"Too much gain"? (Cary SLP05 question)

Just thought I’d ad my two bits as I have a lot of experience with the SLP-05. I do not work for Cary Audio. First off avanti1960 is correct. The two “Balance” controls, essentially extra dual mono controls, can be turned down so you have plenty of range on the main volume control. If you want to be able to adjust the main volume control to 12 o’clock, then set it there and adjust the two balance controls until you find a comfortable level. This accomplishes the exact same thing as buying an external set of volume controls.
The main volume control in the SLP-05 is a motorized Alps Blue Velvet control. Fairly good controls. The other two balance controls are pretty cheap crap controls. And yes the quality of the controls will affect the sound quality. I know some people have wired past these two controls to get them out of the circuit and yes, it is noticeable. In the old days we used to be able to get the Tokyo KO-ON Denpa stepped attenuators which were fantastic and yes expensive! Khozmo now makes some really nice controls.
A poor quality control will add grain, noise and cause a loss of the overall clarity and smooth character of you sound, etc.

Another thing that can be done is to get the ultimate upgrade that Cary offers. One part of the upgrade is that they change the plate and cathode resistors which reduce the gain some and also improve the sound. There is a lot more done but this part is of interest to you. This upgrade is totally well worth it and dramatically improves the sound quality. I would also have them wire passed the two balance controls unless you really need them. Or purchase two really good controls and install them in place of the two inside the SLP-05. I don’t recall the value of the two but it is stamped on the casing of the controls.  I know the main Alps is 100K.

Just like any part in the circuit or a cable, etc.  The controls make a difference. Now whether your system can reveal that or you’re ears can hear that difference is where you draw the line on how far to go and how much to spend.  Don’t forget, if you add external volume controls that also means more cables.

@xcool’s statements are perfect.  Love it. 

Although the Cary support person is very nice, sometimes he doesn’t give me a straight answer [. . .] He never really answered my question.

“Haha. Yeah. There was a time when I used to rave to anyone who would listen to me about Cary Audio’s telephone tech support. I will say no more on that subject.”

Yes, absolutely right!  Now the answers are just cut and paste.  Dan and Marc used used to be great on the phones there but there’s no more phone support as many companies are doing.  And Dennis Hadd’s statement still holds true and now even more so.  The two balance pots are even cheaper ones then they used to use.  Years ago they used the Clarostat  pots in that position.  Then when those got more expensive they change to some very cheap generic pots which are terrible. At least they still use the Alps Blue Velvet in the main volume position.  
 

Also glad you didn’t go for the lower gain mod.  Part of that mod is already in your ultimate upgrade when they change the cathode resistors. The rest is simply adding four resistors in the line gain stage to reduce the signal and I didn’t think the preamp sounded as good then.  Just lost its life. 
 

If you want to keep the two balance controls and improve the sound quality get a couple of high quality mono pots for that position.  Like a couple of the mono version Alps Blue Beauty or better.  Or better get the Khozmo or whatever.  There isn’t a lot of room there before it hits the pc board so you’ll have to measure things.  As I mentioned the value of the pots are stamped on the back of it their values. 
 

Another answer that is better then two pots, find the position that sounds best on the balance pots and, that gives you some master volume adjustment freedom, measure the resistance of the balance pots and install to high quality resistors in there place.  That will sound better then most any pot.  Of course then you have no control over balance.

What to understand in the way the 05 is that the gain of the tube circuit is set.  It’s just on.  What you are controlling is how much of the signal coming in from your source you are going to allow to go forward into the circuit and be amplified.  Now the balanced input circuit (6SN7 tubes 3&6) of the SLP-05 produce gain also.  About 9db on ultimate upgrade units and 12db on a standard one.  So the balanced input gets amplified and then routes through the balance controls and then the volume control, then on to the line stage circuit consisting of the four 6SN7 tubes 1,2,4,5. The single-ended inputs route in from the switching relays directly to the balance and volume controls.  That is one reason why there is so much gain on the balanced inputs.  Along with twice the signal from the +/- phases.  I’ve heard of people trying and I’ve tried lowering the gain into the balanced inputs from the source but I’ve really noticed a lack of dynamics and overall sound quality then. They need the +/-2V in for best sound.  Another thing to be careful of is how much input goes into the balanced inputs.  They overload the tube if you go much more the 2V per phase of the balanced signal.  Meaning balanced +2V and -2V.  Like once you hit about 2.3V to 2.4V per phase you will start hearing it distort/clip. Things get hard and bright first then fully distort.  So be careful of your balanced source components. To understand better, those two tubes are “full on” and there is no volume control in front of them. It was designed in the day when the standard source component output was 2V.  

All right sorry!  I always explain too much. 

Philharmonicpete - Yes the total gain is reduced about 3db to about 21 I believe on the ultimate upgrade. The reason is that the plate load and cathode resistor values were changed which changes essentially the “slope” if you will, of the sound.  This made the sound less thin and a little more full in the bass and midrange.  I liked this as I always thought the original 05, although great, was a bit thin and a hint bright for my taste. Also all the better Mundorf caps and beefed up power supply cleaned it up.  So the gain wasn’t purposely reduced (although it has more then it needs) it’s more of a byproduct of the value changes on the plate and cathode.

The headphone circuit is very good.  The only thing to upgrade there would be better output transformers to improve the bass response and overall sound quality. Maybe something like the Lundahll or Sowter or something like that.  Of course it has to fit too!  I thought it would be nice to look into but I never have.

immatthewj - By all means the SLP-05 sounds much better run full balanced.  Don’t go back to RCA single-ended.  You won’t like it after running balanced.  Balanced is fuller sounding, more dynamic, better imaging, cleaner, etc.  
Cary Audio of course won’t upgrade the controls or headphone output transformers.  They are only going to put in what they supply.  You’ll need a tweaker to do that.  I’m sure there’s plenty of people on the forum that have the expertise to tackle that if they wanted to.