCA connector. These can cause the connector to feel like it is on all the way when really it has a little ways to go.
Unfortunately I sent my cables back... so I have now ordered some new LC-1s to see if this is indeed the solution. Crazy. |
