DARED SL2000a

[audiocr381ve]

The Dared arrived today! It didn't ship with a rectifier tube (seller broke it during packaging) so I had to pick up a temporary one from a guitar shop nearby which ended up being a blessing because it was one of the only places that carried a 5Y3 and it was 10 minutes away. It's' a Sovtek 5Y3GT tube made in Russia (know nothing about tubes yet, so I'm not sure where this stands as far as sonics go in the audiophile tube world). It shipped with the stock signal tubes.

I have a few things to run by you guys. The remote control does not work properly. Pressing the volume up button turns the Dared down. The volume down button does nothing. I'm hoping this is a weak battery issue?

Next thing is hum. I'm definitely getting some hum from the speakers with or with out music playing. Is this normal with tube preamps?

Thanks in advanced for the help!

[heiney9]

The Sovtek is very, very ordinary. Hus should not be an issue, but could be related to the stock tubes. Change the batteries in the remote and report back.

H9

[audiocr381ve]

The Sovtek is very, very ordinary. Hus should not be an issue, but could be related to the stock tubes. Change the batteries in the remote and report back.

H9

Yeah I figured it would be.

To be clear you're saying that hum should NOT be there? Is it normal in some tubes? Thanks Brock.

BTW, it sounds GREAT as is. I'm thoroughly enjoying it. Completely different sound than my Pass B1 buffer. It has tons more depth and warmth. Love.

[george daniel]

MY Dared is dead quiet,,signal tubes maybe?

[soundfreak1]

Never heard a complaint about a hun from a dared, mine is dead quiet. Maybe stock tubes. Gat rid of them and upgrade all . Others can speak in detail better than i but with the right tubes you be amazed with what that pre can do! Enjoy

[audiocr381ve]

Appreciate it, thanks guys. I got a very generous offer from Brock and I'm going to pick up a set of signal tubes & another rectifier from him soon.

[audiocr381ve]

So my Parasound HCA-750a has gain knobs on the back of the amp. They were turned up all the way, so today I lowered them to about a 1/3 way up, and that FIXED the hum issue. Can anyone explain this?

Some tube porn for you.

[Keiko]

Never had a hum issue with mine either. As far as the remote problem, if the problem persists after changing the battery, crack it open and flip the circuit board. It's possible it was installed upside down.

[audiocr381ve]

Never had a hum issue with mine either. As far as the remote problem, if the problem persists after changing the battery, crack it open and flip the circuit board. It's possible it was installed upside down.

Well turning down the amps built in volume knobs fixed it, but I hope it's not just a bandaid. If the new signal tubes don't fix it, I hope I won't have to look into repairs.

[Upstatemax]

So my Parasound HCA-750a has gain knobs on the back of the amp. They were turned up all the way, so today I lowered them to about a 1/3 way up, and that FIXED the hum issue. Can anyone explain this?
g]

I never had a hum issue when my SL2000A was connected to my Parasound...

Did you clean all the connections?

[chandler9a]

That just looks sexy...

[evhudsons]

what about the power supply or grounding side? I had a hum in an older NAD amp, and I simply flipped the cord the other way in the outlet and problem solved. The older power cords didn't have the larger side to let you know how to properly plug them in for proper grounding.

[audiocr381ve]

Aaron, get one. I don't know why I ever spent double when I could have had the sound I've always wanted for under $500.

The sound I don't want is hum/noise. It is audible from my listening position. ev, this has a typical IEC connection, so I couldn't flip it. I have it running into my APC H15 power conditioner with no help. What's weird is even when the preamp is off, their is still noise going to the speakers with the amp on. The Pass B1 didn't do this.

I'm hoping Brock is right about it being the tubes, but another person is having the same problem in another thread and HAS changed out his tubes.

[heiney9]

If the pre-amp is off you shouldn't still be getting a noise. Disconnect the pre and see what happens then. Have you tried swapping I/C cables? I would also try that. Tube pre's, especially this one shouldn't hum at the level you describe. Sometimes they *might* have a low level hum that you would need to put your ear up to the speakers to hear, even that is the exception. Where is the pre physically located in your rig? If it's near the amp perhaps try relocating it. Sound to me like some sort of electromechanical feedback or ground loop. Do you have another rig you can try the pre-amp in? Maybe a buddies rig?

I'm still guessing better tubes in every position will cure this problem. Or maybe even a combination of all the above and new tubes.

H9

[heiney9]

Try very gently wiggling the tubes when the pre is off and clean the pins with DeOxit and Q-tips. It's amazing how cleaning the pins makes such a difference, especially for noise. Even if they don't look like they are dirty.

H9

[soundfreak1]

If u r getting the hum when the pre is not on , look elsewhere. Maybe the amp is overdriving or has an issue considering it went away when u lowered the amp gain. Could be in the amp powersupply? I have had several parasound amps and still do but no hum but that dosent mean it cant be your amp. Do u jave another amp u could put in to test? Also check your ic's they could be the prob.

[audiocr381ve]

Hey guys, thanks for chiming in.

I have another pre (buffer) that I used when troubleshooting to find the culprit. It is most definitely the Dared. When the Dared is off and amp is on, their is hum. When I take the IC's out of the Dared, hum stops. When doing the exact same thing with my other pre, no hum at all. (to make sure I didn't blow the speakers, when removing the IC's from the Dared I'd turn the amp off of course, then on again once the IC's were removed for this test). This makes me think that their is something weird going on in the circuit of the Dared?

Now with the Dared on, their is very obvious hum & noise at an even higher level even at the listening position. I can easily record the noise if it helps. Anyway, when I turn up the music it's not a problem, but it is loud enough to concern me when I'm hearing it from 10 feet away.

I will try all of the above and hope for the best! Brock, I've been meaning to get to the post office but it has been a busy week. I'll keep you posted!

[FTGV]

Does it (Dared)have a 3 pronged AC cord and do you have a multi meter?

[audiocr381ve]

Does it (Dared)have a 3 pronged AC cord and do you have a multi meter?

Yes it does and I do have a multimeter.

[FTGV]

Then with everything disconnected and unpowered use the Ohm's scale and check the resistance between the ground lug of the AC cord and outside of one of the output RCA connectors.

[sda2mike]

interesting ftgv, i wondering how he made out

[FTGV]

Well if he measures near zero resistance that would indicate the preamps chassis and circuit grounds are tied together which can be a recipe for a ground loop which from his description seems to indicate.

[heiney9]

Your buffer has no gain and the Dared has a good amount of gain.

H9

[FTGV]

True but he states

. When the Dared is off and amp is on, their is hum. When I take the IC's out of the Dared, hum stops.

[heiney9]

Shane, please update what you've tried from all the check lists people have suggested. I get mildly annoyed when people post a problem and then there is a methodical procedure outlined and the OP never states what they have tried. Not busting your balls, but what have you tried to try and eliminate some of the obvious things?

H9

[Upstatemax]

After moving my Parasound up to my HT this week, I noticed a hum. I could be 15' away and still hear it...

I cleaned all connections and nothing. So I decided to run a dedicated power line to my HT and the hum is gone.

I also had a dedicated line in my old 2ch system and I never had a hum. I plug my amp directly into the wall with a Signal Cable power cord.

[audiocr381ve]

Then with everything disconnected and unpowered use the Ohm's scale and check the resistance between the ground lug of the AC cord and outside of one of the output RCA connectors.

Sorry everybody, long work weekend.

Here's what I've tried so far:

1. Cleaned tube pins with Deoxit and Q-tips.
2. Moved pre farther away from amp.
3. Changed IC's
4. Plugged Dared directly into socket bypassing my APC H15

No luck so far. FTGV, what do I choose on the Ohm's scale on my multimeter? 200, 2K, 20K, 200K, or 2M? I tried 200 and it gave me a reading of 00.0 through 00.3. It didn't quite lock on anything. I tried 2k, 20k, 200k, and 2M and it gave me a consistent reading of zeros across the board. I unplugged the IC's from the amp and source so the only thing connected to the Dared was the power cord. Was I supposed to get the readings I did?

[FTGV]

Then it would appear the grounds are connected which could be creating a loop.While I don't recommend it as a permanent solution but for diagnostic purposes you can try a cheater plug on the Dared,s AC cord and see if that eliminates the hum.

[audiocr381ve]

Then it would appear the grounds are connected which could be creating a loop.While I don't recommend it as a permanent solution but for diagnostic purposes you can try a cheater plug on the Dared,s AC cord and see if that eliminates the hum.

I'll try that, but what's the permanent solution and why do you think others aren't reporting this?

[pepster]

Have you looked inside at any work that may have been done, upgrades, ect, from someone else?
Odd caps, bypass caps, upgraded rca inputs.......ect. as an example?