[vortrex]

I've got a vinyl only rig and recently placed a new phono pre and integrated into my system.  Now there are two issues I need to sort out.  Both related to having too much gain?

1.  Volume at 8 o'clock is pretty much my max listening level.  This makes it almost impossible to use the remote.

2.  Hum/noise that seems excessive since my last lower gain setup (same table, cart, SUT, interconnects, power cables, conditioner) was dead silent.

My grounding seems fine, which is table to phono pre and SUT to phono pre.  Touching various parts or adding more grounds has no change.  I connected a CD player and it's dead silent.  If I remove the SUT from the path and use the MM inputs of the phono pre it's better.  The volume knob is now around 10 o'clock at my max level (which is probably middle of the ground), but there still is a low level hum.  It sounds better with the SUT though so I really want to use it.  The KAB gain calculator says I should be around 62db, but it appears as though I am at 71db.  Would 9db extra be enough to create these issues?  I've read other posts about gain which discussed matching things, but I really didn't understand all the details.

Known values:

Cartridge: output is .25mv and 14 ohm
SUT: output is 26db? and 1:20 step up ratio
Phono pre: input is 47k ohm, output is 45db and 50 ohm
Integrated: input is 100k ohm and 200mv sensitivity

Does this seem compatible?  I can lower the gain of the phono pre with a resistor change per the manufacturer.  As far as I can tell nothing in my specs looks out of the normal.  I guess I'm wondering how others are doing it.  In my last system I had no pre-amp and my volume control was handled at the phono stage connected direct to my amp.  I've got some lower gain 5751's on the way to replace the 12AX7's in my integrated, not sure if that will help any.

[cheap-Jack]

Hi.

I've got a vinyl only rig and recently placed a new phono pre and integrated into my system.  Now there are two issues I need to sort out.  Both related to having too much gain?

1.  Volume at 8 o'clock is pretty much my max listening level.

 In my last system I had no pre-amp and my volume control was handled at the phono stage connected direct to my amp.

Problems are so often caused by too much gain.

Why you want to replace yr old phonostage with a new one with too much gain?
I can tell you, more gain more pain.

I never add any active linestage which only does harm to the music instead of curing it. For me, passive only for progamme selection & level control. Less gain more music.

c-J

[vortrex]

Well...it's not so much the phono pre.  My previous one was 38db and I can throw that in with the new integrated and it has similar issues.  I guess it comes down to how are people running SUT's with pre's/integrated's?  At 45db MM my new phono stage seems fairly normal gain wise, from what I see.   The only real low gain unit I see is the Leben at 23db.  I'd like to get some of those stepped attenuators to troubleshoot this, but nobody makes them anymore.
   

[blakep]

With low output MC's, the right gain is critical IMO and the KAB calculator pretty much nails how much the right gain is with most systems.

Sadly, you have a mismatch and a pretty bad one at that. My experience is that you want to be, at most, 2-3 dB either side of the KAB calculator's recommendation and as close to right on it if at all possible.

Once you're beyond that (light or heavy, doesn't matter) you are seriously compromising sound quality. At 9 dB over, I would not think you would be even close to hearing what your setup is really capable of. Apart from maxing out early on the volume pot, I'd expect it to sound pretty awful when compared to what you'd be hearing with the appropriate gain.

Get the gain right and you will be rewarded.

[Quiet Earth]

I connected a CD player and it's dead silent. 

Integrated: input is 100k ohm and 200mv sensitivity

Is the CD player also too loud at the 8 o'clock volume position (with the new integrated), or just the phono stage?

What was the input sensitivity of the old integrated?

[vortrex]

actually, it sounds pretty good.  there's that sensation of it being wound too tight though and slightly etched at times.  I'll get the gain dropped on the phono stage and go from there.

With low output MC's, the right gain is critical IMO and the KAB calculator pretty much nails how much the right gain is with most systems.

Sadly, you have a mismatch and a pretty bad one at that. My experience is that you want to be, at most, 2-3 dB either side of the KAB calculator's recommendation and as close to right on it if at all possible.

Once you're beyond that (light or heavy, doesn't matter) you are seriously compromising sound quality. At 9 dB over, I would not think you would be even close to hearing what your setup is really capable of. Apart from maxing out early on the volume pot, I'd expect it to sound pretty awful when compared to what you'd be hearing with the appropriate gain.

Get the gain right and you will be rewarded.

[vortrex]

Is the CD player also too loud at the 8 o'clock volume position (with the new integrated), or just the phono stage?

What was the input sensitivity of the old integrated?

I've done so much testing I kind of forgot.  I think the volume control was better with the CD.  it's not something that is kept in my system so I would have to extract it from the video setup and install in the audio rack.

the old was not an integrated, it was a BAT VK-55 amp which my phono stage ran directly to.

[Quiet Earth]

I think the extra gain you picked up might be in your new integrated. Hook the CD player back up to the integrated just to see if that also seems too loud at 8 o'clock. Listen for an aggressive or congested/constipated sound at a very low volume level.

[Quiet Earth]

Also regarding the hum -

I was thinking that since you bought a new amplifier and a new phono stage you may need to relocate your SUT because now you have different magnetic fields generated around the system. Something worth trying anyway.... On the other hand, you may have had the same hum before but you did not notice it with the lower system gain.

It seems to me like the small addition of new phono stage gain, minus the loss of the volume control from the old phono stage, plus the higher gain of the new (more sensitive) integrated is all adding up to give you a little too much system gain. I think you can drop it a little somewhere and be happy.

If the CD player is choking the integrated, I would look there first. BTW, what integrated did you Get?

[vortrex]

if I remove the SUT from the system the issue is still there with the hum/noise, only less pronounced.

I put the CD back in and the volume control is a little better, but still not what I would want if I used it in my system.  after reading a lot of threads on audiogon over the past few days about gain issues it seems fairly popular for people to use attenuators with their CD players.  I think a 10db with the CD would make it perfect.

it's a Line Magnetic 218IA.

[Ericus Rex]

Try moving the phono section away from other equipment and power supplies.  If it still hums then move any power supplies away from integrated as well.  Tell us about the grounding on your tt setup.

[vortrex]

Try moving the phono section away from other equipment and power supplies.  If it still hums then move any power supplies away from integrated as well.  Tell us about the grounding on your tt setup.

I can't really do that due to interconnect length.

standard ground from table to phono pre, nothing special.

[rollo]

   Does your CDP have a ground release switch ? If so reverse it. Try a cheater plug on each component to determine if the hum is from a ground loop first.
    Do you cable TV ? Check the grounding of the cable, sometimes a culprit in loops. If all else fails try swapping ICs. BTW are any of your ICs marked directional ? Sometimes if so the grounding schemes muck it up with hum.
     So my dear friend you ave some work to do. Just gotta get down and experiment or it will drive ya nuts. good luck and have fun learning.


charles

[vortrex]

I don't use a CDP in my system, so I am not really worried about that.

I've tried a cheater plug on the integrated, no change.  I will try it on the other gear tonight.

yes, I have cable TV.  it's on the other side of the room though and I think all the video gear is on a different circuit.

no spare interconnects to use and yes the ones I have are directional.

Manley says the issue is because of the input sensitivity of my integrated.

[blakep]

Vortrex: I am looking at this thread again and trying to read between the lines a bit. I'm assuming your phono stage is the Manley Chinook and I'm taking a wild guess that your cartridge is a Denon 103R?

If that's the case, why not just lose the SUT, configure the Chinook for MC with 60 dB of gain and a 100 ohm load and be done with it?

If you are indeed using a 103R with the Chinook, those settings should be just about dead on perfect (both my 103R's have actual output closer to .3 mV with 61 db of gain being ideal).

My guess is that you would be a very happy man then.

[vortrex]

with the SUT it sounds better, which is why I want to use it.

I've tried the 103R on the 45db setting of the Chinook with no SUT and it's pretty good gain wise.  60db would be too much.  trust me though, the Chinook sounds better using a SUT with the 103R.

I think Manley is right and the input sensitivity of the integrated is the real issue here.  I'm going to try a Leben phono stage with the SUT, that is only 23.5db.

Vortrex: I am looking at this thread again and trying to read between the lines a bit. I'm assuming your phono stage is the Manley Chinook and I'm taking a wild guess that your cartridge is a Denon 103R?

If that's the case, why not just lose the SUT, configure the Chinook for MC with 60 dB of gain and a 100 ohm load and be done with it?

If you are indeed using a 103R with the Chinook, those settings should be just about dead on perfect (both my 103R's have actual output closer to .3 mV with 61 db of gain being ideal).

My guess is that you would be a very happy man then.

[blakep]

with the SUT it sounds better, which is why I want to use it.

I've tried the 103R on the 45db setting of the Chinook with no SUT and it's pretty good gain wise.  60db would be too much.  trust me though, the Chinook sounds better using a SUT with the 103R.

I think Manley is right and the input sensitivity of the integrated is the real issue here.  I'm going to try a Leben phono stage with the SUT, that is only 23.5db.

If you haven't tried it on the correct MC setting/input with 60 db of gain and the cartridge properly loaded (probably at 50 or 100 ohms) I'm not sure how you could say that it sounds better using the SUT.  I would strongly suggest you at least try it before spending more money.

Running a 103R into the appropriate input with the correct gain AND loading is a far cry from running it into a MM input loaded at 47K. It's "pretty good gain wise" on the MM because it's not properly loaded, but it will still sound like crap. This is about getting BOTH the gain and the loading right. To say that the SUT sounds better if that is the comparison is really not saying much. I'd expect them to both sound pretty bad.

If I'm reading you correctly you are now going to move from 71 db of gain to 49 db of total gain with a cartridge that works best with 60-61 db of gain (I've been running 103R's or modified 103R's for more than 5 years now) when you have the ability to have essentially the perfect settings on your Chinook without the SUT.

If the increased sensitivity on the integrated is indeed an issue (make sure you are running into an AUX input as opposed to a CD input on the integrated if they are differentiated!) I would think you would still be much further ahead and have much better sound quality by loading the 103R down to 50 ohms with the Chinook and 60 dB of gain than having 49 dB of total gain with the Leben and SUT.

If you've tried it as I've suggested and found it to not work I apologise. Only trying to help. I'm a bit surprised that Manley would not suggest trying it under the circumstances if you've been in contact with them. It makes absolutely no sense to me if that is the case.

[vortrex]

I'm fairly certain I have tried every combination at 60db with various loading, but I will do it all again this weekend and pay closer attention to each specific setting.  I quickly moved off the 60db though, since there was still the problem with the sensitivity of the volume control.  And yes, I have explained this all to EveAnna herself and she suggested to use the 45db setting with my 103R.  I am not using the CD input on the integrated.

[blakep]

Good luck. In looking at the Chinook manual online it looks like you will have to open the unit to adjust the gain to 60 db on each channel internally.

From there, as I suggested I would adjust the dips on the rear of the unit for either 100 ohms (5th dip from the left labelled 100 ohms-should be labelled #5-up and all other dips down) or 50 ohms (4th dip from the left-should be labelled #4-up and all other dips down) for both channels.  Those should get you in the ballpark-you can tweak later if it works out.

You have the ability to load right down to 26 ohms by the looks of things (reducing the load has a net effect of slightly reducing the output from the cartridge or reducing the gain, but it may also have detrimental effects on sonics) but I would try 100 and 50 first as they're nice and easy!

No SUT!!!!

Let us know how it works out.

[vortrex]

yes, the gain switches are on the inside.

I will update with my findings, but I suspect I know what they will be...