"Too much gain"? (Cary SLP05 question)

@xcool the confusion is not your fault. I just would have thought that for a job parts + whatever the hourly rate for labor is would have covered a job. I may be out of touch on that as I really try to farm as little as possible out. Like for The Ultimate Upgrade, for example, they give you what the rate is for the job (kind of like getting your ball-joints on your auto replaced); I wonder why they don’t do that for the Gain Reduction Mod.

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.

As far as using the ’input level’ pots in conjunction with the ’listening level’ (the big knob) pot to compensate for gain, reading through the replies I have received, there do seem to be two schools of thought re that. As I typed in one of my last responses to a reply, way back when I bought my Dennis Had "hot-rodded" SLP90, Dennis must have felt that L & R input level pots were, at least to some degree, degrading the signal path (but that was 30 years or so ago he built that preamp, and I wouldn’t be surprised if the pots are better now a days). I said I would say no more about a certain subject, but I really don’t see why Cary Support cannot provide a simple straight answer on that. Oh well, one of many things in life that I do not understand.

So, not to be redundant (but I guess I constantly am), but for me the bottom line is that I can find a volume setting that makes me happy, and if there is no difference in sonic quality between a certain volume at 3 o-clock & that same volume at 6 o-clock (and reading replies, there seem to be a couple of schools of thought on that as well) I am good with it as it is. I think it would be useless to try and get a straight answer from CAD Support on that also.

Hey, it is real good to hear that you will be reunited with your SLP shortly. I bet you are loving that news. And since you didn’t mention it, I am assuming that, at least for the time being, they didn’t tell you what was broke..

The Roth well attenuators work well with very minimal loss of micro detail 

in a very high resolution system, depending on quality of cables and rest od system .what is in your Cary for a volume attenuator is key, if it is a Alps volume pot that is cheap and seen as a silver round drop ,just a plastic conductive wiper.

ifitis a resistive ladder attenuators then it should not me much of a issue.

The discussion on this topic is very puzzling.  The idea that people would buy attenuators or a gain reduction mod for their SLP 05 is something I see and hear no reason for.  

Buy a NOS rectifier and some 6SN7 tubes.  Use the balanced connections.  Optimize your interconnects.  Absolutely.  

Set the gain by listening to your highest output source with the gain knobs set at full.  According to an old Stereophile review this effectively eliminates their circuitry. But does it sound the best?  

Not for me.  Too much gain and the sound was edgy at low volume levels.  

Backing off the gain knobs gradually until it sounds best (listen carefully) and you are good to go.  It sounds amazing!  The sound will be better at the same net loudness levels.  It works!  

Backing off the gain knobs gradually until it sounds best (listen carefully) and you are good to go.

@avanti1960 I am actually going to try this. With your L and R ’input level’ knobs backed off to where you feel is optimal, where is your ’listening level’ (the big knob) usually at?

Oh, and on edit:  I do have some vintage RCA black glass vt231s in my balanced input sockets (#3 & #6) and I am working on four more.  I am also working on a vintage 5AR4. 

@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.